• TABLE OF CONTENTS
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 Title Page
 How to use this soil survey
 Table of Contents
 Index to mapping units
 Summary of tables
 How this survey was made
 General soil map
 Description of the soils
 Use and management of the...
 Formation and classification of...
 Climate
 Literature cited
 Glossary
 Guide to mapping units
 General Soil Map
 Maps






Title: Soil survey of Humacao area of eastern Puerto Rico.
CITATION PAGE IMAGE ZOOMABLE
Full Citation
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Permanent Link: http://ufdc.ufl.edu/UF00027414/00001
 Material Information
Title: Soil survey of Humacao area of eastern Puerto Rico.
Physical Description: Book
Creator: Boccheciamp, Rafael A.
Publisher: The Service
Publication Date: 1977
 Notes
Funding: U.S. Department of Agriculture Soil Surveys
 Record Information
Bibliographic ID: UF00027414
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: Government Documents Department, George A. Smathers Libraries, University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 6086103

Table of Contents
    Title Page
        Title
    How to use this soil survey
        Page i
    Table of Contents
        Page i
    Index to mapping units
        Page ii
    Summary of tables
        Page iii
    How this survey was made
        Page 1
    General soil map
        Page 2
        Soils of the humid areas
            Page 2
            Swamps-Marshes association
                Page 2
            Pandura-Rock land-Patillas association
                Page 3
            Coloso-Toa-Bajura association
                Page 3
            Los Guineos-Humatas-Lirios association
                Page 3
            Mabi-Rio Arriba-Cayagua association
                Page 3
            Caguabo-Mucara-Naranjito association
                Page 4
            Los Guineos-Guayabota-Rock land association
                Page 4
            Catano-Aguadilla association
                Page 4
        Soils of the dry areas
            Page 4
            Coamo-Guamani-Vives association
                Page 4
            Descalabrado-Guayama association
                Page 4
            Jacana-Amelia-Fraternidad association
                Page 5
    Description of the soils
        Page 5
        Aceitunas series
            Page 5
            Page 6
        Aguadilla series
            Page 7
        Arenales series
            Page 8
        Bajura series
            Page 9
        Caguabo series
            Page 9
        Candelero series
            Page 10
        Cartagena series
            Page 11
        Catano series
            Page 12
        Cayagua series
            Page 12
        Ciales series
            Page 13
        Coamo series
            Page 14
        Coastal beaches
            Page 14
        Cobbly alluvial land
            Page 14
        Coloso series
            Page 14
        Corcega series
            Page 15
        Daguao variant
            Page 16
        Daguao series
            Page 16
        Descalabrado series
            Page 17
        Fajardo series
            Page 17
        Fortuna series
            Page 18
        Fraternidad series
            Page 19
        Guamani series
            Page 19
        Guayabota series
            Page 20
        Guayama series
            Page 21
        Guayama variant
            Page 22
        Humacao
            Page 22
        Humatas series
            Page 23
        Ingenio series
            Page 23
        Jacana series
            Page 24
        Jagueyes series
            Page 25
        Junquitos series
            Page 26
        Leveled clayey land
            Page 26
        Limones series
            Page 26
        Lirios series
            Page 27
        Los Guineos series
            Page 28
        Mabi series
            Page 29
        Machete series
            Page 30
        Made land
            Page 30
        Maunabo series
            Page 31
        Mayo series
            Page 31
        Meros series
            Page 32
        Mucara series
            Page 32
        Naranjito series
            Page 33
        Pandura series
            Page 34
        Parcelas series
            Page 34
        Paso Seco series
            Page 35
        Patillas series
            Page 35
        Picacho series
            Page 36
        Pinones series
            Page 37
        Poncena series
            Page 37
        Pozo Blanco series
            Page 38
        Reilly series
            Page 38
        Reparada series
            Page 39
        Rio Arriba series
            Page 39
        Rock land
            Page 40
        Salt water marsh
            Page 41
        Talante series
            Page 41
        Teja series
            Page 41
        Tidal flats
            Page 42
        Tidal swamps
            Page 42
        Toa series
            Page 42
        Utuado series
            Page 42
            Page 43
        Vayas series
            Page 44
        Vega Baja series
            Page 45
        Via series
            Page 45
        Vieques series
            Page 46
        Vives series
            Page 46
        Vivi series
            Page 47
        West alluvial land
            Page 47
        Yunes series
            Page 48
        Yunque series
            Page 48
    Use and management of the soils
        Page 49
        Capability grouping
            Page 49
            Page 50
            Page 51
        Estimated yields
            Page 52
        Use of the soils for wetland
            Page 53
        Engineering uses of the soils
            Page 53
            Page 54
            Page 55
            Page 56
            Page 57
            Page 58
            Page 59
            Page 60
            Engineering soil classification systems
                Page 61
            Soil properties significant in engineering
                Page 61
                Page 62
                Page 63
                Page 64
                Page 65
                Page 66
                Page 67
                Page 68
                Page 69
            Engineering interpretations of the soils
                Page 70
                Page 71
                Page 72
                Page 73
                Page 74
                Page 75
                Page 76
                Page 77
                Page 78
                Page 79
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                Page 82
                Page 83
                Page 84
                Page 85
                Page 86
                Page 87
                Page 88
                Page 89
            Soil test data
                Page 90
        Use of the soils for recreation facilities
            Page 90
    Formation and classification of the soils
        Page 90
        Factors of soil formation
            Page 90
            Page 91
            Page 92
            Page 93
            Page 94
            Page 95
            Parent material
                Page 96
            Climate
                Page 96
            Plants and animals
                Page 96
            Relief
                Page 96
            Time
                Page 96
        Classification of the soils
            Page 96
    Climate
        Page 97
        Page 98
    Literature cited
        Page 99
    Glossary
        Page 100
        Page 101
        Page 102
        Page 103
    Guide to mapping units
        Page 104
        Page 105
        Page 106
    General Soil Map
        Page 107
        Page 108
    Maps
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
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Full Text
-. 'C W-s-n J) r.LjL'jO ^Ltc<- I- ~77
)











Ur SOJIClSUR EYOF


Humacao Area of Easterr" Puerto Rico
S|.F.A.S. ; ot Floridaj



















United States Department of Agriculture
Soil Conservation Service
S, In cooperation with
University of Puerto Rico
College of Agricultural Sciences









This is a publication of the National Cooperative Soil Survey, a joint effort of the
United States Department of Agriculture and agencies of the States, usually the Agri-
cultural Experiment Stations. In some surveys, other Federal and local agencies also
contribute. The Soil Conservation Service has leadership for the Federal part of the Na-
tional Cooperative Soil Survey.
Major fieldwork for this soil survey was completed in the period 1962-68. Soil
names and descriptions were approved in 1969. Unless otherwise indicated, statements in
the publication refer to conditions in the area in 1969. This survey was made cooperatively
by the Soil Conservation Service and tile University of Puerto Rico, College of Agri-
cultural Sciences, Mayaguez Campus. It is part of the technical assistance furnished to
the Noreste, Este, and Sudeste Soil Conservation Districts.
Soil maps in this survey may be copied without permission, but any enlargement of
these maps could cause misunderstanding of the detail of mapping and result in errone-
ous interpretations. Enlarged maps do not show small areas of contrasting soils that could
have been shown at a larger mapping scale.






HOW TO USE THIS SOIL SURVEY

THIS SOIL SURVEY contains infor- lucent material can be used as an over-
mation that can be applied in man- lay over the soil map and colored to
aging farms, ranches, woodlands, and show soils that have the same limitation
wildlife areas; in selecting sites for or suitability. For example, soils that
roads, ponds, buildings, and other struc- have a slight limitation for a given use
tures; and in judging the suitability of can be colored green, those with a mod-
tracts of land for farming, industry, and rate limitation can be colored yellow,
recreation. and those with a severe limitation can
be colored red.
Location Soils Farmers and those who work with
Farmers can learn about use and man-
All the soils of the Humacao Area are agement of the soils from the soil de-
shown on the detailed map at the back of scriptions and from the descriptions of
this publication. This map consists of the capability units and the woodland
many sheets made from aerial photo- suitability groups.
graphs. Each sheet is numbered to cor- Foresters and others can refer to the
respond with a number on the Index to section "Use of the Soils for Woodland,"
Map Sheets. where the soils of the county are
On each sheet of the detailed map, grouped according to their suitability
soil areas are outlined and are identified for trees.
by symbols. All areas marked with the Community planners and others can
same symbol are the same kind of soil. read about soil properties that affect the
The soil symbol is inside the area if choice of sites for recreation areas in the
there is enough room; otherwise, it is section "Use of the Soils for Recreation
outside and a pointer shows where the Facilities."
symbol belongs. Engineers and builders can find, un-
der "Engineering Uses of the Soils,"
Finding and Using Information tables that contain test data, estimates
of soil properties, and information about
The "Guide to Mapping Units" can be soil features that affect engineering
used to find information. This guide lists practices.
all the soils of the area in alphabetic or- Scientists and others can read about
der by map symbol and gives the capa- how the soils formed and how they are
ability classification and the woodland classified in the section "Formation and
suitability group of each. It also shows Classification of the Soils."
the page where each soil is described. Newcomers to the Humacao Area may
Individual colored maps showing the be especially interested in the section
relative suitability or degree of limita- "General Soil Map," where broad pat-
tion of soils for many specific purposes terns of soils are described. They may
can be developed by using the soil map also be interested in the information
and the information in the text. Trans- about the county given on page 1.
















Contents

Page Page
Index to mapping units -- _--------------------_ ii Mayo series ----- ------------------------- 31
Summary of tables ----------------- ------- iii Meros series ---------------------- 32
How this survey was made ----- ----------------- 1 Mucara series ------------- --------------------- 32
General soil map ----------------------- 2 Naranjito series--------------------------------- 33
S Soils of the humid areas _--- ------------______- 2 Pandura series ----------- ---------- 34
1. Swamps-Marshes association ______---------- 2 Parcelas series ---------------------------------- 34
2. Pandura-Rock land-Patillas association -------- 3 Paso Seco series ---------------35
3. Coloso-Toa-Baiura association ------------ 3 Patillas series ------------------------------------- 35
CQ 4. Los Guineos-Humatas-Lirios association _______ 3 Picacho series ------------------- 36
5. Mabi-Rio Arriba-Cayagua association ------ 3 Pinones series ------------------------------------ 37
6. Caguabo-Mucara-Naranjito association __---_ 4 Poncena series ------------37
7. Los Guineos-Guayabota-Rock land association __ 4 Pozo Blanco series _____ ----------------------- 38
8. Catano-Aguadilla association ----------- 4 Reilly series --- ------------------- 38
Soils of the dry areas __------------------------ 4 Reparada series ------------------- ------------ 39
9. Coamo-Guamani-Vives association ____------- 4 Rio Arriba series ---------------- ---------- 39
10. Descalabrado-Guayama association -----------_ 4 Rock land ----------------------------- ------ 40
11. Jacana-Amelia-Fraternidad association -------- 5 Rough stony land --------------------- 40
Descriptions of the soils__--------__-- ------------- 5 Sabana series ----------------- -----40
Aceitunas series ------------------ 5 Salt water marsh ----------41
Aguadilla series --------------------------------- 7 Talante series _------------ --------------- -- 41
Amelia series ------------------ 7 Teja series ----- ---- ------- 41
Arenales series ---------------------------- -- 8 Tidal flats ----- -- ----- -------- 42
Bajura series ---------------------------- 9 Tidal swamp ------------------ -------- 42
Caguabo series _____----_________------------- 9 Toa series ----------- --------- 42
Candelero series -------------------------------- 10 Utuado series ----------- --- ---- 42
Cartagena series _- _____________----___---------- 11 Vayas series --- -------- --------44
Catano series --- ------------------------- 12 Vega Alta series ---- --- ------------- 44
Cayagua series __-----------------________ ---12 Vega Baja series ------------------- 45
Ciales series ------------------------- 13 Via series --------------------------------- 45
Coamo series _______________________-------------- 14 Vieques series ---------------- ----------------- 46
Coastal beaches ____- ------------------------ 14 Vives series ------------------- --- --- 46
Cobbly alluvial land _-------__-------- --------- 14 Vivi series ------------------------------47
Coloso series ------------------------- -----14 Wet alluvial land ----------------------- 47
Corcega series ---------------------------------- 15 Yunes series ------------------------ ----- 48
Daguao variant ------------------------ ---- 16 Yunque series ---------------------------------- 48
Daguao series ----------------------- --------- 16 Use and management of the soils --------------- 49
Descalabrado series _________--------__ --------------- 17 Capability grouping -------------------- -- 49
Fajardo series -------- ------------------------ 17 Estimated yields ------------------- 52
Fortuna series -------------_------ --------- 18 Use of the soils for woodland --------------------- 53
Fraternidad series __----____--------------- --- 19 Engineering uses of the soils ---------------------- 53
Guamani series ---------------------- -------- 19 Engineering soil classification systems ------------ 61
Guayabota series --------------------------------- 20 Soil properties significant in engineering -------- 61
Guayama series ________- -------------------- 21 Engineering interpretations of the soils ----------- 70
Guayama variant ___________-------------------- 22 Soil test data ----------------------- 90
Humacao series --------______----------- ----- 22 Use of the soils for recreation facilities ----------- 90
Humatas series ------------------------------- 23 Formation and classification of the soils ---------------- 90
Ingenio series -------- -------------------- 23 Factors of soil formation --- -------- --- 90
.Tacana series ---- --------------------- 24 Parent material ------------------- 96
Jagueyes series ---- ------------------- 25 Climate -- ------- ------------------------ 96
Junquitos series ----------------------------------- 26 Plants and animals ----------------------- 96
Leveled clayey land -------- --------------- 26 Relief ------------------------------------- 96
Limones series ----------------------- 26 Time ----- --------------------------- 96
Lirios series __---------- -------27 Classification of the soils ----- ------- ------ 96
Los Guineos series ------ ---------------- 28 Climate ------------------------------------- 97
Mabi series --------------------------------- 29 Literature cited ------------------------------- 99
Machete series ------------------------ 30 Glossary ----------------------------------------- 100
Made land -------- ------------------------ 30 Guide to mapping units---------------Following---- 103
Maunabo series ---------------------------------- 31



Issued January 1977






i















Index to Mapping Units
Page Page
AcC-Aceitunas silty clay loam, 5 to 12 percent slopes ___ 7 LsF2-Los Guineos silty clay loam, 40 to 60 percent slopes,
Ad-Aguadilla loamy sand ----------------------- 7 eroded ----------------------__---------_ 28
Ag-Aguadilla sandy loam, moderately wet ------------ 7 LyF-Los Guineos-Yunque-Stony rock land association,
AmB-Amelia gravelly clay loam, 2 to 5 percent slopes -_ 8 steep --------- ----------------------- 28
AmC2-Amelia gravelly clay loam, 5 to 12 percent slopes, MaB-Mabi clay, 0 to 5 percent slopes ----------------- 29
eroded ____ ____-- __--_ --------- ------ 8 MaC2-Mabi clay, 5 to 12 percent slopes, eroded -------- 30
An-Arenales sandy loam ----------------------- 8 MaD2-Mabi clay, 12 to 20 percent slopes, eroded ___---- 30
Ar-Arenales sandy loam, gravelly substratum --------- 8 McA-Machete loam, 0 to 2 percent slopes _______----_- 30
Ba-Bajura silty clay, saline -------------- ---- 9 McB-Machete loam, 2 to 5 percent slopes ------------ 30
Bc-Bajura clay, frequently flooded __-------------- 9 Md-Made land ____-- _________--------------------- 30
CbD2-Caguabo clay loam, 12 to 20 percent slopes, eroded 10 Me-Maunabo clay _-------------------------- 31
CbF2-Caguabo clay loam, 20 to 60 percent slopes, eroded 10 MIC-Mayo loam, 3 to 10 percent slopes __- -----------_ 32
CdB-Candelero loam, 2 to 5 percent slopes __----- 11 MrB-Meros sand, 1 to 6 percent slopes ---------------- 32
CdC2-Candelero loam, 5 to 12 percent slopes, eroded __- 11 MuD2-Mucara silty clay loam, 12 to 20 percent slopes,
Ce-Cartagena clay ___----------------------------- 12 eroded ------------------------ 33
Cf-Catano loamy sand --------------------------- 12 MuE2-Mucara silty clay loam, 20 to 40 percent slopes,
CgC2-Cayagua sandy loam, 5 to 12 percent slopes, eroded 13 eroded ___--------------------____ 33
CgD2-Cayagua sandy loam, 12 to 20 percent slopes, NaE2-Naranjito silty clay loam, 20 to 40 percent slopes,
eroded _----------------------------- 13 eroded _____--_-------------------------_ 33
C1B-Coamo clay loam, 2 to 5 percent slopes ---------- 14 NaF2-Naranjito silty clay loam, 40 to 60 percent slopes,
C1C-Coamo clay loam, 5 to 12 percent slopes ________--14 eroded _____----------------------------------- 33
Cm-Coastal beaches _____---------------------------- 14 PaE2-Pandura loam, 12 to 40 percent slopes, eroded ___- 34
Cn-Cobbly alluvial land __------------------------- 14 PaF2-Pandura loam, 40 to 60 percent slopes, eroded --- 34
Co-Coloso silty clay loam, occasionally flooded __- ---_ 15 PdF-Pandura-Very stony land complex, 40 to 60 percent
Cr-Coloso silty clay __----------------------------- 15 slopes--- ----------- 34
Cs-Corcega sandy loam ----------------- 15 PeC2-Parcelas clay, 5 to 12 percent slopes, eroded ------ 35
DaC-Daguao silty clay loam, deep variant, 2 to 12 per- P1B-Paso Seco clay, 0 to 5 percent slopes ------- --- 35
cent slopes _------------------------- ---------- 16 PmD2-Patillas clay loam, 12 to 20 percent slopes, eroded 36
DcE2-Daguao clay, 20 to 40 percent slopes, eroded -_...- 16 PmE2-Patillas clay loam, 20 to 40 percent slopes, eroded 36
DeC2-Descalabrado clay loam, 5 to 12 percent slopes, Pn-Pinones silty clay _------------------------ --- 37
eroded ------------------------------------ 17 Po-Poncena clay -------------------------------- 38
DeE2-Descalabrado clay loam, 20 to 40 percent slopes, PrC2-Pozo Blanco clay loam, 5 to 12 percent slopes,
eroded _------------------------------------ 17 eroded ____----_-------------------------- 38
DgF2-Descalabrado and Guayama soils, 20 to 60 percent Re-Reilly soils -----------------------------39
slopes, eroded ----------- ---------------- 17 Rp-Reparada clay --------------------------- 39
DrF-Descalabrado-Rock land complex, 40 to 60 percent RrB-Rio Arriba clay, 2 to 5 percent slopes------------ 40
slopes -------------------------- 17 RrC2-Rio Arriba clay, 5 to 12 percent slopes, eroded ---- 40
FaC-Fajardo clay, 2 to 10 percent slopes _---------- 18 Rs-Rock land ____ _____---__ __---------------------- 40
FaC2-Fajardo clay, 2 to 10 percent slopes, eroded ___-- 18 Ru-Rough stony land ------------------ 40
Fo-Fortuna clay ----------------------- 19 SaE2-Sabana silty clay loam, 20 to 40 percent slopes,
FrA-Fraternidad clay, 0 to 2 percent slopes ----------- 19 eroded -------___ ---__ -----------------__ 40
FrB-Fraternidad clay, 2 to 5 percent slopes ------------ 19 SaF2-Sabana silty clay loam, 40 to 60 percent slopes,
Gm-Guamani silty clay loam ___------------------- 20 eroded ---------___---------------------- 41
GuE2-Guayabota silty clay loam, 20 to 40 percent slopes, Sm-Salt water marsh---------------------------- 41
eroded ---------------------------------- 21 Ta-Talante soils --- ------------------ -- 41
GvF-Guayabota-Ciales-Picacho association, very steep 21 TeE-Teja gravelly sandy loam, 12 to 40 percent slopes 42
GyC2-Guayama clay loam, moderately deep variant, 2 to Tf-Tidal flats ____---- ----------------------- 42
12 percent slopes, eroded' ------- ------------- 22 Ts-Tidal swamp ___----------_---------------- 42
HmB-Humacao loam, 2 to 5 percent slopes __________ 22 Tt-Toa silty clay loam ----------------------_ 42
HtE2-Humatas clay, 20 to 40 percent slopes, eroded ___ 23 UpF-Utuado-Picacho-Stony rock land association, very
HtF2-Humatas clay, 40 to 60 percent slopes, eroded ___ 23 steep __ _____ ________________ 43
HuF-Humatas-Stony land complex, 40 to 60 percent Va-Vayas silty clay loam, occasionally flooded --_---_ 44
slopes ------- ------------_------------- 23 Vc-Vayas silty clay, frequently flooded -__----_______ 44
InE2-Ingenio silty clay loam, 20 to 40 percent slopes, VeB-Vega Alta silty clay loam, 2 to 5 percent slopes 45
eroded ---------------------------------------24 VeC-Vega Alta silty clay loam, 5 to 12 percent slopes 45
JaB-Jacana clay, 2 to 5 percent slopes __----------- 25 VgA-Vega Baja silty clay loam, 0 to 3 percent slopes 45
JaC2-Jacana clay, 5 to 12 percent slopes, eroded ------ 25 V1C-Via silty clay loam, 3 to 10 percent slopes ______ --46
JgE2-Jagueyes loam, 20 to 40 percent slopes, eroded --_ 25 VmC-Vieques loam, 5 to 12 percent slopes -------- 46
JuC-Junquitos gravelly clay loam, 5 to 12 percent slopes 26 VmE2-Vieques loam, 12 to 40 percent slopes, eroded --__ 46
Lc-Leveled clayey land ____------------- _____ ----26 Vs-Vives silty clay loam, high bottom ________________ 47
LeE2-Limones silty clay, 20 to 40 percent slopes, eroded 27 VvA-Vives clay, 0 to 2 percent slopes _________________ 47
LoC2-Lirios clay loam, 3 to 10 percent slopes, eroded -- 27 VvB-Vives clay, 2 to 7 percent slopes --------------__ 47
LrE2-Lirios silty clay loam, 20 to 40 percent slopes, Vw-Vivi loam ------------------_-----_-------__ 47
eroded ----------------------------------- 27 Wa-Wet alluvial land ----------- -------------- 47
LsD-Los Guineos silty clay loam, 12 to 20 percent slopes 28 YuF2-Yunes silty clay loam, 20 to 60 percent slopes,
LsE2-Los Guineos silty clay loam, 20 to 40 percent eroded --------------------------------_----_ 48
slopes, eroded ------------ ------------------ 28




ii

































Summary of Tables
Page
Descriptions of the Soils
Approximate acreage and proportionate extent of the soils (Table 1) -_ 6
Estimated Yields
Estimated average yields per acre of principal crops under two levels of
management (Table 2) __--_____----------------------- ___-- ___ 54
Estimated average yields per acre of principal pasture grasses (Table 3)-_ 58
Use of the Soils for Woodland
Woodland management (Table 4) ----------------------------------__ 60
Engineering Uses of the Soils
Estimated soil properties significant in engineering (Table 5) -----_----- 62
Interpretations of engineering properties of the soils (Table 6) ----------- 72
Engineering test data (Table 7) -------------------------------------- 88
Use of the Soils for Recreation Facilities
Degree and kind of limitations of the soils for recreation facilities (Table 8) 91
Formation and Classification of the Soils
Classification of the soil series (Table 9) ______________________________ 98
Climate
Temperature and rainfall data from selected stations (Table 10) ---------- 100
Mean evaporation rates, in inches, for three locations (Table 11) ____---- 101


























iii















SOIL SURVEY OF THE
HUMACAO AREA OF EASTERN PUERTO RICO

BY RAFAEL A. BOCCHECIAMP, SOIL CONSERVATION SERVICE
FIELDWORK BY RAFAEL A. BOCCHECIAMP, WILLIAM FRANCIA RIVERA, JULIO E. TRIGO, JUAN E. BRUNET, ENRIQUE
ORTIZ TORRES, WILLIAM E. McKINZIE, AND LUIS H. RIVERA, SOIL CONSERVATION SERVICE
UNITED STATES DEPARTMENT OF AGRICULTURE, SOIL CONSERVATION SERVICE, IN COOPERATION WITH THE
UNIVERSITY OF PUERTO RICO, COLLEGE OF AGRICULTURAL SCIENCES



THE HUMACAO AREA OF EASTERN PUERTO How This Survey Was Made
RICO is about 470,202 acres in size. It includes 16
municipalities and two offshore islands of Vieques and Soil scientists made this survey to learn what kinds
Culebra (fig. 1). Important cities are Humacao, the of soil are in the Humacao Area, where they are located,
and how they can be used. The soil scientists went into
the county knowing they likely would find many soils
they had already seen and perhaps some they had not.
They observed the steepness, length, and shape of
AGUADILLA AREC-BO. slopes, the size and speed of streams, the kinds of na-
, tive plants or crops, the kinds of rock, and many facts
S- about the soils. They dug many holes to expose soil pro-
MAYAi. '. files. A profile is the sequence of natural layers, or
horizons, in a soil; it extends from the surface down
o.E into the parent material that has not been changed
'- -much by leaching or by the action of plant roots.
The soil scientists made comparisons among the pro-
files they studied, and they compared these profiles with
Agreic..ltu. E.pe.. rient Stio.... My,... those in areas nearby and in places more distant. They
classified and named the soils according to nationwide,
Figure 1.-Location of the Humacao Area in Puerto Rico. uniform procedures. The soil series and the soil phase
are the categories of soil classification most used in a
more centrally located city in the area, Carolina, Fa- local survey.
jardo, and Guayama. The area has three well-defined Soils that have profiles almost alike make up a soil
climatic regions. The southern part is semiarid, the series. Except for different texture in the surface layer,
northern and eastern parts are humid, and in the north all the soils of one series have major horizons that are
central part there is a tropical rain forest where the similar in thickness, arrangement, and other impor-
annual precipitation is very high. Within these climatic tant characteristics. Each soil series is named for a town
regions are well-defined physiographic areas, such as or other geographic feature near the place where a soil
the coastal plains and lowlands, inner valleys, nearly of that series was first observed and mapped. Humacao
level river flood plains, and sloping to very steep up- and Fajardo, for example, are the names of two soil
lands. Sugarcane is grown in the nearly level to sloping series. All the soils in the United States having the
areas, and pasture and a variety of food crops are same series name are essentially alike in those charac-
grown in the steeper uplands, teristics that affect their behavior in the undisturbed
In 1970, 444,369 persons lived in the Humacao Area; landscape.
in 1960, only 346,930 lived there. Much of the increase Soils of one series can differ in texture of the surface
has been in the suburbs of the larger cities, especially layer and in slope, stoniness, or some other characteris-
Carolina, which is the closest township to San Juan. tic that affects use of the soils by man. On the basis of
Land use is changing rapidly near San Juan. such differences, a soil series is divided into phases. The
The Guayands River Watershed Project has been ap- name of a soil phase indicates a feature that affects
proved for this survey area. Two large petrochemical management. For example, Bajura clay, frequently
complexes and numerous light industries are estab- flooded, is one of several phases within the Bajura
lished in the area. Public and private transportation series.
link towns and the rural areas on an excellent network After a guide for classifying and naming the soils
of state and municipal roads. had been worked out, the soil scientists drew the bound-
1







2 SOIL SURVEY

aries of the individual soils on aerial photographs. tures. They relate this behavior to properties of the
These photographs show buildings, field borders, trees, soils. For example, if they observe that filter fields for
and other details that help in drawing boundaries accu- onsite disposal of sewage fail on a given kind of soil,
rately. The soil map at the back of this publication was they relate this to the slow permeability of the soil or
prepared from aerial photographs. its high water table. If they see that streets, road pave-
The areas shown on a soil map are called mapping ments, and foundations for houses are cracked on a
units. On most maps detailed enough to be useful in named kind of soil, they relate that failure to the high
planning the management of farms and fields, a map- shrink-swell potential of the soil. Thus, they use obser-
ping unit is nearly equivalent to a soil phase. It is not vation and knowledge of soil properties, together with
exactly equivalent, because it is not practical to show on available research data, to predict limitations or suit-
such a map all the small, scattered bits of soil of some ability of soils for present and potential uses.
other kind that have been seen within an area that is After data have been collected and tested for the key,
dominantly of a recognized soil phase. or benchmark, soils in a survey area, the soil scientists
Some mapping units are made up of soils of different set up trial groups of soils. They test these groups by
series, or of different phases within one series. Three further study and by consulting farmers, agronomists,
such kinds of mapping units are shown on the soil map engineers, and others. They then adjust the groups
of the Humacao Area: soil complexes, soil associations, according to the results of their studies and consulta-
and undifferentiated soil groups. tion. Thus, the groups that are finally evolved reflect up-
A soil complex consists of areas of two or more soils, to-date knowledge of the soils and their behavior under
so intricately mixed or so small in size that they cannot current methods of use and management.
be shown separately on the soil map. Each area of a
complex contains some of each of the two or more dom-
inant soils, and the pattern and relative proportions General Soil Map
are about the same in all areas. Generally, the name of
a soil complex consists of the names of the dominant The general soil map at the back of this survey shows,
soils, joined by a hyphen. Descalabrado-Rock land com- in color, the soil associations in the Humacao Area. A
plex, 40 to 60 percent slopes, is an example. soil association is a landscape that has a distinctive pat-
A soil association is made up of adjacent soils that oc- tern of soils in defined proportions. It normally consists
cur as areas large enough to be shown individually on of one or more major soils and at least one minor soil,
the soil map but are shown as one unit because the time and it is named for the major soils. The soils in one
and effort of delineating them separately cannot be association can occur in another but in a different
justified. There is a considerable degree of uniformity pattern.
in pattern and relative extent of the dominant soils, but A map showing soil associations is useful to people
the soils may differ greatly one from another. The name who want a general idea of the soils in an area, who
of an association consists of the names of the dominant want to compare different parts of an area, or who
soils, joined by a hyphen. Guayabota-Ciales-Picacho want to know the location of large tracts that are suit-
association, very steep, is an example, able for a certain kind of land use. Such a map is a use-
An undifferentiated soil group is made up of two or ful general guide in managing a watershed, a wooded
more soils that could be delineated individually but are tract, or a wildlife area or in planning engineering
shown as one unit because, for the purpose of the soil works, recreation facilities, and community develop-
survey, there is little value in separating them. The ments. It is not a suitable map for planning the manage-
pattern and proportion of soils are not uniform. An area ment of a farm or field or for selecting a site for a road
shown on the map may be made up of only one of the or building or other structure, because the soils in any
dominant soils, or of two or more. The name of an un- one association ordinarily differ in slope, depth, stoni-
differentiated group consists of the names of the domi- ness, drainage, and other characteristics that affect
nant soils, joined by "and." Descalabrado and Guayama their management.
soils, 20 to 60 percent slopes, eroded, is an example. The soil associations in this survey have been grouped
In most areas surveyed there are places where the into two general kinds of landscapes for broad inter-
soil material is so rocky, so shallow, so severely eroded, pretative purposes. Each of the broad groups and their
or so variable that it has not been classified by soil se- included soil associations are described in the following
ries. These places are shown on the soil map and are pages.
described in the survey, but they are called land types
and are given descriptive names. Rock land is a land
type in the Humacao Area. Soils of the Humid Areas
While a soil survey is in progress, soil scientists take s of the Humd Areas
soil samples needed for laboratory measurements and Nearly level to hilly soils that receive sufficient mois-
for engineering tests. Laboratory data from the same ture for growing the common plants. Eight soil associa-
kind of soil in other places are also assembled. Data on tions are in this group.
yields of crops under defined practices are assembled
from farm records and from field or plot experiments on 1. Swamps-Marshes association
the same kind of soil. Yields under defined manage-
menthe samre estimad for allthe soilsunder defined nage- Deep, very poorly drained soils on the coastal plains
Soil scientists observe how soils behave when used as This association is in level or nearly level, narrow
a growing place for native and cultivated plants and as strips adjacent to the ocean. The areas are slightly
building material, foundation, or covering for struc- above sea level but are wet and, when the tide is high,







2 SOIL SURVEY

aries of the individual soils on aerial photographs. tures. They relate this behavior to properties of the
These photographs show buildings, field borders, trees, soils. For example, if they observe that filter fields for
and other details that help in drawing boundaries accu- onsite disposal of sewage fail on a given kind of soil,
rately. The soil map at the back of this publication was they relate this to the slow permeability of the soil or
prepared from aerial photographs. its high water table. If they see that streets, road pave-
The areas shown on a soil map are called mapping ments, and foundations for houses are cracked on a
units. On most maps detailed enough to be useful in named kind of soil, they relate that failure to the high
planning the management of farms and fields, a map- shrink-swell potential of the soil. Thus, they use obser-
ping unit is nearly equivalent to a soil phase. It is not vation and knowledge of soil properties, together with
exactly equivalent, because it is not practical to show on available research data, to predict limitations or suit-
such a map all the small, scattered bits of soil of some ability of soils for present and potential uses.
other kind that have been seen within an area that is After data have been collected and tested for the key,
dominantly of a recognized soil phase. or benchmark, soils in a survey area, the soil scientists
Some mapping units are made up of soils of different set up trial groups of soils. They test these groups by
series, or of different phases within one series. Three further study and by consulting farmers, agronomists,
such kinds of mapping units are shown on the soil map engineers, and others. They then adjust the groups
of the Humacao Area: soil complexes, soil associations, according to the results of their studies and consulta-
and undifferentiated soil groups. tion. Thus, the groups that are finally evolved reflect up-
A soil complex consists of areas of two or more soils, to-date knowledge of the soils and their behavior under
so intricately mixed or so small in size that they cannot current methods of use and management.
be shown separately on the soil map. Each area of a
complex contains some of each of the two or more dom-
inant soils, and the pattern and relative proportions General Soil Map
are about the same in all areas. Generally, the name of
a soil complex consists of the names of the dominant The general soil map at the back of this survey shows,
soils, joined by a hyphen. Descalabrado-Rock land com- in color, the soil associations in the Humacao Area. A
plex, 40 to 60 percent slopes, is an example. soil association is a landscape that has a distinctive pat-
A soil association is made up of adjacent soils that oc- tern of soils in defined proportions. It normally consists
cur as areas large enough to be shown individually on of one or more major soils and at least one minor soil,
the soil map but are shown as one unit because the time and it is named for the major soils. The soils in one
and effort of delineating them separately cannot be association can occur in another but in a different
justified. There is a considerable degree of uniformity pattern.
in pattern and relative extent of the dominant soils, but A map showing soil associations is useful to people
the soils may differ greatly one from another. The name who want a general idea of the soils in an area, who
of an association consists of the names of the dominant want to compare different parts of an area, or who
soils, joined by a hyphen. Guayabota-Ciales-Picacho want to know the location of large tracts that are suit-
association, very steep, is an example, able for a certain kind of land use. Such a map is a use-
An undifferentiated soil group is made up of two or ful general guide in managing a watershed, a wooded
more soils that could be delineated individually but are tract, or a wildlife area or in planning engineering
shown as one unit because, for the purpose of the soil works, recreation facilities, and community develop-
survey, there is little value in separating them. The ments. It is not a suitable map for planning the manage-
pattern and proportion of soils are not uniform. An area ment of a farm or field or for selecting a site for a road
shown on the map may be made up of only one of the or building or other structure, because the soils in any
dominant soils, or of two or more. The name of an un- one association ordinarily differ in slope, depth, stoni-
differentiated group consists of the names of the domi- ness, drainage, and other characteristics that affect
nant soils, joined by "and." Descalabrado and Guayama their management.
soils, 20 to 60 percent slopes, eroded, is an example. The soil associations in this survey have been grouped
In most areas surveyed there are places where the into two general kinds of landscapes for broad inter-
soil material is so rocky, so shallow, so severely eroded, pretative purposes. Each of the broad groups and their
or so variable that it has not been classified by soil se- included soil associations are described in the following
ries. These places are shown on the soil map and are pages.
described in the survey, but they are called land types
and are given descriptive names. Rock land is a land
type in the Humacao Area. Soils of the Humid Areas
While a soil survey is in progress, soil scientists take s of the Humd Areas
soil samples needed for laboratory measurements and Nearly level to hilly soils that receive sufficient mois-
for engineering tests. Laboratory data from the same ture for growing the common plants. Eight soil associa-
kind of soil in other places are also assembled. Data on tions are in this group.
yields of crops under defined practices are assembled
from farm records and from field or plot experiments on 1. Swamps-Marshes association
the same kind of soil. Yields under defined manage-
menthe samre estimad for allthe soilsunder defined nage- Deep, very poorly drained soils on the coastal plains
Soil scientists observe how soils behave when used as This association is in level or nearly level, narrow
a growing place for native and cultivated plants and as strips adjacent to the ocean. The areas are slightly
building material, foundation, or covering for struc- above sea level but are wet and, when the tide is high,







2 SOIL SURVEY

aries of the individual soils on aerial photographs. tures. They relate this behavior to properties of the
These photographs show buildings, field borders, trees, soils. For example, if they observe that filter fields for
and other details that help in drawing boundaries accu- onsite disposal of sewage fail on a given kind of soil,
rately. The soil map at the back of this publication was they relate this to the slow permeability of the soil or
prepared from aerial photographs. its high water table. If they see that streets, road pave-
The areas shown on a soil map are called mapping ments, and foundations for houses are cracked on a
units. On most maps detailed enough to be useful in named kind of soil, they relate that failure to the high
planning the management of farms and fields, a map- shrink-swell potential of the soil. Thus, they use obser-
ping unit is nearly equivalent to a soil phase. It is not vation and knowledge of soil properties, together with
exactly equivalent, because it is not practical to show on available research data, to predict limitations or suit-
such a map all the small, scattered bits of soil of some ability of soils for present and potential uses.
other kind that have been seen within an area that is After data have been collected and tested for the key,
dominantly of a recognized soil phase. or benchmark, soils in a survey area, the soil scientists
Some mapping units are made up of soils of different set up trial groups of soils. They test these groups by
series, or of different phases within one series. Three further study and by consulting farmers, agronomists,
such kinds of mapping units are shown on the soil map engineers, and others. They then adjust the groups
of the Humacao Area: soil complexes, soil associations, according to the results of their studies and consulta-
and undifferentiated soil groups. tion. Thus, the groups that are finally evolved reflect up-
A soil complex consists of areas of two or more soils, to-date knowledge of the soils and their behavior under
so intricately mixed or so small in size that they cannot current methods of use and management.
be shown separately on the soil map. Each area of a
complex contains some of each of the two or more dom-
inant soils, and the pattern and relative proportions General Soil Map
are about the same in all areas. Generally, the name of
a soil complex consists of the names of the dominant The general soil map at the back of this survey shows,
soils, joined by a hyphen. Descalabrado-Rock land com- in color, the soil associations in the Humacao Area. A
plex, 40 to 60 percent slopes, is an example. soil association is a landscape that has a distinctive pat-
A soil association is made up of adjacent soils that oc- tern of soils in defined proportions. It normally consists
cur as areas large enough to be shown individually on of one or more major soils and at least one minor soil,
the soil map but are shown as one unit because the time and it is named for the major soils. The soils in one
and effort of delineating them separately cannot be association can occur in another but in a different
justified. There is a considerable degree of uniformity pattern.
in pattern and relative extent of the dominant soils, but A map showing soil associations is useful to people
the soils may differ greatly one from another. The name who want a general idea of the soils in an area, who
of an association consists of the names of the dominant want to compare different parts of an area, or who
soils, joined by a hyphen. Guayabota-Ciales-Picacho want to know the location of large tracts that are suit-
association, very steep, is an example, able for a certain kind of land use. Such a map is a use-
An undifferentiated soil group is made up of two or ful general guide in managing a watershed, a wooded
more soils that could be delineated individually but are tract, or a wildlife area or in planning engineering
shown as one unit because, for the purpose of the soil works, recreation facilities, and community develop-
survey, there is little value in separating them. The ments. It is not a suitable map for planning the manage-
pattern and proportion of soils are not uniform. An area ment of a farm or field or for selecting a site for a road
shown on the map may be made up of only one of the or building or other structure, because the soils in any
dominant soils, or of two or more. The name of an un- one association ordinarily differ in slope, depth, stoni-
differentiated group consists of the names of the domi- ness, drainage, and other characteristics that affect
nant soils, joined by "and." Descalabrado and Guayama their management.
soils, 20 to 60 percent slopes, eroded, is an example. The soil associations in this survey have been grouped
In most areas surveyed there are places where the into two general kinds of landscapes for broad inter-
soil material is so rocky, so shallow, so severely eroded, pretative purposes. Each of the broad groups and their
or so variable that it has not been classified by soil se- included soil associations are described in the following
ries. These places are shown on the soil map and are pages.
described in the survey, but they are called land types
and are given descriptive names. Rock land is a land
type in the Humacao Area. Soils of the Humid Areas
While a soil survey is in progress, soil scientists take s of the Humd Areas
soil samples needed for laboratory measurements and Nearly level to hilly soils that receive sufficient mois-
for engineering tests. Laboratory data from the same ture for growing the common plants. Eight soil associa-
kind of soil in other places are also assembled. Data on tions are in this group.
yields of crops under defined practices are assembled
from farm records and from field or plot experiments on 1. Swamps-Marshes association
the same kind of soil. Yields under defined manage-
menthe samre estimad for allthe soilsunder defined nage- Deep, very poorly drained soils on the coastal plains
Soil scientists observe how soils behave when used as This association is in level or nearly level, narrow
a growing place for native and cultivated plants and as strips adjacent to the ocean. The areas are slightly
building material, foundation, or covering for struc- above sea level but are wet and, when the tide is high,






HUMACAO AREA OF EASTERN PUERTO RICO 3

are covered or affected by salt water or brackish water, plants. Some of the soils have impeded drainage that
The high concentration of salt inhibits the growth of all can be corrected by a suitable drainage system. The soils
vegetation except mangrove trees and, in small scat- have severe limitations for industrial and recreation
tered patches, other salt-tolerant plants. uses because they are subject to flooding.
The association occupies about 4 percent of the sur-
vey area. Tidal swamps make up 85 percent of the asso- 4. Los Guineos-Humatas-Lirios association
ciation and Tidal flats and Salt water marshes make up Deep, well drained and moderately well drained,
15 percent. gently sloping to very steep, acid soils on volcanic
The soils are sandy or clayey and contain organic ma- uplands
trial from decaying mangrove trees. They are under- This association consists of soils that formed in
lain by coral, shells, and marl at varying depths. medium-textured and fine-textured residual material
This association is not extensive and has no value for derived from highly weathered intrusive and extrusive
farming, but it serves as a feeding and breeding place rocks. It occupies about 10 percent of the survey area.
for birds and crabs. Los Guineos soils make up about 40 percent of the
2. Pandura-Rock land-Patillas association association; Humatas soils, 30 percent; and Lirios soils,
14 percent. The remaining 16 percent consists of minor
Shallow to deep, well-drained, steep and very steep soils soils.
on plutonic uplands The Los Guineos soils are deep, moderately well
This association consists of brown-colored soils that drained, and moderately steep to very steep. They are
formed in residual material that weathered from plu- on side slopes of strongly dissected uplands. The Huma-
tonic rocks, mainly quartz diorite and granodiorite. It tas soils are deep, well drained, and steep to very steep.
occupies about 17 percent of the survey area. The Lirios soils are deep, well drained, and gently slop-
Pandura soils make up about 49 percent of the asso- ing to steep.
ciation; Rock land, 19 percent; and Patillas soils, 12 The minor soils are Limones, Ingenio, Jagueyes, and
percent. The rest is minor soils. Aceitunas soils. The Limones, Ingenio, and Jagueyes
The Pandura soils are moderately deep and well soils are on side slopes and narrow ridgetops, and the
drained and are underlain by granitic rocks. Rock land Aceitunas soils are on foot slopes and terraces.
consists of areas where granitic boulders cover 50 to 70 Soils of this association are used mainly as wood-
percent of the land surface. The Patillas soils are mod- land and for crops. Food crops, such as plantains, tan-
erately deep to saprolite, are well drained, and are niers, and yams, are the most important. Because the
underlain by partly weathered granitic rocks, soils are gently sloping to very steep and subject to
The minor soils are of the Vieques and Teja series, erosion, they have limitations for urban, farm, and rec-
These soils are on side slopes. creation uses.
The soils of this association are used mainly for food
crops and native grasses. Steep slopes and shallow 5. Mai-Ri Arrba-Cayagua association
depth to bedrock are limitations for farming and for Deep, somewhat poorly drained and moderately well
recreation and urban uses. drained, nearly level to moderately steep soils on foot
3. Colosa a n slopes, side slopes, terraces, and alluvial fans
3. Coloso-Toa-Bajura association
This association consists of soils that formed in mod-
Deep, moderately well drained to poorly drained, nearly erately coarse-textured to fine-textured sediment de-
level soils on flood plains rived from intrusive and extrusive rocks. It occupies
This association consists of nearly level soils that about 7 percent of the survey area.
formed in fine textured and moderately fine textured Mabi soils make up about 29 percent of the associa-
sediment of mixed origin on flood plains. It occupies tion; Rio Arriba soils, 23 percent; and Cayagua soils,
about 12 percent of the survey area. 15 percent. The remaining 33 percent consists of minor
Coloso soils make up about 18 percent of the associa- soils.
tion; Toa soils, 13 percent; Bajura soils, 10 percent; Mabi soils are deep, somewhat poorly drained, and
Maunabo soils, 8 percent; and Reilly soils, 7 percent, nearly level to moderately steep. They lie on terraces
The remaining 44 percent consists of minor soils, and alluvial fans above the river flood plains. Rio Arriba
The Coloso soils are deep and somewhat poorly soils also are on terraces and alluvial fans. They are
drained. The Toa soils are deep and moderately well deep, moderately well drained, and gently sloping to
drained. The Bajura soils and the Maunabo soils are strongly sloping. Cayagua soils are deep, somewhat
deep and poorly drained. The Reilly soils are shallow to poorly drained, and gently sloping to moderately steep.
sand and gravel and are excessively drained; they lie They occupy side slopes and foot slopes.
adjacent to streams. The minor soils are Junquitos, Candelero, Via, Hu-
The minor soils are Talante, Vivi, Fortuna, Vega macao, Fajardo, and Parcelas soils. The Junquitos soils
Alta, and Vega Baja soils. The Fortuna, Talante, Vivi, are on foot slopes, and the Candelero, Via, Humacao,
and Vega Baja soils are on flood plains, but the Vega Fajardo, and Parcelas soils are on terraces.
Alta soils occupy slightly higher positions on terraces. The soils of this association are used for crops. Un-
Soils of this association are the best soils for farming favorable drainage is the main limitation for farming.
in the humid part of the survey area, though they are The shrink-swell potential limits recreation and urban
occasionally flooded. They are suited to many kinds of uses of the soils.






HUMACAO AREA OF EASTERN PUERTO RICO 3

are covered or affected by salt water or brackish water, plants. Some of the soils have impeded drainage that
The high concentration of salt inhibits the growth of all can be corrected by a suitable drainage system. The soils
vegetation except mangrove trees and, in small scat- have severe limitations for industrial and recreation
tered patches, other salt-tolerant plants. uses because they are subject to flooding.
The association occupies about 4 percent of the sur-
vey area. Tidal swamps make up 85 percent of the asso- 4. Los Guineos-Humatas-Lirios association
ciation and Tidal flats and Salt water marshes make up Deep, well drained and moderately well drained,
15 percent. gently sloping to very steep, acid soils on volcanic
The soils are sandy or clayey and contain organic ma- uplands
trial from decaying mangrove trees. They are under- This association consists of soils that formed in
lain by coral, shells, and marl at varying depths. medium-textured and fine-textured residual material
This association is not extensive and has no value for derived from highly weathered intrusive and extrusive
farming, but it serves as a feeding and breeding place rocks. It occupies about 10 percent of the survey area.
for birds and crabs. Los Guineos soils make up about 40 percent of the
2. Pandura-Rock land-Patillas association association; Humatas soils, 30 percent; and Lirios soils,
14 percent. The remaining 16 percent consists of minor
Shallow to deep, well-drained, steep and very steep soils soils.
on plutonic uplands The Los Guineos soils are deep, moderately well
This association consists of brown-colored soils that drained, and moderately steep to very steep. They are
formed in residual material that weathered from plu- on side slopes of strongly dissected uplands. The Huma-
tonic rocks, mainly quartz diorite and granodiorite. It tas soils are deep, well drained, and steep to very steep.
occupies about 17 percent of the survey area. The Lirios soils are deep, well drained, and gently slop-
Pandura soils make up about 49 percent of the asso- ing to steep.
ciation; Rock land, 19 percent; and Patillas soils, 12 The minor soils are Limones, Ingenio, Jagueyes, and
percent. The rest is minor soils. Aceitunas soils. The Limones, Ingenio, and Jagueyes
The Pandura soils are moderately deep and well soils are on side slopes and narrow ridgetops, and the
drained and are underlain by granitic rocks. Rock land Aceitunas soils are on foot slopes and terraces.
consists of areas where granitic boulders cover 50 to 70 Soils of this association are used mainly as wood-
percent of the land surface. The Patillas soils are mod- land and for crops. Food crops, such as plantains, tan-
erately deep to saprolite, are well drained, and are niers, and yams, are the most important. Because the
underlain by partly weathered granitic rocks, soils are gently sloping to very steep and subject to
The minor soils are of the Vieques and Teja series, erosion, they have limitations for urban, farm, and rec-
These soils are on side slopes. creation uses.
The soils of this association are used mainly for food
crops and native grasses. Steep slopes and shallow 5. Mai-Ri Arrba-Cayagua association
depth to bedrock are limitations for farming and for Deep, somewhat poorly drained and moderately well
recreation and urban uses. drained, nearly level to moderately steep soils on foot
3. Colosa a n slopes, side slopes, terraces, and alluvial fans
3. Coloso-Toa-Bajura association
This association consists of soils that formed in mod-
Deep, moderately well drained to poorly drained, nearly erately coarse-textured to fine-textured sediment de-
level soils on flood plains rived from intrusive and extrusive rocks. It occupies
This association consists of nearly level soils that about 7 percent of the survey area.
formed in fine textured and moderately fine textured Mabi soils make up about 29 percent of the associa-
sediment of mixed origin on flood plains. It occupies tion; Rio Arriba soils, 23 percent; and Cayagua soils,
about 12 percent of the survey area. 15 percent. The remaining 33 percent consists of minor
Coloso soils make up about 18 percent of the associa- soils.
tion; Toa soils, 13 percent; Bajura soils, 10 percent; Mabi soils are deep, somewhat poorly drained, and
Maunabo soils, 8 percent; and Reilly soils, 7 percent, nearly level to moderately steep. They lie on terraces
The remaining 44 percent consists of minor soils, and alluvial fans above the river flood plains. Rio Arriba
The Coloso soils are deep and somewhat poorly soils also are on terraces and alluvial fans. They are
drained. The Toa soils are deep and moderately well deep, moderately well drained, and gently sloping to
drained. The Bajura soils and the Maunabo soils are strongly sloping. Cayagua soils are deep, somewhat
deep and poorly drained. The Reilly soils are shallow to poorly drained, and gently sloping to moderately steep.
sand and gravel and are excessively drained; they lie They occupy side slopes and foot slopes.
adjacent to streams. The minor soils are Junquitos, Candelero, Via, Hu-
The minor soils are Talante, Vivi, Fortuna, Vega macao, Fajardo, and Parcelas soils. The Junquitos soils
Alta, and Vega Baja soils. The Fortuna, Talante, Vivi, are on foot slopes, and the Candelero, Via, Humacao,
and Vega Baja soils are on flood plains, but the Vega Fajardo, and Parcelas soils are on terraces.
Alta soils occupy slightly higher positions on terraces. The soils of this association are used for crops. Un-
Soils of this association are the best soils for farming favorable drainage is the main limitation for farming.
in the humid part of the survey area, though they are The shrink-swell potential limits recreation and urban
occasionally flooded. They are suited to many kinds of uses of the soils.






HUMACAO AREA OF EASTERN PUERTO RICO 3

are covered or affected by salt water or brackish water, plants. Some of the soils have impeded drainage that
The high concentration of salt inhibits the growth of all can be corrected by a suitable drainage system. The soils
vegetation except mangrove trees and, in small scat- have severe limitations for industrial and recreation
tered patches, other salt-tolerant plants. uses because they are subject to flooding.
The association occupies about 4 percent of the sur-
vey area. Tidal swamps make up 85 percent of the asso- 4. Los Guineos-Humatas-Lirios association
ciation and Tidal flats and Salt water marshes make up Deep, well drained and moderately well drained,
15 percent. gently sloping to very steep, acid soils on volcanic
The soils are sandy or clayey and contain organic ma- uplands
trial from decaying mangrove trees. They are under- This association consists of soils that formed in
lain by coral, shells, and marl at varying depths. medium-textured and fine-textured residual material
This association is not extensive and has no value for derived from highly weathered intrusive and extrusive
farming, but it serves as a feeding and breeding place rocks. It occupies about 10 percent of the survey area.
for birds and crabs. Los Guineos soils make up about 40 percent of the
2. Pandura-Rock land-Patillas association association; Humatas soils, 30 percent; and Lirios soils,
14 percent. The remaining 16 percent consists of minor
Shallow to deep, well-drained, steep and very steep soils soils.
on plutonic uplands The Los Guineos soils are deep, moderately well
This association consists of brown-colored soils that drained, and moderately steep to very steep. They are
formed in residual material that weathered from plu- on side slopes of strongly dissected uplands. The Huma-
tonic rocks, mainly quartz diorite and granodiorite. It tas soils are deep, well drained, and steep to very steep.
occupies about 17 percent of the survey area. The Lirios soils are deep, well drained, and gently slop-
Pandura soils make up about 49 percent of the asso- ing to steep.
ciation; Rock land, 19 percent; and Patillas soils, 12 The minor soils are Limones, Ingenio, Jagueyes, and
percent. The rest is minor soils. Aceitunas soils. The Limones, Ingenio, and Jagueyes
The Pandura soils are moderately deep and well soils are on side slopes and narrow ridgetops, and the
drained and are underlain by granitic rocks. Rock land Aceitunas soils are on foot slopes and terraces.
consists of areas where granitic boulders cover 50 to 70 Soils of this association are used mainly as wood-
percent of the land surface. The Patillas soils are mod- land and for crops. Food crops, such as plantains, tan-
erately deep to saprolite, are well drained, and are niers, and yams, are the most important. Because the
underlain by partly weathered granitic rocks, soils are gently sloping to very steep and subject to
The minor soils are of the Vieques and Teja series, erosion, they have limitations for urban, farm, and rec-
These soils are on side slopes. creation uses.
The soils of this association are used mainly for food
crops and native grasses. Steep slopes and shallow 5. Mai-Ri Arrba-Cayagua association
depth to bedrock are limitations for farming and for Deep, somewhat poorly drained and moderately well
recreation and urban uses. drained, nearly level to moderately steep soils on foot
3. Colosa a n slopes, side slopes, terraces, and alluvial fans
3. Coloso-Toa-Bajura association
This association consists of soils that formed in mod-
Deep, moderately well drained to poorly drained, nearly erately coarse-textured to fine-textured sediment de-
level soils on flood plains rived from intrusive and extrusive rocks. It occupies
This association consists of nearly level soils that about 7 percent of the survey area.
formed in fine textured and moderately fine textured Mabi soils make up about 29 percent of the associa-
sediment of mixed origin on flood plains. It occupies tion; Rio Arriba soils, 23 percent; and Cayagua soils,
about 12 percent of the survey area. 15 percent. The remaining 33 percent consists of minor
Coloso soils make up about 18 percent of the associa- soils.
tion; Toa soils, 13 percent; Bajura soils, 10 percent; Mabi soils are deep, somewhat poorly drained, and
Maunabo soils, 8 percent; and Reilly soils, 7 percent, nearly level to moderately steep. They lie on terraces
The remaining 44 percent consists of minor soils, and alluvial fans above the river flood plains. Rio Arriba
The Coloso soils are deep and somewhat poorly soils also are on terraces and alluvial fans. They are
drained. The Toa soils are deep and moderately well deep, moderately well drained, and gently sloping to
drained. The Bajura soils and the Maunabo soils are strongly sloping. Cayagua soils are deep, somewhat
deep and poorly drained. The Reilly soils are shallow to poorly drained, and gently sloping to moderately steep.
sand and gravel and are excessively drained; they lie They occupy side slopes and foot slopes.
adjacent to streams. The minor soils are Junquitos, Candelero, Via, Hu-
The minor soils are Talante, Vivi, Fortuna, Vega macao, Fajardo, and Parcelas soils. The Junquitos soils
Alta, and Vega Baja soils. The Fortuna, Talante, Vivi, are on foot slopes, and the Candelero, Via, Humacao,
and Vega Baja soils are on flood plains, but the Vega Fajardo, and Parcelas soils are on terraces.
Alta soils occupy slightly higher positions on terraces. The soils of this association are used for crops. Un-
Soils of this association are the best soils for farming favorable drainage is the main limitation for farming.
in the humid part of the survey area, though they are The shrink-swell potential limits recreation and urban
occasionally flooded. They are suited to many kinds of uses of the soils.






HUMACAO AREA OF EASTERN PUERTO RICO 3

are covered or affected by salt water or brackish water, plants. Some of the soils have impeded drainage that
The high concentration of salt inhibits the growth of all can be corrected by a suitable drainage system. The soils
vegetation except mangrove trees and, in small scat- have severe limitations for industrial and recreation
tered patches, other salt-tolerant plants. uses because they are subject to flooding.
The association occupies about 4 percent of the sur-
vey area. Tidal swamps make up 85 percent of the asso- 4. Los Guineos-Humatas-Lirios association
ciation and Tidal flats and Salt water marshes make up Deep, well drained and moderately well drained,
15 percent. gently sloping to very steep, acid soils on volcanic
The soils are sandy or clayey and contain organic ma- uplands
trial from decaying mangrove trees. They are under- This association consists of soils that formed in
lain by coral, shells, and marl at varying depths. medium-textured and fine-textured residual material
This association is not extensive and has no value for derived from highly weathered intrusive and extrusive
farming, but it serves as a feeding and breeding place rocks. It occupies about 10 percent of the survey area.
for birds and crabs. Los Guineos soils make up about 40 percent of the
2. Pandura-Rock land-Patillas association association; Humatas soils, 30 percent; and Lirios soils,
14 percent. The remaining 16 percent consists of minor
Shallow to deep, well-drained, steep and very steep soils soils.
on plutonic uplands The Los Guineos soils are deep, moderately well
This association consists of brown-colored soils that drained, and moderately steep to very steep. They are
formed in residual material that weathered from plu- on side slopes of strongly dissected uplands. The Huma-
tonic rocks, mainly quartz diorite and granodiorite. It tas soils are deep, well drained, and steep to very steep.
occupies about 17 percent of the survey area. The Lirios soils are deep, well drained, and gently slop-
Pandura soils make up about 49 percent of the asso- ing to steep.
ciation; Rock land, 19 percent; and Patillas soils, 12 The minor soils are Limones, Ingenio, Jagueyes, and
percent. The rest is minor soils. Aceitunas soils. The Limones, Ingenio, and Jagueyes
The Pandura soils are moderately deep and well soils are on side slopes and narrow ridgetops, and the
drained and are underlain by granitic rocks. Rock land Aceitunas soils are on foot slopes and terraces.
consists of areas where granitic boulders cover 50 to 70 Soils of this association are used mainly as wood-
percent of the land surface. The Patillas soils are mod- land and for crops. Food crops, such as plantains, tan-
erately deep to saprolite, are well drained, and are niers, and yams, are the most important. Because the
underlain by partly weathered granitic rocks, soils are gently sloping to very steep and subject to
The minor soils are of the Vieques and Teja series, erosion, they have limitations for urban, farm, and rec-
These soils are on side slopes. creation uses.
The soils of this association are used mainly for food
crops and native grasses. Steep slopes and shallow 5. Mai-Ri Arrba-Cayagua association
depth to bedrock are limitations for farming and for Deep, somewhat poorly drained and moderately well
recreation and urban uses. drained, nearly level to moderately steep soils on foot
3. Colosa a n slopes, side slopes, terraces, and alluvial fans
3. Coloso-Toa-Bajura association
This association consists of soils that formed in mod-
Deep, moderately well drained to poorly drained, nearly erately coarse-textured to fine-textured sediment de-
level soils on flood plains rived from intrusive and extrusive rocks. It occupies
This association consists of nearly level soils that about 7 percent of the survey area.
formed in fine textured and moderately fine textured Mabi soils make up about 29 percent of the associa-
sediment of mixed origin on flood plains. It occupies tion; Rio Arriba soils, 23 percent; and Cayagua soils,
about 12 percent of the survey area. 15 percent. The remaining 33 percent consists of minor
Coloso soils make up about 18 percent of the associa- soils.
tion; Toa soils, 13 percent; Bajura soils, 10 percent; Mabi soils are deep, somewhat poorly drained, and
Maunabo soils, 8 percent; and Reilly soils, 7 percent, nearly level to moderately steep. They lie on terraces
The remaining 44 percent consists of minor soils, and alluvial fans above the river flood plains. Rio Arriba
The Coloso soils are deep and somewhat poorly soils also are on terraces and alluvial fans. They are
drained. The Toa soils are deep and moderately well deep, moderately well drained, and gently sloping to
drained. The Bajura soils and the Maunabo soils are strongly sloping. Cayagua soils are deep, somewhat
deep and poorly drained. The Reilly soils are shallow to poorly drained, and gently sloping to moderately steep.
sand and gravel and are excessively drained; they lie They occupy side slopes and foot slopes.
adjacent to streams. The minor soils are Junquitos, Candelero, Via, Hu-
The minor soils are Talante, Vivi, Fortuna, Vega macao, Fajardo, and Parcelas soils. The Junquitos soils
Alta, and Vega Baja soils. The Fortuna, Talante, Vivi, are on foot slopes, and the Candelero, Via, Humacao,
and Vega Baja soils are on flood plains, but the Vega Fajardo, and Parcelas soils are on terraces.
Alta soils occupy slightly higher positions on terraces. The soils of this association are used for crops. Un-
Soils of this association are the best soils for farming favorable drainage is the main limitation for farming.
in the humid part of the survey area, though they are The shrink-swell potential limits recreation and urban
occasionally flooded. They are suited to many kinds of uses of the soils.







4 SOIL SURVEY

6. Caguabo-Mucara-Naranjito association 8. Catano-Aguadilla association
Shallow and moderately deep, well-drained, sloping to Deep, excessively drained, nearly level to gently sloping
very steep soils on volcanic uplands soils on coastal plains
This association consists of soils that formed in re- This association consists of soils that formed in a
sidual material that weathered from volcanic rocks. It mixture of sand-sized fragments of shells and volcanic
occupies 19 percent of the survey area. material and grains of quartz sand. It occupies about 2
Caguabo soils make up about 42 percent of the asso- percent of the survey area.
ciation; Mucara soils, 19 percent; and Naranjito soils, Catano soils make up about 53 percent of the associa-
13 percent. The remaining 26 percent consists of minor tion, and Aguadilla soils, 30 percent. The remaining 17
soils. percent is minor soils.
The Caguabo soils are shallow, well drained, and mod- The Catano soils are deep and excessively drained and
erately steep to very steep. They occupy side slopes of lie close to sea level. The Aguadilla soils are deep, ex-
strongly dissected volcanic uplands. The Mucara soils cessively drained, acid, and nearly level.
are moderately deep, well drained, and strongly sloping The minor soils are Meros soils and the land type
to very steep. They also occupy side slopes of strongly Coastal beaches. These are along the coast, slightly
dissected volcanic uplands. Naranjito soils are moder- above sea level.
ately deep, well drained, and steep to very steep. They Soils of this association are mainly in pasture and
are on dissected volcanic uplands, coconut trees. The available water capacity, organic-
The minor soils are Sabana, Daguao, and Yunes soils, matter content, and fertility all are low, and these are
The Sabana and Yunes soils are on side slopes, and the the main limitations for farming. The soils have slight
Daguao soils are on foot slopes and side slopes. limitations for recreation uses.
The soils of this association are used for pasture and
food crops, such as tanniers, yams, plantains, bananas, Soils of the Dry Areas
and pigeonpeas. Steep slopes, the hazard of erosion, and
depth to bedrock are the main limitations for farming Nearly level to hilly soils that receive limited rainfall
and for recreation and urban uses. and are deficient in moisture for growing the common
7. Los Guineos-Guayabota-Rock land association plants. Three soil associations are in this group.
Shallow to deep, well-drained to poorly drained, 9. Coamo-Guamani-Vives association
strongly sloping to very steep soils on volcanic uplands Deep, well-drained, nearly level to strongly sloping soils
of the tropical rain forest on terraces and alluvial fans
This association consists of soils that formed in fine- This association consists of soils that formed in sedi-
textured residual material that weathered from intru- ment derived from limestone and volcanic rocks. It
sive and extrusive rocks. It occupies about 6 percent of occupies about 6 percent of the survey area.
the survey area. Coamo soils make up 30 percent of the association;
Los Guineos and Yunque soils and Stony rock land Guamani soils, 18 percent; and Vives soils, 17 percent.
together make up about 56 percent of the association; The remaining 35 percent consists of minor soils.
Guayabota, Ciales, and Picacho soils together, 27 per- The Coamo soils are deep, well drained, and nearly
cent; and Rock land, the remaining 17 percent, level to strongly sloping. They are on terraces. The Gua-
The Los Guineos soils are deep, moderately well mani soils are shallow to sand and gravel, well drained,
drained, and moderately steep to very steep. They are on and nearly level. They occur on flood plains. The Vives
side slopes of dissected uplands. The Yunque soils also soils are deep, well drained, and nearly level to strongly
are deep and moderately well drained. They lie on ridge- sloping. They are on flood plains, alluvial fans, and
tops and upper side slopes of strongly dissected uplands. terraces.
Stony rock land is on the lower part of side slopes and The minor soils are Machete, Arenales, Pozo Blanco,
along drainageways, where 90 to 100 percent of the and Vayas soils. The Vayas and Arenales soils are on
surface is made up of grayish and bluish volcanic rocks, river flood plains, the Pozo Blanco soils are on foot
The Guayabota soils are shallow, poorly drained soils slopes, and the Machete soils are on alluvial fans and
on ridgetops and upper side slopes. The Ciales soils are terraces.
deep and poorly drained. They occupy strongly dis- Soils of this association are some of the best soils for
sected, moderately steep ridgetops and steep upper side farming in the semiarid part of the survey area, and
slopes. The Picacho soils are deep, moderately well they are used mainly for pasture and sugarcane. Low
drained soils that are on upper side slopes. Rough stony rainfall is a limitation, but if the soils are properly irri-
land consists of the high, jagged mountain peaks and gated, many kinds of cultivated crops can be grown.
long, very steep side slopes. Rocks make up about 75 to Some of the soils in the association are suitable for ur-
100 percent of the surface. ban and industrial uses, but others have severe limita-
Rock land consists of areas where rock outcrops oc- tions.
cupy 50 to 70 percent of the surface.
The soils of this association are used mainly as wood- 10. Descalabrado-Guayama association
land, and some areas of virgin timber still remain. These
soils have severe limitations for farm and urban uses Shallowo well-drained, strongly sloping to very steep
because of very steep slopes, stoniness and rockiness, sos on volcan uplands
and high rainfall. They are suitable for recreation uses This association consists of soils that formed in mod-
because of their high esthetic value. erately fine textured to fine textured residual material







4 SOIL SURVEY

6. Caguabo-Mucara-Naranjito association 8. Catano-Aguadilla association
Shallow and moderately deep, well-drained, sloping to Deep, excessively drained, nearly level to gently sloping
very steep soils on volcanic uplands soils on coastal plains
This association consists of soils that formed in re- This association consists of soils that formed in a
sidual material that weathered from volcanic rocks. It mixture of sand-sized fragments of shells and volcanic
occupies 19 percent of the survey area. material and grains of quartz sand. It occupies about 2
Caguabo soils make up about 42 percent of the asso- percent of the survey area.
ciation; Mucara soils, 19 percent; and Naranjito soils, Catano soils make up about 53 percent of the associa-
13 percent. The remaining 26 percent consists of minor tion, and Aguadilla soils, 30 percent. The remaining 17
soils. percent is minor soils.
The Caguabo soils are shallow, well drained, and mod- The Catano soils are deep and excessively drained and
erately steep to very steep. They occupy side slopes of lie close to sea level. The Aguadilla soils are deep, ex-
strongly dissected volcanic uplands. The Mucara soils cessively drained, acid, and nearly level.
are moderately deep, well drained, and strongly sloping The minor soils are Meros soils and the land type
to very steep. They also occupy side slopes of strongly Coastal beaches. These are along the coast, slightly
dissected volcanic uplands. Naranjito soils are moder- above sea level.
ately deep, well drained, and steep to very steep. They Soils of this association are mainly in pasture and
are on dissected volcanic uplands, coconut trees. The available water capacity, organic-
The minor soils are Sabana, Daguao, and Yunes soils, matter content, and fertility all are low, and these are
The Sabana and Yunes soils are on side slopes, and the the main limitations for farming. The soils have slight
Daguao soils are on foot slopes and side slopes. limitations for recreation uses.
The soils of this association are used for pasture and
food crops, such as tanniers, yams, plantains, bananas, Soils of the Dry Areas
and pigeonpeas. Steep slopes, the hazard of erosion, and
depth to bedrock are the main limitations for farming Nearly level to hilly soils that receive limited rainfall
and for recreation and urban uses. and are deficient in moisture for growing the common
7. Los Guineos-Guayabota-Rock land association plants. Three soil associations are in this group.
Shallow to deep, well-drained to poorly drained, 9. Coamo-Guamani-Vives association
strongly sloping to very steep soils on volcanic uplands Deep, well-drained, nearly level to strongly sloping soils
of the tropical rain forest on terraces and alluvial fans
This association consists of soils that formed in fine- This association consists of soils that formed in sedi-
textured residual material that weathered from intru- ment derived from limestone and volcanic rocks. It
sive and extrusive rocks. It occupies about 6 percent of occupies about 6 percent of the survey area.
the survey area. Coamo soils make up 30 percent of the association;
Los Guineos and Yunque soils and Stony rock land Guamani soils, 18 percent; and Vives soils, 17 percent.
together make up about 56 percent of the association; The remaining 35 percent consists of minor soils.
Guayabota, Ciales, and Picacho soils together, 27 per- The Coamo soils are deep, well drained, and nearly
cent; and Rock land, the remaining 17 percent, level to strongly sloping. They are on terraces. The Gua-
The Los Guineos soils are deep, moderately well mani soils are shallow to sand and gravel, well drained,
drained, and moderately steep to very steep. They are on and nearly level. They occur on flood plains. The Vives
side slopes of dissected uplands. The Yunque soils also soils are deep, well drained, and nearly level to strongly
are deep and moderately well drained. They lie on ridge- sloping. They are on flood plains, alluvial fans, and
tops and upper side slopes of strongly dissected uplands. terraces.
Stony rock land is on the lower part of side slopes and The minor soils are Machete, Arenales, Pozo Blanco,
along drainageways, where 90 to 100 percent of the and Vayas soils. The Vayas and Arenales soils are on
surface is made up of grayish and bluish volcanic rocks, river flood plains, the Pozo Blanco soils are on foot
The Guayabota soils are shallow, poorly drained soils slopes, and the Machete soils are on alluvial fans and
on ridgetops and upper side slopes. The Ciales soils are terraces.
deep and poorly drained. They occupy strongly dis- Soils of this association are some of the best soils for
sected, moderately steep ridgetops and steep upper side farming in the semiarid part of the survey area, and
slopes. The Picacho soils are deep, moderately well they are used mainly for pasture and sugarcane. Low
drained soils that are on upper side slopes. Rough stony rainfall is a limitation, but if the soils are properly irri-
land consists of the high, jagged mountain peaks and gated, many kinds of cultivated crops can be grown.
long, very steep side slopes. Rocks make up about 75 to Some of the soils in the association are suitable for ur-
100 percent of the surface. ban and industrial uses, but others have severe limita-
Rock land consists of areas where rock outcrops oc- tions.
cupy 50 to 70 percent of the surface.
The soils of this association are used mainly as wood- 10. Descalabrado-Guayama association
land, and some areas of virgin timber still remain. These
soils have severe limitations for farm and urban uses Shallowo well-drained, strongly sloping to very steep
because of very steep slopes, stoniness and rockiness, sos on volcan uplands
and high rainfall. They are suitable for recreation uses This association consists of soils that formed in mod-
because of their high esthetic value. erately fine textured to fine textured residual material







4 SOIL SURVEY

6. Caguabo-Mucara-Naranjito association 8. Catano-Aguadilla association
Shallow and moderately deep, well-drained, sloping to Deep, excessively drained, nearly level to gently sloping
very steep soils on volcanic uplands soils on coastal plains
This association consists of soils that formed in re- This association consists of soils that formed in a
sidual material that weathered from volcanic rocks. It mixture of sand-sized fragments of shells and volcanic
occupies 19 percent of the survey area. material and grains of quartz sand. It occupies about 2
Caguabo soils make up about 42 percent of the asso- percent of the survey area.
ciation; Mucara soils, 19 percent; and Naranjito soils, Catano soils make up about 53 percent of the associa-
13 percent. The remaining 26 percent consists of minor tion, and Aguadilla soils, 30 percent. The remaining 17
soils. percent is minor soils.
The Caguabo soils are shallow, well drained, and mod- The Catano soils are deep and excessively drained and
erately steep to very steep. They occupy side slopes of lie close to sea level. The Aguadilla soils are deep, ex-
strongly dissected volcanic uplands. The Mucara soils cessively drained, acid, and nearly level.
are moderately deep, well drained, and strongly sloping The minor soils are Meros soils and the land type
to very steep. They also occupy side slopes of strongly Coastal beaches. These are along the coast, slightly
dissected volcanic uplands. Naranjito soils are moder- above sea level.
ately deep, well drained, and steep to very steep. They Soils of this association are mainly in pasture and
are on dissected volcanic uplands, coconut trees. The available water capacity, organic-
The minor soils are Sabana, Daguao, and Yunes soils, matter content, and fertility all are low, and these are
The Sabana and Yunes soils are on side slopes, and the the main limitations for farming. The soils have slight
Daguao soils are on foot slopes and side slopes. limitations for recreation uses.
The soils of this association are used for pasture and
food crops, such as tanniers, yams, plantains, bananas, Soils of the Dry Areas
and pigeonpeas. Steep slopes, the hazard of erosion, and
depth to bedrock are the main limitations for farming Nearly level to hilly soils that receive limited rainfall
and for recreation and urban uses. and are deficient in moisture for growing the common
7. Los Guineos-Guayabota-Rock land association plants. Three soil associations are in this group.
Shallow to deep, well-drained to poorly drained, 9. Coamo-Guamani-Vives association
strongly sloping to very steep soils on volcanic uplands Deep, well-drained, nearly level to strongly sloping soils
of the tropical rain forest on terraces and alluvial fans
This association consists of soils that formed in fine- This association consists of soils that formed in sedi-
textured residual material that weathered from intru- ment derived from limestone and volcanic rocks. It
sive and extrusive rocks. It occupies about 6 percent of occupies about 6 percent of the survey area.
the survey area. Coamo soils make up 30 percent of the association;
Los Guineos and Yunque soils and Stony rock land Guamani soils, 18 percent; and Vives soils, 17 percent.
together make up about 56 percent of the association; The remaining 35 percent consists of minor soils.
Guayabota, Ciales, and Picacho soils together, 27 per- The Coamo soils are deep, well drained, and nearly
cent; and Rock land, the remaining 17 percent, level to strongly sloping. They are on terraces. The Gua-
The Los Guineos soils are deep, moderately well mani soils are shallow to sand and gravel, well drained,
drained, and moderately steep to very steep. They are on and nearly level. They occur on flood plains. The Vives
side slopes of dissected uplands. The Yunque soils also soils are deep, well drained, and nearly level to strongly
are deep and moderately well drained. They lie on ridge- sloping. They are on flood plains, alluvial fans, and
tops and upper side slopes of strongly dissected uplands. terraces.
Stony rock land is on the lower part of side slopes and The minor soils are Machete, Arenales, Pozo Blanco,
along drainageways, where 90 to 100 percent of the and Vayas soils. The Vayas and Arenales soils are on
surface is made up of grayish and bluish volcanic rocks, river flood plains, the Pozo Blanco soils are on foot
The Guayabota soils are shallow, poorly drained soils slopes, and the Machete soils are on alluvial fans and
on ridgetops and upper side slopes. The Ciales soils are terraces.
deep and poorly drained. They occupy strongly dis- Soils of this association are some of the best soils for
sected, moderately steep ridgetops and steep upper side farming in the semiarid part of the survey area, and
slopes. The Picacho soils are deep, moderately well they are used mainly for pasture and sugarcane. Low
drained soils that are on upper side slopes. Rough stony rainfall is a limitation, but if the soils are properly irri-
land consists of the high, jagged mountain peaks and gated, many kinds of cultivated crops can be grown.
long, very steep side slopes. Rocks make up about 75 to Some of the soils in the association are suitable for ur-
100 percent of the surface. ban and industrial uses, but others have severe limita-
Rock land consists of areas where rock outcrops oc- tions.
cupy 50 to 70 percent of the surface.
The soils of this association are used mainly as wood- 10. Descalabrado-Guayama association
land, and some areas of virgin timber still remain. These
soils have severe limitations for farm and urban uses Shallowo well-drained, strongly sloping to very steep
because of very steep slopes, stoniness and rockiness, sos on volcan uplands
and high rainfall. They are suitable for recreation uses This association consists of soils that formed in mod-
because of their high esthetic value. erately fine textured to fine textured residual material







4 SOIL SURVEY

6. Caguabo-Mucara-Naranjito association 8. Catano-Aguadilla association
Shallow and moderately deep, well-drained, sloping to Deep, excessively drained, nearly level to gently sloping
very steep soils on volcanic uplands soils on coastal plains
This association consists of soils that formed in re- This association consists of soils that formed in a
sidual material that weathered from volcanic rocks. It mixture of sand-sized fragments of shells and volcanic
occupies 19 percent of the survey area. material and grains of quartz sand. It occupies about 2
Caguabo soils make up about 42 percent of the asso- percent of the survey area.
ciation; Mucara soils, 19 percent; and Naranjito soils, Catano soils make up about 53 percent of the associa-
13 percent. The remaining 26 percent consists of minor tion, and Aguadilla soils, 30 percent. The remaining 17
soils. percent is minor soils.
The Caguabo soils are shallow, well drained, and mod- The Catano soils are deep and excessively drained and
erately steep to very steep. They occupy side slopes of lie close to sea level. The Aguadilla soils are deep, ex-
strongly dissected volcanic uplands. The Mucara soils cessively drained, acid, and nearly level.
are moderately deep, well drained, and strongly sloping The minor soils are Meros soils and the land type
to very steep. They also occupy side slopes of strongly Coastal beaches. These are along the coast, slightly
dissected volcanic uplands. Naranjito soils are moder- above sea level.
ately deep, well drained, and steep to very steep. They Soils of this association are mainly in pasture and
are on dissected volcanic uplands, coconut trees. The available water capacity, organic-
The minor soils are Sabana, Daguao, and Yunes soils, matter content, and fertility all are low, and these are
The Sabana and Yunes soils are on side slopes, and the the main limitations for farming. The soils have slight
Daguao soils are on foot slopes and side slopes. limitations for recreation uses.
The soils of this association are used for pasture and
food crops, such as tanniers, yams, plantains, bananas, Soils of the Dry Areas
and pigeonpeas. Steep slopes, the hazard of erosion, and
depth to bedrock are the main limitations for farming Nearly level to hilly soils that receive limited rainfall
and for recreation and urban uses. and are deficient in moisture for growing the common
7. Los Guineos-Guayabota-Rock land association plants. Three soil associations are in this group.
Shallow to deep, well-drained to poorly drained, 9. Coamo-Guamani-Vives association
strongly sloping to very steep soils on volcanic uplands Deep, well-drained, nearly level to strongly sloping soils
of the tropical rain forest on terraces and alluvial fans
This association consists of soils that formed in fine- This association consists of soils that formed in sedi-
textured residual material that weathered from intru- ment derived from limestone and volcanic rocks. It
sive and extrusive rocks. It occupies about 6 percent of occupies about 6 percent of the survey area.
the survey area. Coamo soils make up 30 percent of the association;
Los Guineos and Yunque soils and Stony rock land Guamani soils, 18 percent; and Vives soils, 17 percent.
together make up about 56 percent of the association; The remaining 35 percent consists of minor soils.
Guayabota, Ciales, and Picacho soils together, 27 per- The Coamo soils are deep, well drained, and nearly
cent; and Rock land, the remaining 17 percent, level to strongly sloping. They are on terraces. The Gua-
The Los Guineos soils are deep, moderately well mani soils are shallow to sand and gravel, well drained,
drained, and moderately steep to very steep. They are on and nearly level. They occur on flood plains. The Vives
side slopes of dissected uplands. The Yunque soils also soils are deep, well drained, and nearly level to strongly
are deep and moderately well drained. They lie on ridge- sloping. They are on flood plains, alluvial fans, and
tops and upper side slopes of strongly dissected uplands. terraces.
Stony rock land is on the lower part of side slopes and The minor soils are Machete, Arenales, Pozo Blanco,
along drainageways, where 90 to 100 percent of the and Vayas soils. The Vayas and Arenales soils are on
surface is made up of grayish and bluish volcanic rocks, river flood plains, the Pozo Blanco soils are on foot
The Guayabota soils are shallow, poorly drained soils slopes, and the Machete soils are on alluvial fans and
on ridgetops and upper side slopes. The Ciales soils are terraces.
deep and poorly drained. They occupy strongly dis- Soils of this association are some of the best soils for
sected, moderately steep ridgetops and steep upper side farming in the semiarid part of the survey area, and
slopes. The Picacho soils are deep, moderately well they are used mainly for pasture and sugarcane. Low
drained soils that are on upper side slopes. Rough stony rainfall is a limitation, but if the soils are properly irri-
land consists of the high, jagged mountain peaks and gated, many kinds of cultivated crops can be grown.
long, very steep side slopes. Rocks make up about 75 to Some of the soils in the association are suitable for ur-
100 percent of the surface. ban and industrial uses, but others have severe limita-
Rock land consists of areas where rock outcrops oc- tions.
cupy 50 to 70 percent of the surface.
The soils of this association are used mainly as wood- 10. Descalabrado-Guayama association
land, and some areas of virgin timber still remain. These
soils have severe limitations for farm and urban uses Shallowo well-drained, strongly sloping to very steep
because of very steep slopes, stoniness and rockiness, sos on volcan uplands
and high rainfall. They are suitable for recreation uses This association consists of soils that formed in mod-
because of their high esthetic value. erately fine textured to fine textured residual material







4 SOIL SURVEY

6. Caguabo-Mucara-Naranjito association 8. Catano-Aguadilla association
Shallow and moderately deep, well-drained, sloping to Deep, excessively drained, nearly level to gently sloping
very steep soils on volcanic uplands soils on coastal plains
This association consists of soils that formed in re- This association consists of soils that formed in a
sidual material that weathered from volcanic rocks. It mixture of sand-sized fragments of shells and volcanic
occupies 19 percent of the survey area. material and grains of quartz sand. It occupies about 2
Caguabo soils make up about 42 percent of the asso- percent of the survey area.
ciation; Mucara soils, 19 percent; and Naranjito soils, Catano soils make up about 53 percent of the associa-
13 percent. The remaining 26 percent consists of minor tion, and Aguadilla soils, 30 percent. The remaining 17
soils. percent is minor soils.
The Caguabo soils are shallow, well drained, and mod- The Catano soils are deep and excessively drained and
erately steep to very steep. They occupy side slopes of lie close to sea level. The Aguadilla soils are deep, ex-
strongly dissected volcanic uplands. The Mucara soils cessively drained, acid, and nearly level.
are moderately deep, well drained, and strongly sloping The minor soils are Meros soils and the land type
to very steep. They also occupy side slopes of strongly Coastal beaches. These are along the coast, slightly
dissected volcanic uplands. Naranjito soils are moder- above sea level.
ately deep, well drained, and steep to very steep. They Soils of this association are mainly in pasture and
are on dissected volcanic uplands, coconut trees. The available water capacity, organic-
The minor soils are Sabana, Daguao, and Yunes soils, matter content, and fertility all are low, and these are
The Sabana and Yunes soils are on side slopes, and the the main limitations for farming. The soils have slight
Daguao soils are on foot slopes and side slopes. limitations for recreation uses.
The soils of this association are used for pasture and
food crops, such as tanniers, yams, plantains, bananas, Soils of the Dry Areas
and pigeonpeas. Steep slopes, the hazard of erosion, and
depth to bedrock are the main limitations for farming Nearly level to hilly soils that receive limited rainfall
and for recreation and urban uses. and are deficient in moisture for growing the common
7. Los Guineos-Guayabota-Rock land association plants. Three soil associations are in this group.
Shallow to deep, well-drained to poorly drained, 9. Coamo-Guamani-Vives association
strongly sloping to very steep soils on volcanic uplands Deep, well-drained, nearly level to strongly sloping soils
of the tropical rain forest on terraces and alluvial fans
This association consists of soils that formed in fine- This association consists of soils that formed in sedi-
textured residual material that weathered from intru- ment derived from limestone and volcanic rocks. It
sive and extrusive rocks. It occupies about 6 percent of occupies about 6 percent of the survey area.
the survey area. Coamo soils make up 30 percent of the association;
Los Guineos and Yunque soils and Stony rock land Guamani soils, 18 percent; and Vives soils, 17 percent.
together make up about 56 percent of the association; The remaining 35 percent consists of minor soils.
Guayabota, Ciales, and Picacho soils together, 27 per- The Coamo soils are deep, well drained, and nearly
cent; and Rock land, the remaining 17 percent, level to strongly sloping. They are on terraces. The Gua-
The Los Guineos soils are deep, moderately well mani soils are shallow to sand and gravel, well drained,
drained, and moderately steep to very steep. They are on and nearly level. They occur on flood plains. The Vives
side slopes of dissected uplands. The Yunque soils also soils are deep, well drained, and nearly level to strongly
are deep and moderately well drained. They lie on ridge- sloping. They are on flood plains, alluvial fans, and
tops and upper side slopes of strongly dissected uplands. terraces.
Stony rock land is on the lower part of side slopes and The minor soils are Machete, Arenales, Pozo Blanco,
along drainageways, where 90 to 100 percent of the and Vayas soils. The Vayas and Arenales soils are on
surface is made up of grayish and bluish volcanic rocks, river flood plains, the Pozo Blanco soils are on foot
The Guayabota soils are shallow, poorly drained soils slopes, and the Machete soils are on alluvial fans and
on ridgetops and upper side slopes. The Ciales soils are terraces.
deep and poorly drained. They occupy strongly dis- Soils of this association are some of the best soils for
sected, moderately steep ridgetops and steep upper side farming in the semiarid part of the survey area, and
slopes. The Picacho soils are deep, moderately well they are used mainly for pasture and sugarcane. Low
drained soils that are on upper side slopes. Rough stony rainfall is a limitation, but if the soils are properly irri-
land consists of the high, jagged mountain peaks and gated, many kinds of cultivated crops can be grown.
long, very steep side slopes. Rocks make up about 75 to Some of the soils in the association are suitable for ur-
100 percent of the surface. ban and industrial uses, but others have severe limita-
Rock land consists of areas where rock outcrops oc- tions.
cupy 50 to 70 percent of the surface.
The soils of this association are used mainly as wood- 10. Descalabrado-Guayama association
land, and some areas of virgin timber still remain. These
soils have severe limitations for farm and urban uses Shallowo well-drained, strongly sloping to very steep
because of very steep slopes, stoniness and rockiness, sos on volcan uplands
and high rainfall. They are suitable for recreation uses This association consists of soils that formed in mod-
because of their high esthetic value. erately fine textured to fine textured residual material







4 SOIL SURVEY

6. Caguabo-Mucara-Naranjito association 8. Catano-Aguadilla association
Shallow and moderately deep, well-drained, sloping to Deep, excessively drained, nearly level to gently sloping
very steep soils on volcanic uplands soils on coastal plains
This association consists of soils that formed in re- This association consists of soils that formed in a
sidual material that weathered from volcanic rocks. It mixture of sand-sized fragments of shells and volcanic
occupies 19 percent of the survey area. material and grains of quartz sand. It occupies about 2
Caguabo soils make up about 42 percent of the asso- percent of the survey area.
ciation; Mucara soils, 19 percent; and Naranjito soils, Catano soils make up about 53 percent of the associa-
13 percent. The remaining 26 percent consists of minor tion, and Aguadilla soils, 30 percent. The remaining 17
soils. percent is minor soils.
The Caguabo soils are shallow, well drained, and mod- The Catano soils are deep and excessively drained and
erately steep to very steep. They occupy side slopes of lie close to sea level. The Aguadilla soils are deep, ex-
strongly dissected volcanic uplands. The Mucara soils cessively drained, acid, and nearly level.
are moderately deep, well drained, and strongly sloping The minor soils are Meros soils and the land type
to very steep. They also occupy side slopes of strongly Coastal beaches. These are along the coast, slightly
dissected volcanic uplands. Naranjito soils are moder- above sea level.
ately deep, well drained, and steep to very steep. They Soils of this association are mainly in pasture and
are on dissected volcanic uplands, coconut trees. The available water capacity, organic-
The minor soils are Sabana, Daguao, and Yunes soils, matter content, and fertility all are low, and these are
The Sabana and Yunes soils are on side slopes, and the the main limitations for farming. The soils have slight
Daguao soils are on foot slopes and side slopes. limitations for recreation uses.
The soils of this association are used for pasture and
food crops, such as tanniers, yams, plantains, bananas, Soils of the Dry Areas
and pigeonpeas. Steep slopes, the hazard of erosion, and
depth to bedrock are the main limitations for farming Nearly level to hilly soils that receive limited rainfall
and for recreation and urban uses. and are deficient in moisture for growing the common
7. Los Guineos-Guayabota-Rock land association plants. Three soil associations are in this group.
Shallow to deep, well-drained to poorly drained, 9. Coamo-Guamani-Vives association
strongly sloping to very steep soils on volcanic uplands Deep, well-drained, nearly level to strongly sloping soils
of the tropical rain forest on terraces and alluvial fans
This association consists of soils that formed in fine- This association consists of soils that formed in sedi-
textured residual material that weathered from intru- ment derived from limestone and volcanic rocks. It
sive and extrusive rocks. It occupies about 6 percent of occupies about 6 percent of the survey area.
the survey area. Coamo soils make up 30 percent of the association;
Los Guineos and Yunque soils and Stony rock land Guamani soils, 18 percent; and Vives soils, 17 percent.
together make up about 56 percent of the association; The remaining 35 percent consists of minor soils.
Guayabota, Ciales, and Picacho soils together, 27 per- The Coamo soils are deep, well drained, and nearly
cent; and Rock land, the remaining 17 percent, level to strongly sloping. They are on terraces. The Gua-
The Los Guineos soils are deep, moderately well mani soils are shallow to sand and gravel, well drained,
drained, and moderately steep to very steep. They are on and nearly level. They occur on flood plains. The Vives
side slopes of dissected uplands. The Yunque soils also soils are deep, well drained, and nearly level to strongly
are deep and moderately well drained. They lie on ridge- sloping. They are on flood plains, alluvial fans, and
tops and upper side slopes of strongly dissected uplands. terraces.
Stony rock land is on the lower part of side slopes and The minor soils are Machete, Arenales, Pozo Blanco,
along drainageways, where 90 to 100 percent of the and Vayas soils. The Vayas and Arenales soils are on
surface is made up of grayish and bluish volcanic rocks, river flood plains, the Pozo Blanco soils are on foot
The Guayabota soils are shallow, poorly drained soils slopes, and the Machete soils are on alluvial fans and
on ridgetops and upper side slopes. The Ciales soils are terraces.
deep and poorly drained. They occupy strongly dis- Soils of this association are some of the best soils for
sected, moderately steep ridgetops and steep upper side farming in the semiarid part of the survey area, and
slopes. The Picacho soils are deep, moderately well they are used mainly for pasture and sugarcane. Low
drained soils that are on upper side slopes. Rough stony rainfall is a limitation, but if the soils are properly irri-
land consists of the high, jagged mountain peaks and gated, many kinds of cultivated crops can be grown.
long, very steep side slopes. Rocks make up about 75 to Some of the soils in the association are suitable for ur-
100 percent of the surface. ban and industrial uses, but others have severe limita-
Rock land consists of areas where rock outcrops oc- tions.
cupy 50 to 70 percent of the surface.
The soils of this association are used mainly as wood- 10. Descalabrado-Guayama association
land, and some areas of virgin timber still remain. These
soils have severe limitations for farm and urban uses Shallowo well-drained, strongly sloping to very steep
because of very steep slopes, stoniness and rockiness, sos on volcan uplands
and high rainfall. They are suitable for recreation uses This association consists of soils that formed in mod-
because of their high esthetic value. erately fine textured to fine textured residual material






HUMACAO AREA OF EASTERN PUERTO RICO 5

derived from basic volcanic rocks. It occupies about 12 As mentioned in the section "How This Survey Was
percent of the survey area. Made," not all mapping units are members of a soil
Descalabrado soils make up about 41 percent of the series. Coastal beaches, for example, does not belong to
association, and Guayama soils, 32 percent. The rest is a soil series, but nevertheless, it is listed in alphabetic
small areas of Rock land and minor soils. order along with the soil series.
The Descalabrado and Guayama soils are shallow, Preceding the name of each mapping unit is a symbol
well drained, and strongly sloping to very steep. that identifies the mapping unit on the detailed soil
The soils of this association are used for pasture or map. Listed at the end of each description of a mapping
are in brush. They have severe limitations for farming unit is the capability unit and woodland suitability
and for recreation and urban uses because they are shal- group in which the mapping unit has been placed. The
low to bedrock, lack sufficient moisture, are steep, and capability unit and woodland suitability group of each
are susceptible to erosion. mapping unit is also listed in the "Guide to Mapping
11. Jacana-Amelia-Fralernidad association Units" at the end of this survey.
The acreage and proportionate extent of each map-
Moderately deep and deep, well drained and moderately ping unit are shown in table 1. Many of the terms used
well drained, nearly level to strongly sloping soils on in describing soils can be found in the Glossary, and
terraces, alluvial fans, and foot slopes more detailed information about the terminology and
This association consists of soils that formed in fine- methods of soil mapping can be obtained from the Soil
textured sediment and gravelly sediment derived from Survey Manual (5).
limestone and volcanic rocks. It occupies about 5 percent
of the survey area. Aceitunas Series
Jacana soils make up about 24 percent of the associa-
tion; Amelia soils, 23 percent; and Fraternidad soils, 15 The Aceitunas series consists of deep soils that are
percent. The rest is minor soils. well drained and moderately permeable. These soils
The Jacana soils are moderately deep, well drained, formed in moderately fine textured and fine textured
and gently sloping to strongly sloping. They are on foot sediment. They are on foot slopes and terraces. Slopes
slopes. The Amelia soils are deep, well-drained, gently are 5 to 12 percent. The climate is humid tropical. The
sloping to strongly sloping soils on foot slopes. The Fra- average annual rainfall is 66 inches, and the average
ternidad soils are deep, moderately well drained, and annual temperature is 770 F.
nearly level to strongly sloping. They are on terraces In a representative profile, the surface layer is dark
and alluvial fans. reddish-brown, extremely acid silty clay loam about 10
The minor soils are Cartagena, Paso Seco, and Pon- inches thick. Below this layer, yellowish-red clay ex-
cena soils on alluvial fans and terraces. tends to a depth of 35 inches. It is underlain by
Soils of this association are used mainly for sugar- yellowish-red, friable silty clay, which extends to a
cane and pasture. They have limitations for farm, rec- depth of more than 60 inches.
reaction, and urban uses because of moderate slope, These soils have moderate available water capacity
susceptibility to erosion, low rainfall, and high shrink- and shrink-swell potential and medium fertility. Runoff
swell potential, is medium. Most of the acreage is used for sugarcane,
improved pasture, and food crops, but there are small
areas in native pasture and brush.
D criptions of the ls Representative profile of Aceitunas silty clay loam, 5
Descriptions of the Soils to 12 percent slopes, 200 meters south and 8 meters west
This section describes each soil series in detail and f kilometer marker 131 on Highway No. 31, Naguabo
then, briefly, each mapping unit in that series. Unless to Juncos
stated otherwise, what is stated about the soil series Ap-0 to 10 inches, dark reddish-brown (5YR 3/3) silty
holds true for the mapping units in that series. Thus, to clay loam; weak, medium, subangular blocky struc-
get full information about any one mapping unit, it is ture; friable, slightly sticky and slightly plastic;
get full information about any one mapping unit, it is few fine roots; clay films along root channels; few,
necessary to read both the description of the mapping fine, black concretions; few pebbles 1 to 4 milli
unit and the description of the soil series to which it meters in diameter; few krotovinas; common root
belongs, channels; extremely acid; abrupt, wavy boundary.
An important part of the description of each soil se- B21t-10 to 19 inches, yellowish-red (uYR 5/6) clay;
moderate, medium, subangular blocky structure;
ries is the soil profile, that is, the sequence of layers firm, slightly sticky and slightly plastic; common
from the surface down to rock or other underlying ma- fine roots; thin patchy clay films on root channels
trial. Each series contains two descriptions of the and ped surfaces; few krotovinas; few fine pebbles;
profile. The first is brief and in terms familiar to a lay- ewn ark minerals; extremely acid; gradual, wavy
man. The second is more detailed and is included for B22t-19 to 25 inches, yellowish-red (5YR 4/8) clay; weak,
those who need to make thorough and precise studies of fine, subangular blocky structure; friable, slightly
soils. The profile described in the series is representative sticky and slightly plastic; few fine roots; thin
for mapping units in that series. If the profile of a given acity cl lar m fi pbbles; very strongly
mapping unit is different from the one described for the B23t-25 to 35 inches, yellowish-red (5YR 4/6) clay; weak,
series, these differences are stated in describing the fine, subangular blocky structure; firm, slightly
mapping unit, or they are differences that are apparent sticky and slightly plastic; common fine pores; few
in the name of the mapping unit. Color terms are for
moist soil unless otherwise stated. Italic numbers in parentheses refer to Literature Cited, p. 99





[ I,






HUMACAO AREA OF EASTERN PUERTO RICO 5

derived from basic volcanic rocks. It occupies about 12 As mentioned in the section "How This Survey Was
percent of the survey area. Made," not all mapping units are members of a soil
Descalabrado soils make up about 41 percent of the series. Coastal beaches, for example, does not belong to
association, and Guayama soils, 32 percent. The rest is a soil series, but nevertheless, it is listed in alphabetic
small areas of Rock land and minor soils. order along with the soil series.
The Descalabrado and Guayama soils are shallow, Preceding the name of each mapping unit is a symbol
well drained, and strongly sloping to very steep. that identifies the mapping unit on the detailed soil
The soils of this association are used for pasture or map. Listed at the end of each description of a mapping
are in brush. They have severe limitations for farming unit is the capability unit and woodland suitability
and for recreation and urban uses because they are shal- group in which the mapping unit has been placed. The
low to bedrock, lack sufficient moisture, are steep, and capability unit and woodland suitability group of each
are susceptible to erosion. mapping unit is also listed in the "Guide to Mapping
11. Jacana-Amelia-Fralernidad association Units" at the end of this survey.
The acreage and proportionate extent of each map-
Moderately deep and deep, well drained and moderately ping unit are shown in table 1. Many of the terms used
well drained, nearly level to strongly sloping soils on in describing soils can be found in the Glossary, and
terraces, alluvial fans, and foot slopes more detailed information about the terminology and
This association consists of soils that formed in fine- methods of soil mapping can be obtained from the Soil
textured sediment and gravelly sediment derived from Survey Manual (5).
limestone and volcanic rocks. It occupies about 5 percent
of the survey area. Aceitunas Series
Jacana soils make up about 24 percent of the associa-
tion; Amelia soils, 23 percent; and Fraternidad soils, 15 The Aceitunas series consists of deep soils that are
percent. The rest is minor soils. well drained and moderately permeable. These soils
The Jacana soils are moderately deep, well drained, formed in moderately fine textured and fine textured
and gently sloping to strongly sloping. They are on foot sediment. They are on foot slopes and terraces. Slopes
slopes. The Amelia soils are deep, well-drained, gently are 5 to 12 percent. The climate is humid tropical. The
sloping to strongly sloping soils on foot slopes. The Fra- average annual rainfall is 66 inches, and the average
ternidad soils are deep, moderately well drained, and annual temperature is 770 F.
nearly level to strongly sloping. They are on terraces In a representative profile, the surface layer is dark
and alluvial fans. reddish-brown, extremely acid silty clay loam about 10
The minor soils are Cartagena, Paso Seco, and Pon- inches thick. Below this layer, yellowish-red clay ex-
cena soils on alluvial fans and terraces. tends to a depth of 35 inches. It is underlain by
Soils of this association are used mainly for sugar- yellowish-red, friable silty clay, which extends to a
cane and pasture. They have limitations for farm, rec- depth of more than 60 inches.
reaction, and urban uses because of moderate slope, These soils have moderate available water capacity
susceptibility to erosion, low rainfall, and high shrink- and shrink-swell potential and medium fertility. Runoff
swell potential, is medium. Most of the acreage is used for sugarcane,
improved pasture, and food crops, but there are small
areas in native pasture and brush.
D criptions of the ls Representative profile of Aceitunas silty clay loam, 5
Descriptions of the Soils to 12 percent slopes, 200 meters south and 8 meters west
This section describes each soil series in detail and f kilometer marker 131 on Highway No. 31, Naguabo
then, briefly, each mapping unit in that series. Unless to Juncos
stated otherwise, what is stated about the soil series Ap-0 to 10 inches, dark reddish-brown (5YR 3/3) silty
holds true for the mapping units in that series. Thus, to clay loam; weak, medium, subangular blocky struc-
get full information about any one mapping unit, it is ture; friable, slightly sticky and slightly plastic;
get full information about any one mapping unit, it is few fine roots; clay films along root channels; few,
necessary to read both the description of the mapping fine, black concretions; few pebbles 1 to 4 milli
unit and the description of the soil series to which it meters in diameter; few krotovinas; common root
belongs, channels; extremely acid; abrupt, wavy boundary.
An important part of the description of each soil se- B21t-10 to 19 inches, yellowish-red (uYR 5/6) clay;
moderate, medium, subangular blocky structure;
ries is the soil profile, that is, the sequence of layers firm, slightly sticky and slightly plastic; common
from the surface down to rock or other underlying ma- fine roots; thin patchy clay films on root channels
trial. Each series contains two descriptions of the and ped surfaces; few krotovinas; few fine pebbles;
profile. The first is brief and in terms familiar to a lay- ewn ark minerals; extremely acid; gradual, wavy
man. The second is more detailed and is included for B22t-19 to 25 inches, yellowish-red (5YR 4/8) clay; weak,
those who need to make thorough and precise studies of fine, subangular blocky structure; friable, slightly
soils. The profile described in the series is representative sticky and slightly plastic; few fine roots; thin
for mapping units in that series. If the profile of a given acity cl lar m fi pbbles; very strongly
mapping unit is different from the one described for the B23t-25 to 35 inches, yellowish-red (5YR 4/6) clay; weak,
series, these differences are stated in describing the fine, subangular blocky structure; firm, slightly
mapping unit, or they are differences that are apparent sticky and slightly plastic; common fine pores; few
in the name of the mapping unit. Color terms are for
moist soil unless otherwise stated. Italic numbers in parentheses refer to Literature Cited, p. 99





[ I,






HUMACAO AREA OF EASTERN PUERTO RICO 5

derived from basic volcanic rocks. It occupies about 12 As mentioned in the section "How This Survey Was
percent of the survey area. Made," not all mapping units are members of a soil
Descalabrado soils make up about 41 percent of the series. Coastal beaches, for example, does not belong to
association, and Guayama soils, 32 percent. The rest is a soil series, but nevertheless, it is listed in alphabetic
small areas of Rock land and minor soils. order along with the soil series.
The Descalabrado and Guayama soils are shallow, Preceding the name of each mapping unit is a symbol
well drained, and strongly sloping to very steep. that identifies the mapping unit on the detailed soil
The soils of this association are used for pasture or map. Listed at the end of each description of a mapping
are in brush. They have severe limitations for farming unit is the capability unit and woodland suitability
and for recreation and urban uses because they are shal- group in which the mapping unit has been placed. The
low to bedrock, lack sufficient moisture, are steep, and capability unit and woodland suitability group of each
are susceptible to erosion. mapping unit is also listed in the "Guide to Mapping
11. Jacana-Amelia-Fralernidad association Units" at the end of this survey.
The acreage and proportionate extent of each map-
Moderately deep and deep, well drained and moderately ping unit are shown in table 1. Many of the terms used
well drained, nearly level to strongly sloping soils on in describing soils can be found in the Glossary, and
terraces, alluvial fans, and foot slopes more detailed information about the terminology and
This association consists of soils that formed in fine- methods of soil mapping can be obtained from the Soil
textured sediment and gravelly sediment derived from Survey Manual (5).
limestone and volcanic rocks. It occupies about 5 percent
of the survey area. Aceitunas Series
Jacana soils make up about 24 percent of the associa-
tion; Amelia soils, 23 percent; and Fraternidad soils, 15 The Aceitunas series consists of deep soils that are
percent. The rest is minor soils. well drained and moderately permeable. These soils
The Jacana soils are moderately deep, well drained, formed in moderately fine textured and fine textured
and gently sloping to strongly sloping. They are on foot sediment. They are on foot slopes and terraces. Slopes
slopes. The Amelia soils are deep, well-drained, gently are 5 to 12 percent. The climate is humid tropical. The
sloping to strongly sloping soils on foot slopes. The Fra- average annual rainfall is 66 inches, and the average
ternidad soils are deep, moderately well drained, and annual temperature is 770 F.
nearly level to strongly sloping. They are on terraces In a representative profile, the surface layer is dark
and alluvial fans. reddish-brown, extremely acid silty clay loam about 10
The minor soils are Cartagena, Paso Seco, and Pon- inches thick. Below this layer, yellowish-red clay ex-
cena soils on alluvial fans and terraces. tends to a depth of 35 inches. It is underlain by
Soils of this association are used mainly for sugar- yellowish-red, friable silty clay, which extends to a
cane and pasture. They have limitations for farm, rec- depth of more than 60 inches.
reaction, and urban uses because of moderate slope, These soils have moderate available water capacity
susceptibility to erosion, low rainfall, and high shrink- and shrink-swell potential and medium fertility. Runoff
swell potential, is medium. Most of the acreage is used for sugarcane,
improved pasture, and food crops, but there are small
areas in native pasture and brush.
D criptions of the ls Representative profile of Aceitunas silty clay loam, 5
Descriptions of the Soils to 12 percent slopes, 200 meters south and 8 meters west
This section describes each soil series in detail and f kilometer marker 131 on Highway No. 31, Naguabo
then, briefly, each mapping unit in that series. Unless to Juncos
stated otherwise, what is stated about the soil series Ap-0 to 10 inches, dark reddish-brown (5YR 3/3) silty
holds true for the mapping units in that series. Thus, to clay loam; weak, medium, subangular blocky struc-
get full information about any one mapping unit, it is ture; friable, slightly sticky and slightly plastic;
get full information about any one mapping unit, it is few fine roots; clay films along root channels; few,
necessary to read both the description of the mapping fine, black concretions; few pebbles 1 to 4 milli
unit and the description of the soil series to which it meters in diameter; few krotovinas; common root
belongs, channels; extremely acid; abrupt, wavy boundary.
An important part of the description of each soil se- B21t-10 to 19 inches, yellowish-red (uYR 5/6) clay;
moderate, medium, subangular blocky structure;
ries is the soil profile, that is, the sequence of layers firm, slightly sticky and slightly plastic; common
from the surface down to rock or other underlying ma- fine roots; thin patchy clay films on root channels
trial. Each series contains two descriptions of the and ped surfaces; few krotovinas; few fine pebbles;
profile. The first is brief and in terms familiar to a lay- ewn ark minerals; extremely acid; gradual, wavy
man. The second is more detailed and is included for B22t-19 to 25 inches, yellowish-red (5YR 4/8) clay; weak,
those who need to make thorough and precise studies of fine, subangular blocky structure; friable, slightly
soils. The profile described in the series is representative sticky and slightly plastic; few fine roots; thin
for mapping units in that series. If the profile of a given acity cl lar m fi pbbles; very strongly
mapping unit is different from the one described for the B23t-25 to 35 inches, yellowish-red (5YR 4/6) clay; weak,
series, these differences are stated in describing the fine, subangular blocky structure; firm, slightly
mapping unit, or they are differences that are apparent sticky and slightly plastic; common fine pores; few
in the name of the mapping unit. Color terms are for
moist soil unless otherwise stated. Italic numbers in parentheses refer to Literature Cited, p. 99





[ I,







6 SOIL SURVEY

TABLE 1.-Approximate acreage and proportionate extent of the soils

Mapping unit Area Extent Mapping unit Area Extent

Acres Percent Acres Percent

Aceitunas silty clay loam, 5 to 12 percent Lirios clay loam, 3 to 10 percent slopes,
slopes --------- ---------------- 2,920 0.6 eroded- ____-------------------- 509 0.1
Aguadilla loamy sand --------------------- 2,100 .4 Lirios silty clay loam, 20 to 40 percent
Aguadilla sandy loam, moderately wet __---- 743 .2 slopes, eroded _------------------------ 5,132 1.1
Amelia gravelly clay loam, 2 to 5 percent Los Guineos silty clay loam, 12 to 20 percent
slopes ----------------------- 1,961 .4 slopes --------------- ----------- 354 .1
Amelia gravelly clay loam, 5 to 12 percent Los Guineos silty clay loam, 20 to 40 percent
slopes, eroded -------------------- -- 2,971 .6 slopes, eroded __________------------- 3,868 .8
Arenales sandy loam ---------------- 407 .1 Los Guineos silty clay loam, 40 to 60 percent
Arenales sandy loam, gravelly substratum ___ 345 .1 slopes, eroded ___--------------------- 14,233 3.1
Bajura silty clay, saline ---------------- 253 (') Los Guineos-Yunque-Stony rock land associ-
Bajura clay, frequently flooded __----------_ 5,170 1.1 ation, steep ______________-------------_ 15,766 3.3
Caguabo clay loam, 12 to 20 percent slopes, Mabi clay, 0 to 5 percent slopes ___--------- 4,653 1.0
eroded _____________---_--------------- 163 .1 Mabi clay, 5 to 12 percent slopes, eroded --__ 2,669 .6
Caguabo clay loam, 20 to 60 percent slopes, Mabi clay, 12 to 20 percent slopes, eroded -- 541 .1
eroded _______________________-- -------_ 40,337 8.6 Machete loam, 0 to 2 percent slopes _-------- 1,049 .2
Candelero loam, 2 to 5 percent slopes ---__-__ 1,193 .2 Machete loam, 2 to 5 percent slopes --------- 1,333 .3
Candelero loam, 5 to 12 percent slopes, eroded_ 3,149 .7 Made land ----------------------------- 3,167 .7
Cartagena clay _---- __-- __-------------_- 1,704 .4 Maunabo clay _____-_______----_____----_ 4,215 .9
Catano loamy sand _________________-_----- 4,957 1.1 Mayo loam, 3 to 10 percent slopes -------- 578 .1
Cayagua sandy loam, 5 to 12 percent slopes, Meros sand, 1 to 6 percent slopes ----------- 725 .1
eroded _____________-----------------_ 3,170 .7 Mucara silty clay loam, 12 to 20 percent
Cayagua sandy loam, 12 to 20 percent slopes, slopes, eroded _________------- -------1,891 .4
eroded ----------------------------_ 1,393 .3 Mucara silty clay loam, 20 to 40 percent
Coamo clay loam, 2 to 5 percent slopes ___--- 5,659 1.2 slopes, eroded ------------------ --- 17,166 3.6
Coamo clay loam, 5 to 12 percent slopes ---- 1,805 .4 Naranjito silty clay loam, 20 to 40 percent
Coastal beaches --- ---------------- 1,094 .2 slopes, eroded _____-______------ -- --- 5,979 1.3
Cobbly alluvial land _--------------------- 3,824 .8 Naranjito silty clay loam, 40 to 60 percent
Coloso silty clay loam, occasionally flooded __ 7,892 1.7 slopes, eroded ______----- _____-__---- 6,001 1.3
Coloso silty clay -______------------ ----- 2,139 .4 Pandura loam, 12 to 40 percent slopes, eroded- 2,177 .5
Corcega sandy loam --------------------- 1,210 .3 Pandura loam, 40 to 60 percent slopes, eroded_ 23,353 5.0
Daguao silty clay loam, deep variant, 2 to Pandura-Very stony land complex, 40 to 60
12 percent slopes _--------------------- 237 (') percent slopes --- ---------------__ 14,845 3.2
Daguao clay, 20 to 40 percent slopes, eroded_ 826 .2 Parcelas clay, 5 to 12 percent slopes, eroded- 1,125 .2
Descalabrado clay loam, 5 to 12 percent Paso Seco clay, 0 to 5 percent slopes -------- 1,157 .2
slopes, eroded ----------------------- 1,125 .2 Patillas clay loam, 12 to 20 percent slopes,
Descalabrado clay loam, 20 to 40 percent eroded ------- _--------------------__ 462 .1
slopes, eroded ------_------------ --- 12,741 2.7 Patillas clay loam, 20 to 40 percent slopes,
Descalabrado and Guayama soils, 20 to 60 eroded ---- ------------------- 3,272 .7
percent slopes, eroded ------------ 19,810 4.2 Pinones silty clay ------------------- 1,215 .3
Descalabrado-Rock land complex, 40 to 60 Poncena clay ------------------ 3,233 .7
percent slopes _____- --------------- 12,462 2.6 Pozo Blanco clay loam, 5 to 12 percent slopes,
Fajardo clay, 2 to 10 percent slopes _------- 274 .1 eroded ------------------------------ 725 .1
Fajardo clay, 2 to 10 percent slopes, eroded 423 .1 Reilly soils -------------------- 3,885 .8
Fortuna clay -------------------------__ 2,044 .4 Reparada clay --- ------------------ 222 .1
Fraternidad clay, 0 to 2 percent slopes ____- 2,288 .5 Rio Arriba clay, 2 to 5 percent slopes ------_ 2,799 .6
Fraternidad clay, 2 to 5 percent slopes ---- 777 .2 Rio Arriba clay, 5 to 12 percent slopes, eroded_ 3,989 .8
Guamani silty clay loam __----------- 4,849 1.1 Rock land -------------------_ 21,913 4.7
Guayabota silty clay loam, 20 to 40 percent Rough stony land ---------------_ 3,964 .8
slopes, eroded ___----------------_ 584 .1 Sabana silty clay loam, 20 to 40 percent
Guayabota-Ciales-Picacho association, very slopes, eroded ---- ---------------- 5,756 1.2
steep ---- -------------------- 6,863 1.5 Sabana silty clay loam, 40 to 60 percent
Guayama clay loam, moderately deep vari- slopes, eroded ----- --------------- 6,247 1.3
ant, 2 to 12 percent slopes, eroded _-__---- 810 .2 Salt water marsh ----- -------------- 1,174 .2
Humacao loam, 2 to 5 percent slopes _-__---_ 885 .2 Talante soils------ ------------------ 3,332 .7
Humatas clay, 20 to 40 percent slopes, eroded_ 5,002 1.1 Teja gravelly sandy loam, 12 to 40 percent
Humatas clay, 40 to 60 percent slopes, eroded_ 5,240 1.1 slopes------------------- 6,768 1.4
Humatas-Stony land complex, 40 to 60 per- Tidal flats ---- -------------------_ 1,513 .3
cent slopes ------------------------__ 1,786 .4 Tidal swamp --- _--------------_---___ 15,364 3.3
Ingenio silty clay loam, 20 to 40 percent Toa silty clay loam _____---------_----____ 5,417 1.1
slopes, eroded ---------------- 1,210 .3 Utuado-Picacho-Stony rock land association,
Jacana clay, 2 to 5 percent slopes --------- 975 .2 very steep ----------------------- 3,476 .7
Jacana clay, 5 to 12 percent slopes, eroded ___ 4,167 .9 Vayas silty clay loam, occasionally flooded __ 442 .1
Jagueyes loam, 20 to 40 percent slopes, eroded_ 828 .2 Vayas silty clay, frequently flooded---- 1,398 .3
Junquitos gravelly clay loam, 5 to 12 per- Vega Alta silty clay loam, 2 to 5 percent
cent slopes _______-----------------___ 1,370 .3 slopes -------765 .2
Leveled clayey land ------------------- 987 .2 Vega Alta silty clay loam, 5 to 12 percent
Limones silty clay, 20 to 40 percent slopes, slopes --------------39 .
eroded --------------------------------- 1,754 .4







HUMACAO AREA OF EASTERN PUERTO RICO 7

TABLE 1.-Approximate acreage and proportionate extent of the soils-Continued

Mapping unit Area Extent Mapping unit Area Extent

Acres Percent Acres Percent
Vega Baja silty clay loam, 0 to 3 percent Vivi loam ------------------_ 1,421 0.3
slopes ____- -------_____ ___--___--435 0.1 Wet alluvial land _________----------- --- 3,722 .8
Via silty clay loam, 3 to 10 percent slopes ___- 1,470 .3 Yunes silty clay loam, 20 to 60 percent slopes,
Vieques loam, 5 to 12 percent slopes _______ 1,114 .2 eroded ---- ___----- --------------- 2,943 .6
Vieques loam, 12 to 40 percent slopes, eroded 7,566 1.6 Urban, built-up, water areas, miscellaneous,
Vives silty clay loam, high bottom -------- 3,147 .7 etc. --------- __--------------- ------ 26,816 5.7
Vives clay, 0 to 2 percent slopes- ___ --- 1,646 .3
Vives clay, 2 to 7 percent slopes------------ 2,490 .5 Total -------------------------------- 470,202 100.0

Less than 0.1 percent.



patchy clay films; few pebbles; very strongly acid; single grained; loose; many fine roots; very
clear, wavy boundary, strongly acid; clear, smooth boundary.
B3-35 to 60 inches, yellowish-red (5YR 4/8) silty clay; C1-8 to 20 inches, brown (10YR 4/3) sand; single grained;
weak, fine, subangular blocky structure; friable, loose; few fine roots; very strongly acid; clear,
nonsticky and slightly plastic; few fine pores; very smooth boundary.
strongly acid. C2-20 to 40 inches, dark yellowish-brown (10YR 4/4)
sand; single grained; loose; very strongly acid;
The solum is more than 60 inches thick. The A horizon gradual sinooth ed; loose; very strongly acid;undary
has a chroma of 3 to 4. The 2t horizon is 25 inches or more C3-40 to 58 inches, grayish-brown (10YR 5/2) sand; single
thick. It has weak or moderate, subangular blocky structure, grained; loose; strongly acid.
and has value of 4 or 5 and chroma of 6 to 8.
The Aceitunas soils are on the same landscape as the The Ap horizon is 6 to 12 inches thick. The A horizon is
Mabi and Rio Arriba soils. They are less plastic and have a sand, sandy loam, or loamy sand and has value of 3 to 4.
lower shrink-swell potential than the Mabi and Rio Arriba The C horizon has value of 4 or 5 and chroma of 2, 3, or 4.
soils. The Aguadilla soils are on the same landscape as Catano
soils and Coastal beaches. Unlike the Catano soils, the Agua-
AcC-Aceitunas silty clay loam, 5 to 12 percent dilla soils are acid. Coastal beaches, a land type, have no
slopes. This soil is on foot slopes and terraces. Included horizon differentiation.
with it in mapping were small areas of Rio Arriba, Ad-Aguadilla loamy sand. This nearly level soil is
Mabi, and Junquitos soils. along the coast. It has the profile described as represent-
This soil has moderate limitations for farming be- active of the Aguadilla series. Included with this soil
cause of slope and the hazard of erosion. Special con- in mapping were small areas of Catano soils.
servation practices are required if the soil is clean This soil has limitations for farming because of its
cultivated. This soil is used for sugarcane, food crops, available water capacity, low organic-matter content,
and pasture. If the soil is properly limed and fertilized, and low fertility. It is not suited to cultivated crops,
it is suited to most crops grown in the area. Capability but it can be used for coconut trees and pasture. Capa-
unit IIIe-1. ability unit VIs-3.
Ag-Aguadilla sandy loam, moderately wet. This
Aguadilla Series nearly level soil is along the coast. The seasonal water
table is close to the surface. Included with this soil in
The Aguadilla series consists of deep soils that are mapping were small areas of Catano loamy sand.
excessively drained and rapidly permeable. These soils Low organic-matter content, low fertility, low
formed in sands of mixed origin. They are near sea available water capacity, and wetness are severe limi-
level, and slopes are 0 to 2 percent. The climate is humid stations for cultivated crops. The soil is better suited to
tropical. The average annual precipitation is 80 inches, pasture than to most other uses. Capability unit VIs-3.
and the average annual temperature is 770 F.
In a representative profile, the surface layer is dark-
brown, very strongly acid loamy sand about 8 inches Amelia Series
thick. The underlying material is brown, dark yellow- The Amelia series consists of deep soils that are well
ish-brown, and grayish-brown, loose sand that extends drained and moderately permeable. These soils formed
to a depth of more than 50 inches. in gravelly sediment derived from volcanic rocks. They
These soils are low in available water capacity, are on alluvial fans and foot slopes. Slopes are 2 to 12
shrink-swell potential, and natural fertility. Most of the percent. The climate is semiarid tropical. The average
acreage is used for coconut trees and pangolagrass, but annual precipitation is 30 to 40 inches, and the average
a few areas are in native grasses and shrubs. temperature is 790 F.
Representative profile of Aguadilla loamy sand, 4.8 In a representative profile, the surface layer is dark
kilometers east of town of Yabucoa, on the Riog farm, yellowish-brown, medium acid gravelly clay loam about
30 meters north from farm road and 90 meters south 6 inches thick. Below this layer is brown, friable grav-
from east end of sugar plantation: elly clay loam 7 inches thick. Dark-brown, friable
Ap-0 to 8 inches, dark-brown (10YR 3/3) loamy sand; gravelly clay is between depths of 13 and 22 inches. The






8 SOIL SURVEY

underlying material is strong-brown gravelly clay loam quires special conservation practices. This soil has been
that extends to a depth of 46 inches. in pasture and sugarcane. If it is irrigated, it is better
These soils are low in available water capacity and suited to sugarcane than to most other uses. Capability
fertility. Their shrink-swell potential is moderate. The unit IVe-8.
soils are difficult to work, and most of their acreage is
used for pasture and sugarcane. Some areas are in na- Arenales Series
tive pasture and brush.
Representative profile of Amelia gravelly clay loam, The Arenales series consists of deep soils that are ex-
5 to 12 percent slopes, eroded, in a cultivated field on cessively drained and rapidly permeable. These soils
Lot No. 505, 5 meters southwest of an Almacigo tree on formed in stratified, coarse-textured sediment derived
this lot, Parcelas Las Ochenta, Salinas: from volcanic and limestone rocks. They are on flood
Ap-0 to 6 inches, dark yellowish-brown (10YR 3/4) gravelly plains and alluvial fans. Slopes are 0 to 2 percent. The
clay loam, brown (7.5YR 5/4) when dry; massive climate is semiarid tropical. The average annual pre-
parting to weak, fine, granular structure; very cipitation is 35 to 50 inches, and the average annual
hard, friable, slightly sticky and slightly plastic; temperature is 790 F.
common fine roots; many gravel fragments 1/ to t
inches in diameter; medium acid; clear, wavy In a representative profile, the surface layer is very
boundary, dark grayish-brown, mildly alkaline sandy loam about
B1-6 to 13 inches, brown (7.5YR 4/6) gravelly clay loam, 8 inches thick. Below that is dark grayish-brown, very
dark yellowish brown (10YR 4/4) when dry; weak, dark gray, and very rk grayish-brown, loose and 34
fine, subangular blocky structure; slightly hard, ray, and very dark grayish-brown, loose sand 34
friable, slightly sticky and slightly plastic; com- inches thick. Gravel mixed with coarse sand is at a depth
mon fine roots; many angular rock fragments 1/ to of 42 inches.
2 inches in diameter and few rock fragments 4 to These soils are low in available water capacity and
16 inches in diameter; medium acid; clear, wavy natural fertility. Runoff is slow. The soils are easily
boundary.
B2t-13 to 22 inches, dark-brown (7.5YR 4/4) gravelly clay, worked, and most of the acreage is used for sugarcane,
brown (7.5YR 5/4) when dry; moderate, medium, but there are small areas in native pasture and brush.
subangular blocky structure; hard, friable, slightly Representative profile of Arenales sandy loam, near
sticky and slightly plastic; few fine roots; many mango tree along farm road, 0.8 kilometers south and
angedur rck f ents c too ind es in diameter; 15 meters west of kilometer marker 92.1 on Highway
C-22 to 46 inches, strong-brown (7.5YR 5/6) gravelly clay No. 1, near town of Salinas:
loam; massive; hard, friable, slightly sticky; many Ap- to 8 inches, very dark grayish-brown (YR 3/2)
angular rock fragments 1 to 3 inches in diameter; Ap-0 to 8 inches, very dark grayish-brown (10R 3/2)
medium acid. sandy loam; weak, fine, granular structure; very
friable, nonsticky and nonplastic; many fine roots;
The solum ranges from 16 to 44 inches in thickness. The common, fine, subrounded volcanic fragments;
A horizon has hue of 10YR, 7.5YR, or 5YR, value of 3 or mildly alkaline; clear, wavy boundary.
4, and chroma of 2 to 4. The B horizon has hue of 10YR, C1-8 to 24 inches, very dark grayish-brown (10YR 3/2)
7.5YR, or 5YR, value of 3 or 4, and chroma of 4 to 6. It has and dark grayish-brown (10YR 4/2) loamy sand;
weak or moderate, medium, subangular blocky structure and single grained; loose, nonsticky and nonplastic;
ranges from medium acid to neutral in reaction. The C hori- few fine roots; moderately alkaline; abrupt, smooth
zon ranges from medium acid to mildly alkaline. The content boundary.
of volcanic rock fragments averages 40 to 75 percent, by IIC2-24 to 31 inches, very dark gray (10YR 3/1) and very
volume, throughout the soil profile. dark grayish-brown (10YR 3/2) coarse sand; single
The Amelia soils are on the same landscape as the Gua- grained; loose, nonsticky and nonplastic; moder-
yama, Descalabrado, and Jacana soils. The Amelia soils are ately alkaline; abrupt, smooth boundary.
deeper to bedrock than all those soils. IIC3-31 to 42 inches, very dark grayish-brown (10YR 3/2)
sand; single grained; loose, nonsticky and non-
AmB-Amelia gravelly clay loam, 2 to 5 percent plastic; mildly alkaline; clear, smooth boundary.
slopes. This soil is on foot slopes and alluvial fans in IIIC4-42 to 50 inches, gravel mixed with coarse sand.
the semiarid part of the survey area. It has a thicker The Ap horizon ranges from 6 to 10 inches in thickness.
surface layer and is less affected by erosion than the It has hue of 10YR or 7.5YR, value of 3 or 4, and chroma
soil described as representative of the Amelia series. of 2 or 3. The A horizon is neutral to mildly alkaline. The C
horizon has hue of 1OYR or 7.5YR, value of 3 to 5, and
Included with this soil in mapping were small areas of chroma of 10YR or 75YR value to 4. and
Jacana soils. The Arenales soils are on the same landscape as the Gua-
Low rainfall in the area and the soil's low available mani soils. They have a coarser textured A horizon than the
water capacity and low fertility are severe limitations Guamani soils.
for farming. This soil has been in native pasture and An-Arenales sandy loam. This nearly level soil is
sugarcane. If the soil is irrigated, it is better suited to on flood plains and alluvial fans in the semiarid part of
sugarcane than to most other uses. Capability units the survey area. It has the profile described as repre-
IVc-3 nonirrigated and IIIs-1 irrigated. sentative of the Arenales series. Included with this soil
AmC2-Amelia gravelly clay loam, 5 to 12 percent in mapping were small areas of Vives silty clay loam,
slopes, eroded. This soil is on foot slopes in the semi- high bottom; Arenales sandy loam, gravelly substra-
arid part of the survey area. It has the profile described tur; and Guamani soils.
as representative of the Amelia series. Included with This soil has severe limitations for farming because
this soil in mapping were small areas of Guayama, Des- of its low available water capacity and rapid permeabil-
calabrado, and Jacana soils. ity. Also, rainfall in the area is low. If the soil is prop-
This soil has severe limitations for farming because erly irrigated and fertilized, it is suited to sugarcane
it has a low available water capacity, low fertility, and and pasture. Capability units VIc-1 nonirrigated and
gravelly texture and because the climate is semiarid. Be- IVs-1 irrigated.
cause of slope and the hazard of erosion, the soil re- Ar-Arenales sandy loam, gravelly substratum. This







HUMACAO AREA OF EASTERN PUERTO RICO 9

nearly level soil lies on river flood plains and alluvial 10YR or 2.5Y, value of 3 to 6, and chroma of 2 or lower.
fans. Its profile is similar to the one described as repre- It has weak, moderate or coarse, subangular blocky struc-
ture.
sentative of the series, but gravel is at a depth of only The Bajura soils occupy the same landscape as the Coloso,
20 to 36 inches. Included with this soil in mapping were Corcega, and Fortuna soils. Unlike the Coloso and Corcega
small areas of Guamani soils. soils, the Bajura soils are poorly drained. The Bajura soils
The rapid permeability and low available water ca- are not so acid as the Fortuna soils, and unlike Fortuna
pacity of the soil and the low rainfall in the area are soils, they have pressure faces.
severe limitations for farming. This soil has been used Ba-Bajura silty clay, saline. This nearly level soil
for sugarcane and pasture. If it is properly irrigated, it is on alluvial flood plains close to seaboard mangrove
is suited to sugarcane. Capability units VIc-1 nonirri- swamps. Its profile is similar to the one described as
gated and IVs-1 irrigated, representative of the series, but it is occasionally af-
fected by salinity caused by high tides. Included with
this soil in mapping were small areas of Tidal flats and
Bajura Series Salt water marsh.
The Bajura series consists of deep soils that are Because this soil is poorly drained, is not easily
poorly drained and slowly permeable. These soils worked, has a high shrink-swell potential, and is af-
formed in fine-textured sediment of mixed origin. They fected by salt water. Its use for farming is limited.
are on alluvial flood plains. Slopes are 0 to 2 percent. Frequent flooding and a seasonal high water table also
The climate is humid tropical. The average annual pre- limit the use of the soil for cultivated crops. Most of the
cipitation is 84 inches, and the average annual tempera- acreage is in salt-tolerant plants. This soil is suited to
ture is 780 F. pasture and wildlife habitat. Capability unit VIIw-1.
In a representative profile, the surface layer is very Bc-Bajura clay, frequently flooded. This nearly
dark grayish-brown, mottled, slightly acid clay about 5 level soil is on alluvial flood plains. It occupies the
inches thick. Below this layer is very dark grayish- farther areas from the river. It has the profile de-
brown, dark-gray, very dark gray, black, and yellowish- scribed as representative of the series. Included with
brown, mottled, firm clay that extends to a depth of 60 this soil in mapping were some areas of Coloso silty
inches. clay.
These soils have a high available water capacity, high Because this soil has slow permeability and a seasonal
shrink-swell potential, and high natural fertility. Run- high water table, is subject to frequent flooding, and is
off is slow. These soils have been in sugarcane and difficult to work, it has severe limitations for farming
pasture for many years. (fig. 2). If the soil is drained and properly managed, it
Representative profile of Bajura clay, frequently is suited to sugarcane, food crops, and pasture. Capa-
flooded, 1.1 kilometers north of Land Authority office ability unit IIIw-1.
and 10 meters west of telephone pole along road, Colonia
San Luis, Carolina: Caguaho Series
Ap-0 to 5 inches, very dark grayish-brown (10YR 3/2)
clay; few, fine, dark-gray (10YR 4/1) mottles; The Caguabo series consists of shallow soils that are
weak, fine, subangular blocky structure; very firm, well drained and moderately permeable. These soils
slightly sticky and slightly plastic; common fine formed in moderately fine textured residuum from
roots; few worm casts; slightly acid; clear, smooth partly weathered volcanic rocks. They are on side
boundary. weathered volcanic rocks. They are on side
Big-5 to 12 inches, very dark grayish-brown (10YR 3/2) slopes. Slopes are 12 to 60 percent. The climate is humid
clay; common, medium, distinct, dark-gray (5Y tropical. The average annual precipitation is 80 inches,
4/1) and dark-brown (7.5YR 4/4) mottles; weak, and the average annual temperature is 760 F.
coarse, subangular blocky structure; very firm, In a representative profile, the surface layer is
sticky and plastic; few fine roots; few pressure
faces; slightly acid; clear, smooth boundary, grayish-brown, slightly acid clay loam about 4 inches
B2g-12 to 19 inches, dark-gray (10YR 4/1) clay; many, thick. The next layer, 5 inches thick, is dark-gray
coarse, prominent, dark-brown mottles; weak, gravelly clay loam and 60 percent rock fragments. Be-
coarse, subangular blocky structure; firm, slightly w that is olive-gray gravelly clay loam that extends
sticky and plastic; few pressure faces; few worm low that is olive-ray gravelly clay loam that extends
casts; few krotovinas; slightly acid; clear, smooth to a depth of 17 inches and is underlain by hard rock.
boundary. These soils have a moderate available water capacity,
Clg-19 to 25 inches, very dark gray (10YR 3/1) clay; moderate shrink-swell potential, and medium natural
many, fine, distinct, dark yellowish-brown (10YR ili. R f i mdiu T soils r
4/4) mottles; weak, medium, subangular blocky fertility Runoff is medium to rapid. The soils are
structure; firm, slightly sticky and plastic; few susceptible to erosion, and they have been in pasture
pressure faces; slightly acid; clear, smooth bound- and brush for many years.
ary. Representative profile of Caguabo clay loam, 20 to 60
C2g-25 to 44 inct, dark yellowish-brown (YR(10YR 2/4/4)) clay many,ottles; percent slopes, eroded, 2.4 kilometers south of kilometer
massive; firm, slightly sticky and plastic; slightly marker 17.4 on Highway No. 31, Juncos to Naguabo:
acid; clear, smooth boundary.
C3g-44 to 66 inches, yellowish-brown (10YR 5/6) clay; A-0 to 4 inches, grayish-brown (0YR 5/2) clay loam;
many, medium, prominent, dark-gray (2.5Y 4/0) weak, fine, subangular blocky structure parting to
mottles and few, fine prominent dark-gray (.5Y granular; very hard, very firm, slightly sticky and
4/0) mottles; massive; firm, slightly sticy and slightly plastic; common fine roots; many fine vol-
4/0) mottles massive; firm, slightly sticky and canic rock fragments; few worm casts; slightly
plastic; slightly acid. acid; abrupt, smooth boundary.
The solum is 16 to 24 inches thick. The Ap horizon has B-4 to 9 inches, dark-gray (10YR 4/1) gravelly clay loam;
hue of 10YR or 2.5Y, value of 2 or 3, and chroma of 2 or weak, medium, subangular blocky structure; very
lower. It is silty clay or clay. The B horizon has hue of hard, very firm, slightly sticky and slightly plastic;







HUMACAO AREA OF EASTERN PUERTO RICO 9

nearly level soil lies on river flood plains and alluvial 10YR or 2.5Y, value of 3 to 6, and chroma of 2 or lower.
fans. Its profile is similar to the one described as repre- It has weak, moderate or coarse, subangular blocky struc-
ture.
sentative of the series, but gravel is at a depth of only The Bajura soils occupy the same landscape as the Coloso,
20 to 36 inches. Included with this soil in mapping were Corcega, and Fortuna soils. Unlike the Coloso and Corcega
small areas of Guamani soils. soils, the Bajura soils are poorly drained. The Bajura soils
The rapid permeability and low available water ca- are not so acid as the Fortuna soils, and unlike Fortuna
pacity of the soil and the low rainfall in the area are soils, they have pressure faces.
severe limitations for farming. This soil has been used Ba-Bajura silty clay, saline. This nearly level soil
for sugarcane and pasture. If it is properly irrigated, it is on alluvial flood plains close to seaboard mangrove
is suited to sugarcane. Capability units VIc-1 nonirri- swamps. Its profile is similar to the one described as
gated and IVs-1 irrigated, representative of the series, but it is occasionally af-
fected by salinity caused by high tides. Included with
this soil in mapping were small areas of Tidal flats and
Bajura Series Salt water marsh.
The Bajura series consists of deep soils that are Because this soil is poorly drained, is not easily
poorly drained and slowly permeable. These soils worked, has a high shrink-swell potential, and is af-
formed in fine-textured sediment of mixed origin. They fected by salt water. Its use for farming is limited.
are on alluvial flood plains. Slopes are 0 to 2 percent. Frequent flooding and a seasonal high water table also
The climate is humid tropical. The average annual pre- limit the use of the soil for cultivated crops. Most of the
cipitation is 84 inches, and the average annual tempera- acreage is in salt-tolerant plants. This soil is suited to
ture is 780 F. pasture and wildlife habitat. Capability unit VIIw-1.
In a representative profile, the surface layer is very Bc-Bajura clay, frequently flooded. This nearly
dark grayish-brown, mottled, slightly acid clay about 5 level soil is on alluvial flood plains. It occupies the
inches thick. Below this layer is very dark grayish- farther areas from the river. It has the profile de-
brown, dark-gray, very dark gray, black, and yellowish- scribed as representative of the series. Included with
brown, mottled, firm clay that extends to a depth of 60 this soil in mapping were some areas of Coloso silty
inches. clay.
These soils have a high available water capacity, high Because this soil has slow permeability and a seasonal
shrink-swell potential, and high natural fertility. Run- high water table, is subject to frequent flooding, and is
off is slow. These soils have been in sugarcane and difficult to work, it has severe limitations for farming
pasture for many years. (fig. 2). If the soil is drained and properly managed, it
Representative profile of Bajura clay, frequently is suited to sugarcane, food crops, and pasture. Capa-
flooded, 1.1 kilometers north of Land Authority office ability unit IIIw-1.
and 10 meters west of telephone pole along road, Colonia
San Luis, Carolina: Caguaho Series
Ap-0 to 5 inches, very dark grayish-brown (10YR 3/2)
clay; few, fine, dark-gray (10YR 4/1) mottles; The Caguabo series consists of shallow soils that are
weak, fine, subangular blocky structure; very firm, well drained and moderately permeable. These soils
slightly sticky and slightly plastic; common fine formed in moderately fine textured residuum from
roots; few worm casts; slightly acid; clear, smooth partly weathered volcanic rocks. They are on side
boundary. weathered volcanic rocks. They are on side
Big-5 to 12 inches, very dark grayish-brown (10YR 3/2) slopes. Slopes are 12 to 60 percent. The climate is humid
clay; common, medium, distinct, dark-gray (5Y tropical. The average annual precipitation is 80 inches,
4/1) and dark-brown (7.5YR 4/4) mottles; weak, and the average annual temperature is 760 F.
coarse, subangular blocky structure; very firm, In a representative profile, the surface layer is
sticky and plastic; few fine roots; few pressure
faces; slightly acid; clear, smooth boundary, grayish-brown, slightly acid clay loam about 4 inches
B2g-12 to 19 inches, dark-gray (10YR 4/1) clay; many, thick. The next layer, 5 inches thick, is dark-gray
coarse, prominent, dark-brown mottles; weak, gravelly clay loam and 60 percent rock fragments. Be-
coarse, subangular blocky structure; firm, slightly w that is olive-gray gravelly clay loam that extends
sticky and plastic; few pressure faces; few worm low that is olive-ray gravelly clay loam that extends
casts; few krotovinas; slightly acid; clear, smooth to a depth of 17 inches and is underlain by hard rock.
boundary. These soils have a moderate available water capacity,
Clg-19 to 25 inches, very dark gray (10YR 3/1) clay; moderate shrink-swell potential, and medium natural
many, fine, distinct, dark yellowish-brown (10YR ili. R f i mdiu T soils r
4/4) mottles; weak, medium, subangular blocky fertility Runoff is medium to rapid. The soils are
structure; firm, slightly sticky and plastic; few susceptible to erosion, and they have been in pasture
pressure faces; slightly acid; clear, smooth bound- and brush for many years.
ary. Representative profile of Caguabo clay loam, 20 to 60
C2g-25 to 44 inct, dark yellowish-brown (YR(10YR 2/4/4)) clay many,ottles; percent slopes, eroded, 2.4 kilometers south of kilometer
massive; firm, slightly sticky and plastic; slightly marker 17.4 on Highway No. 31, Juncos to Naguabo:
acid; clear, smooth boundary.
C3g-44 to 66 inches, yellowish-brown (10YR 5/6) clay; A-0 to 4 inches, grayish-brown (0YR 5/2) clay loam;
many, medium, prominent, dark-gray (2.5Y 4/0) weak, fine, subangular blocky structure parting to
mottles and few, fine prominent dark-gray (.5Y granular; very hard, very firm, slightly sticky and
4/0) mottles; massive; firm, slightly sticy and slightly plastic; common fine roots; many fine vol-
4/0) mottles massive; firm, slightly sticky and canic rock fragments; few worm casts; slightly
plastic; slightly acid. acid; abrupt, smooth boundary.
The solum is 16 to 24 inches thick. The Ap horizon has B-4 to 9 inches, dark-gray (10YR 4/1) gravelly clay loam;
hue of 10YR or 2.5Y, value of 2 or 3, and chroma of 2 or weak, medium, subangular blocky structure; very
lower. It is silty clay or clay. The B horizon has hue of hard, very firm, slightly sticky and slightly plastic;







10 SOIL SURVEY

























C-9 to 17 inches, olive-gray (5Y 5/2) gravelly clay loam; practices are needed to slow surface runoff. This soil has
|
4 ii
























Figure 2.-A field of sugarcane that is flooded on Bajura clay, frequently flooded.



few fine roots; few fine pores; rock fragments make Shallowness to hard rock and medium runoff are
up 60 percent, by volume, of soil mass; slightly severe limitations for cultivated crops. Conservation
acid; clear, wavy boundary.
C-9 to 17 inches, oolive-gray (Y 5/2) gravelly clay loam; practices are needed to slow surface runoff. This soil has
common, medium, distinct, very dark grayish-brown been used for food crops and pasture. It is suited to
(10YR 3/2) mottles and few, fine, distinct, reddish- pasture and woodland. Capability unit VIs-2; wood-
yellow (7.5YR 7/8) mottles; massive; very hard, land suitability group 3d5.
firm, slightly sticky and slightly plastic; few fine
roots; many rock fragments; common, dark, weath- CbF2Caguabo clay loam, 20 to 60 percent slopes,
ered minerals; most of this horizon is saprolite; eroded. This soil is on ridgetops and side slopes in the
medium acid; gradual, wavy boundary. volcanic uplands. It has the profile described as repre-
R-17 inches, hard consolidated volcanic rock. tentative of the series. Included with this soil in map-
The solum is 6 to 11 inches thick. Some profiles have an ping were small areas of Mucara and Sabana soils and
Ap horizon that has value of 3 or 4 and chroma of 2 or 3. Rock land.
The amount of rock fragments in the B and C horizons
ranges from 35 to 70 percent. Depth to consolidated volcanic Rapid to very rapid runoff, shallowness to hard rock,
rock ranges from 12 to 20 inches. and steep slopes are severe limitations for farming.
The Caguabo soils are on the same landscape as the Mu- Conservation practices are needed to slow surface run-
cara and Sabana soils. They are shallower and coarser tex- off. This soil has been used for native pasture. It is not
tured than the Mucara soils. The Caguabo soils are less acid
than the Sabana soils, and unlike Sabana soils, they are suited to cultivated crops, but it is suited to pasture and
gravelly. woodland. Capability unit VIIs-1; woodland suitability
CbD2-Caguabo clay loam, 12 to 20 percent slopes, groups 3d5 and 4d5.
eroded. This soil is on side slopes. Its profile is similar
to the one described as representative of the Caguabo Candelero Series
series, but the surface layer is slightly thicker. Included
with this soil in mapping were small areas of Mucara The Candelero series consists of deep soils that are
and Sabana soils. somewhat poorly drained and slowly permeable. These







HUMACAO AREA OF EASTERN PUERTO RICO 11

soils formed in moderately fine textured sediment de- The solum is 25 to 42 inches thick. The Ap horizon has
rived from granitic rocks. They are on alluvial fans, value of 3 to 4 and is very strongly acid or extremely acid.
The upper part of the B horizon has value of 5 or 6. Few
terraces, and foot slopes. Slopes are 2 to 12 percent. The to many quartz grains are mixed throughout the profile.
climate is humid tropical. The average annual precipi- The Candelero soils are on the same landscape as the
station is 87 inches, and the average annual tempera- Humacao, Parcelas, and Mayo soils. Unlike the Humacao
ture is 77 F. and Parcelas soils, they have dominant low-chroma colors
In a representative profile, the surface layer is dak and a B2t horizon. The Candelero soils are less permeable
In a representative profile, the surface layer is dark than the Mayo soils, and they are somewhat poorly drained.
grayish-brown, extremely acid loam about 7 inches
thick. The next layer is gray and yellowish-brown, mot- CdB-Candelero loam, 2 to 5 percent slopes. This
tied, very firm sandy clay loam 8 inches thick. Below soil is on terraces and alluvial fans. Its profile is similar
that is greenish-gray and light greenish-gray, very to the one described as representative of the series, but
firm sandy clay loam 19 inches thick. Underlying the the surface layer is 2 to 4 inches thicker. Included with
material is friable sandy clay loam that is mottled with this soil in mapping were some areas of Humacao and
yellowish-brown and greenish-gray and extends to a Mayo soils.
depth of more than 60 inches. This soil has severe limitations for farming because
These soils have a moderate available water capacity it is slowly permeable, somewhat poorly drained, sus-
and shrink-swell potential. Runoff is medium. The soils ceptible to flooding, and has a seasonal water table.
are subject to occasional flooding. They have been in Complex soil conservation practices and proper man-
sugarcane, native pasture, and brush. agement are required to overcome these limitations. If
Representative profile of Candelero loam, 5 to 12 the soil is properly drained, limed, and fertilized, it is
percent slopes, eroded, 87 meters southwest from kilo- suited to sugarcane and pasture. Capability unit IIIw-
meter marker 1.9 on Highway No. 905 and 10 meters 2. l 5 t
northwest from farm road: CdC2-Candelero loam, 5 to 12 percent slopes,
eroded. This soil is on alluvial fans and foot slopes. It
Ap-0 to 7 inches, dark grayish-brown (10YR 4/2) loam; has the profile described as representative of the
eak, fne, granular structure; very friable, slightly ndeleo series. Included ith this soil in mapping
sticky and slightly plastic; few fine roots; few, Cadeero series. Included with this soil in mapping
fine, black mineral grains; few concretions 2 to 3 were small areas of Mayo and Parcelas soils.
millimeters in diameter; extremely acid; clear, This soil has severe limitations for farming because
smooth boundary. it is somewhat poorly drained. If the soil is clean
(1- YR 5/8) sandy clay loam; fine purplish mottles cultivated, it requires special conservation practices
weak, coarse, subangular blocky structure; very because it is susceptible to erosion. It has been used for
firm, slightly sticky and plastic; few roots; thin, sugarcane, native pasture, and brush. If the soil is
discontinuous, gray (10YR 6/1) films on ped sur- properly limed, drained, and fertilized, it is suited to
faces; black coatings on root channels; common fine
quartz grains; extremely acid; clear, smooth bound- sugarcane and pasture. Capability unit IVe-1.
ary.
B21t--11 to 15 inches, gray (10YR 6/1) and yellowish-
brown (10YR 5/6) sandy clay loam; weak, medium, Cartagena Series
subangular blocky structure; very firm, slightly
sticky and plastic; few roots; thin, discontinuous, The Cartagena series consists of deep soils that are
gray (10YR 6/1) films on ped surfaces; dark films somewhat poorly drained, mildly alkaline, and slowly
on root channels; common fine quartz grains; few, a pr di md akinead sl
fine, black mineral grains; many weathered fldspar ermeable. These soils formed in fine-textured sedi-
and hornblende crystals; very strongly acid; grad- ment derived from volcanic rocks and limestone. They
ual, smooth boundary. are on alluvial fans. Slopes are 0 to 5 percent. The
B22tg-15 to 24 inches, greenish-gray (5GY 6/1) sandy clay climate is semiarid tropical. The average annual pre-
loam; common, medium, distinct, brownish-yellow
(lYR 6/6) mottles and few, fine, distinct, reddish- cipitation is 30 to 45 inches, and the average annual
brown mottles; weak, coarse, subangular blocky temperature is 790 F.
structure; very firm, slightly sticky and plastic; In a representative profile, the surface layer is dark-
few roots; thin, discontinuous, greenish-gray (5GY brown, mildly alkaline or neutral, mottled clay about 19
6/1) films on ped surfaces; dark films on root chan- inches thick. Below that layer is dark yellowish-bron,
nels; many fine quartz grains; many weathered inches thick. Below that layer is dark yellowish-brown
feldspar and hornblende crystals; strongly acid; firm, mottled silty clay that extends to a depth of 45
gradual, smooth boundary. inches.
B23tg-24 to 34 inches, light greenish-gray (5GY 7/1) These soils have a high available water capacity and
sandy clay loam; common, fine, distinct, greenish- shink-sell potential. Runoff is slow The soils are diffi-
gray mottles and common, medium, distinct, shrink-swell potential. unoff is slow. The soils ae diffi-
yellowish-brown (10YR 5/8) and grayish-brown cult to work, and they have been in sugarcane, pasture,
(10YR 5/2) mottles; weak, coarse, prismatic struc- and brush for many years.
ture; very firm, slightly sticky and slightly plastic; Representative profile of Cartagena clay, 46 meters
thin, discontinuous, light greenish-gray (5GY 7/1) north and 1.3 kilometers est of gasoline station on
films on ped surfaces, gray tends to run in vertical north and 1.3 kilometers west of gasoline station on
tongues; many fine quartz grains; few, fine, black Highway No. 705, from kilometer marker 151.3 on
mineral grains; many weathered feldspar and horn- Highway No. 3 to Central Aguirre, Salinas:
blende crystals; slightly acid; clear, smooth bound-
ary. Ap-0 to 10 inches, dark-brown (10YR 3/3) clay; common,
C-34 to 64 inches, dark yellowish-brown (10YR 4/4) sandy fine faint, dark-brown (7.5YR 4/4) and dark-gray
clay loam; common, medium, distinct, yellowish- (10YR 4/1) mottles; weak, medium, subangular
brown (10YR 5/6) mottles and common, fine dis- blocky structure; firm, slightly sticky and slightly
tinct, greenish-gray mottles; massive; friable, plastic; common roots; few, fine, dark concretions;
slightly sticky; many fine quartz grains; many few limestone fragments; common pressure faces;
weathered feldspar crystals; common, fine, black mildly alkaline; clear, smooth boundary.
mineral grains; slightly acid. AC--10 to 19 inches, dark-brown (10YR 4/3) clay; common,







12 SOIL SURVEY

fine, faint, dark-gray (10YR 4/1) mottles; mas- Aguadilla soils and the land type Coastal beaches. The
sive; few roots; firm, slightly sticky and slightly Catano soils, unlike the Aguadilla soils, are moderately
plastic; common, fine, dark concretions; few pres- alkaline. Coastal beaches are wave-reworked sands that are
sure faces; few slickensides; neutral; clear, smooth saturated with sea water or lack horizon differentiation.
boundary.
Clca-19 to 31 inches, dark yellowish-brown (10YR 4/4) Cf-Catano loamy sand. This nearly level soil is
silty clay; common, fine, distinct, gray (5Y 5/1) along the coast. Included with it in mapping were small
mottles and few n, fine, distinct, dark redddish-brown areas of Aguadilla soils and Coastal beaches.
(5YR 3/4) mottles; massive; few roots; firm, This soil is not suited to cultivated crops because of
slightly sticky and slightly plastic; common, fne, its low available water capacity, rapid permeability, and
dark concretions; few limestone fragments; few
pressure faces and slickensides; moderately alka- low fertility. It is used for coconut trees, cassava,
line; gradual, wavy boundary. pangolagrass, and Guineagrass. It is suitable for coco-
C2-31 to 45 inches, dark yellowish-brown (10YR 4/4) silty nut trees, pasture, wildlife food and cover, and recrea-
clay; common, fine, distinct, yellowish-brown (10YR
5/8) mottles; massive; firm, slightly sticky and tion. Capability unit VIs-1.
slightly plastic; many or common very dark brown
(10YR 2/2) stains; few seashell fragments; mod- Cayagua Series
erately alkaline. ayaga Series
The Ap horizon is 4 to 12 inches thick. It has value of The Cayagua series consists of deep soils that are
3 or 4 and chroma of 2 or 3. somewhat poorly drained and slowly permeable. These
The Cartagena soils are on the same landscape as the
Fraternidad and Paso Seco soils. Unlike the Fraternidad soils formed in residuum derived from coarse-textured
soils, they are somewhat poorly drained. The Cartagena plutonic rocks. They are on foot slopes. Slopes are 5 to
soils lack the gravelly horizons of the Paso Seco soils. 20 percent. The climate is humid tropical. The average
Ce-Cartagena clay. This nearly level to gently slop- precipitation is 80 to 90 inches, and the average annual
ing soil is on alluvial fans. Included with it in mapping temperature is 790 F.
were small areas of Fraternidad soils. In a representative profile, the surface layer is dark
This soil has severe limitations for farming because grayish-brown, strongly acid sandy loam about 4 inches
it is somewhat poorly drained, slowly permeable, and thick. Below that layer is light brownish gray, mottled
difficult to work. It has been in sugarcane. If the soil is clay 16 inches thick. The next layer is yellowish-red
properly drained and managed, it is suited to sugar- sandy loam and light-gray clay 7 inches thick. The
cane and grasses. Capability units IIIc-1 nonirrigated underlying material is yellowish-red sandy loam and
and IIs-1 irrigated, light-gray clay to a depth of 36 inches. Yellowish-red
and reddish-yellow, very friable sandy loam extends to
Catano Series a depth of 100 inches.
atano series These soils have medium natural fertility. Runoff is
The Catano series consists of deep soils that are slow. The soils have been in sugarcane and native pas-
excessively drained and rapidly permeable. These soils ture. A few areas are in pineapples.
formed in miscellaneous sands and sand-sized rock Representative profile of Cayagua sandy loam, 5 to
fragments. They are along the sea. Slopes are 0 to 2 12 percent slopes, eroded, 4.8 kilometers northwest of
percent. The climate is humid tropical. The average the town of Humacao, 135 meters west of kilometer
annual precipitation is 75 inches, and the average marker 0.7 on Highway No. 935, 22 meters west of
annual temperature is 780 F. fence:
In a representative profile, the surface layer is dark- Ap-0 to 4 inches, dark grayish-brown (10YR 4/2) sandy
brown, moderately alkaline loamy sand about 8 inches loam; weak, fine, granular structure; very friable,
thick. Below that layer is dark-brown, brown, and nonsticky and nonplastic; many fine roots; few
grayish-brown, loose sand that extends to a depth of 64 medium iron concretions in lower part; strongly
inches. acid; abrupt, smooth boundary.
B21t-4 to 10 inches, light brownish-gray (10YR 6/2) clay;
These soils have a low available water capacity, many, coarse, distinct, strong-brown (7.5YR 5/6)
shrink-swell potential, and natural fertility. They have mottles; weak, medium, subangular blocky struc-
been in coconut trees, native pasture, and brush, but a ture; very firm, slightly sticky and plastic; com-
few areas are in food crops. mon fine roots; patchy clay films on ped surfaces
and root channels; very strongly acid; clear, wavy
Representative profile of Catano loamy sand, 30 boundary.
meters east of Guayanes River delta and about 120 B22t-10 to 20 inches, light brownish-gray (10YR 6/2)
meters west of the coast, Yabucoa: clay; many, coarse, distinct, strong-brown (7.5YR
5/6) mottles and few, fine, distinct, red (2.5YR
A1-0 to 8 inches, dark-brown (10YR 3/3) loamy sand; 5/6) mottles; weak, coarse, angular blocky struc-
single grained; loose, nonsticky and nonplastic; ture; firm, slightly sticky and plastic; few fine
moderately alkaline; clear, smooth boundary. roots; thin patchy clay films on ped surfaces and
C1-8 to 18 inches, dark-brown (10YR 4/3) sand; single root channels; very strongly acid; clear, wavy
grained; loose, nonsticky and nonplastic; moder- boundary.
ately alkaline; clear, smooth boundary. B3-20 to 27 inches, sixty percent yellowish-red (5YR 5/6)
C2-18 to 59 inches, brown (10YR 5/3) sand; single sandy loam; massive; friable, nonstick and non-
grained; loose, nonstick and nonplastic; moder- plastic; 40 percent light-gray (10YR 7/1) clay;
ately alkaline; clear, smooth boundary, massive; friable, nonstick and plastic; few fine
C3-59 to 64 inches, grayish-brown (10YR 5/2) sand; loose, roots; very strongly acid; gradual, wavy boundary.
nonsticky and nonplastic; moderately alkaline. C1--27 to 36 inches, sixty percent yellowish-red (5YR 4/6)
The A horizon is 6 to 12 inches thick. It has value and sandy loam; riassive; friable, nonsticky and non-
The A horizon is 6 to 12 inches thick. It has value and plastic; 40 percent light-gray (10YR 7/1) clay;
chroma of 2 or 3. The C horizon has value of 4 or 5 and massive; friable, nonstick and plastic; quartz
chroma of 2 or 3. nonstick and plastic; quartz
seams in the clayey sections; very strongly acid;
The Catano soils are on the same landscape as the gradual, wavy boundary. very strong acid;
gradual, wavy boundary.







12 SOIL SURVEY

fine, faint, dark-gray (10YR 4/1) mottles; mas- Aguadilla soils and the land type Coastal beaches. The
sive; few roots; firm, slightly sticky and slightly Catano soils, unlike the Aguadilla soils, are moderately
plastic; common, fine, dark concretions; few pres- alkaline. Coastal beaches are wave-reworked sands that are
sure faces; few slickensides; neutral; clear, smooth saturated with sea water or lack horizon differentiation.
boundary.
Clca-19 to 31 inches, dark yellowish-brown (10YR 4/4) Cf-Catano loamy sand. This nearly level soil is
silty clay; common, fine, distinct, gray (5Y 5/1) along the coast. Included with it in mapping were small
mottles and few n, fine, distinct, dark redddish-brown areas of Aguadilla soils and Coastal beaches.
(5YR 3/4) mottles; massive; few roots; firm, This soil is not suited to cultivated crops because of
slightly sticky and slightly plastic; common, fne, its low available water capacity, rapid permeability, and
dark concretions; few limestone fragments; few
pressure faces and slickensides; moderately alka- low fertility. It is used for coconut trees, cassava,
line; gradual, wavy boundary. pangolagrass, and Guineagrass. It is suitable for coco-
C2-31 to 45 inches, dark yellowish-brown (10YR 4/4) silty nut trees, pasture, wildlife food and cover, and recrea-
clay; common, fine, distinct, yellowish-brown (10YR
5/8) mottles; massive; firm, slightly sticky and tion. Capability unit VIs-1.
slightly plastic; many or common very dark brown
(10YR 2/2) stains; few seashell fragments; mod- Cayagua Series
erately alkaline. ayaga Series
The Ap horizon is 4 to 12 inches thick. It has value of The Cayagua series consists of deep soils that are
3 or 4 and chroma of 2 or 3. somewhat poorly drained and slowly permeable. These
The Cartagena soils are on the same landscape as the
Fraternidad and Paso Seco soils. Unlike the Fraternidad soils formed in residuum derived from coarse-textured
soils, they are somewhat poorly drained. The Cartagena plutonic rocks. They are on foot slopes. Slopes are 5 to
soils lack the gravelly horizons of the Paso Seco soils. 20 percent. The climate is humid tropical. The average
Ce-Cartagena clay. This nearly level to gently slop- precipitation is 80 to 90 inches, and the average annual
ing soil is on alluvial fans. Included with it in mapping temperature is 790 F.
were small areas of Fraternidad soils. In a representative profile, the surface layer is dark
This soil has severe limitations for farming because grayish-brown, strongly acid sandy loam about 4 inches
it is somewhat poorly drained, slowly permeable, and thick. Below that layer is light brownish gray, mottled
difficult to work. It has been in sugarcane. If the soil is clay 16 inches thick. The next layer is yellowish-red
properly drained and managed, it is suited to sugar- sandy loam and light-gray clay 7 inches thick. The
cane and grasses. Capability units IIIc-1 nonirrigated underlying material is yellowish-red sandy loam and
and IIs-1 irrigated, light-gray clay to a depth of 36 inches. Yellowish-red
and reddish-yellow, very friable sandy loam extends to
Catano Series a depth of 100 inches.
atano series These soils have medium natural fertility. Runoff is
The Catano series consists of deep soils that are slow. The soils have been in sugarcane and native pas-
excessively drained and rapidly permeable. These soils ture. A few areas are in pineapples.
formed in miscellaneous sands and sand-sized rock Representative profile of Cayagua sandy loam, 5 to
fragments. They are along the sea. Slopes are 0 to 2 12 percent slopes, eroded, 4.8 kilometers northwest of
percent. The climate is humid tropical. The average the town of Humacao, 135 meters west of kilometer
annual precipitation is 75 inches, and the average marker 0.7 on Highway No. 935, 22 meters west of
annual temperature is 780 F. fence:
In a representative profile, the surface layer is dark- Ap-0 to 4 inches, dark grayish-brown (10YR 4/2) sandy
brown, moderately alkaline loamy sand about 8 inches loam; weak, fine, granular structure; very friable,
thick. Below that layer is dark-brown, brown, and nonsticky and nonplastic; many fine roots; few
grayish-brown, loose sand that extends to a depth of 64 medium iron concretions in lower part; strongly
inches. acid; abrupt, smooth boundary.
B21t-4 to 10 inches, light brownish-gray (10YR 6/2) clay;
These soils have a low available water capacity, many, coarse, distinct, strong-brown (7.5YR 5/6)
shrink-swell potential, and natural fertility. They have mottles; weak, medium, subangular blocky struc-
been in coconut trees, native pasture, and brush, but a ture; very firm, slightly sticky and plastic; com-
few areas are in food crops. mon fine roots; patchy clay films on ped surfaces
and root channels; very strongly acid; clear, wavy
Representative profile of Catano loamy sand, 30 boundary.
meters east of Guayanes River delta and about 120 B22t-10 to 20 inches, light brownish-gray (10YR 6/2)
meters west of the coast, Yabucoa: clay; many, coarse, distinct, strong-brown (7.5YR
5/6) mottles and few, fine, distinct, red (2.5YR
A1-0 to 8 inches, dark-brown (10YR 3/3) loamy sand; 5/6) mottles; weak, coarse, angular blocky struc-
single grained; loose, nonsticky and nonplastic; ture; firm, slightly sticky and plastic; few fine
moderately alkaline; clear, smooth boundary. roots; thin patchy clay films on ped surfaces and
C1-8 to 18 inches, dark-brown (10YR 4/3) sand; single root channels; very strongly acid; clear, wavy
grained; loose, nonsticky and nonplastic; moder- boundary.
ately alkaline; clear, smooth boundary. B3-20 to 27 inches, sixty percent yellowish-red (5YR 5/6)
C2-18 to 59 inches, brown (10YR 5/3) sand; single sandy loam; massive; friable, nonstick and non-
grained; loose, nonstick and nonplastic; moder- plastic; 40 percent light-gray (10YR 7/1) clay;
ately alkaline; clear, smooth boundary, massive; friable, nonstick and plastic; few fine
C3-59 to 64 inches, grayish-brown (10YR 5/2) sand; loose, roots; very strongly acid; gradual, wavy boundary.
nonsticky and nonplastic; moderately alkaline. C1--27 to 36 inches, sixty percent yellowish-red (5YR 4/6)
The A horizon is 6 to 12 inches thick. It has value and sandy loam; riassive; friable, nonsticky and non-
The A horizon is 6 to 12 inches thick. It has value and plastic; 40 percent light-gray (10YR 7/1) clay;
chroma of 2 or 3. The C horizon has value of 4 or 5 and massive; friable, nonstick and plastic; quartz
chroma of 2 or 3. nonstick and plastic; quartz
seams in the clayey sections; very strongly acid;
The Catano soils are on the same landscape as the gradual, wavy boundary. very strong acid;
gradual, wavy boundary.







HUMACAO AREA OF EASTERN PUERTO RICO 13

C2-36 to 100 inches, yellowish-red (5YR 4/6) and reddish- soils have been in hardwood trees and tree ferns for
yellow (7.5YR 6/6) sandy loam; massive; very many years.
friable, nonsticky and nonplastic; slightly acid. In the Humacao Area of Eastern Puerto Rico, the
The solum is 18 to 36 inches thick. The Ap horizon has Ciales soils are mapped only in an association with
value of 3 or 4 and chroma of 2 or 3. The B2t horizon is 12
to 20 inches thick and has value of 4 to 6. Mottles range Guayabota and Picacho soils.
from few to many and from fine to coarse; they are in Representative profile of Ciales silty clay loam, 12 to
shades of strong brown, light gray, and red. The B3 hori- 20 percent slopes, in an area of the Guayabota-Ciales-
zon has hue of 7.5YR or 5YR, value of 4 or 5, and chroma Picacho association, very steep, 17 meters west of kilo-
of 4 to 6.
The Cayagua soils are on the same landscape as the meter marker 15.7 on Highway No. 191:
Candelero, Mayo, and Pandura soils. They occupy higher
positions and are finer textured in the B2t horizon than the 01-1 to 0 inches, undecomposed and partially decomposed
Candelero soils. The Cayagua soils occupy higher positions leaves and twigs.
than the Mayo soils, and unlike Mayo soils, they are some- A1-0 to 7 inches, dark-brown (10YR 3/3) silty clay loam;
what poorly drained. They occupy lower positions and are weak, fine, subangular blocky structure breaking to
deeper than the Pandura soils, moderate, medium, granular; friable, slightly sticky
and slightly plastic; many fine and medium roots;
CgC2-Cayagua sandy loam, 5 to 12 percent slopes, many fine quartz grains; very strongly acid; clear,
eroded. This soil is on foot slopes. It has the profile smooth boundary.
described as representative of the Cayagua series. B21tg-7 to 15 inches, gray (10YR 5/1) clay; common, fine,
described as representative of the Cayagua series, distinct, light yellowish-brown mottles and com-
Small areas of Candelero and Mayo soils were included mon, medium, distinct, yellowish-brown (10YR 5/8)
with this soil in mapping. mottles; weak, medium, subangular blocky struc-
This soil has moderate limitations for farming be- ture; friable, slightly sticky and slightly plastic;
common fine and medium roots; thin patchy clay
cause it is somewhat poorly drained and is slowly per- films on ped surfaces and along root channels;
meable. It requires soil conservation practices and many fine quartz grains; very strongly acid; clear,
proper management. It has been planted to pineapples smooth boundary.
for many years. If the soil is properly limed and B22tg-15 to 26 inches, gray (5Y 5/1) clay; common, me-
dium, distinct, light yellowish-brown (2.5YR 6/4)
drained, it is suited to cultivated crops. If it is properly mottles, few, medium, distinct, strong-brown
drained and cultivated, it is suited to sugarcane and (7.5YR 5/6) mottles, and common, medium, faint,
pasture. Capability unit IIIe-2. gray (N 5/0) mottles; weak, coarse, subangular
CgD2-Cayagua sandy loam, 12 to 20 percent slopes, blocky structure; friable, slightly sticky and
slightly plastic; few fine roots; patchy clay films
eroded. This soil is on foot slopes. Its profile is similar on ped surfaces and along root channels; common
to the one described as representative of the Cayagua worm casts; many fine quartz grains; very strongly
series, but the surface layer is 2 or 3 inches thinner and acid; clear, smooth boundary.
this soil is more susceptible to erosion if it is clean B3-26 to 33 inches, reddish-yellow (7.5YR 6/8) clay; com-
mon, fine, distinct, gray and light yellowish-brown
cultivated. Included in mapping were small areas of mottles; weak, fine, subangular blocky structure;
Mayo and Pandura soils. friable, slightly sticky and slightly plastic; few fine
This soil has severe limitations for farming because roots; common fine quartz grains; very strongly
it is moderately steep and somewhat poorly drained. If acid; clear, smooth boundary.
the soil is clean cultivated, it requires special conserva- C1-33 to 41 inches, reddish-yellow (YR 6/6) silty clay
loam; common, medium, faint, strong-brown (7.5YR
tion practices because it is susceptible to erosion. If the 5/8) mottles; massive; friable, slightly sticky and
soil is properly drained, it is suited to cultivated crops, slightly plastic; common fine quartz grains; very
This soil is suited to sugarcane, pineapples, and pas- strongly acid; clear, smooth boundary.
ture. Capability unit IVe-2. C2-41 to 48 inches, yellowish-red (SYR 5/6) silt loam;
ture. Capability ut IVe. common, medium, distinct, strong-brown (7.5YR
5/6) mottles; massive; very friable, nonsticky and
slightly plastic; many fine quartz grains; very
Ciales Series strongly acid; clear, smooth boundary. About 40
percent of the soil mass of this horizon is saprolite.
The Ciales series consists of deep soils that are C3-48 to 60 inches +, variegated colors of the saprolite;
poorly drained and slowly permeable in the upper part yellowish-red (5YR 5/6), strong-brown (7.5YR
and well drained and moderately permeable in the lower 5/8), yellowish-brown (lYa R 5/8), and dark-red
(7.5R 3/6) silty clay loam; massive; very friable,
part. These soils formed in fine-textured, highly weath- nonsticky and slightly plastic; common, fine, shiny
ered residuum of igneous rocks. They are on ridgetops flakes and quartz grains; very strongly acid.
and upper side slopes in the humid uplands. Slopes are The solum is 25 to 41 inches thick. The A horizon has hue
12 to 45 percent. The average annual precipitation is of 10YR to 2.5 YR, value of 3 or less, and chroma of 1 to 3.
185 inches, and the average annual temperature is It is dominantly silty clay loam. The B2t horizon has hue of
720 F. 10YR, 2.5Y, or 5Y, value of 4 to 6, and chroma of 2 or
In a representative profile, the surface layer is dark- less. It is clay or silty clay and has weak, coarse or weak,
medium, subangular blocky structure. Clay films range from
brown, very strongly acid silty clay loam about 7 inches thin patchy to thin continuous. The C horizon has dominant
thick. The upper part of the subsoil, to a depth of 26 hue of 7.5YR or 5YR, value of 4 to 6, and chroma of 4 to
inches, is gray, very strongly acid clay that is mottled 8. Reaction ranges from strongly acid to extremely acid
and friable. The lower part of the subsoil is reddish- throughout.
and friable. The lower part of the subsoil is reddish- The Ciales soils occupy the same landscape as the Yunque,
yellow, very strongly acid, friable clay 7 inches thick. Picacho, Utuado, Guayabota, and Los Guineos soils. The
The underlying material is friable silty clay loam and Ciales soils, unlike the Yunque soils, have low chroma mot-
silt loam of variegated colors of red, yellow, and brown tles in the B2t horizon. In contrast to the Picacho soils, they
have dominant colors with chromas of 2 or less in the B2t
that extends to a depth of 60 inches or more. horizon. They have a B2t horizon that the Utuado and
These soils have a moderate available water capacity Guayabota soils lack; they are finer textured than the
and medium fertility. Runoff is medium to rapid. The Utuado soils and deeper than the Guayabota soils. Unlike




0







14 SOIL SURVEY

the Los Guineos soils, Ciales soils have low-chroma colors part of the survey area. It has the profile described as
in the B2t horizon. representative of the series. Included with this soil in
mapping were small areas of Vives silty clay loam, high
Coamo Series bottom, and Paso Seco soils.
This soil has severe limitations for farming because
The Coamo series consists of well-drained, moder- rainfall is low. The soil is fertile, however, and if it is
ately permeable soils that are moderately deep to strati- irrigated, it is suited to sugarcane, minor crops, sor-
fled, coarse-textured materials. These soils formed in ghum, and pasture. Capability units IIIc-2 nonirri-
sediment derived from volcanic and limestone rocks. gated and IIe-1 irrigated.
They are on alluvial fans or terraces. Slopes are 2 to 12 C1C-Coamo clay loam, 5 to 12 percent slopes. This
percent. The climate is semiarid. The average annual soil is on alluvial fans and terraces. Small areas of
rainfall is 30 to 40 inches, and the average annual Jacana and Amelia soils were included with this soil in
temperature is 790 F. mapping.
In a representative profile, the surface layer is very Low rainfall and a high evaporation rate are severe
dark brown, slightly acid clay loam about 15 inches limitations for cultivated crops. Conservation practices
thick. Below that layer is dark-brown, firm clay and are needed to slow surface runoff. This soil has been
gravelly clay 23 inches thick. The underlying material used for sugarcane, pasture, and sorghum. If it is irri-
is gravel and gravelly clay loam that extends to a depth gated, it is suited to food crops, sugarcane, sorghum,
of 48 inches. and pasture. Capability unit IVe-3.
These soils have a moderate available water capacity,
moderate shrink-swell potential, and high natural fer-
tility. Runoff is medium. The soils have been in food Coastal Beaches
crops, sorghum, sugarcane, native pasture, and brush. Cm-Coastal beaches consists of narrow strips of
If the soils are irrigated, they can be used for many light-colored beach sand along the coast. This wave-
kinds of food crops. worked sand is saturated with seawater and contains
Representative profile of Coamo clay loam, 2 to 5 per- many seashells and shell fragments throughout.
cent slopes, 2.7 kilometers south of kilometer marker This land type has no value for farming. Most of it is
85.1 on Highway No. 1, Salinas to Cayey, Salinas: devoid of vegetation, except for a few coconut palms and
All-0 to 5 inches, very dark brown (10YR 2/2) clay loam, halophytic vegetation, such as uva player (Colobis
very dark grayish brown (10YR 3/2) when dry; ubifera) and bejuco de playa (Ipomoea prescaprae).
weak, medium, subangular blocky structure; Capability unit VIIIs-1
slightly hard, friable, slightly sticky and slightly
plastic; few fine roots; few fine pebbles; slightly
acid; diffuse, wavy boundary. Cobbly Alluvial Land
A12-5 to 15 inches, very dark brown (10YR 2/2) clay
loam, very dark grayish brown (10YR 3/2) when Cn-Cobbly alluvial land is along the flood plains of
dry; weak, coarse, subangular blocky structure;
slightly hard, oriable, slightly stcky and slightly streams and rivers. It consists of unconsolidated allu-
plastic; few fine roots; few patchy clay films; few vium and about 70 percent, by volume, rock fragments
fine pebbles; slightly acid; clear, smooth boundary. that range from 3 to 10 inches in diameter.
B2t-15 to 25 inches, dark-brown (7.5YR 4/2) clay, dark This land type has severe limitations for farming
brown (7.5YR 3/2) when dry; weak, medium, sub-
angular blocky stucture; very hard, firm, slightly because it has a low available water capacity and a high
sticky and slightly plastic; few fine lime splotches; content of rock fragments. Some of the areas are used
common fine gravel; few discontinuous clay films for grass. Capability unit Vs-1.
along root channels and vertical cleavage plants;
mildly alkaline; gradual, wavy boundary.
B3ca-25 to 38 inches, dark-brown (10YR 3/3) gravelly Coloso Series
clay, dark brown (7.5YR 4/2) when dry; weak,
medium, subangular blocky structure; very hard, The Coloso series consists of deep soils that are some-
firm, slightly sticky and slightly plastic; moder- what poorly drained and slowly permeable. These soils
ately alkaline; ped surfaces coated with secondary formed in moderately fine textured sediment of mixed
lime; clear, smooth boundary.
IICca-38 to 48 inches, stratified gravel and gravelly clay origin. They are on river flood plains. Slopes are 0 to 2
loam; gravel ranges from 1/2 inch to 2 inches in di- percent. The climate is humid tropical. The average
meter; common, fine, dark minerals; common fine annual temperature is 780 F. Depth to the water table
lime splotches ranges from 24 to 48 inches.
The solum is 31 to 57 inches thick. The A horizon has In a representative profile, the surface layer is dark-
value horizon 2has or 3, and is slightly acid or neutral. The Bnd brown, slightly acid silty clay loam about 9 inches thick.
horizon has hue of 7.5YR or 10YR, value of 3 or 4, and ext layer is dark grayish-brown, mottled silty clay
chroma of 2 or 3. It is mildly alkaline or moderately alka- The next layer is dark grayish-brown mottled silty cay
line. Depth to the ca horizon ranges from 21 to 37 inches. loam 10 inches thick. The underlying layer is gray and
Depth to the gravelly horizon ranges from 31 to 57 inches yellowish-brown, mottled clay, silty clay, and silty clay
The Coamo soils are on the same landscape as the Des- loam that is firm and extends to a depth of 60 inches.
calabrado, Jacana, and Amelia soils. The Coamo soils are loam that s firm and extends to a depth of 60 inches.
deeper and occupy lower positions than the Descalabrado These soils have a high available water capacity,
soils. They are deeper than the Jacana soils and lack the moderate shrink-swell potential, and high natural fer-
semiconsolidated volcanic rocks of those soils. In contrast utility. Runoff is slow. The soils have been in sugarcane
to the Ameliaroughout the profils, the Coamo soils lack gravelly sediment for many years, and some areas are in native pasture
throughout the profile. and brush.
and brush.
CIB-Coamo clay loam, 2 to 5 percent slopes. This Representative profile of the Coloso series from an
soil is on alluvial fans and terraces in the semiarid area of Coloso silty clay loam, occasionally flooded, 300







14 SOIL SURVEY

the Los Guineos soils, Ciales soils have low-chroma colors part of the survey area. It has the profile described as
in the B2t horizon. representative of the series. Included with this soil in
mapping were small areas of Vives silty clay loam, high
Coamo Series bottom, and Paso Seco soils.
This soil has severe limitations for farming because
The Coamo series consists of well-drained, moder- rainfall is low. The soil is fertile, however, and if it is
ately permeable soils that are moderately deep to strati- irrigated, it is suited to sugarcane, minor crops, sor-
fled, coarse-textured materials. These soils formed in ghum, and pasture. Capability units IIIc-2 nonirri-
sediment derived from volcanic and limestone rocks. gated and IIe-1 irrigated.
They are on alluvial fans or terraces. Slopes are 2 to 12 C1C-Coamo clay loam, 5 to 12 percent slopes. This
percent. The climate is semiarid. The average annual soil is on alluvial fans and terraces. Small areas of
rainfall is 30 to 40 inches, and the average annual Jacana and Amelia soils were included with this soil in
temperature is 790 F. mapping.
In a representative profile, the surface layer is very Low rainfall and a high evaporation rate are severe
dark brown, slightly acid clay loam about 15 inches limitations for cultivated crops. Conservation practices
thick. Below that layer is dark-brown, firm clay and are needed to slow surface runoff. This soil has been
gravelly clay 23 inches thick. The underlying material used for sugarcane, pasture, and sorghum. If it is irri-
is gravel and gravelly clay loam that extends to a depth gated, it is suited to food crops, sugarcane, sorghum,
of 48 inches. and pasture. Capability unit IVe-3.
These soils have a moderate available water capacity,
moderate shrink-swell potential, and high natural fer-
tility. Runoff is medium. The soils have been in food Coastal Beaches
crops, sorghum, sugarcane, native pasture, and brush. Cm-Coastal beaches consists of narrow strips of
If the soils are irrigated, they can be used for many light-colored beach sand along the coast. This wave-
kinds of food crops. worked sand is saturated with seawater and contains
Representative profile of Coamo clay loam, 2 to 5 per- many seashells and shell fragments throughout.
cent slopes, 2.7 kilometers south of kilometer marker This land type has no value for farming. Most of it is
85.1 on Highway No. 1, Salinas to Cayey, Salinas: devoid of vegetation, except for a few coconut palms and
All-0 to 5 inches, very dark brown (10YR 2/2) clay loam, halophytic vegetation, such as uva player (Colobis
very dark grayish brown (10YR 3/2) when dry; ubifera) and bejuco de playa (Ipomoea prescaprae).
weak, medium, subangular blocky structure; Capability unit VIIIs-1
slightly hard, friable, slightly sticky and slightly
plastic; few fine roots; few fine pebbles; slightly
acid; diffuse, wavy boundary. Cobbly Alluvial Land
A12-5 to 15 inches, very dark brown (10YR 2/2) clay
loam, very dark grayish brown (10YR 3/2) when Cn-Cobbly alluvial land is along the flood plains of
dry; weak, coarse, subangular blocky structure;
slightly hard, oriable, slightly stcky and slightly streams and rivers. It consists of unconsolidated allu-
plastic; few fine roots; few patchy clay films; few vium and about 70 percent, by volume, rock fragments
fine pebbles; slightly acid; clear, smooth boundary. that range from 3 to 10 inches in diameter.
B2t-15 to 25 inches, dark-brown (7.5YR 4/2) clay, dark This land type has severe limitations for farming
brown (7.5YR 3/2) when dry; weak, medium, sub-
angular blocky stucture; very hard, firm, slightly because it has a low available water capacity and a high
sticky and slightly plastic; few fine lime splotches; content of rock fragments. Some of the areas are used
common fine gravel; few discontinuous clay films for grass. Capability unit Vs-1.
along root channels and vertical cleavage plants;
mildly alkaline; gradual, wavy boundary.
B3ca-25 to 38 inches, dark-brown (10YR 3/3) gravelly Coloso Series
clay, dark brown (7.5YR 4/2) when dry; weak,
medium, subangular blocky structure; very hard, The Coloso series consists of deep soils that are some-
firm, slightly sticky and slightly plastic; moder- what poorly drained and slowly permeable. These soils
ately alkaline; ped surfaces coated with secondary formed in moderately fine textured sediment of mixed
lime; clear, smooth boundary.
IICca-38 to 48 inches, stratified gravel and gravelly clay origin. They are on river flood plains. Slopes are 0 to 2
loam; gravel ranges from 1/2 inch to 2 inches in di- percent. The climate is humid tropical. The average
meter; common, fine, dark minerals; common fine annual temperature is 780 F. Depth to the water table
lime splotches ranges from 24 to 48 inches.
The solum is 31 to 57 inches thick. The A horizon has In a representative profile, the surface layer is dark-
value horizon 2has or 3, and is slightly acid or neutral. The Bnd brown, slightly acid silty clay loam about 9 inches thick.
horizon has hue of 7.5YR or 10YR, value of 3 or 4, and ext layer is dark grayish-brown, mottled silty clay
chroma of 2 or 3. It is mildly alkaline or moderately alka- The next layer is dark grayish-brown mottled silty cay
line. Depth to the ca horizon ranges from 21 to 37 inches. loam 10 inches thick. The underlying layer is gray and
Depth to the gravelly horizon ranges from 31 to 57 inches yellowish-brown, mottled clay, silty clay, and silty clay
The Coamo soils are on the same landscape as the Des- loam that is firm and extends to a depth of 60 inches.
calabrado, Jacana, and Amelia soils. The Coamo soils are loam that s firm and extends to a depth of 60 inches.
deeper and occupy lower positions than the Descalabrado These soils have a high available water capacity,
soils. They are deeper than the Jacana soils and lack the moderate shrink-swell potential, and high natural fer-
semiconsolidated volcanic rocks of those soils. In contrast utility. Runoff is slow. The soils have been in sugarcane
to the Ameliaroughout the profils, the Coamo soils lack gravelly sediment for many years, and some areas are in native pasture
throughout the profile. and brush.
and brush.
CIB-Coamo clay loam, 2 to 5 percent slopes. This Representative profile of the Coloso series from an
soil is on alluvial fans and terraces in the semiarid area of Coloso silty clay loam, occasionally flooded, 300







14 SOIL SURVEY

the Los Guineos soils, Ciales soils have low-chroma colors part of the survey area. It has the profile described as
in the B2t horizon. representative of the series. Included with this soil in
mapping were small areas of Vives silty clay loam, high
Coamo Series bottom, and Paso Seco soils.
This soil has severe limitations for farming because
The Coamo series consists of well-drained, moder- rainfall is low. The soil is fertile, however, and if it is
ately permeable soils that are moderately deep to strati- irrigated, it is suited to sugarcane, minor crops, sor-
fled, coarse-textured materials. These soils formed in ghum, and pasture. Capability units IIIc-2 nonirri-
sediment derived from volcanic and limestone rocks. gated and IIe-1 irrigated.
They are on alluvial fans or terraces. Slopes are 2 to 12 C1C-Coamo clay loam, 5 to 12 percent slopes. This
percent. The climate is semiarid. The average annual soil is on alluvial fans and terraces. Small areas of
rainfall is 30 to 40 inches, and the average annual Jacana and Amelia soils were included with this soil in
temperature is 790 F. mapping.
In a representative profile, the surface layer is very Low rainfall and a high evaporation rate are severe
dark brown, slightly acid clay loam about 15 inches limitations for cultivated crops. Conservation practices
thick. Below that layer is dark-brown, firm clay and are needed to slow surface runoff. This soil has been
gravelly clay 23 inches thick. The underlying material used for sugarcane, pasture, and sorghum. If it is irri-
is gravel and gravelly clay loam that extends to a depth gated, it is suited to food crops, sugarcane, sorghum,
of 48 inches. and pasture. Capability unit IVe-3.
These soils have a moderate available water capacity,
moderate shrink-swell potential, and high natural fer-
tility. Runoff is medium. The soils have been in food Coastal Beaches
crops, sorghum, sugarcane, native pasture, and brush. Cm-Coastal beaches consists of narrow strips of
If the soils are irrigated, they can be used for many light-colored beach sand along the coast. This wave-
kinds of food crops. worked sand is saturated with seawater and contains
Representative profile of Coamo clay loam, 2 to 5 per- many seashells and shell fragments throughout.
cent slopes, 2.7 kilometers south of kilometer marker This land type has no value for farming. Most of it is
85.1 on Highway No. 1, Salinas to Cayey, Salinas: devoid of vegetation, except for a few coconut palms and
All-0 to 5 inches, very dark brown (10YR 2/2) clay loam, halophytic vegetation, such as uva player (Colobis
very dark grayish brown (10YR 3/2) when dry; ubifera) and bejuco de playa (Ipomoea prescaprae).
weak, medium, subangular blocky structure; Capability unit VIIIs-1
slightly hard, friable, slightly sticky and slightly
plastic; few fine roots; few fine pebbles; slightly
acid; diffuse, wavy boundary. Cobbly Alluvial Land
A12-5 to 15 inches, very dark brown (10YR 2/2) clay
loam, very dark grayish brown (10YR 3/2) when Cn-Cobbly alluvial land is along the flood plains of
dry; weak, coarse, subangular blocky structure;
slightly hard, oriable, slightly stcky and slightly streams and rivers. It consists of unconsolidated allu-
plastic; few fine roots; few patchy clay films; few vium and about 70 percent, by volume, rock fragments
fine pebbles; slightly acid; clear, smooth boundary. that range from 3 to 10 inches in diameter.
B2t-15 to 25 inches, dark-brown (7.5YR 4/2) clay, dark This land type has severe limitations for farming
brown (7.5YR 3/2) when dry; weak, medium, sub-
angular blocky stucture; very hard, firm, slightly because it has a low available water capacity and a high
sticky and slightly plastic; few fine lime splotches; content of rock fragments. Some of the areas are used
common fine gravel; few discontinuous clay films for grass. Capability unit Vs-1.
along root channels and vertical cleavage plants;
mildly alkaline; gradual, wavy boundary.
B3ca-25 to 38 inches, dark-brown (10YR 3/3) gravelly Coloso Series
clay, dark brown (7.5YR 4/2) when dry; weak,
medium, subangular blocky structure; very hard, The Coloso series consists of deep soils that are some-
firm, slightly sticky and slightly plastic; moder- what poorly drained and slowly permeable. These soils
ately alkaline; ped surfaces coated with secondary formed in moderately fine textured sediment of mixed
lime; clear, smooth boundary.
IICca-38 to 48 inches, stratified gravel and gravelly clay origin. They are on river flood plains. Slopes are 0 to 2
loam; gravel ranges from 1/2 inch to 2 inches in di- percent. The climate is humid tropical. The average
meter; common, fine, dark minerals; common fine annual temperature is 780 F. Depth to the water table
lime splotches ranges from 24 to 48 inches.
The solum is 31 to 57 inches thick. The A horizon has In a representative profile, the surface layer is dark-
value horizon 2has or 3, and is slightly acid or neutral. The Bnd brown, slightly acid silty clay loam about 9 inches thick.
horizon has hue of 7.5YR or 10YR, value of 3 or 4, and ext layer is dark grayish-brown, mottled silty clay
chroma of 2 or 3. It is mildly alkaline or moderately alka- The next layer is dark grayish-brown mottled silty cay
line. Depth to the ca horizon ranges from 21 to 37 inches. loam 10 inches thick. The underlying layer is gray and
Depth to the gravelly horizon ranges from 31 to 57 inches yellowish-brown, mottled clay, silty clay, and silty clay
The Coamo soils are on the same landscape as the Des- loam that is firm and extends to a depth of 60 inches.
calabrado, Jacana, and Amelia soils. The Coamo soils are loam that s firm and extends to a depth of 60 inches.
deeper and occupy lower positions than the Descalabrado These soils have a high available water capacity,
soils. They are deeper than the Jacana soils and lack the moderate shrink-swell potential, and high natural fer-
semiconsolidated volcanic rocks of those soils. In contrast utility. Runoff is slow. The soils have been in sugarcane
to the Ameliaroughout the profils, the Coamo soils lack gravelly sediment for many years, and some areas are in native pasture
throughout the profile. and brush.
and brush.
CIB-Coamo clay loam, 2 to 5 percent slopes. This Representative profile of the Coloso series from an
soil is on alluvial fans and terraces in the semiarid area of Coloso silty clay loam, occasionally flooded, 300







14 SOIL SURVEY

the Los Guineos soils, Ciales soils have low-chroma colors part of the survey area. It has the profile described as
in the B2t horizon. representative of the series. Included with this soil in
mapping were small areas of Vives silty clay loam, high
Coamo Series bottom, and Paso Seco soils.
This soil has severe limitations for farming because
The Coamo series consists of well-drained, moder- rainfall is low. The soil is fertile, however, and if it is
ately permeable soils that are moderately deep to strati- irrigated, it is suited to sugarcane, minor crops, sor-
fled, coarse-textured materials. These soils formed in ghum, and pasture. Capability units IIIc-2 nonirri-
sediment derived from volcanic and limestone rocks. gated and IIe-1 irrigated.
They are on alluvial fans or terraces. Slopes are 2 to 12 C1C-Coamo clay loam, 5 to 12 percent slopes. This
percent. The climate is semiarid. The average annual soil is on alluvial fans and terraces. Small areas of
rainfall is 30 to 40 inches, and the average annual Jacana and Amelia soils were included with this soil in
temperature is 790 F. mapping.
In a representative profile, the surface layer is very Low rainfall and a high evaporation rate are severe
dark brown, slightly acid clay loam about 15 inches limitations for cultivated crops. Conservation practices
thick. Below that layer is dark-brown, firm clay and are needed to slow surface runoff. This soil has been
gravelly clay 23 inches thick. The underlying material used for sugarcane, pasture, and sorghum. If it is irri-
is gravel and gravelly clay loam that extends to a depth gated, it is suited to food crops, sugarcane, sorghum,
of 48 inches. and pasture. Capability unit IVe-3.
These soils have a moderate available water capacity,
moderate shrink-swell potential, and high natural fer-
tility. Runoff is medium. The soils have been in food Coastal Beaches
crops, sorghum, sugarcane, native pasture, and brush. Cm-Coastal beaches consists of narrow strips of
If the soils are irrigated, they can be used for many light-colored beach sand along the coast. This wave-
kinds of food crops. worked sand is saturated with seawater and contains
Representative profile of Coamo clay loam, 2 to 5 per- many seashells and shell fragments throughout.
cent slopes, 2.7 kilometers south of kilometer marker This land type has no value for farming. Most of it is
85.1 on Highway No. 1, Salinas to Cayey, Salinas: devoid of vegetation, except for a few coconut palms and
All-0 to 5 inches, very dark brown (10YR 2/2) clay loam, halophytic vegetation, such as uva player (Colobis
very dark grayish brown (10YR 3/2) when dry; ubifera) and bejuco de playa (Ipomoea prescaprae).
weak, medium, subangular blocky structure; Capability unit VIIIs-1
slightly hard, friable, slightly sticky and slightly
plastic; few fine roots; few fine pebbles; slightly
acid; diffuse, wavy boundary. Cobbly Alluvial Land
A12-5 to 15 inches, very dark brown (10YR 2/2) clay
loam, very dark grayish brown (10YR 3/2) when Cn-Cobbly alluvial land is along the flood plains of
dry; weak, coarse, subangular blocky structure;
slightly hard, oriable, slightly stcky and slightly streams and rivers. It consists of unconsolidated allu-
plastic; few fine roots; few patchy clay films; few vium and about 70 percent, by volume, rock fragments
fine pebbles; slightly acid; clear, smooth boundary. that range from 3 to 10 inches in diameter.
B2t-15 to 25 inches, dark-brown (7.5YR 4/2) clay, dark This land type has severe limitations for farming
brown (7.5YR 3/2) when dry; weak, medium, sub-
angular blocky stucture; very hard, firm, slightly because it has a low available water capacity and a high
sticky and slightly plastic; few fine lime splotches; content of rock fragments. Some of the areas are used
common fine gravel; few discontinuous clay films for grass. Capability unit Vs-1.
along root channels and vertical cleavage plants;
mildly alkaline; gradual, wavy boundary.
B3ca-25 to 38 inches, dark-brown (10YR 3/3) gravelly Coloso Series
clay, dark brown (7.5YR 4/2) when dry; weak,
medium, subangular blocky structure; very hard, The Coloso series consists of deep soils that are some-
firm, slightly sticky and slightly plastic; moder- what poorly drained and slowly permeable. These soils
ately alkaline; ped surfaces coated with secondary formed in moderately fine textured sediment of mixed
lime; clear, smooth boundary.
IICca-38 to 48 inches, stratified gravel and gravelly clay origin. They are on river flood plains. Slopes are 0 to 2
loam; gravel ranges from 1/2 inch to 2 inches in di- percent. The climate is humid tropical. The average
meter; common, fine, dark minerals; common fine annual temperature is 780 F. Depth to the water table
lime splotches ranges from 24 to 48 inches.
The solum is 31 to 57 inches thick. The A horizon has In a representative profile, the surface layer is dark-
value horizon 2has or 3, and is slightly acid or neutral. The Bnd brown, slightly acid silty clay loam about 9 inches thick.
horizon has hue of 7.5YR or 10YR, value of 3 or 4, and ext layer is dark grayish-brown, mottled silty clay
chroma of 2 or 3. It is mildly alkaline or moderately alka- The next layer is dark grayish-brown mottled silty cay
line. Depth to the ca horizon ranges from 21 to 37 inches. loam 10 inches thick. The underlying layer is gray and
Depth to the gravelly horizon ranges from 31 to 57 inches yellowish-brown, mottled clay, silty clay, and silty clay
The Coamo soils are on the same landscape as the Des- loam that is firm and extends to a depth of 60 inches.
calabrado, Jacana, and Amelia soils. The Coamo soils are loam that s firm and extends to a depth of 60 inches.
deeper and occupy lower positions than the Descalabrado These soils have a high available water capacity,
soils. They are deeper than the Jacana soils and lack the moderate shrink-swell potential, and high natural fer-
semiconsolidated volcanic rocks of those soils. In contrast utility. Runoff is slow. The soils have been in sugarcane
to the Ameliaroughout the profils, the Coamo soils lack gravelly sediment for many years, and some areas are in native pasture
throughout the profile. and brush.
and brush.
CIB-Coamo clay loam, 2 to 5 percent slopes. This Representative profile of the Coloso series from an
soil is on alluvial fans and terraces in the semiarid area of Coloso silty clay loam, occasionally flooded, 300






HUMACAO AREA OF EASTERN PUERTO RICO 15

meters northeast, 515 meters northwest, and 6 meters Because this soil is somewhat poorly drained, it has
northeast from kilometer marker 2.8 on Highway No. limitations for farming. Occasional flooding, slow per-
925, Humacao: meability, and a seasonal high water table are limita-
tions for cultivated crops. Careful management and
Ap-0 to 9 inches, dark-brown (10YR 4/3) silty clay loam; water control practices are required to overcome these
common, medium, faint, dark grayish-brown mot-
tles; weak, fine, subangular blocky structure; hard, limitations. Most of the acreage of this soil is in sugar-
firm, slightly sticky and slightly plastic; common cane. If the soil is properly drained, it is suited to
fine roots; common krotovinas; few, fine, dark con- sugarcane and pasture. Capability unit IIw-1.
cretions; common residue of burned sugarcane;
slightly acid; abrupt, smooth boundary.
B-9 to 19 inches, dark grayish-brown (10YR 4/2) silty Corcega Series
clay loam; common, fine, distinct, strong-brown
(7.5YR 5/8) mottles and common, medium, dis- The Corcega series consists of deep soils that are
tinct, dark yellowish-brown (10YR 4/4) mottles; somewhat poorly drained and moderately permeable.
weak, fine, subangular blocky structure; hard, firm,
slightly sticky and slightly plastic; common worm These soils formed in moderately fine textured sedi-
casts; common, fine, dark minerals; worm channels ment of mixed origin over sand. They are on river
coated with thin continuous clay films; few, fine, flood plains. Slopes are 0 to 2 percent. The climate is
dead roots; slightly acid; clear, smooth boundary. humid tropical. The average annual precipitation is
C1-19 to 27 inches, gray (10YR 5/1) silty clay loam;
common, medium, distinct, dark yellowish-brown 80 inches, and the average annual temperature is 770 F.
(10YR 4/4) mottles and few, fine, prominent, red In a representative profile, the surface layer is dark-
(2.5YR 4/6) mottles; massive; hard, firm, slightly brown, slightly acid sandy loam about 8 inches thick.
sticky and slightly plastic; few fine pores; common Below that layer is dark-brown and dark-gray, mottled,
fine sand grains; few, fine, dead roots; few worm
casts; slightly acid; clear, smooth boundary, firm, silty clay loam or sandy clay loam that extends to
C2-27 to 32 inches, yellowish-brown (10YR 5/6) silty clay; a depth of 32 inches. The underlying material is dark-
common, medium, distinct, grayish-brown (10YR gray, loose sand 18 inches thick.
5/2) mottles; massive; hard, firm, slightly sticky These soils have a moderate available water capacity
and slightly plastic; few fine pores; common wormese soils have a moderate available water capacity
casts with thin layer of clay films; few, fine, dead and high natural fertility. They are easily worked.
roots; slightly acid; clear, smooth boundary. Surface runoff is slow. These soils have been in sugar-
IIC3-32 to 43 inches, gray (10YR 5/1) clay; few, medium, cane and pasture, and a few areas are in coconut trees.
distinct, dark-brown (10YR 4/3) mottles; weak,
distine, subangular blocky structure; hard, firm, Representative profile of Corcega sandy loam, 1 kilo-
slightly sticky and slightly plastic; common fine to meter east of kilometer marker 2.0 on Highway No.
medium pores; few dark minerals; few, fine, dead 115:
roots; roots and worm channels coated with thick
clay films; slightly acid; gradual, wavy boundary. Ap-0 to 8 inches, dark-brown (10YR 4/3) sandy loam;
IIIC4-43 to 60 inches, gray (10YR 5/1) clay; few, fine, weak, medium, granular structure; firm, slightly
faint, dark-brown (10YR 4/3) mottles; massive; sticky and slightly plastic; many fine roots; slightly
hard, firm, slightly sticky and slightly plastic; few, acid; clear, smooth boundary.
fine, dead roots; few fine pores; slightly acid. B2-8 to 14 inches, dark-brown (10YR 4/3) silty clay loam;
common, fine, prominent, yellowish-red (5YR 4/6)
The solum is 14 to 22 inches thick. The A horizon has mottles and few, fine, distinct, light-gray (10YR
value and chroma of 3 or 4. The Ap horizon is silty clay or 7/2) mottles; weak, fine, subangular blocky struc-
silty clay loam. The B horizon has chroma of 2 or 3 and ture; firm, slightly sticky and slightly plastic;
has weak, fine or medium, subangular blocky structure. The common fine roots; common, fine, black concre-
C horizon has a matrix color of gray and has yellowish- tions; slightly acid; clear, smooth boundary.
brown and gley mottles. It ranges from silty clay loam to B3-14 to 32 inches, dark-gray (10YR 4/1) sandy clay
clay. loam; common, fine, distinct, reddish-brown (5YR
The Coloso soils occupy the same landscape as the Bajura, 4/3) mottles and common, fine, distinct, gray
Toa, Fortuna, Reilly, Talante, and Maunabo soils. Unlike all (10YR 5/1) mottles; weak, medium, subangular
those soils, the Coloso soils are somewhat poorly drained, blocky structure; firm, slightly sticky and slightly
They are finer textured in the lower horizons than the Toa plastic; common, fine, black concretions; few fine
soils. The Coloso soils are finer textured than the Reilly and roots; slightly acid; clear, smooth boundary.
Talante soils, and unlike the Reilly soils, they are not under- IIC-32 to 50 inches, dark-gray (10YR 4/1) sand; single
lain by sand and gravel. grained; loose, nonsticky and nonplastic; slightly
Co-Coloso silty clay loam, occasionally flooded. This acid.
nearly level soil is on flood plains. It has the profile Thickness of the solum and depth to sandy horizons range
from 24 to 40 inches. The Ap horizon has value of 3 or 4.
described as representative of the series. Small areas of The B2 horizon has chroma of 2 to 4. Few to common,
Toa, Bajura, and Fortuna soils were included with this yellowish-red, reddish-brown, light-gray, and gray mottles
soil in mapping. are in the B and C horizons. The C horizon has a hue of
Occasional flooding, slow permeability, and a seasonal 10YR or 2.5Y and chroma of 1 or 2. ape as the Coloso
The Corcega soils are on the same landscape as the Coloso
high water table are moderate limitations for farming. and Bajura soils and the land type Wet alluvial land. They
This soil requires soil and water conservation practices are coarser textured throughout than the Coloso and Bajura
for proper cultivation. It has been used for sugarcane. soils. The Corcega soils occupy higher positions and are less
If the soil is properly drained, it is suited to sugarcane affected by water during the year than Wet alluvial land.
and pasture. Capability unit IIw-1. Cs-Corcega sandy loam. This nearly level soil is on
Cr-Coloso silty clay. This nearly level soil is on river flood plains. Included with it in mapping were
flood plains. Its profile is similar to the one described small areas of Coloso and Bajura soils.
as representative of the series, but it lies at a higher Frequent flooding and a seasonal water table are
elevation and is less subject to flooding. Included with moderate limitations for farming. Soil and water con-
this soil in mapping were small areas of Toa, Bajura, servation practices are needed for proper cultivation.
and Fortuna soils. This soil has been in sugarcane and pasture, and some






16 SOIL SURVEY

small areas are in coconut trees. If the soil is properly percent slopes. This soil is on foot slopes. Included
drained, it is suited to cultivated crops, sugarcane, and with it in mapping were small areas of Naranjito and
pasture. Capability unit IIw-5. Lirios soils.
Moderately slow permeability and slope are moderate
Daguao Variant limitations for farming. If the soil is properly limed
and fertilized, it is suited to food crops, sugarcane, and
The Daguao variant consists of deep soils that are pasture. Capability unit IIIe-3; woodland suitability
well drained and moderately slowly permeable. These group 3d5.
soils formed in moderately fine textured residuum de-
rived from volcanic rocks. They occupy foot slopes. Daguao Series
Slopes are 2 to 12 percent. The climate is humid tropi-
cal. The average annual rainfall is 80 inches, and the The Daguao series consists of moderately deep soils
average annual temperature is 790 F. that are well drained and moderately slowly permeable.
In a representative profile, the surface layer is dark- These soils formed in moderately fine textured to fine
brown, medium acid silty clay loam about 11 inches textured residuum derived from volcanic rocks. They
thick. Below that layer is dark-brown and strong- are on foot slopes and mountain side slopes. Slopes are
brown, friable clay that extends to a depth of 35 inches. 2 to 60 percent. The climate is humid tropical. The
The underlying material is dark yellowish-brown, fri- average annual rainfall is 80 to 85 inches, and the
able silty clay loam weathered saprolite that can be average annual temperature is 790 F.
crushed between the fingers. In a representative profile, the surface layer is very
These soils have a high available water capacity, dark gray, strongly acid clay about 8 inches thick.
moderate shrink-swell potential, and medium natural Below that layer is dark yellowish-brown and yellowish-
fertility. They have been in food crops, sugarcane, pas- brown, firm clay that extends to a depth of 21 inches.
ture, and trees. The underlying material is saprolite of varying colors.
Representative profile of Daguao silty clay loam, Consolidated volcanic rock is at a depth of 34 inches.
deep variant, 2 to 12 percent slopes, 2 miles south of the These soils have a moderate available water capacity,
town of Humacao, 900 feet south of Central Ejemplo, moderate shrink-swell potential, and medium natural
990 feet along farm road, and 28 feet west of lone fertility and have been in crops, pasture, and trees.
mahogany tree: Representative profile of Daguao clay, 20 to 40 per-
A1-0 to 11 inches, dark-brown (7.5YR 3/2) silty clay cent slopes, eroded, 45 meters north of kilometer
loam; weak, fine, subangular blocky structure; marker 0.55 on Highway No. 31 near its intersection
hard, friable, nonsticky and slightly plastic; many with Highway No. 3:
fine roots; few, fine, dark concretions; few, fine,
angular rock fragments; medium acid; clear, wavy Ap-0 to 8 inches, very dark gray (10YR 3/1) clay; weak,
boundary. fine, granular structure; very firm, slightly sticky
B21t-11 to 23 inches, dark-brown (10YR 3/3) clay; weak, and plastic; strongly acid; gradual, wavy bound-
medium, subangular blocky structure; friable, ary.
slightly sticky and plastic; common fine roots; B1-8 to 13 inches, dark yellowish-brown (10YR 4/4) clay;
many, fine, dark concretions; few, thin, patchy clay weak, coarse, subangular blocky structure; firm,
films on ped surfaces; few, fine, weathered rock slightly sticky and slightly plastic; thin discon-
fragments; medium acid; clear, wavy boundary. tinuous clay films; strongly acid; gradual, wavy
B22t-23 to 35 inches, strong-brown (7.5YR 5/8) clay; boundary.
moderate, medium, subangular blocky structure; B2t-13 to 21 inches, yellowish-brown (10YR 5/4) clay;
friable, sticky and plastic; few fine roots; many, moderate, coarse, subangular blocky structure;
fine, dark grains and concretions; thin patchy clay firm, slightly sticky and slightly plastic; clay films
films on ped surfaces; few fine rock fragments; on vertical ped surfaces and few clay films on
strongly acid; clear, smooth boundary, horizontal ped surfaces; few partly weathered horn-
C-35 to 45 inches, dark yellowish-brown (10YR 3/4) silty blende crystals; few pressure faces and small
clay loam; massive; friable, nonsticky and slightly slickensides; strongly acid; clear, wavy boundary.
plastic; medium acid. (This horizon consists of C-21 to 34 inches, variegated, yellowish-brown (10YR 5/6),
highly weathered volcanic rock saprolite that can yellowish-red (5YR 4/6), and dark greenish-gray
be crushed easily between the fingers.) (5GY 4/1) saprolite; many hornblende crystals.
The solum is 28 to 44 inches thick. The A horizon has R-34 inches +, dark greenish, consolidated volcanic rock.
hue of 10YR or 7.5YR, value of 2 or 3, and chroma of 2 to The solum is 14 to 26 inches thick. The Ap horizon has
4. It ranges from clay loam to silty clay loam and from hue of 10YR or 7.5YR, value of 2 or 3, and chroma of 1 or
weak subangular blocky to moderate granular in structure. 2. It ranges from silty clay loam to clay. The B2t horizon
The B2 horizon has hue of 10YR or 7.5YR, value of 3 to 5, has value of 4 or 5 and chroma of 4 to 6. It has weak or
and chroma of 3 to 8. It is 20 to 28 inches thick and ranges moderate, medium or coarse, subangular blocky structure.
from silty clay to clay in texture. Structure is weak or Few to many rock fragments are scattered throughout the
moderate subangular blocky, and clay films vary from thin profile. Depth to consolidated rock ranges from 20 to 40
patchy to thin continuous. The reaction is strongly acid or inches.
medium acid. Depth to consolidated rock is more than 40 The Daguao soils are on the same landscape as the Lirios,
inches. Naranjito, and Pandura soils. The Daguao soils are finer
The Daguao variant soils occupy the same landscape as textured than the Lirios soils and lack the red B2t horizon
the Daguao, Lirios, Naranjito, and Pandura soils. The of those soils. They lack the yellowish-red horizons of the
Daguao variant soils have a thicker profile and are deeper Naranjito soils. The Daguao soils are finer textured and
to consolidated rock than the Daguao soils. They are have a thicker solum than the Pandura soils.
browner and finer textured than the Lirios soils, and they
lack the yellowish-red horizons of the Naranjito soils. The DcE2-Daguao clay, 20 to 40 percent slopes, eroded.
Daguao variant soils are finer textured and have a thicker This soil is on mountain side slopes. Small areas of
solum than the Pandura soils. Pandura, Lirios, and Naranjito soils were included
DaC-Daguao silty clay loam, deep variant, 2 to 12 with this soil in mapping.






16 SOIL SURVEY

small areas are in coconut trees. If the soil is properly percent slopes. This soil is on foot slopes. Included
drained, it is suited to cultivated crops, sugarcane, and with it in mapping were small areas of Naranjito and
pasture. Capability unit IIw-5. Lirios soils.
Moderately slow permeability and slope are moderate
Daguao Variant limitations for farming. If the soil is properly limed
and fertilized, it is suited to food crops, sugarcane, and
The Daguao variant consists of deep soils that are pasture. Capability unit IIIe-3; woodland suitability
well drained and moderately slowly permeable. These group 3d5.
soils formed in moderately fine textured residuum de-
rived from volcanic rocks. They occupy foot slopes. Daguao Series
Slopes are 2 to 12 percent. The climate is humid tropi-
cal. The average annual rainfall is 80 inches, and the The Daguao series consists of moderately deep soils
average annual temperature is 790 F. that are well drained and moderately slowly permeable.
In a representative profile, the surface layer is dark- These soils formed in moderately fine textured to fine
brown, medium acid silty clay loam about 11 inches textured residuum derived from volcanic rocks. They
thick. Below that layer is dark-brown and strong- are on foot slopes and mountain side slopes. Slopes are
brown, friable clay that extends to a depth of 35 inches. 2 to 60 percent. The climate is humid tropical. The
The underlying material is dark yellowish-brown, fri- average annual rainfall is 80 to 85 inches, and the
able silty clay loam weathered saprolite that can be average annual temperature is 790 F.
crushed between the fingers. In a representative profile, the surface layer is very
These soils have a high available water capacity, dark gray, strongly acid clay about 8 inches thick.
moderate shrink-swell potential, and medium natural Below that layer is dark yellowish-brown and yellowish-
fertility. They have been in food crops, sugarcane, pas- brown, firm clay that extends to a depth of 21 inches.
ture, and trees. The underlying material is saprolite of varying colors.
Representative profile of Daguao silty clay loam, Consolidated volcanic rock is at a depth of 34 inches.
deep variant, 2 to 12 percent slopes, 2 miles south of the These soils have a moderate available water capacity,
town of Humacao, 900 feet south of Central Ejemplo, moderate shrink-swell potential, and medium natural
990 feet along farm road, and 28 feet west of lone fertility and have been in crops, pasture, and trees.
mahogany tree: Representative profile of Daguao clay, 20 to 40 per-
A1-0 to 11 inches, dark-brown (7.5YR 3/2) silty clay cent slopes, eroded, 45 meters north of kilometer
loam; weak, fine, subangular blocky structure; marker 0.55 on Highway No. 31 near its intersection
hard, friable, nonsticky and slightly plastic; many with Highway No. 3:
fine roots; few, fine, dark concretions; few, fine,
angular rock fragments; medium acid; clear, wavy Ap-0 to 8 inches, very dark gray (10YR 3/1) clay; weak,
boundary. fine, granular structure; very firm, slightly sticky
B21t-11 to 23 inches, dark-brown (10YR 3/3) clay; weak, and plastic; strongly acid; gradual, wavy bound-
medium, subangular blocky structure; friable, ary.
slightly sticky and plastic; common fine roots; B1-8 to 13 inches, dark yellowish-brown (10YR 4/4) clay;
many, fine, dark concretions; few, thin, patchy clay weak, coarse, subangular blocky structure; firm,
films on ped surfaces; few, fine, weathered rock slightly sticky and slightly plastic; thin discon-
fragments; medium acid; clear, wavy boundary. tinuous clay films; strongly acid; gradual, wavy
B22t-23 to 35 inches, strong-brown (7.5YR 5/8) clay; boundary.
moderate, medium, subangular blocky structure; B2t-13 to 21 inches, yellowish-brown (10YR 5/4) clay;
friable, sticky and plastic; few fine roots; many, moderate, coarse, subangular blocky structure;
fine, dark grains and concretions; thin patchy clay firm, slightly sticky and slightly plastic; clay films
films on ped surfaces; few fine rock fragments; on vertical ped surfaces and few clay films on
strongly acid; clear, smooth boundary, horizontal ped surfaces; few partly weathered horn-
C-35 to 45 inches, dark yellowish-brown (10YR 3/4) silty blende crystals; few pressure faces and small
clay loam; massive; friable, nonsticky and slightly slickensides; strongly acid; clear, wavy boundary.
plastic; medium acid. (This horizon consists of C-21 to 34 inches, variegated, yellowish-brown (10YR 5/6),
highly weathered volcanic rock saprolite that can yellowish-red (5YR 4/6), and dark greenish-gray
be crushed easily between the fingers.) (5GY 4/1) saprolite; many hornblende crystals.
The solum is 28 to 44 inches thick. The A horizon has R-34 inches +, dark greenish, consolidated volcanic rock.
hue of 10YR or 7.5YR, value of 2 or 3, and chroma of 2 to The solum is 14 to 26 inches thick. The Ap horizon has
4. It ranges from clay loam to silty clay loam and from hue of 10YR or 7.5YR, value of 2 or 3, and chroma of 1 or
weak subangular blocky to moderate granular in structure. 2. It ranges from silty clay loam to clay. The B2t horizon
The B2 horizon has hue of 10YR or 7.5YR, value of 3 to 5, has value of 4 or 5 and chroma of 4 to 6. It has weak or
and chroma of 3 to 8. It is 20 to 28 inches thick and ranges moderate, medium or coarse, subangular blocky structure.
from silty clay to clay in texture. Structure is weak or Few to many rock fragments are scattered throughout the
moderate subangular blocky, and clay films vary from thin profile. Depth to consolidated rock ranges from 20 to 40
patchy to thin continuous. The reaction is strongly acid or inches.
medium acid. Depth to consolidated rock is more than 40 The Daguao soils are on the same landscape as the Lirios,
inches. Naranjito, and Pandura soils. The Daguao soils are finer
The Daguao variant soils occupy the same landscape as textured than the Lirios soils and lack the red B2t horizon
the Daguao, Lirios, Naranjito, and Pandura soils. The of those soils. They lack the yellowish-red horizons of the
Daguao variant soils have a thicker profile and are deeper Naranjito soils. The Daguao soils are finer textured and
to consolidated rock than the Daguao soils. They are have a thicker solum than the Pandura soils.
browner and finer textured than the Lirios soils, and they
lack the yellowish-red horizons of the Naranjito soils. The DcE2-Daguao clay, 20 to 40 percent slopes, eroded.
Daguao variant soils are finer textured and have a thicker This soil is on mountain side slopes. Small areas of
solum than the Pandura soils. Pandura, Lirios, and Naranjito soils were included
DaC-Daguao silty clay loam, deep variant, 2 to 12 with this soil in mapping.






HUMACAO AREA OF EASTERN PUERTO RICO 17

This soil has severe limitations for cultivated crops This soil has severe limitations for farming because
because it is steep. Conservation practices must be used it is shallow to rock and rainfall is low. It is suited to
to control surface runoff. This soil is better suited to pasture. Capability unit IVs-2; woodland suitability
pasture and woodland than to most other uses. Capabil- group 3d5.
ity unit VIe-1; woodland suitability group 3d5. DeE2-Descalabrado clay loam, 20 to 40 percent
slopes, eroded. This soil is on mountain side slopes and
Descalabrado Series ridgetops in the semiarid volcanic uplands. It has the
profile described as representative of the Descalabrado
The Descalabrado series consists of well-drained, series. Included with this soil in mapping were small
moderately permeable soils that are shallow to consoli- areas of Guayama soils and Rock land.
dated volcanic rock. These soils formed in moderately Steep slopes, shallowness to bedrock, rapid runoff,
fine textured residuum derived from volcanic rocks, low rainfall, and the hazard of erosion are severe
Slopes are 5 to 60 percent. The climate is semiarid. limitations for farming. This soil is limited to pasture
The average annual rainfall is 30 to 35 inches, and the grazing and wildlife food and cover. Stocking rates
average annual temperature is 790 F. should be controlled to avoid overgrazing and control
In a representative profile, the surface layer is very erosion. The soil has been in pasture and brush for
dark grayish-brown, neutral clay loam about 6 inches many years. It is better suited to grazing than to most
thick. The next layer, 4 inches thick, is brown, friable other uses. Capability unit VIIs-4; woodland suitabil-
clay loam with small volcanic rock fragments. Dark- ity group 3d5.
brown, firm silty clay is between depths of 10 and 14 DgF2-Descalabrado and Guayama soils, 20 to 60
inches. The underlying material is olive-brown loam percent slopes, eroded. This mapping unit is on the
saprolite that extends to a depth of about 19 inches. It sides and tops of ridges in the volcanic uplands. It
is underlain by weathered volcanic rock. consists of Descalabrado and Guayama soils. The pro-
These soils have a moderate available water capacity, portion of each soil varies from one mapped area to
moderate shrink-swell potential, and medium natural another, and some areas may be entirely Guayama
fertility. Runoff is medium to rapid. The soils are sus- soils.
ceptible to erosion, and they have been in pasture and The Guayama soils are not so steep as the Descala-
brush for many years, brado soils. The Guayama soils have chert throughout
Representative profile of Descalabrado clay loam, 20 the surface layer and subsoil in places.
to 40 percent slopes, eroded, 1.4 kilometers north of Steep slopes, shallowness to bedrock, rapid runoff,
kilometer marker 155.9 on Highway 3 and 45 meters low rainfall, and the hazard of erosion are severe limita-
northeast of a shack: tions for farming. These soils have been in pasture and
Ap-0 to 6 inches, very dark grayish-brown (10YR 3/3) brush for many years. They are suitable for pasture
clay loam; weak, fine, subangular blocky structure and wildlife food and cover. Capability unit VIIs-4;
parting to moderate, medium, granular; friable, woodland suitability group 4d5.
slightly sticky and slightly plastic; many fine roots; DrF-Descalabrado-Rock land complex, 40 to 60
few small volcanic fragments; neutral; clear,
smooth boundary. percent slopes. This mapping unit is on mountain side
B1-6 to 10 inches, brown (10YR 4/3) clay loam; moderate, slopes and ridgetops in the semiarid volcanic uplands.
fine, subangular blocky structure; friable, slightly It consists of Descalabrado soils and Rock land in such
sticky and slightly plastic; many fine roots; few intricate patterns that they cannot be shown separately
small volcanic fragments; neutral; clear, smooth
boundary. at the scale used in mapping. The Descalabrado soils
B2-10 to 14 inches, dark-brown (10YR 4/3) silty clay; make up about 80 to 85 percent of the mapping unit,
moderate, fine and medium, subangular blocky and Rock land makes up 15 to 20 percent.
structure; firm, nonstick and slightly plastic; The Descalabrado soils in this complex are similar to
common fine roots; thin very dark grayish-brown
(10YR 3/2) clay films; few small volcanic frag- the soil having the profile described as representative
ments; few dark worm casts; 10 to 15 percent of the Descalabrado series, but they are steeper.
saprolite; neutral; clear, smooth boundary. Because the soils of this mapping unit are steep,
C-14 to 19 inches, olive-brown (2.5Y 4/4) loam (saprolite); shallow to rocks, and rocky, they have severe limitations
fracture planes of the original rock structure
coated with dark-brown (10YR 3/3) clay or or- for farming. They are suitable for pasture and wildlife
ganic matter, or both, food and cover. Capability unit VIIs-4; woodland suit-
R-19 inches, greenish-gray slightly weathered volcanic ability group 4d5.
rock.
The solum is 7 to 15 inches thick. The A horizon has Fajardo Series
value and chroma of 2 and 3. The B2 horizon has value of
3 or 4 and chroma of 2 or 3. Iepth to consolidated vol- The Fajardo series consists of deep soils that are
canic rock ranges from 10 to 20 inches.
The Descalabrado soils are on the same landscape as the somewhat poorly drained and slowly permeable. These
Guayama and Jacana soils. Unlike the Guayama soils, the soils formed in fine-textured sediment of mixed origin.
Descalabrado soils are neutral and lack red horizons. They occupy alluvial fans and terraces. Slopes are 2 to
The Descalabrado soils are coarser textured and shallower 10 percent. The climate is humid tropical. The average
than the Jacana soils, yearly precipitation is 75 to 80 inches, and the average
DeC2-Descalabrado clay loam, 5 to 12 percent annual temperature is 780 F.
slopes, eroded. This soil is on mountain side slopes. It In a representative profile, the surface layer is dark
occupies lower positions and has a thicker surface layer grayish-brown, medium acid, mottled clay about 9
than the soil having the profile described as represen- inches thick. Below that layer is yellowish-brown, red,
tative of the Descalabrado series, and light-gray, very firm, mottled clay 27 inches thick.






HUMACAO AREA OF EASTERN PUERTO RICO 17

This soil has severe limitations for cultivated crops This soil has severe limitations for farming because
because it is steep. Conservation practices must be used it is shallow to rock and rainfall is low. It is suited to
to control surface runoff. This soil is better suited to pasture. Capability unit IVs-2; woodland suitability
pasture and woodland than to most other uses. Capabil- group 3d5.
ity unit VIe-1; woodland suitability group 3d5. DeE2-Descalabrado clay loam, 20 to 40 percent
slopes, eroded. This soil is on mountain side slopes and
Descalabrado Series ridgetops in the semiarid volcanic uplands. It has the
profile described as representative of the Descalabrado
The Descalabrado series consists of well-drained, series. Included with this soil in mapping were small
moderately permeable soils that are shallow to consoli- areas of Guayama soils and Rock land.
dated volcanic rock. These soils formed in moderately Steep slopes, shallowness to bedrock, rapid runoff,
fine textured residuum derived from volcanic rocks, low rainfall, and the hazard of erosion are severe
Slopes are 5 to 60 percent. The climate is semiarid. limitations for farming. This soil is limited to pasture
The average annual rainfall is 30 to 35 inches, and the grazing and wildlife food and cover. Stocking rates
average annual temperature is 790 F. should be controlled to avoid overgrazing and control
In a representative profile, the surface layer is very erosion. The soil has been in pasture and brush for
dark grayish-brown, neutral clay loam about 6 inches many years. It is better suited to grazing than to most
thick. The next layer, 4 inches thick, is brown, friable other uses. Capability unit VIIs-4; woodland suitabil-
clay loam with small volcanic rock fragments. Dark- ity group 3d5.
brown, firm silty clay is between depths of 10 and 14 DgF2-Descalabrado and Guayama soils, 20 to 60
inches. The underlying material is olive-brown loam percent slopes, eroded. This mapping unit is on the
saprolite that extends to a depth of about 19 inches. It sides and tops of ridges in the volcanic uplands. It
is underlain by weathered volcanic rock. consists of Descalabrado and Guayama soils. The pro-
These soils have a moderate available water capacity, portion of each soil varies from one mapped area to
moderate shrink-swell potential, and medium natural another, and some areas may be entirely Guayama
fertility. Runoff is medium to rapid. The soils are sus- soils.
ceptible to erosion, and they have been in pasture and The Guayama soils are not so steep as the Descala-
brush for many years, brado soils. The Guayama soils have chert throughout
Representative profile of Descalabrado clay loam, 20 the surface layer and subsoil in places.
to 40 percent slopes, eroded, 1.4 kilometers north of Steep slopes, shallowness to bedrock, rapid runoff,
kilometer marker 155.9 on Highway 3 and 45 meters low rainfall, and the hazard of erosion are severe limita-
northeast of a shack: tions for farming. These soils have been in pasture and
Ap-0 to 6 inches, very dark grayish-brown (10YR 3/3) brush for many years. They are suitable for pasture
clay loam; weak, fine, subangular blocky structure and wildlife food and cover. Capability unit VIIs-4;
parting to moderate, medium, granular; friable, woodland suitability group 4d5.
slightly sticky and slightly plastic; many fine roots; DrF-Descalabrado-Rock land complex, 40 to 60
few small volcanic fragments; neutral; clear,
smooth boundary. percent slopes. This mapping unit is on mountain side
B1-6 to 10 inches, brown (10YR 4/3) clay loam; moderate, slopes and ridgetops in the semiarid volcanic uplands.
fine, subangular blocky structure; friable, slightly It consists of Descalabrado soils and Rock land in such
sticky and slightly plastic; many fine roots; few intricate patterns that they cannot be shown separately
small volcanic fragments; neutral; clear, smooth
boundary. at the scale used in mapping. The Descalabrado soils
B2-10 to 14 inches, dark-brown (10YR 4/3) silty clay; make up about 80 to 85 percent of the mapping unit,
moderate, fine and medium, subangular blocky and Rock land makes up 15 to 20 percent.
structure; firm, nonstick and slightly plastic; The Descalabrado soils in this complex are similar to
common fine roots; thin very dark grayish-brown
(10YR 3/2) clay films; few small volcanic frag- the soil having the profile described as representative
ments; few dark worm casts; 10 to 15 percent of the Descalabrado series, but they are steeper.
saprolite; neutral; clear, smooth boundary. Because the soils of this mapping unit are steep,
C-14 to 19 inches, olive-brown (2.5Y 4/4) loam (saprolite); shallow to rocks, and rocky, they have severe limitations
fracture planes of the original rock structure
coated with dark-brown (10YR 3/3) clay or or- for farming. They are suitable for pasture and wildlife
ganic matter, or both, food and cover. Capability unit VIIs-4; woodland suit-
R-19 inches, greenish-gray slightly weathered volcanic ability group 4d5.
rock.
The solum is 7 to 15 inches thick. The A horizon has Fajardo Series
value and chroma of 2 and 3. The B2 horizon has value of
3 or 4 and chroma of 2 or 3. Iepth to consolidated vol- The Fajardo series consists of deep soils that are
canic rock ranges from 10 to 20 inches.
The Descalabrado soils are on the same landscape as the somewhat poorly drained and slowly permeable. These
Guayama and Jacana soils. Unlike the Guayama soils, the soils formed in fine-textured sediment of mixed origin.
Descalabrado soils are neutral and lack red horizons. They occupy alluvial fans and terraces. Slopes are 2 to
The Descalabrado soils are coarser textured and shallower 10 percent. The climate is humid tropical. The average
than the Jacana soils, yearly precipitation is 75 to 80 inches, and the average
DeC2-Descalabrado clay loam, 5 to 12 percent annual temperature is 780 F.
slopes, eroded. This soil is on mountain side slopes. It In a representative profile, the surface layer is dark
occupies lower positions and has a thicker surface layer grayish-brown, medium acid, mottled clay about 9
than the soil having the profile described as represen- inches thick. Below that layer is yellowish-brown, red,
tative of the Descalabrado series, and light-gray, very firm, mottled clay 27 inches thick.






18 SOIL SURVEY

This is underlain by very firm, mottled clay that has cane. If the soil is drained and properly managed, it is
variegated colors and extends to a depth of 60 inches. suited to sugarcane and pasture. Capability unit IIw-
These soils have a high available water capacity, high 2.
shrink-swell potential, and medium natural fertility. FaC2-Fajardo clay, 2 to 10 percent slopes, eroded.
Runoff is slow. The soils are not easily worked, and they This soil is on alluvial fans. Its profile is similar to the
have been in sugarcane for many years. one described as representative of the Fajardo series,
Representative profile of Fajardo clay, 2 to 10 per- but erosion has removed some of the dark grayish-
cent slopes, on the Land Authority Farm, 165 meters brown clay surface layer and small rills have formed
south and 13 meters west of entrance to Luquillo Public from rains. In some places plowing has mixed the
Beach on Highway 3: surface layer with the subsoil. Included with this soil in
Ap-0 to 9 inches, dark grayish-brown (10YR 4/2) clay, mapping were small areas of Vega Alta soils.
common, fine, faint, gray (10YR 5/1) mottles; Slow permeability, a seasonal high water table, and
weak, medium, subangular blocky structure to unfavorable workability are moderate limitations for
moderate, medium, granular; firm, slightly sticky farming. Soil conservation practices and proper man-
and slightly plastic; many fine roots; few fine agement are needed to control erosion. This soil has
volcanic fragments; common, fine, black concre-
tions; medium acid; abrupt, smooth boundary. been used for sugarcane for many years. If it is drained
B21t-9 to 14 inches, yellowish-brown (10YR 5/6) clay; and properly managed, it is suited to sugarcane and
many, medium, distinct, greenish-gray (5GY 6/1) pasture. Capability unit IIw-2.
mottles and many, medium, prominent, red (2.5YR
4/6) mottles; moderate, medium, subangular blocky
structure; very firm, sticky and plastic; common Fortuna Series
fine roots; thin continuous clay films on ped sur-
faces and root channels; common, fine, black con-
cretions; slightly acid; gradual, smooth boundary. The Fortuna series consists of deep soils that are
B22t-14 to 25 inches, yellowish-brown (10YR 5/6) clay; poorly drained and slowly permeable. These soils
many, medium, prominent, gray (5Y 6/1) and red formed in fine-textured sediment of mixed origin. They
(2.5YR 4/6) mottles; moderate, medium, subangu-
lar blocky structure; very firm, sticky and plastic; are on the flood plains. Slopes are 0 to 2 percent. The
common fine roots; thin patchy clay films on ped climate is humid tropical. The average annual precipi-
surfaces and root channels; common slickensides station is 80 inches, and the average annual temperature
and pressure faces; common, fine, black concre- is 780 F.
tions; medium acid; gradual, smooth boundary.
B23t-25 to 36 inches, red (2.5YR 4/6) and light-gray (N In a representative profile, the surface layer is olive-
7/0) clay; common, medium, prominent, dark-red gray, strongly acid clay about 5 inches thick. Below that
(2.5YR 3/6) and yellowish-brown (10YR 5/6) is dark greenish-gray and greenish-gray, very firm clay
mottles; weak, medium, angular blocky structure; that extends to a depth of 60 inches or more.
very firm, sticky and plastic; few fine roots; These soils have a high available water capacity,
mon slickensides and pressure faces; few, fine, dark These soils have a high available water capacity,
concretions; medium acid; gradual, smooth bound- shrink-swell potential, and natural fertility. Runoff is
ary. slow. The soils are difficult to work. They have been in
B24t-36 to 48 inches, variegated, yellowish-brown (10YR sugarcane, but a few areas are in native pasture and
5/6), gray (N 6/0), light bluish-gray (5B 7/1), brush.
and dark-red (2.5YR 3/6) clay; weak, fine, sub- brush
angular blocky structure; very firm, sticky and Representative profile of Fortuna clay, 2.0 kilo-
plastic; medium acid; gradual, smooth boundary, meters south of the town of Maunabo and 10 kilometers
B25t-48 to 60 inches, gray (N 6/0) clay; many, medium, northeast of the town of Humacao; 2.1 kilometers
distinctYR 5/6), anrk-red light bluish-gray (53/6) yellowish-brown north of bridge over Anton Ruiz River on Highway 3,
(10YR 5/6), and light bluish-gray (5B 7/1) mot-
tles; weak, fine, subangular blocky structure; very near an abandoned railroad:
firm, sticky and plastic; medium acid.
SAp-0 to 5 inches, olive-gray (5Y 4/2) clay; few, fine,
The solum is more than 60 inches thick. The Ap horizon faint, greenish-gray (5Y 6/1) mottles and few,
has chroma of 2 or 3. The B21t and B22t horizons have hue fine, distinct, strong-brown (7.5YR 5/8) mottles;
of 10YR or 7.5YR and value of 4 or 5. Structure is weak massive; very firm, slightly sticky and slightly
or moderate, subangular blocky. Clay films vary from thin plastic; common fine roots; strongly acid; abrupt,
patchy to thin continuous. The B22 horizon has variegated smooth boundary.
colors of gray, yellowish brown, and red in varying propor- B21g-5 to 9 inches, dark greenish-gray (5GY 4/1) clay;
tions. Mottles throughout the profile are common or many common, medium, distinct, strong-brown (7.5YR
and are shades of gray, yellowish brown, red, and dark red. 5/8) mottles; massive; very firm, slightly sticky
Slickensides range from few to common and plastic; common fine roots; few fine rock frag-
The Fajardo soils are on the same landscape as the Vega ments;d songly acid; abrupt, smooth boundary.
Baja and Vega Alta soils. In contrast to the Vega Ba B2g--9 to 18 inches, greenish-gray (5GY 5/1) clay; many,
soils, the Fajardo soils have pressure faces and slicken- medium, distinct, yellowish-brown (10YR 5/8)mot-
sides in the B2t horizon. Unlike the Vega Alta soils, they ties; weak, coarse, subangular blocky structure;
mare somewhat poor ravery firm, slightly sticky and plastic; common fine
roots; few, fine, black nodules; strongly acid; grad-
FaC-Fajardo clay, 2 to 10 percent slopes. This soil ual, smooth boundary.
occupies alluvial fans. It has the profile described as B3g-18 to 30 inches, greenish-gray (,GY 5/1) clay; cor-




high water table are moderate limitations for farming. Cg-30 to 77 inches, greenish-gray (5GY 5/1) clay; many,
Careful management is required to improve the air and coarse, distinct, yellowish-brown (10YR 5/8) mot-
water relationship. This soil has been used for ar- mas ; very firm, sticky and plastic; very
water relationship. This soil has been used for sugar- strongly acid.







HUMACAO AREA OF EASTERN PUERTO RICO 19

The solum is 22 to 45 inches thick. The Ap horizon has clay; massive; firm, plastic; few fine pores; few
chroma of 2 or 3. The B horizon has value of 4 or 5 and pressure faces; few, soft, dark concretions; com-
chroma of 2 or less. Consistence is slightly sticky or sticky mon dark stains; strongly alkaline.
and generally is plastic. The A horizon is 9 to 16 inches thick. It has value of
The Fortuna soils are on the same landscape as the 3 or 4 and chroma of 2 or 3. The C horizon has chroma
Maunabo, Bajura, and Toa soils. The Fortuna soils occupy of 3 or 4.
lower positions than the Maunabo soils, and unlike those The Fraternidad soils are on the same landscape as the
soils, they are fine textured in the lower horizons. They Paso Seco and Cartagena soils. Unlike the Paso Seco soils,
lack the pressure faces that are present in the Bajura soils the Fraternidad soils lack gravelly horizons at a depth of
and are more acid than those soils. In contrast to the Toa 20 to 37 inches. The Fraternidad soils are better drained
soils, the Fortuna soils are fine textured and poorly drained. than the Cartagena soils.
Fo-Fortuna clay. This nearly level soil is on river FrA-Fraternidad clay, 0 to 2 percent slopes. This
flood plains in the humid part of the survey area. Small soil is on alluvial fans and terraces in the semiarid
areas of Maunabo and Bajura soils were included with coastal plains. It has the profile described as represen-
this soil in mapping. tative of the series. Included with this soil in mapping
Slow permeability, poor workability, poor drainage, were small areas of Paso Seco and Cartagena soils.
and a seasonal high water table are severe limitations Slow permeability, poor workability, and low rainfall
for cultivated crops. Soil conservation practices and are moderate limitations for farming. This soil has
management are needed. This soil has been used for been used for food crops, sorghum, sugarcane, and pas-
sugarcane. If the soil is properly drained, it is suited to ture. Capability units IIIc-1 nonirrigated and IIs-1
sugarcane and pasture. Capability unit IIIw-4. irrigated.
FrB-Fraternidad clay, 2 to 5 percent slopes. This
Fraternidad Series soil is on terraces in the coastal plains. Included with it
in mapping were small areas of Paso Seco soils.
The Fraternidad series consists of deep soils that are Slow permeability, poor workability, slope, and low
moderately well drained and slowly permeable. These rainfall are moderate limitations for farming. These
soils formed in fine-textured sediment derived from limitations affect land leveling and irrigation. If the
limestone and volcanic rocks. They are on coastal soil is properly irrigated, it is suited to sugarcane,
plains. Slopes are 0 to 5 percent. The climate is semi- sorghum, cut grasses, and pasture. Capability units
arid. The average annual rainfall is 30 to 45 inches, IIIc-1 nonirrigated and IIs-1 irrigated.
and the average annual temperature is 790 F.
In a representative profile, the upper part of the Gi
surface layer is very dark grayish-brown, slightly acid Guamani Series
clay, about 8 inches thick, and the lower part is brown The Guamani series consists of deep soils that are
clay 5 inches thick. Below that layer is dark yellowish- well drained and rapidly permeable. These soils formed
brown, firm clay that extends to a depth of about 50 in moderately fine textured sediment over coarse sand,
inches, gravel, and cobbles derived from volcanic rock (fig. 3).
These soils have a high available water capacity, high They are on river flood plains. Slopes are 0 to 2 percent.
natural fertility, and very high shrink-swell potential. The climate is semiarid. The average annual rainfall is
Surface runoff is slow. The soils are difficult to work, 35 to 45 inches, and the average annual temperature is
and they have been used for sugarcane and pasture for 790 F.
many years. In a representative profile, the surface layer is very
Representative profile of Fraternidad clay, 0 to 2 dark grayish-brown, slightly acid silty clay loam about
percent slopes, 3.2 kilometers north of kilometer 6 inches thick. Below that layer is brown, friable silty
marker 161.9 on Highway No. 3, and 42 meters north of clay loam 14 inches thick. That material is underlain
an irrigation reservoir: by sand, gravel, and cobbles.
Ap-0 to 8 inches, very dark grayish-brown (10YR 3/2) These soils have a low available water capacity, me-
clay; weak, medium, subangular blocky structure; dium runoff, and low shrink-swell potential. They are
hard, firm, slightly sticky and plastic; common high in natural fertility and are easy to work. Runoff
roots; slightly acid; abrupt, smooth boundary. is medium. The soils have been used for sugarcane and
A12-8 to 13 inches, brown (10YR 4/3) clay; pockets of
very dark grayish-brown (10YR 3/2) clay; weak, pasture.
medium subangular blocky structure; firm, slightly Representative profile of Guamani silty clay loam,
sticky and plastic; common pressure faces and 30 meters west of kilometer marker 144.3 on Highway
slickensides; common small pores; common pebbles No. 3, between Guayama and Salinas:
1 to 3 millimeters in diameter; few dark minerals;
slightly acid; clear, wavy boundary. Ap-0 to 6 inches, very dark grayish-brown (10YR 3/2)
C1-13 to 18 inches, dark yellowish-brown (10YR 4/4) clay; silty clay loam; weak, fine, subangular blocky struc-
weak, coarse, angular blocky structure; firm, ture parting to fine, granular; slightly hard, fri-
slightly sticky and plastic; very few patchy clay able, slightly sticky and slightly plastic; many fine
films along vertical cleavage planes and root chan- roots; fine pores; few, fine, subrounded rock frag-
nels; common pressure faces and slickensides; ments; slightly acid; gradual, smooth boundary.
neutral; clear, wavy boundary. B-6 to 20 inches, brown (10YR 4/3) silty clay loam; weak,
C2ca-18 to 31 inches, dark yellowish-brown (10YR 4/4) fine, subangular blocky structure; slightly hard,
clay; massive; firm, slightly sticky and plastic; friable, slightly sticky and slightly plastic; com-
common fine pores; few dead roots; few pressure mon roots; common fine pores; few rock fragments
faces and slickensides; common lime splotches and and gravel; slightly acid; abrupt, wavy boundary.
limestone fragments; few pebbles; few dark min- IIC-20 inches, sand, gravel, and cobbles that are 3 to 8
erals; few krotovinas; strongly alkaline; clear, inches in diameter.
wavy boundary.
C3-31 to 50 inches, dark yellowish-brown (10YR 4/4) The solum is 15 to 20 inches thick. The Ap horizon has







HUMACAO AREA OF EASTERN PUERTO RICO 19

The solum is 22 to 45 inches thick. The Ap horizon has clay; massive; firm, plastic; few fine pores; few
chroma of 2 or 3. The B horizon has value of 4 or 5 and pressure faces; few, soft, dark concretions; com-
chroma of 2 or less. Consistence is slightly sticky or sticky mon dark stains; strongly alkaline.
and generally is plastic. The A horizon is 9 to 16 inches thick. It has value of
The Fortuna soils are on the same landscape as the 3 or 4 and chroma of 2 or 3. The C horizon has chroma
Maunabo, Bajura, and Toa soils. The Fortuna soils occupy of 3 or 4.
lower positions than the Maunabo soils, and unlike those The Fraternidad soils are on the same landscape as the
soils, they are fine textured in the lower horizons. They Paso Seco and Cartagena soils. Unlike the Paso Seco soils,
lack the pressure faces that are present in the Bajura soils the Fraternidad soils lack gravelly horizons at a depth of
and are more acid than those soils. In contrast to the Toa 20 to 37 inches. The Fraternidad soils are better drained
soils, the Fortuna soils are fine textured and poorly drained. than the Cartagena soils.
Fo-Fortuna clay. This nearly level soil is on river FrA-Fraternidad clay, 0 to 2 percent slopes. This
flood plains in the humid part of the survey area. Small soil is on alluvial fans and terraces in the semiarid
areas of Maunabo and Bajura soils were included with coastal plains. It has the profile described as represen-
this soil in mapping. tative of the series. Included with this soil in mapping
Slow permeability, poor workability, poor drainage, were small areas of Paso Seco and Cartagena soils.
and a seasonal high water table are severe limitations Slow permeability, poor workability, and low rainfall
for cultivated crops. Soil conservation practices and are moderate limitations for farming. This soil has
management are needed. This soil has been used for been used for food crops, sorghum, sugarcane, and pas-
sugarcane. If the soil is properly drained, it is suited to ture. Capability units IIIc-1 nonirrigated and IIs-1
sugarcane and pasture. Capability unit IIIw-4. irrigated.
FrB-Fraternidad clay, 2 to 5 percent slopes. This
Fraternidad Series soil is on terraces in the coastal plains. Included with it
in mapping were small areas of Paso Seco soils.
The Fraternidad series consists of deep soils that are Slow permeability, poor workability, slope, and low
moderately well drained and slowly permeable. These rainfall are moderate limitations for farming. These
soils formed in fine-textured sediment derived from limitations affect land leveling and irrigation. If the
limestone and volcanic rocks. They are on coastal soil is properly irrigated, it is suited to sugarcane,
plains. Slopes are 0 to 5 percent. The climate is semi- sorghum, cut grasses, and pasture. Capability units
arid. The average annual rainfall is 30 to 45 inches, IIIc-1 nonirrigated and IIs-1 irrigated.
and the average annual temperature is 790 F.
In a representative profile, the upper part of the Gi
surface layer is very dark grayish-brown, slightly acid Guamani Series
clay, about 8 inches thick, and the lower part is brown The Guamani series consists of deep soils that are
clay 5 inches thick. Below that layer is dark yellowish- well drained and rapidly permeable. These soils formed
brown, firm clay that extends to a depth of about 50 in moderately fine textured sediment over coarse sand,
inches, gravel, and cobbles derived from volcanic rock (fig. 3).
These soils have a high available water capacity, high They are on river flood plains. Slopes are 0 to 2 percent.
natural fertility, and very high shrink-swell potential. The climate is semiarid. The average annual rainfall is
Surface runoff is slow. The soils are difficult to work, 35 to 45 inches, and the average annual temperature is
and they have been used for sugarcane and pasture for 790 F.
many years. In a representative profile, the surface layer is very
Representative profile of Fraternidad clay, 0 to 2 dark grayish-brown, slightly acid silty clay loam about
percent slopes, 3.2 kilometers north of kilometer 6 inches thick. Below that layer is brown, friable silty
marker 161.9 on Highway No. 3, and 42 meters north of clay loam 14 inches thick. That material is underlain
an irrigation reservoir: by sand, gravel, and cobbles.
Ap-0 to 8 inches, very dark grayish-brown (10YR 3/2) These soils have a low available water capacity, me-
clay; weak, medium, subangular blocky structure; dium runoff, and low shrink-swell potential. They are
hard, firm, slightly sticky and plastic; common high in natural fertility and are easy to work. Runoff
roots; slightly acid; abrupt, smooth boundary. is medium. The soils have been used for sugarcane and
A12-8 to 13 inches, brown (10YR 4/3) clay; pockets of
very dark grayish-brown (10YR 3/2) clay; weak, pasture.
medium subangular blocky structure; firm, slightly Representative profile of Guamani silty clay loam,
sticky and plastic; common pressure faces and 30 meters west of kilometer marker 144.3 on Highway
slickensides; common small pores; common pebbles No. 3, between Guayama and Salinas:
1 to 3 millimeters in diameter; few dark minerals;
slightly acid; clear, wavy boundary. Ap-0 to 6 inches, very dark grayish-brown (10YR 3/2)
C1-13 to 18 inches, dark yellowish-brown (10YR 4/4) clay; silty clay loam; weak, fine, subangular blocky struc-
weak, coarse, angular blocky structure; firm, ture parting to fine, granular; slightly hard, fri-
slightly sticky and plastic; very few patchy clay able, slightly sticky and slightly plastic; many fine
films along vertical cleavage planes and root chan- roots; fine pores; few, fine, subrounded rock frag-
nels; common pressure faces and slickensides; ments; slightly acid; gradual, smooth boundary.
neutral; clear, wavy boundary. B-6 to 20 inches, brown (10YR 4/3) silty clay loam; weak,
C2ca-18 to 31 inches, dark yellowish-brown (10YR 4/4) fine, subangular blocky structure; slightly hard,
clay; massive; firm, slightly sticky and plastic; friable, slightly sticky and slightly plastic; com-
common fine pores; few dead roots; few pressure mon roots; common fine pores; few rock fragments
faces and slickensides; common lime splotches and and gravel; slightly acid; abrupt, wavy boundary.
limestone fragments; few pebbles; few dark min- IIC-20 inches, sand, gravel, and cobbles that are 3 to 8
erals; few krotovinas; strongly alkaline; clear, inches in diameter.
wavy boundary.
C3-31 to 50 inches, dark yellowish-brown (10YR 4/4) The solum is 15 to 20 inches thick. The Ap horizon has







20
20 SOIL SURVEY





















V *










Figure 3.-An area of Guamani silty clay loam showing the underlying sand, gravel, and cobbles.


value and chroma of 2 to 5. The B horizon has chroma of annual rainfall is 185 inches, and the average annual
2 or 3. temperature is 72 F.
The Guamani soils occupy the same landscape as the m rars 7
Vives and Arenales soils. They have a thinner solum than In a representative profile, the surface layer is very
the Vives soils, and they are rapidly permeable. Unlike the dark gray, very strongly acid silty clay loam about 5
Arenales soils, the Guamani soils have a B horizon. inches thick. Below that layer is mottled, dark olive-
Gm-Guamani silty clay loam. This nearly level gray firm silty clay 9 inches thick. The underlying
soil is on river flood plains. Included with it in mapping material is silty clay loam of varying colors that ex-
were small areas of Vives soils, high bottom, and tends to a depth of 18 inches. It is underlain by hard
Arenales soils. siltstone.
This soil has severe limitations for crops because it is These soils have a high available water capacity and
shallow and has a low available water capacity and be- moderate shrink-swell potential. Runoff is medium to
cause rainfall is low. Deep cuts cannot be made to level rapid. The soils have been in native pasture and forest
the soil; shallow gravelly strata limit the construction vegetation for many years, and most of the acreage is
of irrigation channels and irrigation reservoirs. Con- still in tropical forest.
trolled irrigation practices are needed for proper farm Representative profile of Guayabota silty clay loam,
management. If the soil is irrigated, it is suited to 20 to 40 percent slopes, eroded, in the El Yunque
sugarcane and pasture. Capability unit IVc-1 nonir- National Forest, 90 meters northeast, and 30 meters
rigated and IIIs-2 irrigated, south from kilometer marker 11.8 on Highway No. 191
to Glorieta Bohique:
Guayabota Series A1-0 to 5 inches, very dark gray (5Y 3/1) silty clay loam;
few, fine, reddish-brown mottles; weak, fine, sub-
The Guayabota sris consists f shallow soils that angular blocky structure; firm, slightly sticky and
The Guayabota series consists of shallow soils that slightly plastic; many fine and medium roots; few
are poorly drained and slowly permeable. These soils fine and medium pores; very strongly acid; clear,
formed in residuum of thin-bedded, dark bluish-gray smooth boundary.
siltstone. They are on side slopes in the volcanic up- B2-5 to 11 inches, dark olive-gray (5Y 3/2) silty clay;
lands. Slopes are 20 to more than 60 percent. The cli- many, fine, distinct, dark reddish-brown mottles,
common, medium, distinct, dark bluish-gray (5B
mate is that of a tropical rain forest. The average 4/1) mottles, and few, medium, distinct, yellowish-






HUMACAO AREA OF EASTERN PUERTO RICO 21

brown (10YR 5/8) mottles; weak, coarse, subangu- susceptible to slippage. The soils are desirable for rec-
lar blocky structure parting to weak, medium, reaction uses because of their highly esthetic environ-
subangular blocky; firm, slightly sticky and slightly
plastic; common fine and medium roots; few fine ment, but they have severe limitations for paths, trails,
pores; very strongly acid; gradual, smooth bound- and roads because they are continuously wet and un-
ary. stable. Capability unit VIIe-3; woodland suitability
B3-11 to 14 inches, dark olive-gray (5Y 3/2) silty clay, group 4d3.
common, coarse, distinct, yellowish-brown (10YR
5/8) mottles, few, medium, distinct, yellowish-red
(5YR 5/8) mottles, and few, fine, distinct, dark- Guayama Series
gray mottles; weak, medium, subangular blocky
structure; firm, slightly sticky and plastic; few The Guayama series consists of shallow soils that
pieces of weathered siltstone; extremely acid; e Guayama series consists of shallow soils that
abrupt, smooth boundary, are well drained and moderately permeable. These soils
C-14 to 18 inches, variegated, dark bluish-gray (5B 4/1), formed in moderately fine textured and fine textured
dark greenish-gray (5G 4/1), and yellowish-red residuum of volcanic rocks. They occupy side slopes and
(5YR 4/8) silty clay loam; massive; friable,
slightly sticky and slightly plastic; few fine and narrow ridgetops. Slopes are 12 to 60 percent. The
medium roots; few fine pores; about 50 percent average annual precipitation is 35 inches, and the av-
saprolite; extremely acid; abrupt, smooth boundary. erage annual temperature is 790 F.
R-18 inches, hard, dark bluish-gray and greenish-gray In a representative profile, the surface layer is dark
siltstone. reddish-brown, neutral clay loam about 5 inches thick.
The solum is 10 to 15 inches thick. The A horizon has Below that layer is reddish-brown, friable gravelly clay
value of 2 or 3 and chroma of 2 or less. The B horizon has
chroma of 2 or less and has weak, medium or coarse, sub- 7 inches thick. The underlying layer is yellowish-red,
angular blocky structure. Reaction is strongly acid to ex- firm gravelly clay loam. Volcanic rock is at a depth of
tremely acid throughout the profile. Depth to hard siltstone 18 inches.
ranges from 13 to 20 inches. These soils have a moderate available water capacity,
The Guayabota soils are on the same landscape as the medium fertility, and moderate shrink-swell potential.
Ciales, Yunque, Picacho, Los Guineos, and Utuado soils, medium fertility, and moderate shrnk-swell potential.
They are shallower to hard rock than all those soils. The Runoff is medium to rapid. The soils are somewhat
Guayabota soils lack the B2t horizons of the Ciales, Yunque, difficult to work, and they have been in pasture for
Picacho, and Los Guineos soils, and they are finer textured many years.
than the Utuado soils. In this survey area, Guayama soils are mapped only
GuE2-Guayabota silty clay loam, 20 to 40 percent in an undifferentiated group with Descalabrado soils.
slopes, eroded. This soil occupies mountains in the Representative profile of Guayama clay loam, 20 to
upland rain forest. Included with it in mapping were 40 percent slopes, in an area of Descalabrado and
small areas of Ciales, Yunque, Picacho, Los Guineos, Guayama soils, 20 to 60 percent slopes, eroded, 17
and Utuado soils. meters north of kilometer marker 1.5 on Highway No.
Steep slopes, poor drainage, shallowness, and the haz- 303:
ard of erosion are severe limitations for farming. Con-
servation practices are needed to slow surface runoff. A1-0 to 5 inches, dark reddish-brown (5YR 3/4) clay
loam; weak, fine, granular structure; soft, friable,
This soil is not suited to cultivated crops. It is better slightly sticky and plastic; many fine roots; many,
suited to pasture and woodland than to most other uses. fine, subrounded volcanic rock fragments; neutral;
Capability unit VIIs-6; woodland suitability group clear, smooth boundary.
4d3. B2t-5 to 12 inches, reddish-brown (5YR 4/4) gravelly
clay; moderate, fine, subangular blocky structure;
GvF-Guayabota-Ciales-Picacho association, very soft, friable, sticky and plastic; common fine roots;
steep. This mapping unit is on mountains in the rain thin patchy clay films on peds, and fragments
forest. It occupies narrow, winding ridgetops where coated with clay; many fine volcanic rock frag-
slopes range from 5 to 45 percent and side slopes where ments; neutral; clear, smooth boundary.
slopes range rom to 45 percent and side slopes where C-12 to 18 inches, yellowish-red (5YR 4/6) gravelly clay
slopes range from 40 to 90 percent. loam; weak, fine, subangular blocky structure; soft,
The composition of this unit is more variable than firm, slightly sticky and plastic; few fine roots;
that of most other units in the survey area, but map- many fine volcanic rock fragments; neutral; grad-
ping has been controlled well enough to interpret for 8 ual, irregular boundary.
R--18 to 20 inches, volcanic rock; secondary calcium car-
the expected use of the soils. bonate is in rock cavities and fracture planes.
About 50 percent of this unit is Guayabota soils, and
20 percent is Ciales soils. Picacho soils make up 15 per The solum is 6 to 15 inches thick. The A horizon has hue
20 percent is Ciales soils. Picaco soils make up 15 per- of 5YR or 7.5YR and value of 3 or 4. It is dominantly clay
cent, and Rock land makes up 10 percent. Included in loam or gravelly clay loam. The B2t horizon has hue of
this mapping unit were small areas of better drained, 5YR or 2.5YR, value of 4 to 6, and chroma of 4 or higher.
clayey soils and a few areas of soils that are similar to It is clay or gravelly clay and has weak or moderate, fine,
the Guayabota soils but are deeper to hard rock. subangular blocky structure. Clay films vary from thin
patchy to thin discontinuous in the B2t horizon. The C
The soils in this unit occur in a uniform pattern. The horizon has a hue of 5YR or 7.5YR, value of 4 to 6, and
steeper Picacho soils and the less sloping Ciales soils chroma of 4 to 8. It ranges from clay loam to gravelly clay
are on the ridgetops and the Guayabota soils and Rock loam. Reaction in all horizons ranges from slightly acid to
mildly alkaline. Depth to semiconsolidated volcanic rock is
land are on the side slopes. less than 20 inches.
All of this mapping unit is in hardwood rain forest. The Guayama soils are on the same landscape as the
Because of the very steep slopes, its use is limited to Guayama variant soils and the Descalabrado, Amelia, and
forest, recreation, habitat for wildlife, and water catch- Jacana soils. The Guayama soils are shallower to seicon-
ment. The soils in this unit are wet because of high solidated volcanic rock than the Guayama variant soils, and
n e soils m i itd re wet becae hh they are not so red in the B2t horizon as those soils. Unlike
rainfall, slow permeability, and a perched water table, the Descalabrado soils, Guayama soils have a reddish B2t
Road stabilization is difficult since the soils are wet and horizon. The Guayama soils are shallower than the Amelia







22 SOIL SURVEY

soils. They are shallower to volcanic rock than the Jacana needed to reduce soil loss. This soil is suited to sugar-
soils, and they lack pressure faces, cane, pasture, and woodland. Capability units IVc-2
nonirrigated and IIIe-4 irrigated; woodland suitabil-
Guayama Variant ity group 3d5.
The Guayama variant consists of moderately deep Hu c
soils that are well drained and moderately permeable. umacao Series
These soils formed in moderately fine textured and The Humacao series consists of deep soils that are
fine textured residuum of volcanic rocks. They are on well drained and moderately permeable. These soils
lower side slopes and foot slopes. Slopes are 2 to 12 formed in medium-textured and moderately fine tex-
percent. The average annual precipitation is 35 inches, tured sediment derived from granitic rocks. They oc-
and the average annual temperature is 790 F. cupy terraces above river flood plains. Slopes are 2 to 5
In a representative profile, the surface layer is dark percent. The climate is humid tropical. The average
yellowish-brown, strongly acid clay loam about 8 inches annual rainfall is 85 to 90 inches, and the annual
thick. Below that layer is red clay that extends to a temperature is 780 F.
depth of 26 inches. It is friable in the upper 8 inches In a representative profile, the surface layer is dark-
and firm in the lower 10 inches. The underlying material brown, strongly acid loam about 14 inches thick. The
is semiconsolidated volcanic rock. next layer, to a depth of 18 inches, is dark-brown,
These soils have a moderate available water capacity, friable sandy clay loam. Below that layer is yellowish-
medium fertility, and moderate shrink-swell potential, brown, firm clay loam 13 inches thick. The underlying
Runoff is medium. The soils are somewhat difficult to material is brown, friable clay loam that extends to a
work, and they have been in pasture for many years, depth of 55 inches.
Representative profile of Guayama clay loam, mod- These soils have a moderate available water capacity.
erately deep variant, 2 to 12 percent slopes, eroded, Surface runoff is slow. The soils are easily worked, and
14.4 kilometers north of kilometer marker 132.8 on they have been in food crops and native pasture.
Highway No..3: Representative profile of Humacao loam, 2 to 5 per-
Ap-0 to 8 inches, dark yellowish-brown (10YR 3/4) clay cent slopes, 0.2 kilometer south of kilometer marker
loam; weak, fine, granular structure; friable, non- 1.2 on Highway No. 908 and 3 meters west of farm
sticky and slightly plastic; many fine roots; com- road:
mon, fine, subrounded rock fragments; strongly
acid; clear, smooth boundary. Ap-0 to 14 inches, dark-brown (7.5YR 3/2) loam; few,
B21t-8 to 16 inches, red (2.5YR 4/6) clay; weak, fine, medium, distinct, dark-brown (10YR 4/3) mottles;
subangular blocky structure; friable, slightly sticky weak, fine and medium, granular structure; fri-
and slightly plastic; common fine roots; thin patchy able, nonsticky and slightly plastic; many fine
clay films on ped surfaces and root channels; few, roots; few, fine, subrounded rock fragments; many
fine, subangular rock fragments; medium acid; fine quartz crystals; few, fine, dark minerals;
clear, wavy boundary. strongly acid; clear, smooth boundary.
B22t-16 to 26 inches, red (2.5YR 5/6) clay; weak, medium, B2-14 to 18 inches, dark-brown (10YR 4/3) sandy clay
subangular blocky structure; firm, slightly sticky loam with tongues of dark brown (7.5YR 3/2);
and slightly plastic; few fine roots; thin discontin- weak, fine, subangular blocky structure; friable,
uous clay films on ped surfaces; common, fine, black nonsticky and slightly plastic; few fine roots;
concretions; many, fine, angular rock fragments; many, fine, subrounded rock fragments; common
slightly acid; clear, smooth boundary. fine quartz crystals; common, fine, dark minerals;
R-26 to 30 inches, semiconsolidated volcanic rock; can be strongly acid; clear, smooth boundary.
dug with difficulty with a spade when moist. C1-18 to 31 inches, yellowish-brown (10YR 5/4) clay loam;
Thickness of the solum and depth to semiconsolidated vol- common, medium, faint, dark yellowish-brown
canic rock range from 20 to 34 inches. Reaction is strongly (10YR 4/4) mottles; massive; firm, slightly sticky
acid in the A horizon, and the acidity decreases with in- and slightly plastic; few fine roots; common fine
creasing depth. The A horizon has hue of 10YR, 7.5YR, or quartz crystals; many, fine, subrounded, partially
5YR, value of 2 or 3, and chroma of 3 or 4. The B2t hori- weathered rock fragments; few, fine, dark concre-
zon has hue of 2.5YR or 5YR, value of 4 to 6, and chroma tions; strongly acid; clear, smooth boundary.
of 6 to 8. Angular and subangular rock fragments range C2-31 to 55 inches, yellowish-brown (10YR 5/6) clay
from few to many and clay films range from thin patchy to loam; many, medium, prominent, dark-brown
thin discontinuous in the B2t horizon. (10YR 3/3) mottles and common, medium, distinct,
The Guayama variant soils are on the same landscape as yellowish-red (5YR 5/8) mottles; massive; friable,
the Guayama, Descalabrado, and Amelia soils. The Guayama slightly sticky and slightly plastic; few fine quartz
variant soils are deeper to volcanic rock and have a redder crystals; many, fine, partially weathered rock frag-
B horizon than the Guayama and Descalabrado soils. They ments; common, medium, dark concretions; medium
have a redder B horizon than the Amelia soils, and they acid.
lack gravelly layers. The solum is 12 to 28 inches thick. The A horizon has
GyC2-Guayama clay loam, moderately deep variant, hue of 10YR or 7.5YR, value of 3 or 4, and chroma of 2 or
3. The B horizon has hue of 10YR or 7.5YR, value of 3 or 4,
2 to 12 percent slopes, eroded. This soil is on the lower and chroma of 2 or 3. It has weak, fine or medium, sub-
side slopes and foot slopes in the semiarid part of the angular blocky structure. The C horizon has chroma of 4
survey area. Erosion has removed some of the dark to 6.
yellowish-brown, clay loam surface layer, and in some The Humacao soils occupy the same landscape as the
yellowish-brown, clay loam surface layer, and in some Candelero and Vivi soils. They are better drained than the
places plowing has mixed this layer with the subsoil. In- Candelero and Vv soils They are better drained than theumacao
cluded with this soil in mapping were some small areas soils are finer textured in the C horizon than the Vivi soils,
of Amelia, Guayama, and Descalabrado soils, and unlike those soils, they are moderately permeable.
This soil has severe limitations for crops because HmB-Humacao loam, 2 to 5 percent slopes. This
rainfall is low. Slope and medium surface runoff are soil is on terraces above the flood plains. Included with
moderate limitations, and conservation practices are it in mapping were small areas of Candelero soils.







22 SOIL SURVEY

soils. They are shallower to volcanic rock than the Jacana needed to reduce soil loss. This soil is suited to sugar-
soils, and they lack pressure faces, cane, pasture, and woodland. Capability units IVc-2
nonirrigated and IIIe-4 irrigated; woodland suitabil-
Guayama Variant ity group 3d5.
The Guayama variant consists of moderately deep Hu c
soils that are well drained and moderately permeable. umacao Series
These soils formed in moderately fine textured and The Humacao series consists of deep soils that are
fine textured residuum of volcanic rocks. They are on well drained and moderately permeable. These soils
lower side slopes and foot slopes. Slopes are 2 to 12 formed in medium-textured and moderately fine tex-
percent. The average annual precipitation is 35 inches, tured sediment derived from granitic rocks. They oc-
and the average annual temperature is 790 F. cupy terraces above river flood plains. Slopes are 2 to 5
In a representative profile, the surface layer is dark percent. The climate is humid tropical. The average
yellowish-brown, strongly acid clay loam about 8 inches annual rainfall is 85 to 90 inches, and the annual
thick. Below that layer is red clay that extends to a temperature is 780 F.
depth of 26 inches. It is friable in the upper 8 inches In a representative profile, the surface layer is dark-
and firm in the lower 10 inches. The underlying material brown, strongly acid loam about 14 inches thick. The
is semiconsolidated volcanic rock. next layer, to a depth of 18 inches, is dark-brown,
These soils have a moderate available water capacity, friable sandy clay loam. Below that layer is yellowish-
medium fertility, and moderate shrink-swell potential, brown, firm clay loam 13 inches thick. The underlying
Runoff is medium. The soils are somewhat difficult to material is brown, friable clay loam that extends to a
work, and they have been in pasture for many years, depth of 55 inches.
Representative profile of Guayama clay loam, mod- These soils have a moderate available water capacity.
erately deep variant, 2 to 12 percent slopes, eroded, Surface runoff is slow. The soils are easily worked, and
14.4 kilometers north of kilometer marker 132.8 on they have been in food crops and native pasture.
Highway No..3: Representative profile of Humacao loam, 2 to 5 per-
Ap-0 to 8 inches, dark yellowish-brown (10YR 3/4) clay cent slopes, 0.2 kilometer south of kilometer marker
loam; weak, fine, granular structure; friable, non- 1.2 on Highway No. 908 and 3 meters west of farm
sticky and slightly plastic; many fine roots; com- road:
mon, fine, subrounded rock fragments; strongly
acid; clear, smooth boundary. Ap-0 to 14 inches, dark-brown (7.5YR 3/2) loam; few,
B21t-8 to 16 inches, red (2.5YR 4/6) clay; weak, fine, medium, distinct, dark-brown (10YR 4/3) mottles;
subangular blocky structure; friable, slightly sticky weak, fine and medium, granular structure; fri-
and slightly plastic; common fine roots; thin patchy able, nonsticky and slightly plastic; many fine
clay films on ped surfaces and root channels; few, roots; few, fine, subrounded rock fragments; many
fine, subangular rock fragments; medium acid; fine quartz crystals; few, fine, dark minerals;
clear, wavy boundary. strongly acid; clear, smooth boundary.
B22t-16 to 26 inches, red (2.5YR 5/6) clay; weak, medium, B2-14 to 18 inches, dark-brown (10YR 4/3) sandy clay
subangular blocky structure; firm, slightly sticky loam with tongues of dark brown (7.5YR 3/2);
and slightly plastic; few fine roots; thin discontin- weak, fine, subangular blocky structure; friable,
uous clay films on ped surfaces; common, fine, black nonsticky and slightly plastic; few fine roots;
concretions; many, fine, angular rock fragments; many, fine, subrounded rock fragments; common
slightly acid; clear, smooth boundary. fine quartz crystals; common, fine, dark minerals;
R-26 to 30 inches, semiconsolidated volcanic rock; can be strongly acid; clear, smooth boundary.
dug with difficulty with a spade when moist. C1-18 to 31 inches, yellowish-brown (10YR 5/4) clay loam;
Thickness of the solum and depth to semiconsolidated vol- common, medium, faint, dark yellowish-brown
canic rock range from 20 to 34 inches. Reaction is strongly (10YR 4/4) mottles; massive; firm, slightly sticky
acid in the A horizon, and the acidity decreases with in- and slightly plastic; few fine roots; common fine
creasing depth. The A horizon has hue of 10YR, 7.5YR, or quartz crystals; many, fine, subrounded, partially
5YR, value of 2 or 3, and chroma of 3 or 4. The B2t hori- weathered rock fragments; few, fine, dark concre-
zon has hue of 2.5YR or 5YR, value of 4 to 6, and chroma tions; strongly acid; clear, smooth boundary.
of 6 to 8. Angular and subangular rock fragments range C2-31 to 55 inches, yellowish-brown (10YR 5/6) clay
from few to many and clay films range from thin patchy to loam; many, medium, prominent, dark-brown
thin discontinuous in the B2t horizon. (10YR 3/3) mottles and common, medium, distinct,
The Guayama variant soils are on the same landscape as yellowish-red (5YR 5/8) mottles; massive; friable,
the Guayama, Descalabrado, and Amelia soils. The Guayama slightly sticky and slightly plastic; few fine quartz
variant soils are deeper to volcanic rock and have a redder crystals; many, fine, partially weathered rock frag-
B horizon than the Guayama and Descalabrado soils. They ments; common, medium, dark concretions; medium
have a redder B horizon than the Amelia soils, and they acid.
lack gravelly layers. The solum is 12 to 28 inches thick. The A horizon has
GyC2-Guayama clay loam, moderately deep variant, hue of 10YR or 7.5YR, value of 3 or 4, and chroma of 2 or
3. The B horizon has hue of 10YR or 7.5YR, value of 3 or 4,
2 to 12 percent slopes, eroded. This soil is on the lower and chroma of 2 or 3. It has weak, fine or medium, sub-
side slopes and foot slopes in the semiarid part of the angular blocky structure. The C horizon has chroma of 4
survey area. Erosion has removed some of the dark to 6.
yellowish-brown, clay loam surface layer, and in some The Humacao soils occupy the same landscape as the
yellowish-brown, clay loam surface layer, and in some Candelero and Vivi soils. They are better drained than the
places plowing has mixed this layer with the subsoil. In- Candelero and Vv soils They are better drained than theumacao
cluded with this soil in mapping were some small areas soils are finer textured in the C horizon than the Vivi soils,
of Amelia, Guayama, and Descalabrado soils, and unlike those soils, they are moderately permeable.
This soil has severe limitations for crops because HmB-Humacao loam, 2 to 5 percent slopes. This
rainfall is low. Slope and medium surface runoff are soil is on terraces above the flood plains. Included with
moderate limitations, and conservation practices are it in mapping were small areas of Candelero soils.







HUMACAO AREA OF EASTERN PUERTO RICO 23

Proper management is needed to prevent soil loss. Caguabo and Mucara soils. The Humatas soils are deeper
This soil is suited to cultivated crops, sugarcane, and and redder than the Caguabo and Mucara soils, and they
pasture. Capability unit IIe-2. have a B2t horizon.
HtE2-Humatas clay, 20 to 40 percent slopes,
eroded. This soil is on side slopes and ridgetops in the
Humatas Series humid volcanic uplands. It has the profile described as
representative of the series. In some places plowing has
The Humatas series consists of deep soils that are mixed the surface layer with the subsoil. Included with
well drained and moderately permeable. These soils this soil in mapping were small areas of Mucara and
formed in fine-textured residuum derived from basic Caguabo soils.
volcanic rocks. They are on mountain side slopes and Steep slopes, medium runoff, and the hazard of ero-
narrow ridgetops. Slopes are 20 to 60 percent. The cli- sion limit this soil to occasional clean cultivation. Con-
mate is humid tropical. The average annual precipita- servation practices and proper management are
tion is 86 inches, and the average annual temperature required to slow erosion. This soil has been used for
is 760 F. coffee trees and pasture. If it is properly limed and
In a representative profile, the surface layer is brown managed, it is suited to occasional cultivated crops and
to dark-brown, very strongly acid clay about 5 inches to coffee trees, pasture, and woodland. Capability unit
thick. Below that layer is yellowish-red and red clay and IVe-5; woodland suitability group 2c5.
silty clay that extends to a depth of 38 inches. The HtF2-Humatas clay, 40 to 60 percent slopes,
underlying material is yellowish-red saprolite that is eroded. This soil occupies strongly, dissected side slopes
mottled with dark grayish brown and red. It extends to and narrow ridgetops in the humid volcanic uplands. It
a depth of 60 inches, has a thinner surface layer than the soil described'as
These soils have a high available water capacity, representative of the series. Included with this soil in
medium natural fertility, and moderate shrink-swell mapping were small areas of Mucara and Caguabo soils.
potential. Surface runoff is medium to rapid. The soils Steep slopes, rapid runoff, and the hazard of erosion
are somewhat difficult to work. They have been in food are severe limitations for cultivated crops. The use of
crops, coffee trees, and pasture for many years. this soil is limited to pasture, woodland, and wildlife
Representative profile of Humatas clay, 20 to 40 per- food and cover. Conservation practices are needed to
cent slopes, eroded, 5.2 kilometers southwest, along slow runoff if the soil is used for food crops and coffee
paved road, from kilometer marker 2.7 on Highway No. trees. Capability unit VIe-2; woodland suitability group
957 and 45 meters south, Palma Sola Ward, Canovanas: 3r5.
A1-0 to 5 inches, brown to dark-brown (7.5YR 4/4) clay; HuF-Humatas-Stony land complex, 40 to 60 per-
weak, fine, subangular blocky structure parting to cent slopes. This mapping unit is on mountain side
granular; friable, nonsticky and slightly plastic; slopes and ridgetops in the humid volcanic uplands.
many fine roots; very strongly acid; gradual, Humatas clay and Stony land each make up 50 percent
smooth boundary. of this mapping unit. They occur in such intricate
B21-5 to 10 inches, yellowish-red (5YR 4/6) clay; common, of this mapping unit They occur in such intricate
medium, faint, brown to dark-brown (7.5YR 4/4) patterns that it is not feasible to map them separately.
mottles; weak to moderate, medium, subangular The areas of Stony land are covered with stones and
blocky structure; firm, nonsticky and slightly boulders that range from 1 to 15 feet or more in
plastic; common fine roots; few fine pebbles, 1 to 2 diameter.
millimeters; patchy clay films on peds; very
strongly acid; clear, smooth boundary. Very steep slopes, the hazard of erosion, rapid run-
B22t-10 to 16 inches, red (2.5YR 4/6) clay; moderate, off, and boulders are severe limitations for cultivated
medium, subangular blocky structure; friable, non- crops. The soils of this complex are suitable for pasture,
sticky and plastic; few roots; thin continuous clay woodland, and wildlife food and cover. Capability unit
films on peds; very strongly acid; clear, smooth woodland, and wildlife food and cover. Capability unit
boundary. VIIs-2; woodland suitability group 3r5.
B23t-16 to 27 inches, red (2.5YR 4/6) clay; weak, fine,
subangular blocky structure; friable, nonsticky
and plastic; few roots; common clay films; very Ingenio Series
strongly acid; clear, smooth boundary.
B3-27 to 38 inches, red (2.5YR 4/6) silty clay; common, The Ingenio series consists of deep soils that are well
fine, distinct, red (2.5YR 4/8), very pale brown drained and moderately permeable. These soils formed
(10YR 7/4), and strong-brown (7.5YR 5/6) in medium-textured and fine-textured residuum de-
mottles; weak, fine, subangular plocky structure; rived from highly weathered granitic rocks. They are
friable, nonsticky and slightly plastic; about 10
to 15 percent saprolite; very strongly acid; grad- on mountain side slopes and narrow ridgetops. Slopes
ual, smooth boundary. are 20 to 40 percent. The climate is humid tropical. The
C-38 to 60 inches, yellowish-red (5YR 4/6) silty clay average annual precipitation is 75 to 85 inches, and the
loam; few, fine, distinct, dark grayish-brown average annual temperature is 78 F.
(10YR 4/2) and red (2.5YR 5/8) mottles; mas- a eeatue i F
sive; friable, nonstick and slightly plastic; about In a representative profile, the surface layer is
80 percent saprolite; very strongly acid. yellowish-brown, very strongly acid silty clay loam
about 7 inches thick. The next layer is red, friable clay
The solum is 23 to 50 inches thick. The A horizon has and silty clay 33 inches thick. Below that, to a depth of
hue of 7.5YR or 5YR, value of 3 or 4, and chroma of 4 and silty clay 33 inches thick. Below that, to a depth of
to 6. The B horizon ranges from 20 to 42 inches in thick- 51 inches, is silty clay loam saprolite that has varying
ness, and the B2t horizon from 14 to 30 inches. The B colors. Below this layer the saprolite is silt loam to a
horizon has hue of 5YR or 2.5YR, value of 4 or 5, and depth of 76 inches.
chroma of 6 or more. The C horizon ranges from silty clay These soils have a moderate available water capacity
loam to clay loam.
The Humatas soils are on the same landscape as the and medium fertility. Runoff is medium to rapid. The







HUMACAO AREA OF EASTERN PUERTO RICO 23

Proper management is needed to prevent soil loss. Caguabo and Mucara soils. The Humatas soils are deeper
This soil is suited to cultivated crops, sugarcane, and and redder than the Caguabo and Mucara soils, and they
pasture. Capability unit IIe-2. have a B2t horizon.
HtE2-Humatas clay, 20 to 40 percent slopes,
eroded. This soil is on side slopes and ridgetops in the
Humatas Series humid volcanic uplands. It has the profile described as
representative of the series. In some places plowing has
The Humatas series consists of deep soils that are mixed the surface layer with the subsoil. Included with
well drained and moderately permeable. These soils this soil in mapping were small areas of Mucara and
formed in fine-textured residuum derived from basic Caguabo soils.
volcanic rocks. They are on mountain side slopes and Steep slopes, medium runoff, and the hazard of ero-
narrow ridgetops. Slopes are 20 to 60 percent. The cli- sion limit this soil to occasional clean cultivation. Con-
mate is humid tropical. The average annual precipita- servation practices and proper management are
tion is 86 inches, and the average annual temperature required to slow erosion. This soil has been used for
is 760 F. coffee trees and pasture. If it is properly limed and
In a representative profile, the surface layer is brown managed, it is suited to occasional cultivated crops and
to dark-brown, very strongly acid clay about 5 inches to coffee trees, pasture, and woodland. Capability unit
thick. Below that layer is yellowish-red and red clay and IVe-5; woodland suitability group 2c5.
silty clay that extends to a depth of 38 inches. The HtF2-Humatas clay, 40 to 60 percent slopes,
underlying material is yellowish-red saprolite that is eroded. This soil occupies strongly, dissected side slopes
mottled with dark grayish brown and red. It extends to and narrow ridgetops in the humid volcanic uplands. It
a depth of 60 inches, has a thinner surface layer than the soil described'as
These soils have a high available water capacity, representative of the series. Included with this soil in
medium natural fertility, and moderate shrink-swell mapping were small areas of Mucara and Caguabo soils.
potential. Surface runoff is medium to rapid. The soils Steep slopes, rapid runoff, and the hazard of erosion
are somewhat difficult to work. They have been in food are severe limitations for cultivated crops. The use of
crops, coffee trees, and pasture for many years. this soil is limited to pasture, woodland, and wildlife
Representative profile of Humatas clay, 20 to 40 per- food and cover. Conservation practices are needed to
cent slopes, eroded, 5.2 kilometers southwest, along slow runoff if the soil is used for food crops and coffee
paved road, from kilometer marker 2.7 on Highway No. trees. Capability unit VIe-2; woodland suitability group
957 and 45 meters south, Palma Sola Ward, Canovanas: 3r5.
A1-0 to 5 inches, brown to dark-brown (7.5YR 4/4) clay; HuF-Humatas-Stony land complex, 40 to 60 per-
weak, fine, subangular blocky structure parting to cent slopes. This mapping unit is on mountain side
granular; friable, nonsticky and slightly plastic; slopes and ridgetops in the humid volcanic uplands.
many fine roots; very strongly acid; gradual, Humatas clay and Stony land each make up 50 percent
smooth boundary. of this mapping unit. They occur in such intricate
B21-5 to 10 inches, yellowish-red (5YR 4/6) clay; common, of this mapping unit They occur in such intricate
medium, faint, brown to dark-brown (7.5YR 4/4) patterns that it is not feasible to map them separately.
mottles; weak to moderate, medium, subangular The areas of Stony land are covered with stones and
blocky structure; firm, nonsticky and slightly boulders that range from 1 to 15 feet or more in
plastic; common fine roots; few fine pebbles, 1 to 2 diameter.
millimeters; patchy clay films on peds; very
strongly acid; clear, smooth boundary. Very steep slopes, the hazard of erosion, rapid run-
B22t-10 to 16 inches, red (2.5YR 4/6) clay; moderate, off, and boulders are severe limitations for cultivated
medium, subangular blocky structure; friable, non- crops. The soils of this complex are suitable for pasture,
sticky and plastic; few roots; thin continuous clay woodland, and wildlife food and cover. Capability unit
films on peds; very strongly acid; clear, smooth woodland, and wildlife food and cover. Capability unit
boundary. VIIs-2; woodland suitability group 3r5.
B23t-16 to 27 inches, red (2.5YR 4/6) clay; weak, fine,
subangular blocky structure; friable, nonsticky
and plastic; few roots; common clay films; very Ingenio Series
strongly acid; clear, smooth boundary.
B3-27 to 38 inches, red (2.5YR 4/6) silty clay; common, The Ingenio series consists of deep soils that are well
fine, distinct, red (2.5YR 4/8), very pale brown drained and moderately permeable. These soils formed
(10YR 7/4), and strong-brown (7.5YR 5/6) in medium-textured and fine-textured residuum de-
mottles; weak, fine, subangular plocky structure; rived from highly weathered granitic rocks. They are
friable, nonsticky and slightly plastic; about 10
to 15 percent saprolite; very strongly acid; grad- on mountain side slopes and narrow ridgetops. Slopes
ual, smooth boundary. are 20 to 40 percent. The climate is humid tropical. The
C-38 to 60 inches, yellowish-red (5YR 4/6) silty clay average annual precipitation is 75 to 85 inches, and the
loam; few, fine, distinct, dark grayish-brown average annual temperature is 78 F.
(10YR 4/2) and red (2.5YR 5/8) mottles; mas- a eeatue i F
sive; friable, nonstick and slightly plastic; about In a representative profile, the surface layer is
80 percent saprolite; very strongly acid. yellowish-brown, very strongly acid silty clay loam
about 7 inches thick. The next layer is red, friable clay
The solum is 23 to 50 inches thick. The A horizon has and silty clay 33 inches thick. Below that, to a depth of
hue of 7.5YR or 5YR, value of 3 or 4, and chroma of 4 and silty clay 33 inches thick. Below that, to a depth of
to 6. The B horizon ranges from 20 to 42 inches in thick- 51 inches, is silty clay loam saprolite that has varying
ness, and the B2t horizon from 14 to 30 inches. The B colors. Below this layer the saprolite is silt loam to a
horizon has hue of 5YR or 2.5YR, value of 4 or 5, and depth of 76 inches.
chroma of 6 or more. The C horizon ranges from silty clay These soils have a moderate available water capacity
loam to clay loam.
The Humatas soils are on the same landscape as the and medium fertility. Runoff is medium to rapid. The







24 SOIL SURVEY

soils have been used for pasture. Most of the acreage is crops, the steep slopes, rapid runoff, and the hazard of
in native pasture, shrubs, and minor crops; small areas erosion are severe limitations. The soil is suited to pas-
are in food crops. ture and woodland. Capability unit IVe-5; woodland
Representative profile of Ingenio silty clay loam, 20 suitability group 205.
to 40 percent slopes, eroded, 4.9 kilometers southwest of
Humacao and 1 kilometer southwest from Surillo
School, Tejas Ward: Jacana Series
Ap-0 to 7 inches, yellowish-brown (10YR 5/4) silty clay The Jacana series consists of moderately deep soils
loam; many, medium, distinct, strong-brown (7.5YR that are well drained and moderately slowly permeable.
5/6) mottles; weak, fine, subangular blocky These soils formed in fine-textured sediment and
structure; friable, slightly sticky and slightly
plastic; many fine roots; common fine quartz residuum derived from basic volcanic rocks. They oc-
grains; few, fine, black grains; very strongly cupy foot slopes and low rolling hills. Slopes are 2 to 12
acid; clear, smooth boundary. percent. The climate is semiarid. The average annual
B21t-7 to 15 inches, red (2.5YR 5/6) silty clay; moderate, precipitation is 35 inches, and the average annual tem-
medium and coarse, prismatic structure; friable,
slightly sticky and plastic; thin, continuous, yel- perature is 79' F.
lowish-red (5YR 4/8) coatings on vertical ped In a representative profile, the surface layer is very
surfaces and thin discontinuous coatings on hori- dark grayish-brown and dark-brown, medium acid clay
zontal ped surfaces; common fine roots; few fine about 5 inches thick. The next layer is dark-brown and
pores; common fine quartz grains; few, fine, black
grains; few krotovinas about 5 millimeters in dark yellowish-brown clay that extends to a depth of 21
diameter; very strongly acid; clear, smooth inches. Partly weathered volcanic material is between
boundary. depths of 21 and 26 inches; it is underlain by semi-
B22t-15 to 31 inches, red (2.5YR 4/6) clay; moderate, consolidated volcanic rock.
medium and coarse, subangular blocky structure; These soils have high natural fertility and high
friable, slightly sticky and slightly plastic; thin, Thes soils have high natural fertility and high
continuous, reddish-brown (2.5YR 5/4) coatings shrink-swell potential. Surface runoff is medium. The
on vertical ped surfaces and thin discontinuous soils are difficult to work. They have been in pasture for
coatings on horizontal ped surfaces; common fine many years, and most of the acreage is still in pasture.
roots; few fine pores; common fine quartz grains; l a sarcan
few, fine, black grains; few krotovinas 2 to 5 mall areas are in sugarcane.
millimeters in diameter; very strongly acid; grad- Representative profile of Jacana clay, 2 to 5 percent
ual, smooth boundary. slopes, following farm roads 0.8 kilometer west of kilo-
B3-31 to 40 inches, red (2.5YR 4/6) silty clay; weak, meter marker 92.1 on Highway No. 1, 3.2 kilometers
medium and coarse, subangular blocky structure;
very friable, nonsticky and slightly plastic; thin, north to southwestern corner of irrigation reservoir,
discontinuous, reddish-brown (2.5YR 5/4) coat- then 0.2 kilometer west and 0.3 kilometer north to an
ings on ped surfaces; common fine roots; common irrigation channel and 9 meters north of the channel:
fine pores; common fine quartz grains; few, fine,
black grains; few krotovinas 1 inch in diameter Ap-0 to 5 inches, very dark grayish-brown and dark-
that have thick clay coatings; very strongly acid; brown (10YR 3/2, 3/3) clay; weak, fine, sub-
clear, smooth boundary, angular blocky structure parting to granular;
C1-40 to 51 inches, variegated, dusky red, yellow, and friable, slightly sticky and slightly plastic; com-
white silty clay loam, dark yellowish brown mon fine roots; common, fine, subangular pebbles;
(10YR 4/4) crushed; massive; very friable, non- few, fine, dark minerals; medium acid; gradual,
sticky and slightly plastic; common fine roots; smooth boundary.
few fine pores; common fine quartz grains; 50 1--5 to 13 inches, dark-brown (10YR 3/3) clay; weak,
percent saprolite; very strongly acid; gradual, medium and fine, subangular blocky structure;
smooth boundary, friable, slightly sticky and slightly plastic; few
C2-51 to 76 inches, variegated, dusky-red, yellow, yellowish- very dark grayish-brown (10YR 3/2) stains on
brown, and white silt loam saprolite; massive; ped surfaces; common fine roots; common, fine,
very friable, nonsticky and slightly plastic; few subrounded pebbles; few, fine, dark minerals;
dead roots with clay and organic coatings in root neutral; abrupt, smooth boundary.
channels; very strongly acid. B2-13 to 21 inches, dark yellowish-brown (10YR 4/4)
clay; weak, medium, subangular blocky structure;
The solum is 27 to 48 inches thick. The A horizon has firm, slightly sticky and slightly plastic; few very
hue of 10YR or 5YR, value of 4 or 5, and chroma of 3 or dark grayish-brown (10YR 3/2) stains along root
4. The B2t horizon has hue of 5YR or 2.5YR, value of 4 or channels and ped surfaces; few patchy clay films;
5, and Chroma of 4 to 6. It is silty clay or clay. The C common pressure faces; common subrounded peb-
horizon has variegated colors of dusky red, yellow, brown, bles; few quartz grains; few, fine, dark minerals;
yellowish brown, and white. neutral; abrupt, smooth boundary.
The Ingenio soils are on the same landscape as the C-21 to 26 inches, partly weathered volcanic material.
Lirios, Jagueyes, and Limones soils. The Ingenio soils have R-26 inches +, semiconsolidated volcanic rock.
a thicker B2t horizon than the Lirios soils. They are
redder and finer textured than the Jagueyes soils. The The solum is 16 to 28 inches thick. The Ap horizon has
Ingenio soils are coarser textured throughout than the hue of 10YR or 7.5YR and value of 2 or 3. The B horizon
Limones soils, has hue of 10YR or 7.5YR and value and chroma of 3 or
4. Pressure faces and slickensides range from few to many
InE2-Ingenio silty clay loam, 20 to 40 percent in the B2 horizon. Reaction ranges from medium acid to
slopes, eroded. This soil is on mountain side slopes and neutral. Depth to the partly weathered rock ranges from
ridgetops in the humid granitic uplands. Erosion has 20 to 36 inches.
The Jacana soils are on the same landscape as the
removed part of the original surface layer, and in most Descalabrado, Coamo, and Amelia soils. The Jacana soils
places the remaining part of that layer has been mixed are thicker and finer textured than the Descalabrado soils.
with the subsoil. Included with this soil in mapping were They are shallower than the Coamo soils and lack the
small areas of Jagueyes and Limones soils. stratified C horizon of those soils. The Jacana soils are
Although this soil is used occasionally for cultivated finer textured and shallower than the Amelia soils, and
Although this soil is used occasionally for cultivated they lack gravelly layers.







HUMACAO AREA OF EASTERN PUERTO RICO 25

JaB-Jacana clay, 2 to 5 percent slopes. This soil is grains; very strongly acid; clear, smooth bound-
on foot slopes in the semiarid area. It has the profile B- a14 t 8 ry. oi ron / n
ribd s r aiv o t J s Bl-14 to 18 inches, yellowish-brown (10YR 5/8) sandy
described as representative of the Jacana series. In- clay loam; weak, medium, subangular blocky
cluded with this soil in mapping were small areas of structure; firm, slightly sticky and slightly plastic;
Coamo and Amelia soils, strong-brown (7.5YR 5/6) and yellowish-brown
Low rainfall is a severe limitation that restricts the (10YR 5/4) coatings on ped surfaces; common
fine roots; thin patchy clay films; few, medium,
use of this soil for farming. During years when rainfall black roots; tn catchy ommon,lay films; black grains;
is above average the soil is used for cultivated crops. If many fine quartz grains; very strongly acid; clear,
it is irrigated, the soil is suited to sugarcane, cut smooth boundary.
grasses, and pasture. Capability units IVc-2 nonirri- B21t-18 to 26 inches, yellow (10YR 7/6) clay loam; many,
fine, distinct, dark-red (2.5YR 3/6) mottles and
gated and IIIs-3 irrigated; woodland suitability group many, medium, distinct, red (2.5YR 4/8) mottles;
3d5. moderate, medium, subangular blocky structure;
JaC2-Jacana clay, 5 to 12 percent slopes, eroded, firm, slightly sticky and slightly plastic; common
This soil occupies foot slopes and low rolling hills in the fine roots; thin continuous clay films; few, medium,
black concretions; few, fine, black grains; many
semiarid area. Its profile is similar to the one described fine quartz grains; many weathered feldspar
as representative of the Jacana series, but some of the grains; very strongly acid; clear, smooth bound-
surface layer of dark grayish-brown clay has been re- ary.
moved by erosion, and in most places this layer has B22t-26 to 37 inches, yellow (10YR 7/6) and red (2.5YR
mixd wh te s l by S l a s of 4/8) clay loam; few, fine, faint, brownish-yellow
been mixed with the subsoil by plowing. Small areas of (10YR 6/8) mottles; weak, coarse, subangular
Descalabrado soils were included with this soil in map- blocky structure; firm, nonsticky and slightly
ping. plastic; few fine roots; thin discontinuous clay
This soil has severe limitations for farming because films; many fine quartz grains; few, fine, black
grains; many weathered feldspar grains; very
of moderate slopes, the hazard of erosion, and poor strongly acid; gradual, smooth boundary.
workability. Also, rainfall is low in the area. Good B3-37 to 52 inches, red (2.5YR 4/8) sandy clay loam;
management and conservation practices are required weak, medium, subangular blocky structure; fri-
to slow surface runoff. This soil is suited to pasture, and able, nonstick and nonplastic; brownish-yellow
for many years. Capability unit (10YR 6/8) coatings; few fine roots; thin patchy
it has been in pasture for many years. Capability unit clay films; many fine quartz grains; few, fine,
IVe-4; woodland suitability group 3d5. black grains; very strongly acid; gradual, smooth
boundary.
C1-52 to 71 inches, red (2.5YR 4/8) loam; massive; fri-
able, nonsticky and slightly plastic; few, fine,
Jagueyes Series black grains; many fine quartz grains; many,
fine, weathered feldspar grains; 50 percent
The Jagueyes series consists of deep soils that are saprolite; very strongly acid; gradual, wavy
boundary.
well drained and moderately permeable. These soils C2-71 to 95 inches, red (2.5YR 5/8) loam saprolite; mas-
formed in residuum derived from highly weathered sive; friable. nonsticky and slightly plastic; very
granitic rocks. They are on side slopes and narrow strongly acid; gradual, smooth boundary.
ridgetops. Slopes are 20 to 40 percent. The climate is C3-95 to 120 inches, red (2.5YR 5/6) sandy loam sapro-
lite; massive; friable, nonsticky and slightly
humid tropical. The average annual rainfall is 75 to 85 plastic; very strongly acid.
inches, and the average annual temperature is 780 F. The solum is 39 to 66 inches thick. The A horizon has
In a representative profile, the surface layer is dark hue of 2.5Y or 10YR, value of 4 or 5, and chroma of 2 to
grayish-brown, very strongly acid loam about 8 inches 6. It is loam, sandy loam, or sandy clay loam. The B
thick. Below that layer is yellowish-brown sandy clay horizon has hue of 10YR or 2.5YR, value of 4 to 7, and
loam 6 inches thick. The next layer is yellowish-brown, chroma of 6 to 8. It is clay loam or sandy clay loam and
has weak to moderate, medium to coarse, subangular blocky
yellow, and red, firm clay loam that extends to a depth structure. The C horizon is sandy loam to loam.
of 37 inches. Below that layer is red, friable loam and The Jagueyes soils occupy the same landscape as the
sandy clay loam that extends to a depth of about 71 Lirios, Ingenio, and Limones soils. The Jagueyes soils have
inches. It is underlain by saprolite. a thicker solum than the Lirios soils, and they are coarser
SI textured than the Ingenio and Limones soils.
These soils have a moderate available water capacity,
medium natural fertility, and low shrink-swell poten- JgE2-Jagueyes loam, 20 to 40 percent slopes,
tial. Surface runoff is medium. The soils have been eroded. This soil is on narrow mountain ridgetops and
used for food crops and pasture. side slopes in the humid plutonic uplands. Erosion has
Representative profile of Jagueyes loam, 20 to 40 removed some of the dark grayish-brown loam surface
percent slopes, eroded, 7.5 kilometers southwest from layer, and in many places most of the plow layer is a
Humacao and 7.7 kilometers north from Yabucoa, 445 mixture of the surface layer and the subsoil. Included
meters west from junction of Highway No. 921 and with this soil in mapping were areas of Limones,
farm road, 210 meters south of house and 150 meters Lirios, and Ingenio soils.
northeast of mango trees, Tejas Ward, Yabucoa: This soil has severe limitations for farming because
of slope and the hazard of erosion. Steep slopes, me-
Ap-0 to 8 inches, dark grayish-brown (2.5Y 4/2) loam; dium runoff, and the hazard of erosion are severe
weak, fine, granular structure; soft, very friable, limitations for cultivated crops. Conservation practices
nonsticky and nonplastic; common fine roots; very
strongly acid clear, sooth boundary very and proper management are required to slow surface
A3-8 to 14 inches, yellowish-brown (10YR 5/6) sandy clay runoff. This soil is used occasionally for food crops. If it
loam; weak, medium, subangular blocky structure; is properly managed, it is suited to food crops, pasture,
soft, friable, slightly sticky and slightly plastic; and woodland. Capability unit IVe-11; woodland suit-
common fine roots; few, medium, black concretions; d w d. C u
common, fine, shiny grains; many fine quartz ability group 205.







26 SOIL SURVEY

Junquitos Series JuC-Junquitos gravelly clay loam, 5 to 12 percent
slopes. This soil is on foot slopes in the humid volcanic
The Junquitos series consists of moderately deep uplands. Included with it in mapping were small areas
soils that are moderately well drained and moderately of Rio Arriba, Mabi, and Via soils.
slowly permeable. These soils formed in alluvial and Slope and surface runoff are moderate limitations
colluvial sediment derived from extrusive volcanic for farming. Proper management and conservation
rocks and, to a small degree, in residuum from similar practices are needed to reduce erosion. If this soil is
rocks. They are on foot slopes. Slopes are 5 to 12 per- properly managed, it is suited to sugarcane and pas-
cent. The climate is humid tropical. The average annual ture. Capability unit IIIe-5.
rainfall is 87 inches, and the average annual tempera-
ture is 79 F.
In a representative profile, the surface layer is brown Leveled Clayey Land
to dark-brown, extremely acid gravelly clay loam about Leveled clayey land (Lc) consists of clayey soils that
7 inches thick. The next layer is yellowish-brown, mot- have different colors, plasticity, and mineralogy. These
tled, firm clay 21 inches thick. The underlying material soils have been reworked by machinery during land
is brownish-yellow, mottled clay that extends to a depth leveling for construction. The original soils have been
of 35 inches. It is underlain by volcanic rock frag- so disturbed that it is impossible to identify them.
ments. Generally, the soils in this mapping unit are deep to
These soils have a high available water capacity and consolidated parent material.
moderate shrink-swell potential. Runoff is medium. The This land type has severe limitations for farming
soils are difficult to work. They have been in pasture because the soils have been disturbed. It is suitable for
for many years, but some areas are in sugarcane. such nonfarm uses as foundations and sites for light
Representative profile of Junquitos gravelly clay industries.
loam, 5 to 12 percent slopes, 1 kilometer north, 0.2
kilometer west, and 15 meters south of kilometer
marker 81.3 on Highway No. 3, east of Humacao: Limones Series
Ap-0 to 7 inches, brown to dark-brown (10YR 4/3) The Limones series consists of deep soils that are
gravelly clay loam; massive; slightly hard, firm, moderately well drained and moderately permeable.
nonsticky and slightly plastic; many fine roots;
many, medium and coarse, angular and subrounded These soils formed in fine-textured residtium of very
rock fragments; extremely acid; clear, smooth highly weathered granitic rocks. They are on side
boundary. slopes and narrow ridgetops. Slopes are 20 to 40 per-
B1-7 to 21 inches, yellowish-brown (10YR 5/8) clay; few, cent. The climate is humid tropical. The average annual
fine, distinct, red (2.5YR 5/8) mottles; weak,
medium, subangular blocky structure; hard, firm, rainfall varies from 75 to 85 inches, and the average
slightly sticky and plastic; few fine roots; few, annual temperature is 780 F.
fine, subrounded rock fragments; few, fine, dark In a representative profile, the surface layer is dark
concretions; strongly acid; clear, smooth bound- yellowish-brown, very strongly acid silty clay about 5
ary.
B2-21 to 28 inches, yellowish-brown (10YR 5/8) clay; inches thick. Below that is dark yellowish-brown,
few, fine, distinct, red (2.5YR 5/8) and light-gray yellowish-brown, and yellowish-red clay 35 inches thick.
(10YR 7/1) mottles; weak, fine, subangular blocky The underlying material is clay loam, clay, and silty
structure; hard, firm, slightly sticky and plastic; clay loam saprolite that extends to a depth of 120
few, fine, patchy clay films; many, fine and me-
dium, dark concretions; common, fine and medium, inches.
angular and subrounded rock fragments; slightly These soils have a high available water capacity and
acid; clear, smooth boundary. moderate to rapid runoff and are susceptible to erosion.
C1-28 to 35 inches, brownish-yellow (10YR 6/8) clay; They have been in pasture for many years, and there
many, coarse, prominent, red (2.5YR 5/8) mottles
and common, medium, distinct, gray (10YR 5/1) are small areas in food crops.
mottles; massive; hard, firm, slightly sticky and Representative profile of Limones silty clay, 20 to 40
plastic; many, fine, dark concretions; common, fine, percent slopes, 3 kilometers west of the town of Yabucoa
subrounded rock fragments; neutral; abrupt, and 30 meters north of kilometer marker 14.2 on High-
smooth boundary.
IIC2-35 inches+, angular volcanic rock fragments, way No. 182:
The solum is 20 to 40 inches thick. The A horizon has Ap-0 to 5 inches, dark yellowish-brown (10YR 4/4) silty
value of 3 or 4 and chroma of 2 or 3. The content of clay; few, fine, distinct, strong-brown (7.5YR
volcanic rock fragments in the surface layer ranges from 5/8) and olive-gray (5Y 5/2) mottles; weak, fine
30 to 40 percent. The B horizon has weak, fine or medium, and medium, subangular blocky structure; friable,
subangular blocky structure. The C horizon has hue of nonsticky and plastic; common fine roots; red coat-
10YR or 7.5YR and value of 5 or 6. Mottles in the B and ings along root channels; few fine quartz grains;
C horizons range from few to many and are shades of red very strongly acid; clear, smooth boundary.
and gray. Patchy clay films range from few to many, and 131-5 to 9 inches, dark yellowish-brown (10YR 4/4) clay;
dark concretions range from few to many and are fine or few, fine, faint, strong-brown (7.5YR 5/8) mottles;
medium sized. weak, fine, subangular blocky structure; friable,
The Junquitos soils occupy the same landscape as the nonsticky and plastic; common fine roots; few,
Rio Arriba, Mabi, Aceitunas, and Via soils. The Junquitos thin, patchy clay films; few fine quartz grains;
soils are shallower to rock fragments than the Rio Arriba few, fine, black grains; very strongly acid; clear,
soils. They are shallower and coarser textured than the smooth boundary.
Mabi soils, and their shrink-swell potential is not so high. B21t-9 to 16 inches, yellowish-brown (10YR 5/6) clay;
The Junquitos soils are shallower than the Aceitunas soils many, medium, distinct, red (2.5YR 4/8) mottles;
and lack their reddish horizons. They are shallower and moderate, medium and coarse, subangular blocky
finer textured than the Via soils, and they are not so well structure; firm, slightly sticky and plastic; com-
mon fine roots; thin, continuous, yellowish-brown







26 SOIL SURVEY

Junquitos Series JuC-Junquitos gravelly clay loam, 5 to 12 percent
slopes. This soil is on foot slopes in the humid volcanic
The Junquitos series consists of moderately deep uplands. Included with it in mapping were small areas
soils that are moderately well drained and moderately of Rio Arriba, Mabi, and Via soils.
slowly permeable. These soils formed in alluvial and Slope and surface runoff are moderate limitations
colluvial sediment derived from extrusive volcanic for farming. Proper management and conservation
rocks and, to a small degree, in residuum from similar practices are needed to reduce erosion. If this soil is
rocks. They are on foot slopes. Slopes are 5 to 12 per- properly managed, it is suited to sugarcane and pas-
cent. The climate is humid tropical. The average annual ture. Capability unit IIIe-5.
rainfall is 87 inches, and the average annual tempera-
ture is 79 F.
In a representative profile, the surface layer is brown Leveled Clayey Land
to dark-brown, extremely acid gravelly clay loam about Leveled clayey land (Lc) consists of clayey soils that
7 inches thick. The next layer is yellowish-brown, mot- have different colors, plasticity, and mineralogy. These
tled, firm clay 21 inches thick. The underlying material soils have been reworked by machinery during land
is brownish-yellow, mottled clay that extends to a depth leveling for construction. The original soils have been
of 35 inches. It is underlain by volcanic rock frag- so disturbed that it is impossible to identify them.
ments. Generally, the soils in this mapping unit are deep to
These soils have a high available water capacity and consolidated parent material.
moderate shrink-swell potential. Runoff is medium. The This land type has severe limitations for farming
soils are difficult to work. They have been in pasture because the soils have been disturbed. It is suitable for
for many years, but some areas are in sugarcane. such nonfarm uses as foundations and sites for light
Representative profile of Junquitos gravelly clay industries.
loam, 5 to 12 percent slopes, 1 kilometer north, 0.2
kilometer west, and 15 meters south of kilometer
marker 81.3 on Highway No. 3, east of Humacao: Limones Series
Ap-0 to 7 inches, brown to dark-brown (10YR 4/3) The Limones series consists of deep soils that are
gravelly clay loam; massive; slightly hard, firm, moderately well drained and moderately permeable.
nonsticky and slightly plastic; many fine roots;
many, medium and coarse, angular and subrounded These soils formed in fine-textured residtium of very
rock fragments; extremely acid; clear, smooth highly weathered granitic rocks. They are on side
boundary. slopes and narrow ridgetops. Slopes are 20 to 40 per-
B1-7 to 21 inches, yellowish-brown (10YR 5/8) clay; few, cent. The climate is humid tropical. The average annual
fine, distinct, red (2.5YR 5/8) mottles; weak,
medium, subangular blocky structure; hard, firm, rainfall varies from 75 to 85 inches, and the average
slightly sticky and plastic; few fine roots; few, annual temperature is 780 F.
fine, subrounded rock fragments; few, fine, dark In a representative profile, the surface layer is dark
concretions; strongly acid; clear, smooth bound- yellowish-brown, very strongly acid silty clay about 5
ary.
B2-21 to 28 inches, yellowish-brown (10YR 5/8) clay; inches thick. Below that is dark yellowish-brown,
few, fine, distinct, red (2.5YR 5/8) and light-gray yellowish-brown, and yellowish-red clay 35 inches thick.
(10YR 7/1) mottles; weak, fine, subangular blocky The underlying material is clay loam, clay, and silty
structure; hard, firm, slightly sticky and plastic; clay loam saprolite that extends to a depth of 120
few, fine, patchy clay films; many, fine and me-
dium, dark concretions; common, fine and medium, inches.
angular and subrounded rock fragments; slightly These soils have a high available water capacity and
acid; clear, smooth boundary. moderate to rapid runoff and are susceptible to erosion.
C1-28 to 35 inches, brownish-yellow (10YR 6/8) clay; They have been in pasture for many years, and there
many, coarse, prominent, red (2.5YR 5/8) mottles
and common, medium, distinct, gray (10YR 5/1) are small areas in food crops.
mottles; massive; hard, firm, slightly sticky and Representative profile of Limones silty clay, 20 to 40
plastic; many, fine, dark concretions; common, fine, percent slopes, 3 kilometers west of the town of Yabucoa
subrounded rock fragments; neutral; abrupt, and 30 meters north of kilometer marker 14.2 on High-
smooth boundary.
IIC2-35 inches+, angular volcanic rock fragments, way No. 182:
The solum is 20 to 40 inches thick. The A horizon has Ap-0 to 5 inches, dark yellowish-brown (10YR 4/4) silty
value of 3 or 4 and chroma of 2 or 3. The content of clay; few, fine, distinct, strong-brown (7.5YR
volcanic rock fragments in the surface layer ranges from 5/8) and olive-gray (5Y 5/2) mottles; weak, fine
30 to 40 percent. The B horizon has weak, fine or medium, and medium, subangular blocky structure; friable,
subangular blocky structure. The C horizon has hue of nonsticky and plastic; common fine roots; red coat-
10YR or 7.5YR and value of 5 or 6. Mottles in the B and ings along root channels; few fine quartz grains;
C horizons range from few to many and are shades of red very strongly acid; clear, smooth boundary.
and gray. Patchy clay films range from few to many, and 131-5 to 9 inches, dark yellowish-brown (10YR 4/4) clay;
dark concretions range from few to many and are fine or few, fine, faint, strong-brown (7.5YR 5/8) mottles;
medium sized. weak, fine, subangular blocky structure; friable,
The Junquitos soils occupy the same landscape as the nonsticky and plastic; common fine roots; few,
Rio Arriba, Mabi, Aceitunas, and Via soils. The Junquitos thin, patchy clay films; few fine quartz grains;
soils are shallower to rock fragments than the Rio Arriba few, fine, black grains; very strongly acid; clear,
soils. They are shallower and coarser textured than the smooth boundary.
Mabi soils, and their shrink-swell potential is not so high. B21t-9 to 16 inches, yellowish-brown (10YR 5/6) clay;
The Junquitos soils are shallower than the Aceitunas soils many, medium, distinct, red (2.5YR 4/8) mottles;
and lack their reddish horizons. They are shallower and moderate, medium and coarse, subangular blocky
finer textured than the Via soils, and they are not so well structure; firm, slightly sticky and plastic; com-
mon fine roots; thin, continuous, yellowish-brown







26 SOIL SURVEY

Junquitos Series JuC-Junquitos gravelly clay loam, 5 to 12 percent
slopes. This soil is on foot slopes in the humid volcanic
The Junquitos series consists of moderately deep uplands. Included with it in mapping were small areas
soils that are moderately well drained and moderately of Rio Arriba, Mabi, and Via soils.
slowly permeable. These soils formed in alluvial and Slope and surface runoff are moderate limitations
colluvial sediment derived from extrusive volcanic for farming. Proper management and conservation
rocks and, to a small degree, in residuum from similar practices are needed to reduce erosion. If this soil is
rocks. They are on foot slopes. Slopes are 5 to 12 per- properly managed, it is suited to sugarcane and pas-
cent. The climate is humid tropical. The average annual ture. Capability unit IIIe-5.
rainfall is 87 inches, and the average annual tempera-
ture is 79 F.
In a representative profile, the surface layer is brown Leveled Clayey Land
to dark-brown, extremely acid gravelly clay loam about Leveled clayey land (Lc) consists of clayey soils that
7 inches thick. The next layer is yellowish-brown, mot- have different colors, plasticity, and mineralogy. These
tled, firm clay 21 inches thick. The underlying material soils have been reworked by machinery during land
is brownish-yellow, mottled clay that extends to a depth leveling for construction. The original soils have been
of 35 inches. It is underlain by volcanic rock frag- so disturbed that it is impossible to identify them.
ments. Generally, the soils in this mapping unit are deep to
These soils have a high available water capacity and consolidated parent material.
moderate shrink-swell potential. Runoff is medium. The This land type has severe limitations for farming
soils are difficult to work. They have been in pasture because the soils have been disturbed. It is suitable for
for many years, but some areas are in sugarcane. such nonfarm uses as foundations and sites for light
Representative profile of Junquitos gravelly clay industries.
loam, 5 to 12 percent slopes, 1 kilometer north, 0.2
kilometer west, and 15 meters south of kilometer
marker 81.3 on Highway No. 3, east of Humacao: Limones Series
Ap-0 to 7 inches, brown to dark-brown (10YR 4/3) The Limones series consists of deep soils that are
gravelly clay loam; massive; slightly hard, firm, moderately well drained and moderately permeable.
nonsticky and slightly plastic; many fine roots;
many, medium and coarse, angular and subrounded These soils formed in fine-textured residtium of very
rock fragments; extremely acid; clear, smooth highly weathered granitic rocks. They are on side
boundary. slopes and narrow ridgetops. Slopes are 20 to 40 per-
B1-7 to 21 inches, yellowish-brown (10YR 5/8) clay; few, cent. The climate is humid tropical. The average annual
fine, distinct, red (2.5YR 5/8) mottles; weak,
medium, subangular blocky structure; hard, firm, rainfall varies from 75 to 85 inches, and the average
slightly sticky and plastic; few fine roots; few, annual temperature is 780 F.
fine, subrounded rock fragments; few, fine, dark In a representative profile, the surface layer is dark
concretions; strongly acid; clear, smooth bound- yellowish-brown, very strongly acid silty clay about 5
ary.
B2-21 to 28 inches, yellowish-brown (10YR 5/8) clay; inches thick. Below that is dark yellowish-brown,
few, fine, distinct, red (2.5YR 5/8) and light-gray yellowish-brown, and yellowish-red clay 35 inches thick.
(10YR 7/1) mottles; weak, fine, subangular blocky The underlying material is clay loam, clay, and silty
structure; hard, firm, slightly sticky and plastic; clay loam saprolite that extends to a depth of 120
few, fine, patchy clay films; many, fine and me-
dium, dark concretions; common, fine and medium, inches.
angular and subrounded rock fragments; slightly These soils have a high available water capacity and
acid; clear, smooth boundary. moderate to rapid runoff and are susceptible to erosion.
C1-28 to 35 inches, brownish-yellow (10YR 6/8) clay; They have been in pasture for many years, and there
many, coarse, prominent, red (2.5YR 5/8) mottles
and common, medium, distinct, gray (10YR 5/1) are small areas in food crops.
mottles; massive; hard, firm, slightly sticky and Representative profile of Limones silty clay, 20 to 40
plastic; many, fine, dark concretions; common, fine, percent slopes, 3 kilometers west of the town of Yabucoa
subrounded rock fragments; neutral; abrupt, and 30 meters north of kilometer marker 14.2 on High-
smooth boundary.
IIC2-35 inches+, angular volcanic rock fragments, way No. 182:
The solum is 20 to 40 inches thick. The A horizon has Ap-0 to 5 inches, dark yellowish-brown (10YR 4/4) silty
value of 3 or 4 and chroma of 2 or 3. The content of clay; few, fine, distinct, strong-brown (7.5YR
volcanic rock fragments in the surface layer ranges from 5/8) and olive-gray (5Y 5/2) mottles; weak, fine
30 to 40 percent. The B horizon has weak, fine or medium, and medium, subangular blocky structure; friable,
subangular blocky structure. The C horizon has hue of nonsticky and plastic; common fine roots; red coat-
10YR or 7.5YR and value of 5 or 6. Mottles in the B and ings along root channels; few fine quartz grains;
C horizons range from few to many and are shades of red very strongly acid; clear, smooth boundary.
and gray. Patchy clay films range from few to many, and 131-5 to 9 inches, dark yellowish-brown (10YR 4/4) clay;
dark concretions range from few to many and are fine or few, fine, faint, strong-brown (7.5YR 5/8) mottles;
medium sized. weak, fine, subangular blocky structure; friable,
The Junquitos soils occupy the same landscape as the nonsticky and plastic; common fine roots; few,
Rio Arriba, Mabi, Aceitunas, and Via soils. The Junquitos thin, patchy clay films; few fine quartz grains;
soils are shallower to rock fragments than the Rio Arriba few, fine, black grains; very strongly acid; clear,
soils. They are shallower and coarser textured than the smooth boundary.
Mabi soils, and their shrink-swell potential is not so high. B21t-9 to 16 inches, yellowish-brown (10YR 5/6) clay;
The Junquitos soils are shallower than the Aceitunas soils many, medium, distinct, red (2.5YR 4/8) mottles;
and lack their reddish horizons. They are shallower and moderate, medium and coarse, subangular blocky
finer textured than the Via soils, and they are not so well structure; firm, slightly sticky and plastic; com-
mon fine roots; thin, continuous, yellowish-brown







HUMACAO AREA OF EASTERN PUERTO RICO 27

clay films on ped surfaces and root channels; thick. Below that is red, friable clay and silty clay that
common fine quartz grains; few, fine, black con- extends to a depth of 23 inches. The underlying ma-
cretions; very strongly acid; clear, smooth bound- trial is silty clay loam saprolite.
ary. teral is silty clay loam saprolite.
B22t-16 to 26 inches, yellowish-red (5YR 5/6) clay; mod- These soils have a high available water capacity.
erate, medium and coarse, subangular blocky Surface runoff is moderate to rapid. The soils are sus-
structure; firm, slightly sticky and plastic; com- ceptible to erosion. They have been in pasture for many
mon fine roots; thin, continuous, strong-brown
clay films on ped surfaces, root, and worm years; few areas are in food crops.
channels; common fine quartz grains; few, fine, Representative profile of Lirios silty clay loam, 20 to
black grains; very strongly acid; gradual, smooth 40 percent slopes, eroded, 90 meters south of kilometer
boundary. marker 11.9 on Highway No. 181, Barrio Guayabota,
B3-26 to 40 inches, yellowish-red (5YR 4/8) clay; weak, marker 11. on Highway No. 181, Barrio Guayaota,
medium, subangular blocky structure; friable, Municipality of Yabucoa:
slightly sticky and plastic; few fine roots; thin, Ap-0 to 4 inches, dark-brown (10YR 4/3) silty clay loam;
patchy, strong-brown clay films on ped surfaces weak, fine, subangular blocky structure; friable,
and root channels; few fine quartz grains; few, nonsticky and slightly plastic; many fine roots;
fine, black grains; about 20 percent saprolite; very many fine quartz crystals; common, fine dark
strongly acid; gradual, smooth boundary. concretions; very strongly acid; abrupt, smooth
C1-40 to 54 inches, red (2.5YR 4/8) clay loam saprolite; boundary.
massive; friable, nonsticky and plastic; few fine B2t-4 to 14 inches, red (2.5YR 4/8) clay; weak, medium,
roots; thin clay films along root channels; many subangular blocky structure; friable, slightly
weathered feldspar grains; many fine quartz sticky and slightly plastic; common fine roots;
grains; very strongly acid; gradual, smooth thin patchy clay films on ped surfaces and root
boundary. channels; common fine quartz crystals; few, fine,
C2-54 to 72 inches, variegated colors of the saprolite; red white flakes; very strongly acid; gradual, smooth
(2.5YR 4/8), rubbed, clay; massive; friable, non- boundary.
sticky and plastic; few fine roots; many fine B3-14 to 23 inches, red (10R 4/6) silty clay; common,
quartz grains; common, fine, soft, black grains; fine, distinct, reddish-yellow (5YR 6/6) mottles;
many weathered feldspar grains; very strongly weak, fine, subangular blocky structure; friable,
acid; gradual, smooth boundary. slightly sticky and slightly plastic; few fine roots;
C3-72 to 96 inches, variegated colors of the saprolite; red thin patchy clay films on ped surfaces; common
(2.5YR 4/8), rubbed, silty clay loam; massive; fine quartz crystals; many, fine, shiny, white
friable, nonsticky and slightly plastic; many flakes; very strongly acid; gradual, smooth bound-
weathered feldspar grains; many fine quartz ary.
grains; very strongly acid. C-23 to 50 inches, variegated, red (10R 4/6), strong-
C4-96 to 120 inches, variegated colors of the saprolite; brown (7.5YR 5/8), reddish-brown (5YR 4/3),
red (2.5YR 4/8), rubbed, silty clay loam; massive and pink (5YR 7/3) silty clay loam saprolite;
friable, nonsticky and slightly plastic; many massive; friable, nonsticky and slightly plastic;
weathered feldspar grains; many fine quartz many fine quartz crystals; many, fine, shiny flakes;
grains; very strongly acid. very strongly acid.
The solum is 33 to 53 inches thick. The B2t horizon has T lum s o anche p o
hue of 10YR or 5YR, value of 4 or 5, and chroma of 4 to The solum is 22 to 36 inches thick. The Ap horizon has
8. Clay films vary from thin patchy to thin continuous. The hue of 10YR or 7.5YR and chroma of 3 or 4. It is silty clay
8. Clay films vary from thin patchy to thin c continuous. The loam to clay loam. The B horizon has hue of 5YR, 2.5YR,
The Limones soils are on the same landscape as the or 10R, value of 4 to 6, and chroma of 4 to 8. It is silty
Jagueyes and Ingenio soils. They are finer textured than clay or clay and has weak or moderate, fine or medium,
the Jagueyes soils. Unlike the Ingenio soils, the Limones subangular blocky structure. Clay films vary from thin
soils are moderately well drained and lack red colors in patchy to thin continuous. The C horizon has variegated
the solum. colors of strong brown, reddish brown, pink, and red.
The Lirios soils are on the same landscape as the Jagueyes
LeE2-Limones silty clay, 20 to 40 percent slopes, and Limones soils. They are finer textured than the Jagueyes
eroded. This soil is on side slopes and narrow ridge- soils and are better drained than the Limones soils.
tops in the humid plutonic uplands. Included with it in LoC2-Lirios clay loam, 3 to 10 percent slopes,
mapping were small areas of Ingenio and Jagueyes eroded. This soil is on hilltops and foot slopes in the
soils. humid uplands. It has a thicker surface layer than the
This soil is not suited to cultivated crops because of soil described as representative of the series. Erosion
the hazard of erosion. Steep slopes, surface runoff, and has removed some of the original surface layer, and in
the hazard of erosion are severe limitations for farm- some places plowing has mixed the remaining part of
ing. If the soil is properly managed, it is suited to that layer with the subsoil. Included with this soil in
pasture and woodland. Capability unit IVe-5; wood- mapping were some areas of Jagueyes and Limones
land suitability group 2c5. soils.
This soil is suited to cultivated crops and pasture,
Lirios Series but good management and conservation practices are
required to control erosion. Capability unit IIIe-6;
The Lirios series consists of deep soils that are well woodland suitability group 2c5.
drained and moderately permeable. These soils formed LrE2-Lirios silty clay loam, 20 to 40 percent slopes,
in fine-textured, very highly weathered residuum de- eroded. This soil is on mountain side slopes. It has the
rived from granitic rocks. They are on foot slopes, side profile described as representative of the series. Ero-
slopes, and hilltops. Slopes are 3 to 40 percent. The cli- sion has removed some of the original surface layer,
mate is humid tropical. The average annual rainfall is and in some places the saprolite is exposed.
80 to 90 inches, and the average annual temperature is Steep slopes, surface runoff, and the hazard of ero-
780 F. sion are severe limitations for cultivated crops. Proper
In a representative profile, the surface layer is dark- management and soil conservation practices are re-
brown, very strongly acid silty clay loam about 4 inches quired to control erosion. If the soil is properly limed






28 SOIL SURVEY

and fertilized, it is suited to pasture and woodland. The Los Guineos soils are on the same landscape as the
Capability unit IVe-5; woodland suitability group Ciales and Picacho soils. The Los Guineos soils are better
Capability unit IVe-5; woodland suitability group drained than the Ciales soils. Unlike the Picacho soils, they
2c5. lack low-chroma mottles in the B2t horizon.

Los Guineos Series LsD-Los Guineos silty clay loam, 12 to 20 percent
slopes. This soil is on side slopes and ridgetops in the
The Los Guineos series consists of deep soils that are humid volcanic uplands. It has a thicker surface layer
moderately well drained and moderately permeable. than the soil described as representative of the Los
These soils formed in fine-textured residuum derived Guineos series. Small areas of Los Guineos soils, 20 to
from highly weathered volcanic rocks. They are on 40 percent slopes, eroded, Mucara soils, and Rock land
mountain side slopes and narrow ridgetops. Slopes are were included with this soil in mapping.
12 to 60 percent. The climate is humid tropical. The Slopes, medium runoff, and the hazard of erosion are
average annual precipitation is 100 inches, and the av- severe limitations for farming. These limitations re-
erage annual temperature is 750 F. strict the choice of plants and require very careful man-
In a representative profile, the surface layer is dark- agement if the soil is clean cultivated. The high
brown, extremely acid silty clay loam about 5 inches intensity of rainfall restricts the time of planting, till-
thick. Below that is yellowish-brown and reddish-yellow ing, and harvesting. Most of the acreage is in brush
very firm and firm clay 19 inches thick. The next layer and tropical rain forest. This soil is suited to food crops,
is red, strong-brown, and reddish-yellow, very firm and grass, and woodland. Capability unit IVe-5; wood-
firm clay. Clay saprolite is at a depth of 48 inches. land suitability group 2c3.
These soils have a high available water capacity and LsE2-Los Guineos silty clay loam, 20 to 40 percent
medium natural fertility. Runoff is medium to rapid. slopes, eroded. This soil is on side slopes and ridgetops.
The soils are susceptible to erosion and are difficult to It has the profile described as representative of the
work. They have been in pasture, brush, and woodland series. Included with it in mapping were small areas of
for many years. Some areas are in abandoned coffee moderately steep Los Guineos soils, Mucara soils, and
trees. Rock land.
Representative profile of Los Guineos silty clay loam, Steep slopes, rapid runoff, and the hazard of erosion
20 to 40 percent slopes, eroded, 350 meters southeast of are severe limitations for clean cultivation. If the soil is
kilometer marker 14.1 on Highway No. 179, Ward occasionally clean cultivated, conservation practices
Carite, Guayama: and proper management are required to control erosion.
Ap-0 to 5 inches, dark-brown (10YR 4/3) silty clay loam; If the soil is properly limed and managed, it is suited to
common, fine, distinct, yellowish-brown (10YR 5/8) coffee trees, pasture, and woodland. Capability unit
mottles; weak, fine, granular structure; friable, VIe-2; woodland suitability group 2c3.
slightly sticky and slightly plastic; few fine roots; LsF2-Los Guineos silty clay loam, 40 to 60 percent
extremely acid; clear, smooth boundary. LsF2-Los Guineos sily clay loam, 40 to 60 percent
B21t-5 to 15 inches, yellowish-brown (10YR 5/6) clay; slopes, eroded. This soil is on side slopes and ridgetops
few, fine, yellowish-red (5YR 5/8) mottles; mod- in the humid volcanic uplands. Included with it in map-
erate, coarse, subangular blocky structure; very ping were small areas of Caguabo soils and Rock land.
firm, slightly sticky and plastic; common fine roots;
patchy clay films on ped surfaces and in root Very steep slopes, rapid runoff, and the hazard of ero-
channels; extremely acid; numerous worm casts; sion are severe limitations for clean cultivation. This
gradual, smooth boundary. soil has been in abandoned coffee trees, pasture, and
B22t-15 to 24 inches, reddish-yellow (7.5YR 6/8) clay; forest. It is suitable for pasture, woodland, and food
ped interiors have common, medium, distinct, red willf p ili unit V 1 w
(2.5YR 4/6) mottles; moderate, coarse, subangular and cover for wildlife. Capability unit VIIe-i; wood-
blocky structure; firm, slightly sticky and plastic; land suitability group 2r3.
thin continuous clay films on ped surfaces and LyF-Los Guineos-Yunque-Stony rock land associa-
patchy films in root channels; very strongly acid; tion, steep. This mapping unit is on mountains in the
gradual, wavy boundary.
B31-24 to 4 inches, red (2.5YR 4/6) and strong-brown rain forest. The soils occur in uniform patterns; the
(7.5YR 5/8) clay; weak, fine and medium, sub- Los Guineos soils are on the mountain side slopes, and
angular blocky structure; very firm, slightly sticky the Yunque soils are on the upper side slopes and ridge-
and plastic; few fine roots; patchy clay films on tops. Stony rock land is on the lower part of the side
vertical cleavage planes and in root channels; 20 ro land i on e l
percent saprolite; very strongly acid; gradual, slopes and along drainageways. In these places, 90 to
wavy boundary. 100 percent of the surface is covered with grayish and
B32-34 to 48 inches, red (2.5YR 4/6) and reddish-yellow bluish volcanic rocks. Slopes range from 25 to 65 per-
(7.5YR 6/6) clay; weak, fine and medium, sub- cent on the side slopes, from 10 to 35 percent on the
angular blocky structure; firm, slightly sticky and
plastic; few patchy clay films on vertical ped upper side slopes, and from 25 to 70 percent in areas of
surfaces and in root channels; 40 percent saprolite; Stony rock land.
extremely acid; gradual, wavy boundary. The composition of this mapping unit is more vari-
C-48 to 60 inches, mixed colors of the saprolite; red able than that of most other mapping units in the
(2.5YR 4/6), brownish-yellow (10YR 6/6), very able an that most other mapping units in the
pale brown (10YR 7/4), and very dark brown survey area but has been controlled well enough to in-
(10YR 2/2) clay; massive; friable, slightly sticky terpret for the expected use of the soils. About 50 per-
and plastic; very strongly acid. cent is Los Guineos soils, 31 percent is Yunque soils,
The solum is 36 to 58 inches thick. The Ap horizon has and 10 percent is Stony rock land. The rest consists of
hue of 7.5YR or 10YR and chroma of 3 or 4. The B2t other soils, rocks, and boulders.
horizon has hue of 10YR or 7.5YR, value of 4 to 6, and This mapping unit is in hardwood rain forest. Be-
chroma of 6 or higher. It has moderate or strong, mediums it hardwood rain forest. Be-
or coarse, subangular blocky structure. Reaction is strongly cause of the very steep slopes, its use is limited to
acid or extremely acid. forest, recreation, habitat for wildlife, and water catch-







HUMACAO AREA OF EASTERN PUERTO RICO 29

ment. Road stabilization is difficult because the soils are krotovinas; clay films on root channels; very
continuously wet and susceptible to slippage. Thus, the strongly acid; abrupt, wavy boundary.
ntinuousl wt and suscpt slipae e AC--6 to 18 inches, yellowish-brown (10YR 5/6) clay;
limitations for paths, roads, and trails are severe. Ca- common, medium, distinct, light-gray (5Y 7/2)
ability unit VIIe-3; woodland suitability group 3r3. mottles; weak, coarse, angular blocky structure;
very firm, sticky and plastic; common dead roots
in root channels; few black concretions; slicken-
Mabi Series sides and pressure faces; very strongly acid;
gradual, wavy boundary.
The Mabi series consists of deep soils that are some- C1-18 to 35 inches, yellowish-brown (10YR 5/8) clay;
what poorly drained and slowly permeable. These soils many, coarse, prominent, light greenish-gray (5GY
formed in sediment derived from volcanic rocks. They 7/1) mottles; weak, coarse, angular blocky struc-
ture; very firm, sticky and plastic; common dead
are on stream terraces, long foot slopes, and alluvial roots; common, fine and medium, black concre-
fans. Slopes are 0 to 20 percent. The climate is humid tions; slickensides and pressure faces; strongly
tropical. The average annual precipitation is 70 to 80 acid; clear, wavy boundary.
inches, and the average annual temperature is 780 F. C2-35 to 56 inches, yellowish-brown (10YR 5/6) clay;
many, coarse, prominent, light greenish-gray (5GY
In a representative profile, the surface layer is dark- 7/1) mottles; weak, coarse, angular blocky struc-
brown, very strongly acid clay about 6 inches thick. It ture; very firm, sticky and plastic; fine dead roots;
is underlain by yellowish-brown, mottled, very firm many, medium, black concretions; common dark
clay that extends to a depth of 56 inches. concretions; common dark streaks on ped surfaces;
These soils have a high available water capacity, high slightly acid.
natural fertility, and high shrink-swell potential. Run- The Ap horizon is 6 to 12 inches thick. It has value of
off is medium to slow. The soils are difficult to work. 4 or less and chroma of 2 or more. The C horizon has hue
of 10YR or 2.5Y, value of 4 or 5, and chroma of 4 or more.
They have been in pasture (fig. 4) and sugarcane. Some Low-chroma mottles are below the Ap horizon. Reaction
areas are in tobacco. ranges from very strongly acid in the surface horizon to
Representative profile of Mabi clay, 0 to 5 percent slightly acid in the lower horizons.
slopes, 9 meters south and 9 meters west of kilometer The Mabi soils occupy the same landscape as the Mucara
marker 14.7 on Highway No. 31, Naguabo to Juncos: and Rio Arriba soils. They are at a lower elevation and
marker 14.7 on Highway No. 31, Naguabo to Juncos: are finer textured and deeper than the Mucara soils. Unlike
Ap-0 to 6 inches, dark-brown (10YR 4/3) clay; common, the Rio Arriba soils, the Mabi soils lack a B2t horizon
fine, faint, dark-red (2.5YR 3/6) mottles; weak, and are somewhat poorly drained.
fine, subangular blocky structure; firm, slightly
sticky and slightlyocplastic; common fine roots;lig MaB-Mabi clay, 0 to 5 percent slopes. This soil is
common, medium and fine, black concretions; few on alluvial fans, foot slopes, and terraces below the vol-

























*-^ ^- -^, '-' '?'r- -: -' .... r --_" -" -.; --- --





Figure 4.-Pangolagrass pasture on Mabi soils. Steep Mucara soils are on the side slopes in the background.






30 SOIL SURVEY

canic uplands. It has the profile described as represent- A12-9 to 14 inches, reddish-brown (5YR 4/3) loam; weak,
ative of the series. Included with this soil in mapping fine, granular structure; very friable, slightly
were small areas of Rio Arriba soils sticky and slightly plastic; few fine roots; com-
mon medium and fine pores; common fine sand
This soil has moderate limitations for farming be- grains; strongly acid; clear, smooth boundary.
cause of unfavorable workability and wetness. It is fer- Bl-14 to 20 inches, reddish-brown (5YR 4/4) clay loam;
tile and responds well to fertilizer but it needs careful weak, medium, subangular blocky structure; fri-
management and drainage. The soil is suited to sugar-able, slightly sticky and slightly plastic; few fine
management and drainage. The soil is suited to sugar- roots; common medium and fine pores; thin patchy
cane, tobacco, and pasture. Capability unit IIw-3. clay films; few, fine, black concretions; many fine
MaC2-Mabi clay, 5 to 12 percent slopes, eroded, sand grains; strongly acid; clear, smooth boundary.
This soil is on foot slopes and alluvial fans. Its profile is B2t-20 to 32 inches, yellowish-red (5YR 4/6) clay; mod-
erate, medium, subangular blocky structure; firm,
similar to the one described as representative of the slightly sticky and plastic; thin discontinuous clay
Mabi series, but erosion has removed some of the dark- films, more numerous on vertical ped surfaces and
brown surface layer. In some places plowing has mixed in root channels than on horizontal ped surfaces;
the remaining part of the surface layer with some of few worm casts; few black concretions; many sand
grains; strongly acid; clear, smooth boundary.
the subsoil. Included with this soil in mapping were B3-32 to 39 inches, reddish-brown (YR 4/4) sandy clay
small areas of Rio Arriba soils. loam; weak, medium, subangular blocky structure;
This soil has moderate limitations for farming be- friable, slightly sticky and slightly plastic; few,
cause it is somewhat poorly drained and difficult to cul- thin, patchy clay films on peds and in root chan-
nels; few black concretions; many sand grains;
tivate. If it is properly managed and drained, the soil is few subrounded pebbles; strongly acid; abrupt,
suited to sugarcane, tobacco, and pasture. Capability smooth boundary.
unit IIIe-7. IIC1-39 to 45 inches, reddish-brown (5YR 4/3) gravelly
MaD2-Mabi clay, 12 to 20 percent slopes, eroded. sandy clay loam; massive; friable; strongly acid;
abrupt, smooth boundary.
This soil is on foot slopes. It is steeper and better IIIC2-45 to 60 inches, dark-brown (7.5YR 4/4) loamy
drained than the other Mabi soils. Erosion has removed sand; massive; very friable; strongly acid.
some of the original dark-brown surface layer, and The solum is 27 to 62 inches thick. The Ap horizon has
where the soil is plowed, the remaining part of that hue of 5YR or 7.5YR and chroma of 3 or 4. The B horizon
layer is mixed with some of the subsoil. In some places has hue of 7.5YR or 5YR and chroma of 4 to 6. The B2t
the yellowish-brown subsoil is exposed. Included with horizon has weak or moderate, subangular blocky struc-
ture. The C horizon has reddish-brown and dark-brown
this soil in mapping were some areas of Mucara soils. colors. It ranges from gravelly sandy clay loam to loamy
Slope, the hazard of erosion, and the difficulty of sand.
cultivation are severe limitations for farming. If the The Machete soils are on the same landscape as the
soil is properly managed, it is suited to sugarcane, to- Fraternidad and Vives soils. The Machete soils are coarser
textured and redder than the Fraternidad soils. They are
bacco, and pasture. Capability unit IVe-10. redder in the A horizon than the Vives soils. Unlike both
those soils, the Machete soils are strongly acid.
Machete Series McA-Machete loam, 0 to 2 percent slopes. This soil
occupies terraces and alluvial fans. It has the profile
The Machete series consists of deep soils that are well described as representative of the series. Small areas of
drained and moderately permeable. These soils formed Vives, Fraternidad, and Vives, high bottom, soils were
in moderately coarse textured to fine-textured sedi- included with this soil in mapping.
ment derived from volcanic rocks. They are on terraces Most of the acreage is in sugarcane. This soil is suited
and alluvial fans. Slopes are 0 to 5 percent. The climate to most kinds of crops grown in the area, but irrigation
is semiarid. The average annual rainfall is 30 to 45 is needed for successful crop production. Capability unit
inches, and the average annual temperature is 800 F. IIc-2 nonirrigated and I-1 irrigated.
In a representative profile, the surface layer is MB--Machete loam, 2 to 5 percent slopes. This soil
reddish-brown, strongly acid loam about 14 inches is on terraces and alluvial fans. It has a thinner surface
thick. The next layer is reddish-brown friable clay loam layer than the soil described as representative of the
to a depth of 20 inches. Below that layer is yellowish- Machete series. It occurs at a higher elevation than
red and reddish-brown clay and sandy clay loam 19 Machete loam, 0 to 2 percent slopes. Included with this
inches thick. Underlying that layer is reddish-brown soil in mapping were small areas of Vives soils.
and dark-brown, friable and very friable gravelly sandy If this soil is irrigated, it is suited to cultivated crops
clay loam and loamy sand that extends to a depth of 60 and sugarcane. Capability units IIIc-3 nonirrigated
inches.and sugarcane. Capability units IIIc-3 nonirrigated
These soils have a moderate available water capacity and IIe-3 irrigated.
and high natural fertility. Runoff is medium to slow.
The soils are easily worked, and most of the acreage has Made Land
been in sugarcane for many years. If the soils are irri- Made land (Md) consists of areas where the soil pro-
gated, they are suited to cultivated crops. /Made land (Md) consists of areas where the soil pro-
gated, they are suited to cultivated crops, file has been covered or destroyed by earthmoving op-
Representative profile of Machete loam, 0 to 20 per- erations. The areas generally have been graded for
cent slopes, 800 meters east of Lafayette Sugar Central e n e es eer
irrigation reservoir and 60 meters south of reservoir, engineering purposes.
12 meters east of trail: This land type is not suitable for agricultural uses.
Because soil conditions are variable, it requires special
Ap-0 to 9 inches, reddish-brown (5YR 4/3) loam; weak, management if lawns and trees are to be established.
fine, granular structure; very friable, slightly In some areas the hazards that affect engineering uses
sticky and slightly plastic; many fine roots; few,
fine, black concretions; common fine sand grains; have been overcome, and the land type is used as sites
strongly acid; clear, smooth boundary. for dwellings and light industries.






30 SOIL SURVEY

canic uplands. It has the profile described as represent- A12-9 to 14 inches, reddish-brown (5YR 4/3) loam; weak,
ative of the series. Included with this soil in mapping fine, granular structure; very friable, slightly
were small areas of Rio Arriba soils sticky and slightly plastic; few fine roots; com-
mon medium and fine pores; common fine sand
This soil has moderate limitations for farming be- grains; strongly acid; clear, smooth boundary.
cause of unfavorable workability and wetness. It is fer- Bl-14 to 20 inches, reddish-brown (5YR 4/4) clay loam;
tile and responds well to fertilizer but it needs careful weak, medium, subangular blocky structure; fri-
management and drainage. The soil is suited to sugar-able, slightly sticky and slightly plastic; few fine
management and drainage. The soil is suited to sugar- roots; common medium and fine pores; thin patchy
cane, tobacco, and pasture. Capability unit IIw-3. clay films; few, fine, black concretions; many fine
MaC2-Mabi clay, 5 to 12 percent slopes, eroded, sand grains; strongly acid; clear, smooth boundary.
This soil is on foot slopes and alluvial fans. Its profile is B2t-20 to 32 inches, yellowish-red (5YR 4/6) clay; mod-
erate, medium, subangular blocky structure; firm,
similar to the one described as representative of the slightly sticky and plastic; thin discontinuous clay
Mabi series, but erosion has removed some of the dark- films, more numerous on vertical ped surfaces and
brown surface layer. In some places plowing has mixed in root channels than on horizontal ped surfaces;
the remaining part of the surface layer with some of few worm casts; few black concretions; many sand
grains; strongly acid; clear, smooth boundary.
the subsoil. Included with this soil in mapping were B3-32 to 39 inches, reddish-brown (YR 4/4) sandy clay
small areas of Rio Arriba soils. loam; weak, medium, subangular blocky structure;
This soil has moderate limitations for farming be- friable, slightly sticky and slightly plastic; few,
cause it is somewhat poorly drained and difficult to cul- thin, patchy clay films on peds and in root chan-
nels; few black concretions; many sand grains;
tivate. If it is properly managed and drained, the soil is few subrounded pebbles; strongly acid; abrupt,
suited to sugarcane, tobacco, and pasture. Capability smooth boundary.
unit IIIe-7. IIC1-39 to 45 inches, reddish-brown (5YR 4/3) gravelly
MaD2-Mabi clay, 12 to 20 percent slopes, eroded. sandy clay loam; massive; friable; strongly acid;
abrupt, smooth boundary.
This soil is on foot slopes. It is steeper and better IIIC2-45 to 60 inches, dark-brown (7.5YR 4/4) loamy
drained than the other Mabi soils. Erosion has removed sand; massive; very friable; strongly acid.
some of the original dark-brown surface layer, and The solum is 27 to 62 inches thick. The Ap horizon has
where the soil is plowed, the remaining part of that hue of 5YR or 7.5YR and chroma of 3 or 4. The B horizon
layer is mixed with some of the subsoil. In some places has hue of 7.5YR or 5YR and chroma of 4 to 6. The B2t
the yellowish-brown subsoil is exposed. Included with horizon has weak or moderate, subangular blocky struc-
ture. The C horizon has reddish-brown and dark-brown
this soil in mapping were some areas of Mucara soils. colors. It ranges from gravelly sandy clay loam to loamy
Slope, the hazard of erosion, and the difficulty of sand.
cultivation are severe limitations for farming. If the The Machete soils are on the same landscape as the
soil is properly managed, it is suited to sugarcane, to- Fraternidad and Vives soils. The Machete soils are coarser
textured and redder than the Fraternidad soils. They are
bacco, and pasture. Capability unit IVe-10. redder in the A horizon than the Vives soils. Unlike both
those soils, the Machete soils are strongly acid.
Machete Series McA-Machete loam, 0 to 2 percent slopes. This soil
occupies terraces and alluvial fans. It has the profile
The Machete series consists of deep soils that are well described as representative of the series. Small areas of
drained and moderately permeable. These soils formed Vives, Fraternidad, and Vives, high bottom, soils were
in moderately coarse textured to fine-textured sedi- included with this soil in mapping.
ment derived from volcanic rocks. They are on terraces Most of the acreage is in sugarcane. This soil is suited
and alluvial fans. Slopes are 0 to 5 percent. The climate to most kinds of crops grown in the area, but irrigation
is semiarid. The average annual rainfall is 30 to 45 is needed for successful crop production. Capability unit
inches, and the average annual temperature is 800 F. IIc-2 nonirrigated and I-1 irrigated.
In a representative profile, the surface layer is MB--Machete loam, 2 to 5 percent slopes. This soil
reddish-brown, strongly acid loam about 14 inches is on terraces and alluvial fans. It has a thinner surface
thick. The next layer is reddish-brown friable clay loam layer than the soil described as representative of the
to a depth of 20 inches. Below that layer is yellowish- Machete series. It occurs at a higher elevation than
red and reddish-brown clay and sandy clay loam 19 Machete loam, 0 to 2 percent slopes. Included with this
inches thick. Underlying that layer is reddish-brown soil in mapping were small areas of Vives soils.
and dark-brown, friable and very friable gravelly sandy If this soil is irrigated, it is suited to cultivated crops
clay loam and loamy sand that extends to a depth of 60 and sugarcane. Capability units IIIc-3 nonirrigated
inches.and sugarcane. Capability units IIIc-3 nonirrigated
These soils have a moderate available water capacity and IIe-3 irrigated.
and high natural fertility. Runoff is medium to slow.
The soils are easily worked, and most of the acreage has Made Land
been in sugarcane for many years. If the soils are irri- Made land (Md) consists of areas where the soil pro-
gated, they are suited to cultivated crops. /Made land (Md) consists of areas where the soil pro-
gated, they are suited to cultivated crops, file has been covered or destroyed by earthmoving op-
Representative profile of Machete loam, 0 to 20 per- erations. The areas generally have been graded for
cent slopes, 800 meters east of Lafayette Sugar Central e n e es eer
irrigation reservoir and 60 meters south of reservoir, engineering purposes.
12 meters east of trail: This land type is not suitable for agricultural uses.
Because soil conditions are variable, it requires special
Ap-0 to 9 inches, reddish-brown (5YR 4/3) loam; weak, management if lawns and trees are to be established.
fine, granular structure; very friable, slightly In some areas the hazards that affect engineering uses
sticky and slightly plastic; many fine roots; few,
fine, black concretions; common fine sand grains; have been overcome, and the land type is used as sites
strongly acid; clear, smooth boundary. for dwellings and light industries.







HUMACAO AREA OF EASTERN PUERTO RICO 31

Maunabo Series This soil has severe limitations for farming because
of poor drainage conditions. It requires a complex
The Maunabo series consists of deep soils that are drainage system. Frequent flooding, slow permeability,
poorly drained and slowly permeable. These soils and seasonal high water table are severe limitations for
formed in fine-textured sediment derived from granitic clean cultivation. These limitations require careful
rocks. They are on the river flood plains. Slopes are 0 management and water control practices. Most areas of
to 2 percent. The climate is humid tropical. The average this soil are in sugarcane. If the soil is properly drained,
annual precipitation is 87 inches, and the average tem- it is suited to cultivated crops, sugarcane, and pasture.
perature is 790 F. Capability unit IIIw-4.
In a representative profile, the surface layer is light
brownish-gray, mottled, strongly acid clay in the upper
4 inches and grayish-brown, mottled, very firm clay in Mayo Series
the lower 6 inches. Below that is gray and greenish- The Mayo series consists of deep soils that are well
gray, mottled clay and silty clay 29 inches thick. drained and rapidly permeable. These soils formed in
The underlying material is greenish-gray, very friable coarse-textured sediment derived from plutonic rocks.
sandy loam that extends to a depth of 48 inches. They are on alluvial fans and terraces. Slopes are 3 to
These soils are fertile and have a high available wa- 10 percent. The climate is humid tropical. The average
ter capacity. Runoff is slow. The soils are difficult to annual precipitation is 75 to 85 inches, and the average
work, and they have been in pasture and sugarcane for annual temperature is 770 to 800 F.
many years. In a representative profile, the surface layer is very
Representative profile of Maunabo clay 369 meters dark brown, very strongly acid loam about 8 inches
northeast of the intersection of Highway No. 905 and thick. Below that is dark-brown and pale-brown, very
Highway No. 3: friable and loose sandy loam and loamy sand that ex-
Ap-0 to 4 inches, light brownish-gray (10YR 6/2) clay; tends to a depth of 44 inches. It is underlain by brown,
few, fine, faint, strong-brown (7.5YR 5/6) mottles; very friable sandy loam.
massive; very firm, slightly sticky and plastic;
common roots; few fine quartz grains; few, fine, These soils have a low available water capacity and
black mineral grains; strongly acid; gradual, low shrink-swell potential. Runoff is medium. The soils
smooth boundary. are easily worked. They have been in sugarcane and
A12-4 to 10 inches, grayish-brown (10YR 5/2) clay; pasture for many years; small areas are in food crops.
common, medium, distinct, strong-brown (7.5YR
5/6) mottles; massive; very firm, slightly sticky Representative profile of Mayo loam, 3 to 10 percent
and plastic; common roots; few fine pores; dark- slopes, 4.2 kilometers north of the town of Yabucoa and
colored old roots; small charcoal fragments; few, 3.2 kilometers northwest of intersection of Highway
fine, black mineral grains; strongly acid; gradual, No. 3, Este Soil Conservation District:
smooth boundary.
Big-10 to 15 inches, gray (5Y 5/1) clay; common, me- Ap-0 to 8 inches, very dark brown (10YR 2/2) loam;
dium, distinct, yellowish-red (5YR 5/8) mottles; moderate, medium, granular structure; soft, very
weak, medium, subangular blocky structure; very friable, nonsticky and nonplastic; common fine
firm, slightly sticky and plastic; common fine roots; roots; very strongly acid; clear, smooth boundary.
dark coatings along root channels; few fine quartz B-8 to 18 inches, dark-brown (10YR 3/3) sandy loam;
grains; few, fine, black mineral grains; strongly weak, fine, subangular blocky structure; soft, very
acid; gradual, smooth boundary. friable, nonsticky and nonplastic; few fine roots;
B2g-15 to 22 inches, gray (5Y 6/1) clay; common, me- common fine quartz grains; common, fine, partly
dium, yellowish-brown (10YR 5/8) mottles; weak, weathered feldspar grains; common, fine, black
coarse, subangular blocky structure; very firm, concretions; very strongly acid; clear, smooth
slightly sticky and plastic; dark coatings along boundary.
root channels; fine roots; common fine pores; few C1-18 to 27 inches, dark-brown (10YR 4/3) sandy loam;
fine quartz grains; strongly acid; gradual, smooth massive; soft, very friable, nonsticky and non-
boundary. plastic; few fine roots; many fine quartz grains;
B3g-22 to 39 inches, greenish-gray (5G 6/1) silty clay; common, fine, partly weathered feldspar grains;
many, medium, distinct, strong-brown (7.5YR 5/6) few, fine, black concretions; very strongly acid;
and dark-red (2.5YR 3/6) mottles; massive; very gradual, smooth boundary.
firm, slightly sticky and plastic; few roots; com- IIC2-27 to 34 inches, pale-brown (10YR 6/3) loamy sand;
mon fine quartz grains; common, fine, dark mineral massive; loose, nonsticky and nonplastic; many
grains; strongly acid; gradual, smooth boundary. fine quartz grains; few, fine, shiny flakes; many,
IICg-39 to 48 inches, greenish-gray (5BG 5/1) sandy fine, dark grains; very strongly acid; abrupt,
loam; massive; very friable; many silvery flakes; smooth boundary.
strongly acid. IIIC3-34 to 44 inches, pale-brown (10YR 6/3) loamy
Thickness of the solum and depth to coarser textured sand; massive; loose, nonsticky and nonplastic;
material range from 28 to 50 inches. The Ap horizon has many fine quartz grains; few, fine, dark grains;
value of 5 or 6. The B horizon has hue of 5Y, 5G, or 5GY common, fine, partly weathered feldspar grains;
and value of 5 or 6. It has weak, medium or coarse, sub- very strongly acid; abrupt, smooth boundary.
angular blocky structure or is massive. IIIC4-44 to 60 inches, brown (10YR 5/3) sandy loam;
The Maunabo soils are on the same landscape as the massive; very friable, nonstick and nonplastic;
Coloso, Talante, and Vivi soils. They are finer textured many fine quartz grains; common, fine, black
than all those soils. The Maunabo soils are more poorly grains; common, fine, partly weathered feldspar
drained and occupy lower positions than the Coloso soils. grains; few, fine, black, shiny and flaky grains;
They are poorly drained, whereas the Vivi soils are well strongly acid.
drained. The solum is 14 to 26 inches thick. The A horizon has
Me-Maunabo clay. This nearly level soil is on flood chroma of 2 or 3 and ranges from sandy loam to loam.
plains of the Maunabo and Guayanes Rivers. Included The B horizon has chroma of 3 or 4. The C horizon has
value of 4, 5, or 6 and chroma of 3 or 4. The B and C
with it in mapping were small areas of Coloso and Ta- horizons range from sandy loam to loam. Reaction ranges
late soils. from strongly acid to very strongly acid.







HUMACAO AREA OF EASTERN PUERTO RICO 31

Maunabo Series This soil has severe limitations for farming because
of poor drainage conditions. It requires a complex
The Maunabo series consists of deep soils that are drainage system. Frequent flooding, slow permeability,
poorly drained and slowly permeable. These soils and seasonal high water table are severe limitations for
formed in fine-textured sediment derived from granitic clean cultivation. These limitations require careful
rocks. They are on the river flood plains. Slopes are 0 management and water control practices. Most areas of
to 2 percent. The climate is humid tropical. The average this soil are in sugarcane. If the soil is properly drained,
annual precipitation is 87 inches, and the average tem- it is suited to cultivated crops, sugarcane, and pasture.
perature is 790 F. Capability unit IIIw-4.
In a representative profile, the surface layer is light
brownish-gray, mottled, strongly acid clay in the upper
4 inches and grayish-brown, mottled, very firm clay in Mayo Series
the lower 6 inches. Below that is gray and greenish- The Mayo series consists of deep soils that are well
gray, mottled clay and silty clay 29 inches thick. drained and rapidly permeable. These soils formed in
The underlying material is greenish-gray, very friable coarse-textured sediment derived from plutonic rocks.
sandy loam that extends to a depth of 48 inches. They are on alluvial fans and terraces. Slopes are 3 to
These soils are fertile and have a high available wa- 10 percent. The climate is humid tropical. The average
ter capacity. Runoff is slow. The soils are difficult to annual precipitation is 75 to 85 inches, and the average
work, and they have been in pasture and sugarcane for annual temperature is 770 to 800 F.
many years. In a representative profile, the surface layer is very
Representative profile of Maunabo clay 369 meters dark brown, very strongly acid loam about 8 inches
northeast of the intersection of Highway No. 905 and thick. Below that is dark-brown and pale-brown, very
Highway No. 3: friable and loose sandy loam and loamy sand that ex-
Ap-0 to 4 inches, light brownish-gray (10YR 6/2) clay; tends to a depth of 44 inches. It is underlain by brown,
few, fine, faint, strong-brown (7.5YR 5/6) mottles; very friable sandy loam.
massive; very firm, slightly sticky and plastic;
common roots; few fine quartz grains; few, fine, These soils have a low available water capacity and
black mineral grains; strongly acid; gradual, low shrink-swell potential. Runoff is medium. The soils
smooth boundary. are easily worked. They have been in sugarcane and
A12-4 to 10 inches, grayish-brown (10YR 5/2) clay; pasture for many years; small areas are in food crops.
common, medium, distinct, strong-brown (7.5YR
5/6) mottles; massive; very firm, slightly sticky Representative profile of Mayo loam, 3 to 10 percent
and plastic; common roots; few fine pores; dark- slopes, 4.2 kilometers north of the town of Yabucoa and
colored old roots; small charcoal fragments; few, 3.2 kilometers northwest of intersection of Highway
fine, black mineral grains; strongly acid; gradual, No. 3, Este Soil Conservation District:
smooth boundary.
Big-10 to 15 inches, gray (5Y 5/1) clay; common, me- Ap-0 to 8 inches, very dark brown (10YR 2/2) loam;
dium, distinct, yellowish-red (5YR 5/8) mottles; moderate, medium, granular structure; soft, very
weak, medium, subangular blocky structure; very friable, nonsticky and nonplastic; common fine
firm, slightly sticky and plastic; common fine roots; roots; very strongly acid; clear, smooth boundary.
dark coatings along root channels; few fine quartz B-8 to 18 inches, dark-brown (10YR 3/3) sandy loam;
grains; few, fine, black mineral grains; strongly weak, fine, subangular blocky structure; soft, very
acid; gradual, smooth boundary. friable, nonsticky and nonplastic; few fine roots;
B2g-15 to 22 inches, gray (5Y 6/1) clay; common, me- common fine quartz grains; common, fine, partly
dium, yellowish-brown (10YR 5/8) mottles; weak, weathered feldspar grains; common, fine, black
coarse, subangular blocky structure; very firm, concretions; very strongly acid; clear, smooth
slightly sticky and plastic; dark coatings along boundary.
root channels; fine roots; common fine pores; few C1-18 to 27 inches, dark-brown (10YR 4/3) sandy loam;
fine quartz grains; strongly acid; gradual, smooth massive; soft, very friable, nonsticky and non-
boundary. plastic; few fine roots; many fine quartz grains;
B3g-22 to 39 inches, greenish-gray (5G 6/1) silty clay; common, fine, partly weathered feldspar grains;
many, medium, distinct, strong-brown (7.5YR 5/6) few, fine, black concretions; very strongly acid;
and dark-red (2.5YR 3/6) mottles; massive; very gradual, smooth boundary.
firm, slightly sticky and plastic; few roots; com- IIC2-27 to 34 inches, pale-brown (10YR 6/3) loamy sand;
mon fine quartz grains; common, fine, dark mineral massive; loose, nonsticky and nonplastic; many
grains; strongly acid; gradual, smooth boundary. fine quartz grains; few, fine, shiny flakes; many,
IICg-39 to 48 inches, greenish-gray (5BG 5/1) sandy fine, dark grains; very strongly acid; abrupt,
loam; massive; very friable; many silvery flakes; smooth boundary.
strongly acid. IIIC3-34 to 44 inches, pale-brown (10YR 6/3) loamy
Thickness of the solum and depth to coarser textured sand; massive; loose, nonsticky and nonplastic;
material range from 28 to 50 inches. The Ap horizon has many fine quartz grains; few, fine, dark grains;
value of 5 or 6. The B horizon has hue of 5Y, 5G, or 5GY common, fine, partly weathered feldspar grains;
and value of 5 or 6. It has weak, medium or coarse, sub- very strongly acid; abrupt, smooth boundary.
angular blocky structure or is massive. IIIC4-44 to 60 inches, brown (10YR 5/3) sandy loam;
The Maunabo soils are on the same landscape as the massive; very friable, nonstick and nonplastic;
Coloso, Talante, and Vivi soils. They are finer textured many fine quartz grains; common, fine, black
than all those soils. The Maunabo soils are more poorly grains; common, fine, partly weathered feldspar
drained and occupy lower positions than the Coloso soils. grains; few, fine, black, shiny and flaky grains;
They are poorly drained, whereas the Vivi soils are well strongly acid.
drained. The solum is 14 to 26 inches thick. The A horizon has
Me-Maunabo clay. This nearly level soil is on flood chroma of 2 or 3 and ranges from sandy loam to loam.
plains of the Maunabo and Guayanes Rivers. Included The B horizon has chroma of 3 or 4. The C horizon has
value of 4, 5, or 6 and chroma of 3 or 4. The B and C
with it in mapping were small areas of Coloso and Ta- horizons range from sandy loam to loam. Reaction ranges
late soils. from strongly acid to very strongly acid.







32 SOIL SURVEY

The Mayo soils occupy the same landscape as the Pan- is along the coast at an elevation in the semiarid area.
dura, Teja, Candelero, and Maunabo soils. They are deeper Included with it in mapping were small areas of Coastal
than the Pandura and Teja soils. The Mayo soils are beaches Ti fl
better drained and coarser textured than the Candelero and beaches and Tidal flats.
Maunabo soils, and they are at a higher elevation than the This soil is not suited to cultivated crops. Low avail-
Maunabo soils. able water capacity, very low fertility, and rapid per-
MIC--Mayo loam, 3 to 10 percent slopes. This soil meability are severe limitations, and rainfall is low.
is on alluvial fans and terraces along the Guayanes The soil is suitable for pasture, coconut trees, and wild-
Valley. Included with it in mapping were small areas of life food and cover. Capability unit VIIs-7.
Candelero soils.
This soil has moderate limitations for farming. If Mucara Series
the soil is clean cultivated, conservation practices are
needed to control erosion. The soil is easily worked, has The Mucara series consists of moderately deep soils
a low available water capacity, and responds well to that are well drained and moderately permeable. These
lime and fertilizer. It is suited to food crops, sugarcane, soils formed in residuum derived from basic volcanic
and pasture. Capability unit IIIe-10. rocks. They are on side slopes and ridgetops of strongly
dissected volcanic uplands. Slopes are 12 to 40 percent.
Meros Series The climate is humid tropical. The average annual pre-
cipitation is 75 to 80 inches, and the average annual
The Meros series consists of deep soils that are ex- temperature is 760 F.
cessively drained and rapidly permeable. These soils In a representative profile, the surface layer is very
formed in fine sandy sediment derived from sand-sized dark grayish-brown, medium acid silty clay loam about
volcanic rock fragments, seashells, and coral. They are 6 inches thick. Below that layer is very dark grayish-
on benches along the coast slightly above sea level, brown and yellowish-brown, firm silty clay 7 inches
Slopes are 1 to 6 percent. The climate is semiarid thick. The next layer is light olive-brown, firm silty
tropical. The average annual precipitation is 35 to 40 clay loam that extends to a depth of 32 inches. It is
inches, and the average annual temperature is 790 F. underlain by semiconsolidated volcanic rock.
In a representative profile, the surface layer is very These soils are fertile and have high available water
dark grayish-brown, neutral fine sand in the upper 8 capacity and moderate shrink-swell potential. Runoff
inches and very dark brown fine sand in the lower 6 is medium to rapid. The soils are somewhat difficult to
inches. The underlying material is very dark grayish- work. They have been used mainly for pasture, coffee
brown, dark yellowish-brown, black, and olive-brown, trees, and food crops, but some areas are in sugarcane.
loose sand that extends to a depth of 60 inches. Representative profile of Mucara silty clay loam, 20
These soils have a very low available water capacity to 40 percent slopes, eroded, 45 meters southwest of
and very low fertility. Runoff is slow. The soils have kilometer marker 1.2 on Highway No. 449, Ward Paso
been in pasture and coconut trees for many years. Seco, Naguabo:
Representative profile of Meros sand, 1 to 6 percent A1-0 to 6 inches, very dark grayish-brown (10YR 3/2)
slopes, 45 meters north of kilometer marker 93.8 on silty clay loam; weak, fine, subangular blocky
Highway No. 1: structure; hard, firm, slightly sticky and slightly
A11-0 inch, erdark gayish-brown (R 3/2) plastic; common fine roots; few fine pores; com-
A11-0 to 8 inches, very dark grayish-brown (10YR 3/2) mon fine rock fragments; few worm casts; me-
fine sand; single grained; loose, nonsticky and dium acid; abrupt, smooth boundary.
noplastic; many fine roots; common, fine, black B2-6 to u ched; abru y bon (1YR 8/2)
minerals; neutral; clear, smooth boundary. B2--6 to 9 inches, very dark grayish-brown (10YR 3/2)
A12-8 to 14 inches, very dark brown (10YR 2/2) fine silty clay, inside color of peds is very dark
sand; single grained; loose, nonsticky and non- grayish-brown (2.5Y 3/2); weak, medium, sub-
plastic; few fine roots; many, fine, black minerals; angular blocky structure; hard, firm, slightly
neutral; clear, smooth boundary. sticky and slightly plastic; few fine roots; few
C1-14 to 22 inches, very dark grayish-brown (2.5Y 3/2) fine pores; few patchy clay films along cleavage
fine sand; single grained; loose, nonsticky and planes; common, fine, angular rock fragments;
nonplastic; few fine roots; neutral; clear, smooth few worm casts; medium acid; clear, smooth
boundary. boundary.
C2-22 to 40 inches, dark yellowish-brown (10YR 4/4) and B3-9 to 13 inches, yellowish-brown (10YR 5/4) silty clay;
black (10YR 2/1) sand; single grained; loose, weak, medium, subangular blocky structure; hard,
nonstick and nonplastic; mildly alkaline; clear, firm, slightly sticky and slightly plastic; few dead
smooth boundary. roots; common, fine, weathered rock fragments;
C3-40 to 50 inches, olive-brown (2.5Y 4/4) sand; single few dark minerals; few patchy clay films along
grained; loose, nonsticky and nonplastic; mildly cleavage planes; root channels coated with dark
alkaline; clear, smooth boundary. brown (10YR 3/3); medium acid; clear, smooth
C4-50 to 60 inches, very dark grayish-brown (2.5Y 3/2) boun da ry.
sand; single grained; loose, nonsticky and non- C-13 to 18 inches, light olive-brown (2.5Y 5/4), crushed,
plastic; moderately alkaline. sticky and slightly plastic; common dark minerals;
common, fine, dead roots; few fine pores; many
The A horizon is 12 to 20 inches thick. It has value fine rock fragments weathered in place; medium
and chroma of 2 or 3. The C horizon has hue of 10YR to acid; gradual, smooth boundary.
2.5Y, value of 3 or 4, and chroma of 2 to 4. Reaction ranges C2-18 to 32 inches, pale-yellow (2.5 7/4) clay loam;
from neutral to moderately alkaline. massive; hard, firm, slightly sticky and slightly
The Meros soils are on the same landscape as Coastal plastic; most of this horizon is saprolite; com-
beaches and Tidal flats. Coastal beaches consist of mis- mon dark minerals; slightly acid; gradual, wavy
cellaneous sandy material that has been reworked by wave boundary.
action. Tidal flats consist of miscellaneous materials that R-32 inches, semiconsolidated volcanic rock.
are covered by seawater of high tide.
MrB- eros sand, to percent lope. Thi oil The solum is 10 to 20 inches thick. The A horizon has
MrB-Meros sand, 1 to 6 percent slopes. This soil hue of 10YR or 2.5Y and chroma of 2 or 3. The B horizon







32 SOIL SURVEY

The Mayo soils occupy the same landscape as the Pan- is along the coast at an elevation in the semiarid area.
dura, Teja, Candelero, and Maunabo soils. They are deeper Included with it in mapping were small areas of Coastal
than the Pandura and Teja soils. The Mayo soils are beaches Ti fl
better drained and coarser textured than the Candelero and beaches and Tidal flats.
Maunabo soils, and they are at a higher elevation than the This soil is not suited to cultivated crops. Low avail-
Maunabo soils. able water capacity, very low fertility, and rapid per-
MIC--Mayo loam, 3 to 10 percent slopes. This soil meability are severe limitations, and rainfall is low.
is on alluvial fans and terraces along the Guayanes The soil is suitable for pasture, coconut trees, and wild-
Valley. Included with it in mapping were small areas of life food and cover. Capability unit VIIs-7.
Candelero soils.
This soil has moderate limitations for farming. If Mucara Series
the soil is clean cultivated, conservation practices are
needed to control erosion. The soil is easily worked, has The Mucara series consists of moderately deep soils
a low available water capacity, and responds well to that are well drained and moderately permeable. These
lime and fertilizer. It is suited to food crops, sugarcane, soils formed in residuum derived from basic volcanic
and pasture. Capability unit IIIe-10. rocks. They are on side slopes and ridgetops of strongly
dissected volcanic uplands. Slopes are 12 to 40 percent.
Meros Series The climate is humid tropical. The average annual pre-
cipitation is 75 to 80 inches, and the average annual
The Meros series consists of deep soils that are ex- temperature is 760 F.
cessively drained and rapidly permeable. These soils In a representative profile, the surface layer is very
formed in fine sandy sediment derived from sand-sized dark grayish-brown, medium acid silty clay loam about
volcanic rock fragments, seashells, and coral. They are 6 inches thick. Below that layer is very dark grayish-
on benches along the coast slightly above sea level, brown and yellowish-brown, firm silty clay 7 inches
Slopes are 1 to 6 percent. The climate is semiarid thick. The next layer is light olive-brown, firm silty
tropical. The average annual precipitation is 35 to 40 clay loam that extends to a depth of 32 inches. It is
inches, and the average annual temperature is 790 F. underlain by semiconsolidated volcanic rock.
In a representative profile, the surface layer is very These soils are fertile and have high available water
dark grayish-brown, neutral fine sand in the upper 8 capacity and moderate shrink-swell potential. Runoff
inches and very dark brown fine sand in the lower 6 is medium to rapid. The soils are somewhat difficult to
inches. The underlying material is very dark grayish- work. They have been used mainly for pasture, coffee
brown, dark yellowish-brown, black, and olive-brown, trees, and food crops, but some areas are in sugarcane.
loose sand that extends to a depth of 60 inches. Representative profile of Mucara silty clay loam, 20
These soils have a very low available water capacity to 40 percent slopes, eroded, 45 meters southwest of
and very low fertility. Runoff is slow. The soils have kilometer marker 1.2 on Highway No. 449, Ward Paso
been in pasture and coconut trees for many years. Seco, Naguabo:
Representative profile of Meros sand, 1 to 6 percent A1-0 to 6 inches, very dark grayish-brown (10YR 3/2)
slopes, 45 meters north of kilometer marker 93.8 on silty clay loam; weak, fine, subangular blocky
Highway No. 1: structure; hard, firm, slightly sticky and slightly
A11-0 inch, erdark gayish-brown (R 3/2) plastic; common fine roots; few fine pores; com-
A11-0 to 8 inches, very dark grayish-brown (10YR 3/2) mon fine rock fragments; few worm casts; me-
fine sand; single grained; loose, nonsticky and dium acid; abrupt, smooth boundary.
noplastic; many fine roots; common, fine, black B2-6 to u ched; abru y bon (1YR 8/2)
minerals; neutral; clear, smooth boundary. B2--6 to 9 inches, very dark grayish-brown (10YR 3/2)
A12-8 to 14 inches, very dark brown (10YR 2/2) fine silty clay, inside color of peds is very dark
sand; single grained; loose, nonsticky and non- grayish-brown (2.5Y 3/2); weak, medium, sub-
plastic; few fine roots; many, fine, black minerals; angular blocky structure; hard, firm, slightly
neutral; clear, smooth boundary. sticky and slightly plastic; few fine roots; few
C1-14 to 22 inches, very dark grayish-brown (2.5Y 3/2) fine pores; few patchy clay films along cleavage
fine sand; single grained; loose, nonsticky and planes; common, fine, angular rock fragments;
nonplastic; few fine roots; neutral; clear, smooth few worm casts; medium acid; clear, smooth
boundary. boundary.
C2-22 to 40 inches, dark yellowish-brown (10YR 4/4) and B3-9 to 13 inches, yellowish-brown (10YR 5/4) silty clay;
black (10YR 2/1) sand; single grained; loose, weak, medium, subangular blocky structure; hard,
nonstick and nonplastic; mildly alkaline; clear, firm, slightly sticky and slightly plastic; few dead
smooth boundary. roots; common, fine, weathered rock fragments;
C3-40 to 50 inches, olive-brown (2.5Y 4/4) sand; single few dark minerals; few patchy clay films along
grained; loose, nonsticky and nonplastic; mildly cleavage planes; root channels coated with dark
alkaline; clear, smooth boundary. brown (10YR 3/3); medium acid; clear, smooth
C4-50 to 60 inches, very dark grayish-brown (2.5Y 3/2) boun da ry.
sand; single grained; loose, nonsticky and non- C-13 to 18 inches, light olive-brown (2.5Y 5/4), crushed,
plastic; moderately alkaline. sticky and slightly plastic; common dark minerals;
common, fine, dead roots; few fine pores; many
The A horizon is 12 to 20 inches thick. It has value fine rock fragments weathered in place; medium
and chroma of 2 or 3. The C horizon has hue of 10YR to acid; gradual, smooth boundary.
2.5Y, value of 3 or 4, and chroma of 2 to 4. Reaction ranges C2-18 to 32 inches, pale-yellow (2.5 7/4) clay loam;
from neutral to moderately alkaline. massive; hard, firm, slightly sticky and slightly
The Meros soils are on the same landscape as Coastal plastic; most of this horizon is saprolite; com-
beaches and Tidal flats. Coastal beaches consist of mis- mon dark minerals; slightly acid; gradual, wavy
cellaneous sandy material that has been reworked by wave boundary.
action. Tidal flats consist of miscellaneous materials that R-32 inches, semiconsolidated volcanic rock.
are covered by seawater of high tide.
MrB- eros sand, to percent lope. Thi oil The solum is 10 to 20 inches thick. The A horizon has
MrB-Meros sand, 1 to 6 percent slopes. This soil hue of 10YR or 2.5Y and chroma of 2 or 3. The B horizon







HUMACAO AREA OF EASTERN PUERTO RICO 33

has hue of 10YR or 2.5Y, value of 3 to 5, and chroma of Representative profile of Naranjito silty clay loam,
2 to 4. It is silty clay or clay and has weak, medium or 20 to 40 percent slopes, eroded, 1.6 kilometers east from
coarse, subangular blocky structure. Reaction is slightly junction of Highway No. 924 and Highway No. 927
acid or medium acid.
The Mucara soils occupy the same landscape as the and 450 meters northwest from Highway No. 927, Ward
Caguabo, Sabana, Naranjito, and Humatas soils. The Mambiche, Humacao:
Mucara soils are deeper to rock than the Caguabo and
Sabana soils, and they have a thicker solum than the Ap-0 to 7 inches, dark-brown (10YR 3/3) silty clay loam;
Caguabo soils. They lack red colors and are less acid than weak, fine, subangular blocky structure; very hard,
the Naranjito and Humatas soils, and they are shallower friable, slightly sticky and slightly plastic; com-
than the Humatas soils. mon roots; thin clay films on root channels; few
V4- to 1-inch volcanic rock fragments; extremely
MuD2-Mucara silty clay loam, 12 to 20 percent acid; clear, smooth boundary.
slopes, eroded. This soil is on side slopes in the humid B21t-7 to 20 inches, yellowish-red (5YR 4/6) clay; weak,
fine. subangular blocky structure; very hard, firm,
volcanic uplands. It has a thicker surface layer than the slightly sticky and slightly plastic; thin, patchy,
soil described as representative of the Mucara series, dark-brown (10YR 3/3) clay films; few krotovinas;
Erosion has removed some of the original surface layer many, angular, /s- to 2-inch volcanic rock frag-
of this soil, and in places that have been cultivated in- ments; very strongly acid; gradual, smooth bound-
tensely, plowing has mixed the remaining part of that 22t-20 to 30 inches, yellowish-red (5YR 4/6, 5YR 4/8)
layer with some of the subsoil. Small rills and shallow and yellowish-brown (10YR 5/4) clay; weak, fine,
gullies are common. Included with this soil in mapping subangular blocky structure; very hard, firm,
were small areas of Caguabo, Naranjito, and Sabana slightly sticky and plastic; thin dark-brown (10YR
3/3) clay films; few krotovinas; thin clay films
soils and Rock land. along root channels and worm holes; many, angu-
Slope, medium runoff, the hazard of erosion, and lar, Vs- to 2-inch volcanic rock fragments; about
depth to rock are severe limitations for farming. This 40 percent, by volume, is saprolite; very strongly
soil is somewhat difficult to work, and it requires very acid; gradual, smooth boundary.
careful management if it is clean cultivated. It has been c-3 4 38 inches, yellowish-red (25YR 4/6), red (2.5R
4/6), and light olive-brown (2.5Y 5/4) clay loam;
used for food crops, coffee trees, and native pasture. weak, fine, subangular' blocky structure; hard,
Capability unit IVe-6; woodland suitability group firm, slightly sticky and plastic; common, fine,
3d5. dark concretions; many, angular, 1/s- to 3-inch
rock fragments; about 40 percent is saprolite;
MuE2-Mucara silty clay loam, 20 to 40 percent very strongly acid; abrupt, smooth boundary.
slopes, eroded. This soil is on side slopes and ridgetops R-38 inches, semiconsolidated volcanic rock.
in the humid volcanic uplands. It has the profile de- The solum is 23 to 40 inches thick. The Ap horizon has
scribed as representative of the series. As a result of chroma of 3 or 4. The B horizon has hue of 5YR or 2.5YR,
past cultivation, erosion has removed part of the origi- value of 4 or 5, and chroma of 6 to 8. Rock fragments
nal surface layer, and in some places the yellowish- scattered throughout the profile range from few to many
and from 1/s inch to 3 inches in size. Reaction ranges from
brown subsoil is exposed. Included with this soil in extremely acid to strongly acid.
mapping were areas of Caguabo and Sabana soils and The Naranjito soils are on the same landscape as the
Rock land. Caguabo, Sabana, Mucara, and Humatas soils. The Naran-
This soil is not suited to clean-cultivated crops. jito soils are deeper and more acid than the Caguabo soils.
Slopes, rapid runoff, depth to volcanic rock, and the They are deeper to semiconsolidated rock than the Sabana
Slopes, rapid runoff, depth to volcanic rock, and the soils and are more acid than the Mucara soils. The Naran-
hazard of erosion are severe limitations for farming. jito soils are shallower to rock than the Humatas soils.
This soil has been cultivated occasionally to pigeonpeas, Nra s r
tobacco, and food crops. It is better suited to pasture NaE2-Naranjito silty clay loam, 20 to 40 percent
and woodland than to most other uses. Capability unit slopes, eroded. This soil is on side slopes in the humid
VIe-4; woodland suitability group 3d5. uplands. It has the profile described as representative
e4 woodland of the series. As a result of past cultivation, most of the
original surface layer has been removed by erosion. In-
Naranjito Series cluded with this soil in mapping were small areas of
Mucara, Caguabo, and Humatas soils.
The Naranjito series consists of moderately deep This soil is used occasionally for cultivated crops.
soils that are well drained and moderately permeable. Steep slopes, the hazard of erosion, and rapid runoff
These soils formed in moderately fine textured re- are severe limitations that make the soil unsuited to
siduum weathered from volcanic rocks. They are in cultivated crops, however, and limit its use to pasture
strongly dissected volcanic uplands. Slopes are 20 to 60 and woodland. Capability unit VIe-1; woodland suit-
percent. The climate is humid tropical. The average ability group 2c5.
annual precipitation is 75 to 100 inches, and the aver- NaF2-Naranjito silty clay loam, 40 to 60 percent
age annual temperature is 790 F. slopes, eroded. This soil is on mountain side slopes and
In a representative profile, the surface layer is dark- ridgetops in the humid volcanic uplands. It has a thin-
brown, extremely acid silty clay loam about 7 inches ner surface layer than the soil described as representa-
thick. Below that is yellowish-red, yellowish-brown, tive of the series. Included with this soil in mapping
red, and light olive-brown clay and clay loam. Hard were small areas of Mucara, Caguabo, and Humatas
rock is at a depth of 38 inches. soils.
These soils have a high available water capacity, Very steep slopes, the hazard of erosion, and very
moderate shrink-swell potential, and medium fertility, rapid runoff are severe limitations for clean-cultivated
Runoff is rapid to very rapid, and the soils are suscep- crops. This soil is suitable for pasture, woodland, and
tible to erosion. They have been in food crops and pas- wildlife food and cover. Capability unit VIIe-1; wood-
ture for many years. land suitability group 3r5.







34 SOIL SURVEY

Pandura Series Slope, shallowness, and the hazard of erosion are se-
vere limitations for cultivated crops. This soil is occa-
The Pandura series consists of moderately deep soils sionally used for food crops, and it has been in pasture.
that are well drained and have moderately rapid per- It is better suited to pasture, woodland, and wildlife
meability. These soils formed in residuum derived food and cover than to most other uses. Capability unit
from partly weathered plutonic rocks, mainly quartz VIe-3; woodland suitability group 2o5.
diorite and granodiorite. They are on side slopes of dis- PaF2-Pandura loam, 40 to 60 percent slopes,
sected uplands. Slopes range from 12 to 60 percent. The eroded. This soil is on side slopes and ridgetops in
climate is humid tropical. The average annual precipi- highly dissected, humid uplands. It has a thinner sur-
tation is 75 to 85 inches, and the average annual tem- face layer than the soil described as representative of
perature is 780 F. the Pandura series. Most of the original surface layer
In a representative profile, the surface layer is dark- has been removed by erosion, and in some areas the
brown, strongly acid loam about 3 inches thick. The subsoil is exposed. Small areas of Teja and Lirios soils
next layer is dark grayish-brown, friable loam 4 inches and Rock land were included with this soil in mapping.
thick. Below that is light olive-brown, friable sandy This soil is not suited to clean-cultivated crops, and it
loam that extends to a depth of 19 inches. It is under- has severe limitations for cultivated crops because it is
lain by partly weathered rock. steep, shallow, and susceptible to erosion. Proper man-
These soils have a low available water capacity. Run- agement and conservation practices are required if this
off is medium to very rapid, and the soils are highly soil is cultivated. This soil has been in pasture and
susceptible to erosion. Most of the acreage is in pasture brush. It is better suited to pasture, woodland, and
and brush, but some areas are in food crops, wildlife food and cover than to most other uses. Capa-
Representative profile of Pandura loam, 12 to 40 per- ability unit VIIe-2; woodland suitability group 3r5.
cent slopes, eroded, 45 meters northeast of kilometer PdF-Pandura-Very stony land complex, 40 to 60
marker 23.9 on Highway No. 181: percent slopes. This mapping unit is on side slopes and
Ap-0 to 3 inches, dark-brown (10YR 3/3) loam; weak, ridgetops in the humid granitic uplands. It consists of
fine, granular structure; friable, slightly sticky Pandura soils and Very stony land in such intricate
and slightly plastic; many fine roots; many fine patterns that they cannot be shown separately at the
quartz grains; many worm casts; strongly acid; scale used in mapping. The Pandura soils make up
clear, smooth boundary.
B2-3 to 7 inches, dark grayish-brown (10YR 4/2) loam; about 30 to 40 percent of the mapping unit, and Very
weak, medium, subangular blocky structure; fri- stony land 40 to 50 percent. The remaining area con-
able, slightly sticky and slightly plastic; many sists of soils that are too variable to be classified.
fine roots; thin patchy clay films on ped surfaces; The soils of this mapping unit are not suited to clean-
many fine quartz grains; many worm casts; many,
fine, dark-colored, highly weathered minerals; cultivated crops, and because they are steep, rocky, and
strongly acid; gradual, smooth boundary, shallow, they have severe limitations for cultivated
C1-7 to 15 inches, light olive-brown (2.5Y 5/4) sandy crops. They are suitable for pasture and wildlife food
loam; massive; iable, nonstick and nonplastic; and cover. Capability unit VIIs-5; woodland suitabil-
few fine roots; many fine quartz grains; medium
acid; gradual, wavy boundary. ity group 4d5.
C2-15 to 19 inches, light olive-brown (2.5Y 5/4) sandy loam;
massive; friable, nonsticky and nonplastic; very
few fine roots; slightly acid; gradual, wavy Parcelas Series
boundary.
C3-19 to 35 inches, partly weathered rock. The Parcelas series consists of deep, moderately well
The solum is 6 to 14 inches thick. The A horizon has drained soils that have moderately slow permeability.
hue of 10YR, value of 2 or 3, and chroma of 2 or 3. The B These soils formed in fine-textured sediment derived
horizon has hue of 10YR, value of 3 or 4, and chroma of 2
to 4. It ranges from loam to sandy loam and has weak from plutonic materials. They are on foot slopes, allu-
subangular blocky to weak granular structure. The C hori- vial fans, and terraces. Slopes are 5 to 12 percent. The
zon has hue of 2.5Y, value of 5 or 6, and chroma of 2 to 4. climate is humid tropical. The average annual precipi-
It ranges from strongly acid to slightly acid. station is 80 to 90 inches, and the average annual tem-
The Pandura soils are on the same landscape as the
Teja, Mayo, Limones, Ingenio, Lirios, and Jagueyes soils, perature is 770 F.
Pandura soils are finer textured and deeper to granitic In a representative profile, the surface layer is dark-
rocks than Teja soils, and, unlike those soils, they have a brown, extremely acid clay about 7 inches thick. Be-
B horizon. They are shallower and have a thinner solum low that is dark reddish-brown and dark-brown, firm
than the Mayo soils. The Pandura soils are shallower and
coarser textured than the Limones, Ingenio, Lirios, and clay 24 inches thick. The underlying material is
Jagueyes soils; they have a thinner solum than all those yellowish-brown clay and clay loam that extends to a
soils and lack their red colors, depth of 60 inches.
PaE2-Pandura loam, 12 to 40 percent slopes, These soils have a high available water capacity and
eroded. This soil is on the sides and tops of ridges in high shrink-swell potential. Runoff is medium. The soils
the west-central part of the survey area. It has the pro- are difficult to work and are susceptible to erosion.
file described as representative of the Pandura series. Most areas have been in sugarcane and pasture, but
Erosion has removed most of the original surface layer, some areas are in food crops.
and where the soil is clean cultivated, tillage has mixed Representative profile of Parcelas clay, 5 to 12 per-
the remaining part of that layer with some of the sub- cent slopes, eroded, 300 meters south of kilometer
soil. In some areas the subsoil is exposed. Included with marker 3.6 on Highway No. 901, Barrio Nuevo, munic-
this soil in mapping were small areas of Teja, Lirios, ipality of Yabucoa:
Jagueyes, and Ingenio soils. Ap-0 to 7 inches, dark-brown (7.5YR 3/2) clay; weak,







34 SOIL SURVEY

Pandura Series Slope, shallowness, and the hazard of erosion are se-
vere limitations for cultivated crops. This soil is occa-
The Pandura series consists of moderately deep soils sionally used for food crops, and it has been in pasture.
that are well drained and have moderately rapid per- It is better suited to pasture, woodland, and wildlife
meability. These soils formed in residuum derived food and cover than to most other uses. Capability unit
from partly weathered plutonic rocks, mainly quartz VIe-3; woodland suitability group 2o5.
diorite and granodiorite. They are on side slopes of dis- PaF2-Pandura loam, 40 to 60 percent slopes,
sected uplands. Slopes range from 12 to 60 percent. The eroded. This soil is on side slopes and ridgetops in
climate is humid tropical. The average annual precipi- highly dissected, humid uplands. It has a thinner sur-
tation is 75 to 85 inches, and the average annual tem- face layer than the soil described as representative of
perature is 780 F. the Pandura series. Most of the original surface layer
In a representative profile, the surface layer is dark- has been removed by erosion, and in some areas the
brown, strongly acid loam about 3 inches thick. The subsoil is exposed. Small areas of Teja and Lirios soils
next layer is dark grayish-brown, friable loam 4 inches and Rock land were included with this soil in mapping.
thick. Below that is light olive-brown, friable sandy This soil is not suited to clean-cultivated crops, and it
loam that extends to a depth of 19 inches. It is under- has severe limitations for cultivated crops because it is
lain by partly weathered rock. steep, shallow, and susceptible to erosion. Proper man-
These soils have a low available water capacity. Run- agement and conservation practices are required if this
off is medium to very rapid, and the soils are highly soil is cultivated. This soil has been in pasture and
susceptible to erosion. Most of the acreage is in pasture brush. It is better suited to pasture, woodland, and
and brush, but some areas are in food crops, wildlife food and cover than to most other uses. Capa-
Representative profile of Pandura loam, 12 to 40 per- ability unit VIIe-2; woodland suitability group 3r5.
cent slopes, eroded, 45 meters northeast of kilometer PdF-Pandura-Very stony land complex, 40 to 60
marker 23.9 on Highway No. 181: percent slopes. This mapping unit is on side slopes and
Ap-0 to 3 inches, dark-brown (10YR 3/3) loam; weak, ridgetops in the humid granitic uplands. It consists of
fine, granular structure; friable, slightly sticky Pandura soils and Very stony land in such intricate
and slightly plastic; many fine roots; many fine patterns that they cannot be shown separately at the
quartz grains; many worm casts; strongly acid; scale used in mapping. The Pandura soils make up
clear, smooth boundary.
B2-3 to 7 inches, dark grayish-brown (10YR 4/2) loam; about 30 to 40 percent of the mapping unit, and Very
weak, medium, subangular blocky structure; fri- stony land 40 to 50 percent. The remaining area con-
able, slightly sticky and slightly plastic; many sists of soils that are too variable to be classified.
fine roots; thin patchy clay films on ped surfaces; The soils of this mapping unit are not suited to clean-
many fine quartz grains; many worm casts; many,
fine, dark-colored, highly weathered minerals; cultivated crops, and because they are steep, rocky, and
strongly acid; gradual, smooth boundary, shallow, they have severe limitations for cultivated
C1-7 to 15 inches, light olive-brown (2.5Y 5/4) sandy crops. They are suitable for pasture and wildlife food
loam; massive; iable, nonstick and nonplastic; and cover. Capability unit VIIs-5; woodland suitabil-
few fine roots; many fine quartz grains; medium
acid; gradual, wavy boundary. ity group 4d5.
C2-15 to 19 inches, light olive-brown (2.5Y 5/4) sandy loam;
massive; friable, nonsticky and nonplastic; very
few fine roots; slightly acid; gradual, wavy Parcelas Series
boundary.
C3-19 to 35 inches, partly weathered rock. The Parcelas series consists of deep, moderately well
The solum is 6 to 14 inches thick. The A horizon has drained soils that have moderately slow permeability.
hue of 10YR, value of 2 or 3, and chroma of 2 or 3. The B These soils formed in fine-textured sediment derived
horizon has hue of 10YR, value of 3 or 4, and chroma of 2
to 4. It ranges from loam to sandy loam and has weak from plutonic materials. They are on foot slopes, allu-
subangular blocky to weak granular structure. The C hori- vial fans, and terraces. Slopes are 5 to 12 percent. The
zon has hue of 2.5Y, value of 5 or 6, and chroma of 2 to 4. climate is humid tropical. The average annual precipi-
It ranges from strongly acid to slightly acid. station is 80 to 90 inches, and the average annual tem-
The Pandura soils are on the same landscape as the
Teja, Mayo, Limones, Ingenio, Lirios, and Jagueyes soils, perature is 770 F.
Pandura soils are finer textured and deeper to granitic In a representative profile, the surface layer is dark-
rocks than Teja soils, and, unlike those soils, they have a brown, extremely acid clay about 7 inches thick. Be-
B horizon. They are shallower and have a thinner solum low that is dark reddish-brown and dark-brown, firm
than the Mayo soils. The Pandura soils are shallower and
coarser textured than the Limones, Ingenio, Lirios, and clay 24 inches thick. The underlying material is
Jagueyes soils; they have a thinner solum than all those yellowish-brown clay and clay loam that extends to a
soils and lack their red colors, depth of 60 inches.
PaE2-Pandura loam, 12 to 40 percent slopes, These soils have a high available water capacity and
eroded. This soil is on the sides and tops of ridges in high shrink-swell potential. Runoff is medium. The soils
the west-central part of the survey area. It has the pro- are difficult to work and are susceptible to erosion.
file described as representative of the Pandura series. Most areas have been in sugarcane and pasture, but
Erosion has removed most of the original surface layer, some areas are in food crops.
and where the soil is clean cultivated, tillage has mixed Representative profile of Parcelas clay, 5 to 12 per-
the remaining part of that layer with some of the sub- cent slopes, eroded, 300 meters south of kilometer
soil. In some areas the subsoil is exposed. Included with marker 3.6 on Highway No. 901, Barrio Nuevo, munic-
this soil in mapping were small areas of Teja, Lirios, ipality of Yabucoa:
Jagueyes, and Ingenio soils. Ap-0 to 7 inches, dark-brown (7.5YR 3/2) clay; weak,







HUMACAO AREA OF EASTERN PUERTO RICO 35

fine, subangular blocky structure; firm, slightly Representative profile of Paso Seco clay, 0 to 5 per-
sticky and plastic; many fine roots; extremely cent slopes, 9 meters north of farm road that borders
acid; clear, wavy boundary.
1-7 to 17 inches, dark reddish-brown (5YR 3/3) clay; the main irrigation canal, 0.2 kilometer west of Colonia
weak, medium, subangular blocky structure; firm, house, and 0.9 kilometer south of Highway No. 3 at
sticky and plastic; common fine roots; extremely kilometer marker 185.2, Colonia Sabater, Aguirre:
acid; clear, smooth boundary.
B2-17 to 31 inches, dark-brown (7.5YR 4/4) clay; com- Ap-0 to 5 inches, dark-brown (7.5YR 3/2) clay; weak,
mon, medium, distinct, yellowish-brown (10YR fine. subangular blocky structure; friable, slightly
5/8) mottles; weak, medium, subangular blocky sticky and slightly plastic; few roots; common
structure; firm, sticky and plastic; few fine roots; pebbles; few black minerals; neutral; gradual,
few small slickensides and pressure faces; ex- smooth boundary.
tremely acid; clear, smooth boundary. A12-5 to 13 inches, dark-brown (7.5YR 3/2) clay; weak,
C1-31 to 44 inches, yellowish-brown (10YR 5/6) clay; medium, subangular blocky structure; firm, slightly
massive; firm, slightly sticky and plastic; very sticky and plastic; few pores; few roots; common
fine roots; few small slickensides and pressure pressure faces; few black stains along root chan-
faces; strongly acid; clear, smooth boundary, nels and ped surfaces; common pebbles; few, small,
C2--44 to 60 inches, yellowish-brown (10YR 5/8) clay soft, black concretions; mildly alkaline; abrupt,
loam; massive; friable, slightly sticky and plastic; wavy boundary.
strongly acid. C1-13 to 19 inches, brown to dark-brown (7.5YR 4/4)
clay; weak, medium, angular blocky structure;
The solum is 22 to 37 inches thick. The Ap horizon has firm, slightly sticky and plastic; very dark grayish-
hue of 7.5YR or 10YR and value and chroma of 2 or 3. brown coatings along root channels and ped sur-
The B horizon has hue of 5YR or 7.5YR, value of 3 or 4, faces; common slickensides and pressure faces;
and chroma of 4 or higher. It has weak, medium or coarse, mildly alkaline; clear, wavy boundary.
subangular blocky structure. The C horizon has hue of C2-19 to 38 inches, brown to dark-brown (7.5YR 4/4)
10YR or 7.5YR, value of 4 or 5, and chroma of 4 to 8. gravelly clay; massive; firm, slightly sticky and
Slickensides and pressure faces range from few to com- plastic; mildly alkaline; clear, wavy boundary.
mon. Reaction ranges from strongly acid to extremely acid. IIC3-38 to 50 inches, brown to dark-brown (10YR 4/3)
The Parcelas soils occupy the same landscape as the gravelly loam; massive; friable, nonsticky and
Mayo, Pandura, Teja, and Candelero soils. The Parcelas nonplastic; neutral.
soils are finer textured than the Mayo and Pandura soils,
and unlike the Pandura soils, they have slickensides and The A horizon is 8 to 18 inches thick. It has hue of 10YR
pressure faces. They are on lower slopes and are deeper or 7.5YR and value and chroma of 2 or 3. The C horizon
than the Teja soils. The Parcelas soils are better drained has hue of 10YR or 7.5YR and value and chroma of 3 or
than the Candelero soils, and they have pressure faces and 4. Slickensides are common or many. Depth to gravelly
slickensides. horizons is 20 to 37 inches. Reaction is neutral to mildly
alkaline.
PeC2-Parcelas clay, 5 to 12 percent slopes, eroded. The Paso Seco soils are on the same landscape as the
This soil is on foot slopes and terraces. Erosion has Fraternidad, Jacana, Amelia, and Coamo soils. The Paso
removed some of the original surface layer, and where Seco soils are shallower to gravelly horizons than the
Fraternidad soils. Unlike the Jacana soils, they lack a B
the soil is cultivated, the plow layer is a mixture of the horizon and are not underlain by volcanic rocks. The Paso
remaining dark-brown surface layer and the reddish- Seco soils are neutral to mildly alkaline, whereas the
brown subsoil. Included with this soil in mapping were Amelia soils are neutral to medium acid. Unlike the Coamo
small areas of Candelero and Mayo soils, soils, the Paso Seco soils lack a B2t horizon and have
This soil has moderate limitations for clean- pressure faces and slickensides.
cultivated crops because of slope, drainage, the hazard P1B-Paso Seco clay, 0 to 5 percent slopes. This
of erosion, and high clay content. If the soil is clean soil is on terraces and alluvial fans in the semiarid part
cultivated, careful management and conservation prac- of the survey area. Included with it in mapping were
tices are required. If it is properly drained and limed, small areas of Fraternidad and Amelia soils.
the soil is suited to sugarcane, pasture, cut grasses, and The soil's high shrink-swell potential and poor work-
food crops. Capability unit IIIe-7. ability are limitations for farming, and the climate in
the area is adverse. This soil commonly has been used
for pasture. If irrigated, the soil is suited to sugarcane,
Paso Seco Series pasture, and cut grasses. Capability units IIIc-1 non-

The Paso Seco series consists of deep soils that are irrigated and IIs-1 irrigated.
moderately well drained and slowly permeable. These
soils formed in fine-textured sediment of mixed origin Patillas Series
that overlies gravelly, medium-textured sediment. They
are on terraces and alluvial fans on the coastal plains. The Patillas series consists of deep soils that are well
Slopes are 0 to 5 percent. The climate is semiarid trop- drained and moderately permeable. These soils formed
ical. The average annual precipitation is 30 to 40 inches, in residuum that weathered from intrusive volcanic
and the average annual temperature is 790 F. rocks. They are on side slopes in dissected uplands.
In a representative profile, the surface layer is dark- Slopes are 12 to 40 percent. The climate is humid trop-
brown, neutral or mildly alkaline clay about 13 inches ical. The average annual precipitation is 60 to 70
thick. The next layer is brown to dark-brown, firm clay inches, and the average annual temperature is 790 F.
6 inches thick. It is underlain by brown to dark-brown In a representative profile, the surface layer is dark-
gravelly clay and gravelly loam that extends to a depth brown, strongly acid clay loam about 8 inches thick.
of 50 inches. The next layer is reddish-brown, friable clay loam that
These soils have a high available water capacity and extends to a depth of 19 inches. Below that is yellowish-
high shrink-swell potential and are difficult to work. red sandy loam saprolite.
They have been mainly in sugarcane, pasture, and These soils have a moderate available water capacity.
brush, but some areas are in cut grasses. Runoff is medium to rapid, and the soils are susceptible







HUMACAO AREA OF EASTERN PUERTO RICO 35

fine, subangular blocky structure; firm, slightly Representative profile of Paso Seco clay, 0 to 5 per-
sticky and plastic; many fine roots; extremely cent slopes, 9 meters north of farm road that borders
acid; clear, wavy boundary.
1-7 to 17 inches, dark reddish-brown (5YR 3/3) clay; the main irrigation canal, 0.2 kilometer west of Colonia
weak, medium, subangular blocky structure; firm, house, and 0.9 kilometer south of Highway No. 3 at
sticky and plastic; common fine roots; extremely kilometer marker 185.2, Colonia Sabater, Aguirre:
acid; clear, smooth boundary.
B2-17 to 31 inches, dark-brown (7.5YR 4/4) clay; com- Ap-0 to 5 inches, dark-brown (7.5YR 3/2) clay; weak,
mon, medium, distinct, yellowish-brown (10YR fine. subangular blocky structure; friable, slightly
5/8) mottles; weak, medium, subangular blocky sticky and slightly plastic; few roots; common
structure; firm, sticky and plastic; few fine roots; pebbles; few black minerals; neutral; gradual,
few small slickensides and pressure faces; ex- smooth boundary.
tremely acid; clear, smooth boundary. A12-5 to 13 inches, dark-brown (7.5YR 3/2) clay; weak,
C1-31 to 44 inches, yellowish-brown (10YR 5/6) clay; medium, subangular blocky structure; firm, slightly
massive; firm, slightly sticky and plastic; very sticky and plastic; few pores; few roots; common
fine roots; few small slickensides and pressure pressure faces; few black stains along root chan-
faces; strongly acid; clear, smooth boundary, nels and ped surfaces; common pebbles; few, small,
C2--44 to 60 inches, yellowish-brown (10YR 5/8) clay soft, black concretions; mildly alkaline; abrupt,
loam; massive; friable, slightly sticky and plastic; wavy boundary.
strongly acid. C1-13 to 19 inches, brown to dark-brown (7.5YR 4/4)
clay; weak, medium, angular blocky structure;
The solum is 22 to 37 inches thick. The Ap horizon has firm, slightly sticky and plastic; very dark grayish-
hue of 7.5YR or 10YR and value and chroma of 2 or 3. brown coatings along root channels and ped sur-
The B horizon has hue of 5YR or 7.5YR, value of 3 or 4, faces; common slickensides and pressure faces;
and chroma of 4 or higher. It has weak, medium or coarse, mildly alkaline; clear, wavy boundary.
subangular blocky structure. The C horizon has hue of C2-19 to 38 inches, brown to dark-brown (7.5YR 4/4)
10YR or 7.5YR, value of 4 or 5, and chroma of 4 to 8. gravelly clay; massive; firm, slightly sticky and
Slickensides and pressure faces range from few to com- plastic; mildly alkaline; clear, wavy boundary.
mon. Reaction ranges from strongly acid to extremely acid. IIC3-38 to 50 inches, brown to dark-brown (10YR 4/3)
The Parcelas soils occupy the same landscape as the gravelly loam; massive; friable, nonsticky and
Mayo, Pandura, Teja, and Candelero soils. The Parcelas nonplastic; neutral.
soils are finer textured than the Mayo and Pandura soils,
and unlike the Pandura soils, they have slickensides and The A horizon is 8 to 18 inches thick. It has hue of 10YR
pressure faces. They are on lower slopes and are deeper or 7.5YR and value and chroma of 2 or 3. The C horizon
than the Teja soils. The Parcelas soils are better drained has hue of 10YR or 7.5YR and value and chroma of 3 or
than the Candelero soils, and they have pressure faces and 4. Slickensides are common or many. Depth to gravelly
slickensides. horizons is 20 to 37 inches. Reaction is neutral to mildly
alkaline.
PeC2-Parcelas clay, 5 to 12 percent slopes, eroded. The Paso Seco soils are on the same landscape as the
This soil is on foot slopes and terraces. Erosion has Fraternidad, Jacana, Amelia, and Coamo soils. The Paso
removed some of the original surface layer, and where Seco soils are shallower to gravelly horizons than the
Fraternidad soils. Unlike the Jacana soils, they lack a B
the soil is cultivated, the plow layer is a mixture of the horizon and are not underlain by volcanic rocks. The Paso
remaining dark-brown surface layer and the reddish- Seco soils are neutral to mildly alkaline, whereas the
brown subsoil. Included with this soil in mapping were Amelia soils are neutral to medium acid. Unlike the Coamo
small areas of Candelero and Mayo soils, soils, the Paso Seco soils lack a B2t horizon and have
This soil has moderate limitations for clean- pressure faces and slickensides.
cultivated crops because of slope, drainage, the hazard P1B-Paso Seco clay, 0 to 5 percent slopes. This
of erosion, and high clay content. If the soil is clean soil is on terraces and alluvial fans in the semiarid part
cultivated, careful management and conservation prac- of the survey area. Included with it in mapping were
tices are required. If it is properly drained and limed, small areas of Fraternidad and Amelia soils.
the soil is suited to sugarcane, pasture, cut grasses, and The soil's high shrink-swell potential and poor work-
food crops. Capability unit IIIe-7. ability are limitations for farming, and the climate in
the area is adverse. This soil commonly has been used
for pasture. If irrigated, the soil is suited to sugarcane,
Paso Seco Series pasture, and cut grasses. Capability units IIIc-1 non-

The Paso Seco series consists of deep soils that are irrigated and IIs-1 irrigated.
moderately well drained and slowly permeable. These
soils formed in fine-textured sediment of mixed origin Patillas Series
that overlies gravelly, medium-textured sediment. They
are on terraces and alluvial fans on the coastal plains. The Patillas series consists of deep soils that are well
Slopes are 0 to 5 percent. The climate is semiarid trop- drained and moderately permeable. These soils formed
ical. The average annual precipitation is 30 to 40 inches, in residuum that weathered from intrusive volcanic
and the average annual temperature is 790 F. rocks. They are on side slopes in dissected uplands.
In a representative profile, the surface layer is dark- Slopes are 12 to 40 percent. The climate is humid trop-
brown, neutral or mildly alkaline clay about 13 inches ical. The average annual precipitation is 60 to 70
thick. The next layer is brown to dark-brown, firm clay inches, and the average annual temperature is 790 F.
6 inches thick. It is underlain by brown to dark-brown In a representative profile, the surface layer is dark-
gravelly clay and gravelly loam that extends to a depth brown, strongly acid clay loam about 8 inches thick.
of 50 inches. The next layer is reddish-brown, friable clay loam that
These soils have a high available water capacity and extends to a depth of 19 inches. Below that is yellowish-
high shrink-swell potential and are difficult to work. red sandy loam saprolite.
They have been mainly in sugarcane, pasture, and These soils have a moderate available water capacity.
brush, but some areas are in cut grasses. Runoff is medium to rapid, and the soils are susceptible






36 SOIL SURVEY

to erosion. They have been used for pasture and food Picacho Series
crops for many years, and some areas are used for
sugarcane. The Picacho series consists of deep, moderately well
Representative profile of Patillas clay loam, 20 to 40 drained soils that have moderately slow permeability.
percent slopes, eroded, 1.8 kilometers east from kilo- These soils formed in fine textured and moderately fine
meter marker 162.2 on Highway No. 3 and 1.25 kilo- textured residuum that weathered from igneous rocks.
meters southeast from Highway 757, in the vicinity of They are on upper side slopes and ridgetops in the hu-
Patillas: mid uplands. Slopes range from 20 to 50 percent. The
A1-0 to 8 inches, dark-brown (10YR 3/3) clay loam; average annual precipitation is 185 inches, and the av-
weak, fine, subangular blocky structure parting to erage annual temperature is 720 F.
moderate, medium, granular; friable, nonsticky In a representative profile, the surface layer is dark
and slightly plastic; common fine roots; few fine yellowish-brown, very strongly acid silty clay loam
pores; few, fine, black minerals; few fine quartz about 9 inches thick. Below that layer is yellowish-
crystals; common, fine, subrounded rock frag-
ments; strongly acid; clear, smooth boundary. brown and strong-brown, mottled clay that is very
B2t-8 to 19 inches, reddish-brown (5YR 4/4) clay loam; strongly acid and firm and extends to a depth of 28
weak, fine, subangular blocky structure; friable, inches. The next layer is reddish-yellow, very strongly
slightly sticky and slightly plastic; few fine roots; acid, firm clay 7 inches thick. The upper part of the
common fine pores; thin patchy clay films; few t The upper part of the
fine quartz grains; common, fine, subrounded rock underlying material is yellowish-red, very strongly
fragments; few weathered feldspar fragments; acid, friable clay loam and silty clay loam that ex-
strongly acid; clear, wavy boundary, tends to a depth of 65 inches. The lower part is sapro-
C-19 to 48 inches, yellowish-red (5YR 4/6) sandy loam; lite of variegated colors that extends to a depth of more
massive; friable, nonsticky and nonplastic; coat-
ings of finer textured material from B2t horizon than 72 inches.
on fracture planes; very strongly acid; this hori- These soils have a moderate available water capacity
zon consists of weathered plutonic rock (saprolite). and medium fertility. Runoff is medium to rapid. The
The solum is 15 to 24 inches thick. The A horizon has soils have been in hardwood trees and tree ferns for
hue of 10YR or 7.5YR and value and chroma of 3 or 4. many years.
The B2t horizon has hue of 7.5YR or 5YR, value of 4 or 5, In this survey area, Picacho soils are mapped only in
and chroma of 4 to 6. It ranges from silty clay loam to clay
loam and has weak, fine or medium, subangular blocky associations with Guayabota and Ciales soils and with
structure. The C horizon has hue of 7.5YR or 5YR and Utuado soils and Stony rock land.
value and chroma of 4 to 6. It is sandy loam or loamy Representative profile of Picacho silty clay loam, 20
sand. Quartz crystals vary from few to common. Reaction to 40 percent slopes, in an area of the Guayabota-Ciales-
is strongly acid or very strongly acid.
The Patillas soils are on the same landscape as the Picacho association, very steep, 42 meters south and 17
Limones, Pandura, and Lirios soils. The Patillas soils are meters east of kilometer marker 15.7 on Highway No.
coarser textured and have a thinner solum than the 191:
Limones soils. They are finer textured than the Pandura
soils, and unlike those soils, they have a B2t horizon. They A1-0 to 9 inches, dark yellowish-brown (10YR 4/4) silty
have a thinner solum than the Lirios soils, clay loam; weak, fine, subangular blocky structure;
friable, slightly sticky and slightly plastic; many
PmD2-Patillas clay loam, 12 to 20 percent slopes, fine to coarse roots; few fine pores; common, fine,
eroded. This soil is on side slopes in the humid plutonic silvery flakes; few, fine, dark minerals and quartz
uplands. It has a thicker surface layer than the soil grains; very strongly acid; clear, smooth boundary.
described as representative of the Patillas series. Be- B21t-9 to 19 inches, yellowish-brown (10YR 5/4) clay;
common, fine, distinct, gray and yellowish-red
cause this soil has been used intensively for food crops mottles; weak, coarse and medium, subanguar
and tobacco, most of its surface layer has been eroded, blocky structure; firm, slightly sticky and slightly
and in some areas the reddish-brown subsoil is exposed, plastic; few fine pores coated with brown; thin
Included with this soil in mapping were small areas of patchy clay films on ped surfaces and in root
Pandura, Limones, and Lirios soils channels; few krotovinas, % inch in diameter;
Pandura, Limones, and Lirios soils. common fine quartz grains; few, fine, dark minerals
Slope and the hazard of erosion are severe limitations and silvery flakes; very strongly acid; clear, wavy
for farming. This soil is used occasionally for cultivated boundary.
crops and has been used for pasture and food crops for B22t-19 to 28 inches, strong-brown (7.5YR 5/8) clay; com-
mon, fine, distinct, olive-gray mottles; weak,
many years. Good management and conservation prac- coarse and medium, subangular blocky structure;
tices are needed if the soil is cultivated. If it is properly firm, slightly sticky and plastic; few fine and
limed and managed, the soil is suited to sugarcane, medium roots; few fine pores; thin patchy clay
food crops, pasture, and woodland. Capability unit films on ped surfaces and in root channels; many
IVe-7; woodland suitability group 205. coated quartz grains; common, fine, dark minerals;
IVe-7; woodland suitability group 205. few, fine, silvery flakes; few krotovinas; very
PmE2-Patillas clay loam, 20 to 40 percent slopes, strongly acid; gradual, smooth boundary.
eroded. This soil is on side slopes in the humid uplands. B3-28 to 35 inches, reddish-yellow (7.5YR 6/8) clay;
It has the profile described as representative of the se- weak, fine and medium, subangular blocky struc-
ries. Included with this soil in mapping were small ture; firm, slightly sticky and plastic; few fine
reas o Pndura and Lirios soils in m apng w all pores; thin patchy clay films on ped surfaces and
areas of Pandura and Lirios soils and Rock land. in root channels; common fine quartz grains and
Slope and the hazard of erosion are severe limitations silvery flakes; few krotovinas; very strongly acid;
for clean cultivation. Conservation practices are needed clear, smooth boundary.
if the soil is cultivated. This soil has been used for C1-35 to 48 inches, yellowish-red (5YR 5/6) clay loam;
if the soil is cultivated. This soil has been used for weak, coarse and medium, subangular blocky
food crops, tobacco, and pasture for many years. It structure; friable, nonstick and slightly plastic;
is better suited to pasture and woodland than to most few fine roots; few fine pores coated with dark
other uses. Capability unit VIe-3; woodland suit- material; many silvery flakes and coated quartz
ability group 25. grains; very strongly acid; clear, smooth boundary.
C2-48 to 65 inches, yellowish-red (5YR 4/6) silty clay







HUMACAO AREA OF EASTERN PUERTO RICO 37

loam; few, fine, faint, red mottles; weak, coarse, IIC-18 to 58 inches, dark reddish-brown (5YR 3/2), very
subangular blocky structure; friable, nonsticky strongly acid organic materials consisting of well-
and slightly plastic; few fine roots; few fine pores; decomposed muck.
many silvery flakes; many fine quartz grains; few, Thicess thesolum and depth to organic material
fine, dark minerals; very strongly acid; gradual, Thickness of the solum and depth to organic material
fine dark minerals; very strongly acid; gradual, range from 15 to 30 inches. The A horizon has hue of
C3-65 to 72 inches +, mottled very pale brown (10YR 10YR or 2.5Y, value of 2 or 3, and chroma of 3 or less. The
8/3), reddish-yellow (7.hYR 6/8, 5YR 6/8) and red B horizon has hue of 10YR or 5Y, value of 4 to 6, and
(10YR 4/8) loam saprolite; massive; very friable, chroma of 1 or less. It is silty clay or clay and has weak,
nonstick and nonplastic; many silvery flakes and medium or coarse, subangular blocky structure. Yellowish-
quartz grains; very strongly acid. brown or strong-brown mottles are common or many. Re-
action is strongly acid or very strongly acid.
The solum is 26 to 46 inches thick. The A horizon has The Pinones soils are on the same landscape as the
hue of 10YR or 7.5YR and value and chroma of 3 or 4. Maunabo, Coloso, and Fortuna soils. Unlike all those soils,
It is clay loam, silty clay loam, or clay. The B horizon has the Pinones soils have an organic layer. They are more
dominant hue of 10YR, 7.5YR, or 5YR, value of 4 to 6, and poorly drained and more acid than the Coloso soils.
chroma of 4 to 8. It is clay or silty clay. Gray mottles are
common in the upper part of the B horizon but decrease Pn-Pinones silty clay. This nearly level soil is on
as depth increases. The B2t horizon has weak or moderate, coastal lowlands. Included with it in mapping were
medium or coarse, subangular blocky structure. The C areas of Tidal swamp.
horizon is loam, clay loam, or silty clay loam. The C1 and
C2 horizons have hue of 5YR or 2.5YR, value of 4 to 6, Poor drainage, frequent flooding, and a seasonal
and chroma of 4 to 8. The C3 horizon has variegated colors high water table are severe limitations for farming.
of the saprolite. Reaction is very strongly acid or extremely Careful management and drainage can help overcome
acid throughout the profile same landscape as the Los these limitations. This soil has been used for sugarcane
The Picacho soils are on the same landscape as the Los
Guineos, Ciales, Guayabota, and Utuado soils. Unlike the and pasture. If it is properly drained, it is suited to cul-
Los Guineos soils, the Picacho soils have low-chroma mot- tivated crops, sugarcane, pasture, and cut grasses. Ca-
tles in the B2t horizon. Unlike the Ciales soils, they lack ability 'unit IVw-1.
dominant gray colors in the B2t horizon. The Picacho soils
are deeper than the Guayabota soils and finer textured
than the Utuado soils, and they have a B2t horizon that Poncena Series
those soils lack.
The Poncena series consists of deep soils that are
Pinones Series moderately well drained, calcareous, and slowly per-
meable. These soils formed in fine-textured sediment
The Pinones series consists of deep soils that are derived from volcanic rocks and limestone. They are on
poorly drained and very slowly permeable. These soils terraces and alluvial fans. Slopes are 0 to 2 percent.
formed in fine-textured sediment of mineral origin The climate is semiarid tropical. The average annual
that overlies decomposed and partly decomposed or- precipitation is 35 to 50 inches, and the average annual
ganic layers. They are on coastal lowlands. Slopes are 0 temperature is 79 t 0. Depth to the after table angels
to 2 percent. The climate is humid tropical. The aver- from 30 to 60 inches.
age annual precipitation is 80 to 90 inches, and the In a representative profile, the surface layer is about
average temperature is 780 F. 7 inches thick. In the upper part it is very dark clay,
In a representative profile, the surface layer is very a in the low er part it is vey rk mottled clay Be
dark grayish-brown, very strongly acid silty clay about and in the lower part is dark-gray, mottled clay. Be-
4 inches thick. The next layer is dark-gray, mottled, low this layer is dark-gray and dark greenish-gray,
firm silty clay 14 inches thick. The underlying mate- firm, mottled clay that extends to a depth of 41 inches.
firm s ilt clay 1 ihes hik he derli materi- These soils have a high available water capacity and
rial is dark eddish-brown organic materials that ex- high shrink-swell potential. Runoff is medium. The
These soils have a high available water capacity, soils are fertile but difficult to work. Most of the acre-
high natural fertility and high shrink-swell potential. age is used for sugarcane and0.5 kilometer
They are difficult to work, and most of the acreage is in Representative profile of Poncena clay, 0.5 kilometer
They are difficult to work, and most of the acreage is in south of kilometer marker 163.0 on Highway No. 3,
sugarcane, pasture, and cut grasses. near the town of Salinas
Representative profile of Pinones silty clay, 1 mile near the town of Salias:
northeast of Central Pasto Viejo, 100 feet west of main Ap-0 to 2 inches, very dark gray (10YR 3/1) clay; weak,
farm road on unimproved secondary road, and 30 feet fine, granular structure; friable, slightly sticky
h of ud r : and slightly plastic; many fine roots; few fine
north of unimproved road: volcanic pebbles; few sea shells; calcareous; clear,
AP-0 to 4 inches, very dark grayish-brown (10YR 3/2) smooth boundary.
silty clay; common, medium, distinct, yellowish- AC-2 to 7 inches, dark-gray (5Y 4/1) clay; common, fine,
brown (10YR 5/8) mottles; weak, fine, subangular distinct, brown to dark-brown (7.5YR 4/4) mot-
blocky structure; friable, slightly sticky and ties; weak, medium, subangular blocky structure;
plastic; many fine roots; very strongly acid; firm, slightly sticky and slightly plastic; common
abrupt, smooth boundary, roots; few pressure faces; few fine volcanic
B21-4 to 13 inches, dark-gray (10YR 4/1) silty clay; pebbles; limestone fragments; few sea shells; cal-
common, medium, distinct, yellowish-brown (10YR careous; clear, smooth boundary.
5/6) mottles; weak, medium, subangular blocky C1-7 to 14 inches, dark-gray (5Y 4/1) clay; many, me-
structure; firm, slightly sticky and plastic; cornm dium, distinct, brown to dark-brown (7.5YR 4/4)
mon fine roots; very strongly acid; clear, smooth mottles and few, fine, distinct, gray (5Y 5/1) mot-
boundary. tles; massive; firm, slightly sticky and plastic;
B22-13 to 18 inches, dark-gray (10YR 4/1) silty clay; few roots; many fine volcanic pebbles; calcareous;
many, coarse, distinct, yellowish-brown (10YR clear, smooth boundary.
5/6) mottles; weak, medium, subangular blocky C2g-14 to 25 inches, dark greenish-gray (5GY 4/1) clay;
structure; firm, slightly sticky and plastic; few common, fine, distinct, brown to dark-brown (10YR
fine roots; very strongly acid; clear, smooth 4/3) mottles; massive; firm, slightly sticky and
boundary. plastic; few pressure faces and slickensides; com-







HUMACAO AREA OF EASTERN PUERTO RICO 37

loam; few, fine, faint, red mottles; weak, coarse, IIC-18 to 58 inches, dark reddish-brown (5YR 3/2), very
subangular blocky structure; friable, nonsticky strongly acid organic materials consisting of well-
and slightly plastic; few fine roots; few fine pores; decomposed muck.
many silvery flakes; many fine quartz grains; few, Thicess thesolum and depth to organic material
fine, dark minerals; very strongly acid; gradual, Thickness of the solum and depth to organic material
fine dark minerals; very strongly acid; gradual, range from 15 to 30 inches. The A horizon has hue of
C3-65 to 72 inches +, mottled very pale brown (10YR 10YR or 2.5Y, value of 2 or 3, and chroma of 3 or less. The
8/3), reddish-yellow (7.hYR 6/8, 5YR 6/8) and red B horizon has hue of 10YR or 5Y, value of 4 to 6, and
(10YR 4/8) loam saprolite; massive; very friable, chroma of 1 or less. It is silty clay or clay and has weak,
nonstick and nonplastic; many silvery flakes and medium or coarse, subangular blocky structure. Yellowish-
quartz grains; very strongly acid. brown or strong-brown mottles are common or many. Re-
action is strongly acid or very strongly acid.
The solum is 26 to 46 inches thick. The A horizon has The Pinones soils are on the same landscape as the
hue of 10YR or 7.5YR and value and chroma of 3 or 4. Maunabo, Coloso, and Fortuna soils. Unlike all those soils,
It is clay loam, silty clay loam, or clay. The B horizon has the Pinones soils have an organic layer. They are more
dominant hue of 10YR, 7.5YR, or 5YR, value of 4 to 6, and poorly drained and more acid than the Coloso soils.
chroma of 4 to 8. It is clay or silty clay. Gray mottles are
common in the upper part of the B horizon but decrease Pn-Pinones silty clay. This nearly level soil is on
as depth increases. The B2t horizon has weak or moderate, coastal lowlands. Included with it in mapping were
medium or coarse, subangular blocky structure. The C areas of Tidal swamp.
horizon is loam, clay loam, or silty clay loam. The C1 and
C2 horizons have hue of 5YR or 2.5YR, value of 4 to 6, Poor drainage, frequent flooding, and a seasonal
and chroma of 4 to 8. The C3 horizon has variegated colors high water table are severe limitations for farming.
of the saprolite. Reaction is very strongly acid or extremely Careful management and drainage can help overcome
acid throughout the profile same landscape as the Los these limitations. This soil has been used for sugarcane
The Picacho soils are on the same landscape as the Los
Guineos, Ciales, Guayabota, and Utuado soils. Unlike the and pasture. If it is properly drained, it is suited to cul-
Los Guineos soils, the Picacho soils have low-chroma mot- tivated crops, sugarcane, pasture, and cut grasses. Ca-
tles in the B2t horizon. Unlike the Ciales soils, they lack ability 'unit IVw-1.
dominant gray colors in the B2t horizon. The Picacho soils
are deeper than the Guayabota soils and finer textured
than the Utuado soils, and they have a B2t horizon that Poncena Series
those soils lack.
The Poncena series consists of deep soils that are
Pinones Series moderately well drained, calcareous, and slowly per-
meable. These soils formed in fine-textured sediment
The Pinones series consists of deep soils that are derived from volcanic rocks and limestone. They are on
poorly drained and very slowly permeable. These soils terraces and alluvial fans. Slopes are 0 to 2 percent.
formed in fine-textured sediment of mineral origin The climate is semiarid tropical. The average annual
that overlies decomposed and partly decomposed or- precipitation is 35 to 50 inches, and the average annual
ganic layers. They are on coastal lowlands. Slopes are 0 temperature is 79 t 0. Depth to the after table angels
to 2 percent. The climate is humid tropical. The aver- from 30 to 60 inches.
age annual precipitation is 80 to 90 inches, and the In a representative profile, the surface layer is about
average temperature is 780 F. 7 inches thick. In the upper part it is very dark clay,
In a representative profile, the surface layer is very a in the low er part it is vey rk mottled clay Be
dark grayish-brown, very strongly acid silty clay about and in the lower part is dark-gray, mottled clay. Be-
4 inches thick. The next layer is dark-gray, mottled, low this layer is dark-gray and dark greenish-gray,
firm silty clay 14 inches thick. The underlying mate- firm, mottled clay that extends to a depth of 41 inches.
firm s ilt clay 1 ihes hik he derli materi- These soils have a high available water capacity and
rial is dark eddish-brown organic materials that ex- high shrink-swell potential. Runoff is medium. The
These soils have a high available water capacity, soils are fertile but difficult to work. Most of the acre-
high natural fertility and high shrink-swell potential. age is used for sugarcane and0.5 kilometer
They are difficult to work, and most of the acreage is in Representative profile of Poncena clay, 0.5 kilometer
They are difficult to work, and most of the acreage is in south of kilometer marker 163.0 on Highway No. 3,
sugarcane, pasture, and cut grasses. near the town of Salinas
Representative profile of Pinones silty clay, 1 mile near the town of Salias:
northeast of Central Pasto Viejo, 100 feet west of main Ap-0 to 2 inches, very dark gray (10YR 3/1) clay; weak,
farm road on unimproved secondary road, and 30 feet fine, granular structure; friable, slightly sticky
h of ud r : and slightly plastic; many fine roots; few fine
north of unimproved road: volcanic pebbles; few sea shells; calcareous; clear,
AP-0 to 4 inches, very dark grayish-brown (10YR 3/2) smooth boundary.
silty clay; common, medium, distinct, yellowish- AC-2 to 7 inches, dark-gray (5Y 4/1) clay; common, fine,
brown (10YR 5/8) mottles; weak, fine, subangular distinct, brown to dark-brown (7.5YR 4/4) mot-
blocky structure; friable, slightly sticky and ties; weak, medium, subangular blocky structure;
plastic; many fine roots; very strongly acid; firm, slightly sticky and slightly plastic; common
abrupt, smooth boundary, roots; few pressure faces; few fine volcanic
B21-4 to 13 inches, dark-gray (10YR 4/1) silty clay; pebbles; limestone fragments; few sea shells; cal-
common, medium, distinct, yellowish-brown (10YR careous; clear, smooth boundary.
5/6) mottles; weak, medium, subangular blocky C1-7 to 14 inches, dark-gray (5Y 4/1) clay; many, me-
structure; firm, slightly sticky and plastic; cornm dium, distinct, brown to dark-brown (7.5YR 4/4)
mon fine roots; very strongly acid; clear, smooth mottles and few, fine, distinct, gray (5Y 5/1) mot-
boundary. tles; massive; firm, slightly sticky and plastic;
B22-13 to 18 inches, dark-gray (10YR 4/1) silty clay; few roots; many fine volcanic pebbles; calcareous;
many, coarse, distinct, yellowish-brown (10YR clear, smooth boundary.
5/6) mottles; weak, medium, subangular blocky C2g-14 to 25 inches, dark greenish-gray (5GY 4/1) clay;
structure; firm, slightly sticky and plastic; few common, fine, distinct, brown to dark-brown (10YR
fine roots; very strongly acid; clear, smooth 4/3) mottles; massive; firm, slightly sticky and
boundary. plastic; few pressure faces and slickensides; com-







38 SOIL SURVEY

mon lime splotches; common sea shell fragments; roots; common rock fragments 2 to 20 millimeters
calcareous; clear, smooth boundary, in diameter; very strongly alkaline; clear, smooth
C3g-25 to 41 inches, dark-gray (5Y 4/1) clay; common, boundary.
medium, distinct, olive-brown (2.5Y 4/4) and C2-27 to 47 inches, very pale brown (10YR 7/3) silt loam;
greenish-gray (5G 5/1) mottles; massive; firm, massive; very friable, nonsticky and slightly plas-
slightly sticky and plastic; common seashell frag- tic; few dead roots; common pores; strongly alka-
ments; few volcanic pebbles; common lime line; clear, smooth boundary.
splotches; calcareous. C3-47 to 58 inches, very pale brown (10YR 7/4) gravelly
The A horizon is 2 to 12 inches thick. The C horizon has clay loam; massive; friable, nonsticky and slightly
hue of 10YR, 5Y, 5GY, or 2.5Y, value of 3 to 5, and chroma plastic; many rock fragments; strongly alkaline.
of 1 or 2. Mottles are few or common and fine or medium- The solum is 10 to 20 inches thick. The A horizon has
sized and are in shades of brown, dark brown, olive brown, value of 2 or 3. The B horizon has hue of 10YR or 7.5YR,
greenish gray, and gray. Reaction is neutral to strongly value of 4 or 5, and chroma of 3 or 4. It has weak, medium
acid. or fine, subangular blocky structure. The C horizon has hue
The Poncena soils occupy the same landscape as the Vayas of 7.5YR or 10YR, value of 7 or 8, and chroma of 3 or 4.
and Cartagena soils. They are better drained than the Vayas Reaction ranges from neutral to very strongly alkaline.
soils, and unlike those soils, they have pressure faces and The Pozo Blanco soils are on the same landscape as the
slickensides. The Poncena soils are better drained and have Fraternidad soils. The Pozo Blanco soils are coarser tex-
lower chroma than the Cartagena soils, tured than the Fraternidad soils, and unlike those soils, they
Po-Poncena clay. This nearly level soil is on coastal have a B horizon and lack pressure faces and slickensides.
plains in the semiarid part of the survey area. Included PrC2-Pozo Blanco clay loam, 5 to 12 percent
with it in mapping were areas of Cartagena and Vayas slopes, eroded. This soil is on foot slopes in the semi-
soils, arid part of the survey area. Included with it in map-
Low rainfall in the area and the soil's slow perme- ping were areas of Fraternidad soils.
ability, high shrink-swell potential, and seasonal high This soil has severe limitations for farming because
water table are severe limitations for farming. This of slope. It requires careful management and conserva-
soil has been used for sugarcane. If drained, irrigated, tion practices if it is used for clean-cultivated crops. If
and properly managed, it is suited to cultivated crops, the soil is properly managed, it is suited to sugarcane,
sugarcane, and pasture. Capability units IIIc-1 non- pasture, cut grasses, and woodland. Capability unit
irrigated and IIs-1 irrigated. IVe-3; woodland suitability group 202.

Pozo Blanco Series Reilly Series
The Pozo Blanco series consists of deep soils that are The Reilly series consists of excessively drained,
well drained and moderately permeable. These soils rapidly permeable soils that are shallow to sand and
formed in medium-textured to moderately fine tex- gravel. These soils formed in stratified material, domi-
tured sediment derived from limestone or residuum nantly gravel and sand but partly medium-textured
weathered from volcanic rocks. They are on foot slopes and moderately coarse textured sediment. They are ad-
and, to a minor extent, in the residual uplands. Slopes jacent to the streams on river flood plains. Slopes are 0
are 5 to 12 percent. The climate is semiarid. The aver- to 2 percent. The climate is humid tropical. The aver-
age annual rainfall is 35 to 45 inches, and the average age annual precipitation is 70 inches, and the average
annual temperature is 790 F. annual temperature is 770 F.
In a representative profile, the surface layer is very In a representative profile, the surface layer is dark-
dark grayish-brown, mildly alkaline clay loam about 7 brown, medium acid sandy loam about 9 inches thick.
inches thick. The next layer is brown clay loam 8 Below that is dark-brown, very friable loamy sand and
inches thick. Below that is pink, friable, very strongly dark yellowish-brown, yellowish-brown, brown, and
alkaline silt loam 12 inches thick. That layer is under- pale-brown, loose sand that extends to a depth of 62
lain by very pale brown, friable, strongly alkaline silt inches.
loam and gravelly clay loam that extends to a depth of These soils have a low available water capacity and
58 inches. low natural fertility and are easily worked. Most of the
These soils have a moderate available water capac- acreage is used for pasture, but small areas are in su-
ity, medium natural fertility, and moderate shrink- garcane.
swell potential. Most of the acreage is used for sugar- Representative profile of Reilly sandy loam, 0 to 2
cane and pasture. percent slopes, in an area of Reilly soils, 8 meters north
Representative profile of Pozo Blanco clay loam, 5 to and 90 meters west of kilometer marker 97.8 on High-
12 percent slopes, eroded, 525 meters southwest from a way No. 3:
gas station at north entrance of Central Aguirre, Ap-0 to 9 inches, dark-brown (10YR 3/3) sandy loam;
Salinas: massive; friable, nonsticky and nonplastic; medium
acid; clear, smooth boundary.
A1-0 to 7 inches, very dark grayish-brown (10YR 3/2) C1-9 to 19 inches, dark-brown (7.5YR 4/4) loamy sand;
clay loam; weak, medium, subangular blocky struc- massive; very friable, nonsticky and nonplastic;
ture; friable, slightly sticky and slightly plastic; medium acid; clear, smooth boundary.
common rock fragments 1 to 5 millimeters in diam- IIC2-19 to 35 inches, dark yellowish-brown (10YR 4/4)
eter; mildly alkaline; abrupt, smooth boundary, coarse sand; massive; loose; slightly acid; clear,
B-7 to 15 inches, brown (7.5YR 5/4) clay loam; weak, smooth boundary.
medium, subangular blocky structure; friable, IIIC3-35 to 50 inches, yellowish-brown (10YR 5/4) medium
slightly sticky and slightly plastic; common rock sand; massive; loose; slightly acid; clear, smooth
fragments 2 to 10 millimeters in diameter; mod- boundary.
erately alkaline; clear, smooth boundary. IVC4-50 to 58 inches, brown (10YR 5/3) coarse sand;
Clca-15 to 27 inches, pink (7.5YR 8/4) silt loam; massive; massive; loose; slightly acid; clear, smooth bound-
friable, nonsticky and slightly plastic; few dead ary.







38 SOIL SURVEY

mon lime splotches; common sea shell fragments; roots; common rock fragments 2 to 20 millimeters
calcareous; clear, smooth boundary, in diameter; very strongly alkaline; clear, smooth
C3g-25 to 41 inches, dark-gray (5Y 4/1) clay; common, boundary.
medium, distinct, olive-brown (2.5Y 4/4) and C2-27 to 47 inches, very pale brown (10YR 7/3) silt loam;
greenish-gray (5G 5/1) mottles; massive; firm, massive; very friable, nonsticky and slightly plas-
slightly sticky and plastic; common seashell frag- tic; few dead roots; common pores; strongly alka-
ments; few volcanic pebbles; common lime line; clear, smooth boundary.
splotches; calcareous. C3-47 to 58 inches, very pale brown (10YR 7/4) gravelly
The A horizon is 2 to 12 inches thick. The C horizon has clay loam; massive; friable, nonsticky and slightly
hue of 10YR, 5Y, 5GY, or 2.5Y, value of 3 to 5, and chroma plastic; many rock fragments; strongly alkaline.
of 1 or 2. Mottles are few or common and fine or medium- The solum is 10 to 20 inches thick. The A horizon has
sized and are in shades of brown, dark brown, olive brown, value of 2 or 3. The B horizon has hue of 10YR or 7.5YR,
greenish gray, and gray. Reaction is neutral to strongly value of 4 or 5, and chroma of 3 or 4. It has weak, medium
acid. or fine, subangular blocky structure. The C horizon has hue
The Poncena soils occupy the same landscape as the Vayas of 7.5YR or 10YR, value of 7 or 8, and chroma of 3 or 4.
and Cartagena soils. They are better drained than the Vayas Reaction ranges from neutral to very strongly alkaline.
soils, and unlike those soils, they have pressure faces and The Pozo Blanco soils are on the same landscape as the
slickensides. The Poncena soils are better drained and have Fraternidad soils. The Pozo Blanco soils are coarser tex-
lower chroma than the Cartagena soils, tured than the Fraternidad soils, and unlike those soils, they
Po-Poncena clay. This nearly level soil is on coastal have a B horizon and lack pressure faces and slickensides.
plains in the semiarid part of the survey area. Included PrC2-Pozo Blanco clay loam, 5 to 12 percent
with it in mapping were areas of Cartagena and Vayas slopes, eroded. This soil is on foot slopes in the semi-
soils, arid part of the survey area. Included with it in map-
Low rainfall in the area and the soil's slow perme- ping were areas of Fraternidad soils.
ability, high shrink-swell potential, and seasonal high This soil has severe limitations for farming because
water table are severe limitations for farming. This of slope. It requires careful management and conserva-
soil has been used for sugarcane. If drained, irrigated, tion practices if it is used for clean-cultivated crops. If
and properly managed, it is suited to cultivated crops, the soil is properly managed, it is suited to sugarcane,
sugarcane, and pasture. Capability units IIIc-1 non- pasture, cut grasses, and woodland. Capability unit
irrigated and IIs-1 irrigated. IVe-3; woodland suitability group 202.

Pozo Blanco Series Reilly Series
The Pozo Blanco series consists of deep soils that are The Reilly series consists of excessively drained,
well drained and moderately permeable. These soils rapidly permeable soils that are shallow to sand and
formed in medium-textured to moderately fine tex- gravel. These soils formed in stratified material, domi-
tured sediment derived from limestone or residuum nantly gravel and sand but partly medium-textured
weathered from volcanic rocks. They are on foot slopes and moderately coarse textured sediment. They are ad-
and, to a minor extent, in the residual uplands. Slopes jacent to the streams on river flood plains. Slopes are 0
are 5 to 12 percent. The climate is semiarid. The aver- to 2 percent. The climate is humid tropical. The aver-
age annual rainfall is 35 to 45 inches, and the average age annual precipitation is 70 inches, and the average
annual temperature is 790 F. annual temperature is 770 F.
In a representative profile, the surface layer is very In a representative profile, the surface layer is dark-
dark grayish-brown, mildly alkaline clay loam about 7 brown, medium acid sandy loam about 9 inches thick.
inches thick. The next layer is brown clay loam 8 Below that is dark-brown, very friable loamy sand and
inches thick. Below that is pink, friable, very strongly dark yellowish-brown, yellowish-brown, brown, and
alkaline silt loam 12 inches thick. That layer is under- pale-brown, loose sand that extends to a depth of 62
lain by very pale brown, friable, strongly alkaline silt inches.
loam and gravelly clay loam that extends to a depth of These soils have a low available water capacity and
58 inches. low natural fertility and are easily worked. Most of the
These soils have a moderate available water capac- acreage is used for pasture, but small areas are in su-
ity, medium natural fertility, and moderate shrink- garcane.
swell potential. Most of the acreage is used for sugar- Representative profile of Reilly sandy loam, 0 to 2
cane and pasture. percent slopes, in an area of Reilly soils, 8 meters north
Representative profile of Pozo Blanco clay loam, 5 to and 90 meters west of kilometer marker 97.8 on High-
12 percent slopes, eroded, 525 meters southwest from a way No. 3:
gas station at north entrance of Central Aguirre, Ap-0 to 9 inches, dark-brown (10YR 3/3) sandy loam;
Salinas: massive; friable, nonsticky and nonplastic; medium
acid; clear, smooth boundary.
A1-0 to 7 inches, very dark grayish-brown (10YR 3/2) C1-9 to 19 inches, dark-brown (7.5YR 4/4) loamy sand;
clay loam; weak, medium, subangular blocky struc- massive; very friable, nonsticky and nonplastic;
ture; friable, slightly sticky and slightly plastic; medium acid; clear, smooth boundary.
common rock fragments 1 to 5 millimeters in diam- IIC2-19 to 35 inches, dark yellowish-brown (10YR 4/4)
eter; mildly alkaline; abrupt, smooth boundary, coarse sand; massive; loose; slightly acid; clear,
B-7 to 15 inches, brown (7.5YR 5/4) clay loam; weak, smooth boundary.
medium, subangular blocky structure; friable, IIIC3-35 to 50 inches, yellowish-brown (10YR 5/4) medium
slightly sticky and slightly plastic; common rock sand; massive; loose; slightly acid; clear, smooth
fragments 2 to 10 millimeters in diameter; mod- boundary.
erately alkaline; clear, smooth boundary. IVC4-50 to 58 inches, brown (10YR 5/3) coarse sand;
Clca-15 to 27 inches, pink (7.5YR 8/4) silt loam; massive; massive; loose; slightly acid; clear, smooth bound-
friable, nonsticky and slightly plastic; few dead ary.







HUMACAO AREA OF EASTERN PUERTO RICO 39

VC5-58 to 62 inches, pale-brown (10YR 6/3) coarse sand; Poncena soils. The Reparada soils have an organic layer
massive; loose; slightly acid. whereas the Poncena soils do not.
The A horizon is 7 to 16 inches thick. The A and C ho- Rp-Reparada clay. This nearly level soil is on
rizons have hue of 10YR or 7.5 YR, value of 3 to 6, and coastal lowlands in the semiarid part of the survey
chroma of 2 to 4. The C1 horizon is loamy sand, sand, or
gravelly sand. Below the C1 horizon, sand and gravel vary area. Included with it in mapping were areas of Pon-
in proportion, cena soils.
The Reilly soils are on the same landscape as the Toa, This soil has severe limitations for cultivated crops
Coloso, Vivi, Maunabo, and Talante soils. The Reilly soils because it has very slow permeability, poor drainage,
are coarser textured than all those soils, and unlike those a a s w t a i
soils, they are excessively drained. and a seasonal water table and is difficult to work. If
-Ril sil. T i the soil is properly drained, it is suited to sugarcane
Re-Reilly soils. These nearly level soils are ad- and pasture. Capability unit IVw-2.
jacent to the streams on the flood plains in the humid
part of the survey area. Included with them in map-
ping were small areas of Toa, Coloso, and Talante Rio Arriba Series
soils.
These soils have severe limitations for cultivated The Rio Arriba series consists of deep, moderately
crops, because of the hazard of flooding, low available well drained soils. Permeability is moderately slow.
water capacity, and low fertility. They are suited to These soils formed in fine-textured sediment of mixed
pasture. Capability unit IVs-3. origin. They are on alluvial fans and terraces above the
river flood plains. Slopes are 2 to 12 percent. The cli-
mate is humid tropical. The average annual precipita-
Reparada Series tion is 65 inches, and the average annual temperature
The Reparada series consists of poorly drained soils is 770 F.
that are underlain by organic material. Permeability In a representative profile, the surface layer is brown
is very slow. These soils formed in fine-textured sedi- to dark-brown, very strongly acid clay about 5 inches
ment of mixed origin that overlies decomposed organic thick. The next layer is yellowish-brown and very pale
soil material. They are on coastal lowlands. Slopes are brown, firm clay 21 inches thick. The layer below that
0 to 2 percent. The climate is semiarid tropical. The is mottled, firm clay that has variegated colors and ex-
average annual precipitation is 30 to 40 inches, and the tends to a depth of 56 inches.
average annual temperature is 79 F. These soils have a high available water capacity and
In a representative profile, the surface layer is very high shrink-swell potential. Runoff is slow to medium.
dark brown, mildly alkaline, mottled clay about 8 The soils are somewhat difficult to work. They have
inches thick. Below that is very dark gray, firm, mottled been used for food crops, sugarcane, and pasture for
clay about 8 inches thick. Below that is very dark gray, many years.
firm, mottled clay that extends to a depth of 18 inches. Representative profile of Rio Arriba clay, 2 to 5
It is underlain by black organic material. percent slopes, 0.5 kilometer south and 9 meters west
These soils have a high available water capacity, of intersection of Highway No. 31 and Highway No.
high natural fertility, and high shrink-swell potential. 924, Barrio Mambiche, Naguabo:
They are difficult to work and have been used for na- Ap-0 to 5 inches, brown (10YR 5/3) to dark-brown (10YR
tive pasture and sugarcane for many years. 4/3) clay; few, fine, faint, brown (10YR 5/3)
Representative profile of Reparada clay 0.2 kilo- mottles; weak, fine to medium, subangular blocky
structure; firm, slightly sticky and slightly plastic;
meter south and 0.2 kilometer east of kilometer marker common fine roots; many, fine to medium, dark
131.6 on Highway No. 3, 0.6 kilometer south on dirt concretions; few worm casts; very strongly acid;
road, 12 meters east of road, 75 meters north of coco- abrupt, smooth boundary.
grove B21t-5 to 16 inches, yellowish-brown (10YR 5/8) clay;
nut glove. weak, medium, subangular blocky structure; firm,
Ap-0 to 8 inches, very dark brown (10YR 2/2) clay; slightly sticky; slightly plastic; and few fine roots;
common, medium, distinct, dark-brown (7.5YR 4/4) few fine pores and krotovinas; many, thin, patchy
mottles and few, medium, distinct, dark reddish- clay films on vertical cleavage planes; common, fine
brown (2.5YR 2/4) mottles; weak, medium, sub- to medium, dark concretions; very strongly acid;
angular blocky structure; firm, slightly sticky and clear, wavy boundary.
slightly plastic; common fine roots; very dark gray B22t-16 to 26 inches, very pale brown (10YR 7/4) clay;
coatings on ped surfaces; mildly alkaline; gradual, weak, medium, subangular blocky structure; firm,
smooth boundary, sticky and plastic; few fine roots; peds coated with
B2g-8 to 18 inches, very dark gray (N 3/0) clay; many, thin continuous clay films; few, fine to medium,
coarse, prominents dark greenish-gray (5G 4/1) dark concretions; some concretions coated with red
mottles; massive; firm, slightly sticky and slightly (2.5YR 4/6 few worm casts; strongly acid;
plastic; few fine roots; few partly decomposed gradual, wavy boundary.
plant residues; mildly alkaline; gradual, smooth C1-26 to 39 inches, variegated light-gray (5Y 7/1), gray
(5Y 6/1), brownish-yellow (10YR 6/6), and dark-
boundary. red (10R 3/6) clay; massive firm, sticky and
IIC-18 to 60 inches, black (10YR 2/1), decomposed, mildly r st0R ewfi3) clay; massive; fwrm, sticky mnd
alkaline organic material, plastic; few, fine, dead roots; few pores; common
alkaline organic materialpressure faces and slickensides; few waterworn
Thickness of the solum and depth to organic layers range pebbles; few fine concretions; very strongly acid;
from 12 to 22 inches. The A horizon has hue of 10YR to clear, smooth boundary.
2.5Y, value of 2 or 3, and chroma of 2 or less. Mottles C2-39 to 56 inches, variegated brownish-yellow (10YR
range from few to common and are in shades of brown and 6/6), light-gray (5Y 7/1), gray (5Y 6/1), and
red. The B horizon has hue of 2.5Y or N and has weak, dark-red (10R 3/6) clay; massive; firm, sticky
subangular blocky structure or is massive. Reaction ranges and plastic; few, fine, dead roots; common pressure
from neutral to moderately alkaline, faces and slickensides; few subrounded pebbles;
The Reparada soils are on the same landscape as the very strongly acid.







HUMACAO AREA OF EASTERN PUERTO RICO 39

VC5-58 to 62 inches, pale-brown (10YR 6/3) coarse sand; Poncena soils. The Reparada soils have an organic layer
massive; loose; slightly acid. whereas the Poncena soils do not.
The A horizon is 7 to 16 inches thick. The A and C ho- Rp-Reparada clay. This nearly level soil is on
rizons have hue of 10YR or 7.5 YR, value of 3 to 6, and coastal lowlands in the semiarid part of the survey
chroma of 2 to 4. The C1 horizon is loamy sand, sand, or
gravelly sand. Below the C1 horizon, sand and gravel vary area. Included with it in mapping were areas of Pon-
in proportion, cena soils.
The Reilly soils are on the same landscape as the Toa, This soil has severe limitations for cultivated crops
Coloso, Vivi, Maunabo, and Talante soils. The Reilly soils because it has very slow permeability, poor drainage,
are coarser textured than all those soils, and unlike those a a s w t a i
soils, they are excessively drained. and a seasonal water table and is difficult to work. If
-Ril sil. T i the soil is properly drained, it is suited to sugarcane
Re-Reilly soils. These nearly level soils are ad- and pasture. Capability unit IVw-2.
jacent to the streams on the flood plains in the humid
part of the survey area. Included with them in map-
ping were small areas of Toa, Coloso, and Talante Rio Arriba Series
soils.
These soils have severe limitations for cultivated The Rio Arriba series consists of deep, moderately
crops, because of the hazard of flooding, low available well drained soils. Permeability is moderately slow.
water capacity, and low fertility. They are suited to These soils formed in fine-textured sediment of mixed
pasture. Capability unit IVs-3. origin. They are on alluvial fans and terraces above the
river flood plains. Slopes are 2 to 12 percent. The cli-
mate is humid tropical. The average annual precipita-
Reparada Series tion is 65 inches, and the average annual temperature
The Reparada series consists of poorly drained soils is 770 F.
that are underlain by organic material. Permeability In a representative profile, the surface layer is brown
is very slow. These soils formed in fine-textured sedi- to dark-brown, very strongly acid clay about 5 inches
ment of mixed origin that overlies decomposed organic thick. The next layer is yellowish-brown and very pale
soil material. They are on coastal lowlands. Slopes are brown, firm clay 21 inches thick. The layer below that
0 to 2 percent. The climate is semiarid tropical. The is mottled, firm clay that has variegated colors and ex-
average annual precipitation is 30 to 40 inches, and the tends to a depth of 56 inches.
average annual temperature is 79 F. These soils have a high available water capacity and
In a representative profile, the surface layer is very high shrink-swell potential. Runoff is slow to medium.
dark brown, mildly alkaline, mottled clay about 8 The soils are somewhat difficult to work. They have
inches thick. Below that is very dark gray, firm, mottled been used for food crops, sugarcane, and pasture for
clay about 8 inches thick. Below that is very dark gray, many years.
firm, mottled clay that extends to a depth of 18 inches. Representative profile of Rio Arriba clay, 2 to 5
It is underlain by black organic material. percent slopes, 0.5 kilometer south and 9 meters west
These soils have a high available water capacity, of intersection of Highway No. 31 and Highway No.
high natural fertility, and high shrink-swell potential. 924, Barrio Mambiche, Naguabo:
They are difficult to work and have been used for na- Ap-0 to 5 inches, brown (10YR 5/3) to dark-brown (10YR
tive pasture and sugarcane for many years. 4/3) clay; few, fine, faint, brown (10YR 5/3)
Representative profile of Reparada clay 0.2 kilo- mottles; weak, fine to medium, subangular blocky
structure; firm, slightly sticky and slightly plastic;
meter south and 0.2 kilometer east of kilometer marker common fine roots; many, fine to medium, dark
131.6 on Highway No. 3, 0.6 kilometer south on dirt concretions; few worm casts; very strongly acid;
road, 12 meters east of road, 75 meters north of coco- abrupt, smooth boundary.
grove B21t-5 to 16 inches, yellowish-brown (10YR 5/8) clay;
nut glove. weak, medium, subangular blocky structure; firm,
Ap-0 to 8 inches, very dark brown (10YR 2/2) clay; slightly sticky; slightly plastic; and few fine roots;
common, medium, distinct, dark-brown (7.5YR 4/4) few fine pores and krotovinas; many, thin, patchy
mottles and few, medium, distinct, dark reddish- clay films on vertical cleavage planes; common, fine
brown (2.5YR 2/4) mottles; weak, medium, sub- to medium, dark concretions; very strongly acid;
angular blocky structure; firm, slightly sticky and clear, wavy boundary.
slightly plastic; common fine roots; very dark gray B22t-16 to 26 inches, very pale brown (10YR 7/4) clay;
coatings on ped surfaces; mildly alkaline; gradual, weak, medium, subangular blocky structure; firm,
smooth boundary, sticky and plastic; few fine roots; peds coated with
B2g-8 to 18 inches, very dark gray (N 3/0) clay; many, thin continuous clay films; few, fine to medium,
coarse, prominents dark greenish-gray (5G 4/1) dark concretions; some concretions coated with red
mottles; massive; firm, slightly sticky and slightly (2.5YR 4/6 few worm casts; strongly acid;
plastic; few fine roots; few partly decomposed gradual, wavy boundary.
plant residues; mildly alkaline; gradual, smooth C1-26 to 39 inches, variegated light-gray (5Y 7/1), gray
(5Y 6/1), brownish-yellow (10YR 6/6), and dark-
boundary. red (10R 3/6) clay; massive firm, sticky and
IIC-18 to 60 inches, black (10YR 2/1), decomposed, mildly r st0R ewfi3) clay; massive; fwrm, sticky mnd
alkaline organic material, plastic; few, fine, dead roots; few pores; common
alkaline organic materialpressure faces and slickensides; few waterworn
Thickness of the solum and depth to organic layers range pebbles; few fine concretions; very strongly acid;
from 12 to 22 inches. The A horizon has hue of 10YR to clear, smooth boundary.
2.5Y, value of 2 or 3, and chroma of 2 or less. Mottles C2-39 to 56 inches, variegated brownish-yellow (10YR
range from few to common and are in shades of brown and 6/6), light-gray (5Y 7/1), gray (5Y 6/1), and
red. The B horizon has hue of 2.5Y or N and has weak, dark-red (10R 3/6) clay; massive; firm, sticky
subangular blocky structure or is massive. Reaction ranges and plastic; few, fine, dead roots; common pressure
from neutral to moderately alkaline, faces and slickensides; few subrounded pebbles;
The Reparada soils are on the same landscape as the very strongly acid.






40 SOIL SURVEY

The solum is 20 to 42 inches thick. The Ap horizon has and picnic areas. The use of this land type is limited to
hue of 10YR or 7.5YR, value of 4 or 5, and chroma of 3 forest, habitat for wildlife, and water catchment. Ca-
or 4. The B horizon has hue of 10YR or 7.5YR, value of
5 to 7, and chroma of 4 to 8. It has weak or moderate, ability unit VIIIs-2.
subangular blocky structure.
The Rio Arriba soils are on the same landscape as the
Mabi, Aceitunas, and Via soils. The Rio Arriba soils have Sabana Series
a B2t horizon that the Mabi soils lack. They have a higher Th n ri cnit f llw so t r
shrink-swell potential than the Aceitunas soils. The Rio The Sabana series consists of shallow soils that are
Arriba soils are finer textured than the Via soils, and well drained and moderately permeable. These soils
unlike those soils, they have pressure faces and slickensides. formed in fine-textured residuum derived from partly
RrB-Rio Arriha clay, 2 to 5 percent slopes. This weathered volcanic rocks. They are on mountain side
soil is on alluvial fans and terraces. It has the profile slopes and ridgetops. Slopes are 20 to 60 percent. The
described as representative of the series. Included with climate is humid tropical. The average annual precipi-
this soil in mapping were areas of Mabi and Aceitunas station is 80 to 90 inches, and the average annual tem-
soils. perature is 780 F.
This soil has moderate limitations for farming be- In a representative profile, the surface layer is very
cause of slope, the hazard of erosion, and workability, dark gray, strongly acid silty clay loam about 4 inches
Careful management and conservation practices can thick. The next layer is dark grayish-brown, mottled
help overcome these limitations. The soil is suited to silty clay 8 inches thick. Below that layer is yellowish-
sugarcane, food crops, cut grasses, and pasture. Capa- red, mottled clay 6 inches thick. It is underlain by con-
bility unit IIs-2. solidated rock.
RrC2-Rio Arriba clay, 5 to 12 percent slopes, These soils have a moderate available water capacity
eroded. This soil is on alluvial fans and terraces. Its and moderate shrink-swell potential. Runoff is rapid to
profile is similar to the one described as representative very rapid. Most of the acreage is used for pasture and
of the series, but most of the original surface layer has woodland, and some areas are in brush.
been removed by erosion, and the plow layer is a mix- Representative profile of Sabana silty clay loam, 20
ture of the remaining part of that layer and the to 40 percent slopes, eroded, 2.4 kilometers north on
yellowish-brown subsoil. In some places the present Highway No. 925 from its junction with Highway No.
surface layer is subsoil material. Included with this 3, 45 meters north of Parcelas Junquitos:
soil in mapping were areas of Mabi and Via soils. Ap-0 to 4 inches, very dark gray (10YR 3/1) silty clay
This soil has moderate limitations for farming be- loam; moderate, medium, granular structure; firm,
cause of the hazard of erosion, slope, and workability, slightly sticky and slightly plastic; common fine
f it is properly limed and fertilized, itis suited to roots; common fine volcanic fragments; strongly
If it is properly limed and fertilized, it is suited to acid; clear wavy boundary.
sugarcane and pasture. Capability unit IIIe-7. B1-4 to 12 inches, dark grayish-brown (10YR 4/2) silty
clay; common, medium, prominent, strong-brown
(7.5YR 5/6) mottles; weak, fine, subangular blocky
Rock Land structure; firm, slightly sticky and slightly plastic;
few fine roots; few fine pores; occasional thin clay
Rock land (Rs) consists of areas where rock crops films; few, fine, volcanic rock fragments; strongly
out on 50 to 70 percent of the surface. Loose stones also B 2 acid; smooth boundary.
are common on the surface. Very shallow soil material B2-12 to 18 inches, yellowish-red (5YR 5/6) clay; many,
are common on the surface. Very shallow soil material coarse, prominent, dark-brown (7.5YR 4/4) mot-
lies between the outcrops and stones. This land type is tles; weak, medium, subangular blocky structure;
in the mountainous part of the survey area. Slopes are firm, slightly sticky and slightly plastic; few fine
60 to 70 percent. The vegetation is brush. roots; few fine pores; few, thin, patchy clay films;
common, fine, volcanic rock fragments; strongly
Rock land has little value for farming or engineer- acid; abrupt, smooth boundary strongly
ing uses. Its use is restricted mainly to wildlife habitat. R-18 inches, consolidated volcanic rock.
Capability unit VIIIs-2. Thickness of the solum and depth to volcanic rock ranges
from 10 to 20 inches. The Ap horizon has hue of 10YR or
7.5YR, value of 3 or 4, and chroma of 1 or 2. Coarse frag-
Rough Stony Land ments are few or common. The B2 horizon has hue of 7.5YR
or 5YR, value of 4 or 5, and chroma of 4 to 6. It has weak,
Rough stony land (Ru) consists of the high, jagged fine or medium, subangular blocky structure.
mountain peaks and long, very steep side slopes in the The Sabana soils occupy the same landscape as the
Sfore Rck and b ldrs cove 7 o 9 prcnt Caguabo, Mucara, and Naranjito soils. They are more acid
rain forest. Rocks and boulders cover 75 to 90 percent than the Caguabo soils and lack their gravelly B horizon.
of the surface. The areas are inaccessible, so the soils The Sabana soils are shallower to hard rock than the
have not been classified. Scattered observations indi- Mucara and Naranjito soils, and they have a thinner solum
cate that the soils are clayey and poorly drained on the than the Naranjito soils.
smoother slopes and somewhat poorly drained on the SaE2-Sabana silty clay loam, 20 to 40 percent
very steep side slopes. Nearly continuous rainfall is fa- slopes, eroded. This soil is on side slopes in the humid
vorable for mosses and ferns, part of the survey area. It has the profile described as
Very steep slopes, stoniness, and rockiness are se- representative of the series. Erosion has removed some
vere limitations for crops and pasture and for non- of the original surface layer, and in some places the
farm uses such as highway location, foundations for subsoil is exposed. Included with this soil in mapping
low buildings, septic tank filter fields, and sewage la- were areas of Caguabo, Mucara, and Naranjito soils.
goons. This land type has scenic value, but the very This soil is not suited to clean-cultivated crops.
steep slopes, rockiness, and stoniness are severe limita- Steep slopes, depth to volcanic rocks, rapid runoff, and
tions for paths, trails, intensive play areas, campsites, the hazard of erosion are severe limitations for farm-






HUMACAO AREA OF EASTERN PUERTO RICO 41

ing. The soil is suited to pasture and woodland. Capa- sticky and slightly plastic; many mica flakes;
ability unit VIIs-1; woodland suitability group 3d5. strongly acid; clear, smooth boundary.
SaF2--Saana silty clay loam, 40 to 60 percent B2g-10 to 18 inches, brown (10YR 5/3) loam; medium,
SaF2-Sahana silty clay loam 40 to 60 percent prominent, gray (5Y 5/1) and dark-brown (7.5YR
slopes, eroded. This soil is on side slopes and ridgetops 4/4) mottles; weak, fine, subangular blocky struc-
in the humid volcanic uplands. Its profile is similar to ture; friable, slightly sticky and slightly plastic;
the one described as representative of the Sabana se- strongly acid; clear, smooth boundary.
ries, but erosion has removed most of the surface IIClg-18 to 40 inches, mixed dark-brown (7.5YR 4/4) and
ries, but erosion has removed most of the surface gray (5Y 5/1) loamy sand; massive; very friable,
layer. In some places the subsoil is exposed. Included nonsticky and nonplastic; strongly acid; clear,
with this soil in mapping were small areas of Caguabo smooth boundary.
soils. IIIC2g-40 to 58 inches, gray (2.5YR 5/1) coarse sand;
many; medium, prominent, yellowish-brown (10YR
This soil is not suited to clean-cultivated crops. It 5/6) mottles; single grined; loose; strongly acid.
has severe limitations for farming because of steep
has severe limitations for farming because of steep The solum is 14 to 38 inches thick. The A horizon has
slopes, the hazard of erosion, very rapid runoff, and value of 3 or 4 and chroma of 2 or 3. Mottles are in shades
shallowness to rock. It is suited to woodland and pas- of brown, yellowish red, and gray. The B horizon has value
ture. Capability unit VIIs-1; woodland suitability of 4 or 5 and chroma of 2 or 3. It ranges from loam to
group 4d5. sandy loam and has gray, dark-brown, and brown mottles.
Reaction is strongly acid or very strongly acid.
The Talante soils are on the same landscape as the
Salt Water Marsh Coloso, Maunabo, Reilly, and Vivi soils. The Talante soils
are more poorly drained than the Coloso soils, and they are
Salt water marsh (Sm) consists of wet, periodically coarser textured than the Coloso and Maunabo soils. They
are finer textured than the Reilly soils, and unlike these soils,
flooded areas that are covered mainly by grass, they are poorly drained. Unlike the Vivi soils, the Talante
cattails, brush, or other herbaceous plants. It is occa- soils are poorly drained and have low-chroma mottles.
sionally flooded by salty water from adjacent man- Ta-Talante soils. These nearly level soils are on
grove swamps. During periods when rainfall is intense, flood plains. Included with them in mapping were
rivers and streams drain into Salt water marsh and small areas of Maunabo, Coloso, and Reilly soils.
cause the water table to fluctuate. The soil material These soils have severe limitations for farming be-
varies widely in texture. cause of flooding, a seasonal water table, and poor
This land type has severe limitations for farming drainage. If the soils are properly drained, they are
because it is wet and salty. Expensive drainage systems suited to sugarcane, cut grasses, and pasture. Capa-
are required to reclaim it. It is suitable for wildlife ability unit IIIw-3.
food and cover. Capability unit VIIIw-1.

Talante Series Teja Series
The Talante series consists of deep soils that are The Teja series consists of shallow soils that are well
poorly drained and moderately permeable. These soils drained and rapidly permeable. These soils formed in
formed in medium-textured to coarse-textured sedi- gravelly residuum derived from granitic rocks. They
ment that derived from granitic rocks. They are on are on mountain side slopes and ridgetops. Slopes are
flood plains. Slopes are 0 to 2 percent. The climate is 12 to 40 percent. The climate is humid tropical. The
humid tropical. The average annual precipitation is 87 average annual precipitation is 80 to 90 inches, and
inches, and the average annual temperature is 790 F. the average annual temperature is 780 F.
Depth to the water table ranges from 15 to 30 inches. In a representative profile, the surface layer is dark-
In a representative profile, the surface layer is about brown, very strongly acid gravelly sandy loam about 6
10 inches thick. In the upper part it is dark-brown, inches thick. Below that layer is dark-brown and
very strongly acid, mottled clay loam, and in the lower yellowish-brown, loose gravelly sandy loam 8 inches
part it is grayish-brown, mottled sandy clay loam. The thick. This is underlain by hard rock.
next layer is brown, friable loam 8 inches thick. The These soils have a low available water capacity and
layer below that is dark-brown and gray loamy sand are somewhat difficult to work. Runoff is medium to
and coarse sand that extends to a depth of 58 inches. rapid. Most of the acreage is in pasture and woodland.
These soils have a moderate available water capacity Representative profile of Teja gravelly sandy loam,
and low shrink-swell potential. They are subject to 12 to 40 percent slopes, 8 meters south of kilometer
flooding and difficult to work. Runoff is slow. The soils marker 2.7 on Highway No. 906:
have been in pasture and sugarcane for many years. A1-0 to 6 inches, dark-brown (10YR 3/3) gravelly sandy
Representative profile of Talante clay loam, 0 to 2 loam; weak, fine, granular structure; very friable,
percent slopes, in an area of Talante soils, 1000 meters nonstick and nonplastic; common fine roots; many
fine quartz grains; very strongly acid; clear,
northeast of Central Roig and 180 meters north 'of smooth boundary.
Guayanes River: C-6 to 14 inches, dark-brown (10YR 4/3) and yellowish-
brown (10YR 5/4) gravelly sandy loam; single
Ap-0 to 4 inches, dark-brown (10YR 4/3) clay loam; many, grained; loose, nonsticky and nonplastic; few fine
medium, distinct, gray (10YR 5/1) and dark-brown roots; about 40 percent, by volume, angular rock
(7.5YR 4/4) mottles; weak, fine, subangular blocky fragments; very strongly acid; abrupt, smooth
structure parting to granular; friable, slightly plas- boundary.
tic; very strongly acid; clear, smooth boundary. R-14 to 20 inches, hard, coarse-grained plutonic rock.
Alg-4 to 10 inches, grayish-brown (10YR 5/2) sandy clay
loam; many, medium, prominent, dark-gray (5Y The A horizon is 4 to 10 inches thick. It has value and
4/1) and yellowish-red (SYR 4/8) mottles; weak, chroma of 2 or 3. The C horizon has value of 4 or 5 and
fine, subangular blocky structure; friable, slightly chroma of 3 or 4. Depth to consolidated plutonic rock ranges






HUMACAO AREA OF EASTERN PUERTO RICO 41

ing. The soil is suited to pasture and woodland. Capa- sticky and slightly plastic; many mica flakes;
ability unit VIIs-1; woodland suitability group 3d5. strongly acid; clear, smooth boundary.
SaF2--Saana silty clay loam, 40 to 60 percent B2g-10 to 18 inches, brown (10YR 5/3) loam; medium,
SaF2-Sahana silty clay loam 40 to 60 percent prominent, gray (5Y 5/1) and dark-brown (7.5YR
slopes, eroded. This soil is on side slopes and ridgetops 4/4) mottles; weak, fine, subangular blocky struc-
in the humid volcanic uplands. Its profile is similar to ture; friable, slightly sticky and slightly plastic;
the one described as representative of the Sabana se- strongly acid; clear, smooth boundary.
ries, but erosion has removed most of the surface IIClg-18 to 40 inches, mixed dark-brown (7.5YR 4/4) and
ries, but erosion has removed most of the surface gray (5Y 5/1) loamy sand; massive; very friable,
layer. In some places the subsoil is exposed. Included nonsticky and nonplastic; strongly acid; clear,
with this soil in mapping were small areas of Caguabo smooth boundary.
soils. IIIC2g-40 to 58 inches, gray (2.5YR 5/1) coarse sand;
many; medium, prominent, yellowish-brown (10YR
This soil is not suited to clean-cultivated crops. It 5/6) mottles; single grined; loose; strongly acid.
has severe limitations for farming because of steep
has severe limitations for farming because of steep The solum is 14 to 38 inches thick. The A horizon has
slopes, the hazard of erosion, very rapid runoff, and value of 3 or 4 and chroma of 2 or 3. Mottles are in shades
shallowness to rock. It is suited to woodland and pas- of brown, yellowish red, and gray. The B horizon has value
ture. Capability unit VIIs-1; woodland suitability of 4 or 5 and chroma of 2 or 3. It ranges from loam to
group 4d5. sandy loam and has gray, dark-brown, and brown mottles.
Reaction is strongly acid or very strongly acid.
The Talante soils are on the same landscape as the
Salt Water Marsh Coloso, Maunabo, Reilly, and Vivi soils. The Talante soils
are more poorly drained than the Coloso soils, and they are
Salt water marsh (Sm) consists of wet, periodically coarser textured than the Coloso and Maunabo soils. They
are finer textured than the Reilly soils, and unlike these soils,
flooded areas that are covered mainly by grass, they are poorly drained. Unlike the Vivi soils, the Talante
cattails, brush, or other herbaceous plants. It is occa- soils are poorly drained and have low-chroma mottles.
sionally flooded by salty water from adjacent man- Ta-Talante soils. These nearly level soils are on
grove swamps. During periods when rainfall is intense, flood plains. Included with them in mapping were
rivers and streams drain into Salt water marsh and small areas of Maunabo, Coloso, and Reilly soils.
cause the water table to fluctuate. The soil material These soils have severe limitations for farming be-
varies widely in texture. cause of flooding, a seasonal water table, and poor
This land type has severe limitations for farming drainage. If the soils are properly drained, they are
because it is wet and salty. Expensive drainage systems suited to sugarcane, cut grasses, and pasture. Capa-
are required to reclaim it. It is suitable for wildlife ability unit IIIw-3.
food and cover. Capability unit VIIIw-1.

Talante Series Teja Series
The Talante series consists of deep soils that are The Teja series consists of shallow soils that are well
poorly drained and moderately permeable. These soils drained and rapidly permeable. These soils formed in
formed in medium-textured to coarse-textured sedi- gravelly residuum derived from granitic rocks. They
ment that derived from granitic rocks. They are on are on mountain side slopes and ridgetops. Slopes are
flood plains. Slopes are 0 to 2 percent. The climate is 12 to 40 percent. The climate is humid tropical. The
humid tropical. The average annual precipitation is 87 average annual precipitation is 80 to 90 inches, and
inches, and the average annual temperature is 790 F. the average annual temperature is 780 F.
Depth to the water table ranges from 15 to 30 inches. In a representative profile, the surface layer is dark-
In a representative profile, the surface layer is about brown, very strongly acid gravelly sandy loam about 6
10 inches thick. In the upper part it is dark-brown, inches thick. Below that layer is dark-brown and
very strongly acid, mottled clay loam, and in the lower yellowish-brown, loose gravelly sandy loam 8 inches
part it is grayish-brown, mottled sandy clay loam. The thick. This is underlain by hard rock.
next layer is brown, friable loam 8 inches thick. The These soils have a low available water capacity and
layer below that is dark-brown and gray loamy sand are somewhat difficult to work. Runoff is medium to
and coarse sand that extends to a depth of 58 inches. rapid. Most of the acreage is in pasture and woodland.
These soils have a moderate available water capacity Representative profile of Teja gravelly sandy loam,
and low shrink-swell potential. They are subject to 12 to 40 percent slopes, 8 meters south of kilometer
flooding and difficult to work. Runoff is slow. The soils marker 2.7 on Highway No. 906:
have been in pasture and sugarcane for many years. A1-0 to 6 inches, dark-brown (10YR 3/3) gravelly sandy
Representative profile of Talante clay loam, 0 to 2 loam; weak, fine, granular structure; very friable,
percent slopes, in an area of Talante soils, 1000 meters nonstick and nonplastic; common fine roots; many
fine quartz grains; very strongly acid; clear,
northeast of Central Roig and 180 meters north 'of smooth boundary.
Guayanes River: C-6 to 14 inches, dark-brown (10YR 4/3) and yellowish-
brown (10YR 5/4) gravelly sandy loam; single
Ap-0 to 4 inches, dark-brown (10YR 4/3) clay loam; many, grained; loose, nonsticky and nonplastic; few fine
medium, distinct, gray (10YR 5/1) and dark-brown roots; about 40 percent, by volume, angular rock
(7.5YR 4/4) mottles; weak, fine, subangular blocky fragments; very strongly acid; abrupt, smooth
structure parting to granular; friable, slightly plas- boundary.
tic; very strongly acid; clear, smooth boundary. R-14 to 20 inches, hard, coarse-grained plutonic rock.
Alg-4 to 10 inches, grayish-brown (10YR 5/2) sandy clay
loam; many, medium, prominent, dark-gray (5Y The A horizon is 4 to 10 inches thick. It has value and
4/1) and yellowish-red (SYR 4/8) mottles; weak, chroma of 2 or 3. The C horizon has value of 4 or 5 and
fine, subangular blocky structure; friable, slightly chroma of 3 or 4. Depth to consolidated plutonic rock ranges






42 SOIL SURVEY

from 10 to 20 inches. Reaction is strongly acid or very been in sugarcane and pasture for many years, and
strongly acid. some small areas are in food crops.
The Teja soils are on the same landscape as the Pandura, Re snttiv fil f Ta silty cla loam, 6 me
Mayo, Daguao, and Candelero soils. The Teja soils are shal- Representative profile of Toa silty clay loam, 6 me-
lower and coarser textured than the Pandura soils. They are ters west of railroad bridge and 6 meters south, near
shallower than the Mayo soils and lack their B horizon. The main office of Colonia Santa Rosa, Naguabo:
Teja soils are shallower and coarser textured and have a
thinner solum than the Daguao soils. They are shallower, Ap-0 to 10 inches, dark-brown (10YR 3/3) silty clay loam;
coarser textured, and better drained than the Candelero moderate, medium, granular structure; friable, non-
soils. sticky and slightly plastic; medium acid; clear,
smooth boundary.
TeE-Teja gravelly sandy loam, 12 to 40 percent B-10 to 16 inches, dark grayish-brown (10YR 4/2) silty
slopes. This soil is on side slopes and ridgetops. In- clay loam; common, medium, distinct, yellowish-red
clouded with it in mapping were small areas of Pandura (5YR 5/6) mottles; weak, fine, subangular blocky
structure; friable, slightly sticky and slightly plas-
soils and Rock land. tic; medium acid; clear, smooth boundary.
This soil is not suited to cultivated crops, and it has C1-16 to 60 inches, grayish-brown (10YR 5/2) clay loam;
severe limitations for farming because of slope, shal- many, fine, faint, dark-brown (10YR 4/3) mottles;
lowness, and the hazard of erosion. It is suited to wood- weak, medium, subangular blocky structure; friable,
slightly sticky and slightly plastic; thin lenses of
land and pasture. Capability unit VIIs-1; woodland sand and gravel fragments, 2 to 3 inches in di-
suitability group 4d5. ameter, at a depth of 30 inches; medium acid; clear,
smooth boundary.
C2-60 to 70 inches, dark-brown (7.5YR 4/4) clay loam;
Tidal Flats many, fine, distinct, gray and brown mottles; mas-
sive; friable, nonsticky and slightly plastic; com-
Tidal flats (Tf) consists of low areas, slightly above mon fine sand grains; common gravel fragments.
sea level, that are affected by seawater during high The solum is 12 to 28 inches thick. The A horizon has
tide. Because of the high concentration of salt, only value and chroma of 2 or 3. The B horizon has chroma of
salt-tolerant plants grow in these areas. Occasional 2 to 4 and weak, fine or medium, subangular blocky struc-
ture. The C horizon has hue of 10YR or 7.5YR, value of
barren spots that have visible salt accumulation are 4 or 5, and chroma of 2 to 4. Reaction is slightly acid or
common. The soil material varies widely in texture, medium acid.
This land type has severe limitations for farming The Toa soils occupy the same landscape as the Bajura,
because of salinity. It is suitable for wildlife food and Fortuna, Coloso, and Reilly soils. The Toa soils are better
drained and coarser textured throughout than the Bajura
cover. Capability unit VIIIw-1. and Fortuna soils. They are coarser textured in the lower
horizons and better drained than the Coloso soils. The Toa
soils are finer textured than the Reilly soils and lack their
Tidal Swamp underlying sand and gravel.
l s ( c o a t a c Tt-Toa silty clay loam. This nearly level soil is on
Tidal swamp (Ts) consists of areas that are covered river flood plains in the humid coastal plains. Included
with a thick growth of mangrove trees and are under with it in mapping were areas of Coloso, Fortuna, and
salty water most of the year. These areas are along the Bajura soils
seacoast and inlets. The sandy or clayey soils are light This soil is suited to cultivated crops and can be used
coloredThis soil is suited to cultivated crops and can be used
colored and saline and contain organic material for food crops, sugarcane, grasses, and pasture (fig. 5).
from decaying mangrove trees. They are underlain by It needs ordinary management and practices that help
coral, shells, and marl at varying depths. to maintain fertility and good tilth. Capability unit 1-2.
This land type is not extensive and has no value for to maintain fertility and good tilth. Capability unit -2.
farming, but it serves as a feeding and breeding place
for birds, oysters, and crabs. Some of the mangrove Utuado Series
trees are used for making charcoal. The land type has
very severe limitations for nonfarm uses, and reclama- The Utuado series consists of deep, well-drained soils
tion is expensive. Capability unit VIIIw-1. that have moderately rapid permeability. These soils
formed in moderately fine textured or medium-
textured, highly weathered residuum derived from ig-
Toa Series neous rock. They are on mountain side slopes in the
plutonic uplands. Slopes are 40 to 100 percent. The av-
The Toa series consists of deep soils that are moder- erage annual precipitation is 185 inches, and the
ately well drained and moderately permeable. These average annual temperature is 720 F.
soils formed from moderately fine textured and fine In a representative profile, the surface layer is dark-
textured alluvial sediment of mixed origin. They are on brown, very strongly acid clay loam about 5 inches
river flood plains. Slopes are 0 to 2 percent. The climate thick. Below that is yellowish-brown, very strongly
is humid tropical. The average annual precipitation is acid, friable clay loam 13 inches thick. Yellowish-
82 inches, and the average annual temperature is 780 F. brown, very friable loam is between depths of 18 and
In a representative profile, the surface layer is dark- 23 inches. The underlying material is pale-brown and
brown, medium acid silty clay loam about 10 inches very pale brown, very friable sandy loam that extends
thick. The next layer is dark grayish-brown, mottled to a depth of 72 inches or more.
silty clay loam 6 inches thick. Below this layer is These soils have a moderate to low available water
grayish-brown and dark-brown, friable, mottled clay capacity and medium fertility. Runoff is rapid. The
loam that extends to a depth of 60 inches or more. soils have been in hardwood trees, sierra palms, and
These soils have a moderate available water capacity tree ferns for many years.
and high fertility and are easily worked. They have Representative profile of Utuado clay loam, 40 to 60






42 SOIL SURVEY

from 10 to 20 inches. Reaction is strongly acid or very been in sugarcane and pasture for many years, and
strongly acid. some small areas are in food crops.
The Teja soils are on the same landscape as the Pandura, Re snttiv fil f Ta silty cla loam, 6 me
Mayo, Daguao, and Candelero soils. The Teja soils are shal- Representative profile of Toa silty clay loam, 6 me-
lower and coarser textured than the Pandura soils. They are ters west of railroad bridge and 6 meters south, near
shallower than the Mayo soils and lack their B horizon. The main office of Colonia Santa Rosa, Naguabo:
Teja soils are shallower and coarser textured and have a
thinner solum than the Daguao soils. They are shallower, Ap-0 to 10 inches, dark-brown (10YR 3/3) silty clay loam;
coarser textured, and better drained than the Candelero moderate, medium, granular structure; friable, non-
soils. sticky and slightly plastic; medium acid; clear,
smooth boundary.
TeE-Teja gravelly sandy loam, 12 to 40 percent B-10 to 16 inches, dark grayish-brown (10YR 4/2) silty
slopes. This soil is on side slopes and ridgetops. In- clay loam; common, medium, distinct, yellowish-red
clouded with it in mapping were small areas of Pandura (5YR 5/6) mottles; weak, fine, subangular blocky
structure; friable, slightly sticky and slightly plas-
soils and Rock land. tic; medium acid; clear, smooth boundary.
This soil is not suited to cultivated crops, and it has C1-16 to 60 inches, grayish-brown (10YR 5/2) clay loam;
severe limitations for farming because of slope, shal- many, fine, faint, dark-brown (10YR 4/3) mottles;
lowness, and the hazard of erosion. It is suited to wood- weak, medium, subangular blocky structure; friable,
slightly sticky and slightly plastic; thin lenses of
land and pasture. Capability unit VIIs-1; woodland sand and gravel fragments, 2 to 3 inches in di-
suitability group 4d5. ameter, at a depth of 30 inches; medium acid; clear,
smooth boundary.
C2-60 to 70 inches, dark-brown (7.5YR 4/4) clay loam;
Tidal Flats many, fine, distinct, gray and brown mottles; mas-
sive; friable, nonsticky and slightly plastic; com-
Tidal flats (Tf) consists of low areas, slightly above mon fine sand grains; common gravel fragments.
sea level, that are affected by seawater during high The solum is 12 to 28 inches thick. The A horizon has
tide. Because of the high concentration of salt, only value and chroma of 2 or 3. The B horizon has chroma of
salt-tolerant plants grow in these areas. Occasional 2 to 4 and weak, fine or medium, subangular blocky struc-
ture. The C horizon has hue of 10YR or 7.5YR, value of
barren spots that have visible salt accumulation are 4 or 5, and chroma of 2 to 4. Reaction is slightly acid or
common. The soil material varies widely in texture, medium acid.
This land type has severe limitations for farming The Toa soils occupy the same landscape as the Bajura,
because of salinity. It is suitable for wildlife food and Fortuna, Coloso, and Reilly soils. The Toa soils are better
drained and coarser textured throughout than the Bajura
cover. Capability unit VIIIw-1. and Fortuna soils. They are coarser textured in the lower
horizons and better drained than the Coloso soils. The Toa
soils are finer textured than the Reilly soils and lack their
Tidal Swamp underlying sand and gravel.
l s ( c o a t a c Tt-Toa silty clay loam. This nearly level soil is on
Tidal swamp (Ts) consists of areas that are covered river flood plains in the humid coastal plains. Included
with a thick growth of mangrove trees and are under with it in mapping were areas of Coloso, Fortuna, and
salty water most of the year. These areas are along the Bajura soils
seacoast and inlets. The sandy or clayey soils are light This soil is suited to cultivated crops and can be used
coloredThis soil is suited to cultivated crops and can be used
colored and saline and contain organic material for food crops, sugarcane, grasses, and pasture (fig. 5).
from decaying mangrove trees. They are underlain by It needs ordinary management and practices that help
coral, shells, and marl at varying depths. to maintain fertility and good tilth. Capability unit 1-2.
This land type is not extensive and has no value for to maintain fertility and good tilth. Capability unit -2.
farming, but it serves as a feeding and breeding place
for birds, oysters, and crabs. Some of the mangrove Utuado Series
trees are used for making charcoal. The land type has
very severe limitations for nonfarm uses, and reclama- The Utuado series consists of deep, well-drained soils
tion is expensive. Capability unit VIIIw-1. that have moderately rapid permeability. These soils
formed in moderately fine textured or medium-
textured, highly weathered residuum derived from ig-
Toa Series neous rock. They are on mountain side slopes in the
plutonic uplands. Slopes are 40 to 100 percent. The av-
The Toa series consists of deep soils that are moder- erage annual precipitation is 185 inches, and the
ately well drained and moderately permeable. These average annual temperature is 720 F.
soils formed from moderately fine textured and fine In a representative profile, the surface layer is dark-
textured alluvial sediment of mixed origin. They are on brown, very strongly acid clay loam about 5 inches
river flood plains. Slopes are 0 to 2 percent. The climate thick. Below that is yellowish-brown, very strongly
is humid tropical. The average annual precipitation is acid, friable clay loam 13 inches thick. Yellowish-
82 inches, and the average annual temperature is 780 F. brown, very friable loam is between depths of 18 and
In a representative profile, the surface layer is dark- 23 inches. The underlying material is pale-brown and
brown, medium acid silty clay loam about 10 inches very pale brown, very friable sandy loam that extends
thick. The next layer is dark grayish-brown, mottled to a depth of 72 inches or more.
silty clay loam 6 inches thick. Below this layer is These soils have a moderate to low available water
grayish-brown and dark-brown, friable, mottled clay capacity and medium fertility. Runoff is rapid. The
loam that extends to a depth of 60 inches or more. soils have been in hardwood trees, sierra palms, and
These soils have a moderate available water capacity tree ferns for many years.
and high fertility and are easily worked. They have Representative profile of Utuado clay loam, 40 to 60






42 SOIL SURVEY

from 10 to 20 inches. Reaction is strongly acid or very been in sugarcane and pasture for many years, and
strongly acid. some small areas are in food crops.
The Teja soils are on the same landscape as the Pandura, Re snttiv fil f Ta silty cla loam, 6 me
Mayo, Daguao, and Candelero soils. The Teja soils are shal- Representative profile of Toa silty clay loam, 6 me-
lower and coarser textured than the Pandura soils. They are ters west of railroad bridge and 6 meters south, near
shallower than the Mayo soils and lack their B horizon. The main office of Colonia Santa Rosa, Naguabo:
Teja soils are shallower and coarser textured and have a
thinner solum than the Daguao soils. They are shallower, Ap-0 to 10 inches, dark-brown (10YR 3/3) silty clay loam;
coarser textured, and better drained than the Candelero moderate, medium, granular structure; friable, non-
soils. sticky and slightly plastic; medium acid; clear,
smooth boundary.
TeE-Teja gravelly sandy loam, 12 to 40 percent B-10 to 16 inches, dark grayish-brown (10YR 4/2) silty
slopes. This soil is on side slopes and ridgetops. In- clay loam; common, medium, distinct, yellowish-red
clouded with it in mapping were small areas of Pandura (5YR 5/6) mottles; weak, fine, subangular blocky
structure; friable, slightly sticky and slightly plas-
soils and Rock land. tic; medium acid; clear, smooth boundary.
This soil is not suited to cultivated crops, and it has C1-16 to 60 inches, grayish-brown (10YR 5/2) clay loam;
severe limitations for farming because of slope, shal- many, fine, faint, dark-brown (10YR 4/3) mottles;
lowness, and the hazard of erosion. It is suited to wood- weak, medium, subangular blocky structure; friable,
slightly sticky and slightly plastic; thin lenses of
land and pasture. Capability unit VIIs-1; woodland sand and gravel fragments, 2 to 3 inches in di-
suitability group 4d5. ameter, at a depth of 30 inches; medium acid; clear,
smooth boundary.
C2-60 to 70 inches, dark-brown (7.5YR 4/4) clay loam;
Tidal Flats many, fine, distinct, gray and brown mottles; mas-
sive; friable, nonsticky and slightly plastic; com-
Tidal flats (Tf) consists of low areas, slightly above mon fine sand grains; common gravel fragments.
sea level, that are affected by seawater during high The solum is 12 to 28 inches thick. The A horizon has
tide. Because of the high concentration of salt, only value and chroma of 2 or 3. The B horizon has chroma of
salt-tolerant plants grow in these areas. Occasional 2 to 4 and weak, fine or medium, subangular blocky struc-
ture. The C horizon has hue of 10YR or 7.5YR, value of
barren spots that have visible salt accumulation are 4 or 5, and chroma of 2 to 4. Reaction is slightly acid or
common. The soil material varies widely in texture, medium acid.
This land type has severe limitations for farming The Toa soils occupy the same landscape as the Bajura,
because of salinity. It is suitable for wildlife food and Fortuna, Coloso, and Reilly soils. The Toa soils are better
drained and coarser textured throughout than the Bajura
cover. Capability unit VIIIw-1. and Fortuna soils. They are coarser textured in the lower
horizons and better drained than the Coloso soils. The Toa
soils are finer textured than the Reilly soils and lack their
Tidal Swamp underlying sand and gravel.
l s ( c o a t a c Tt-Toa silty clay loam. This nearly level soil is on
Tidal swamp (Ts) consists of areas that are covered river flood plains in the humid coastal plains. Included
with a thick growth of mangrove trees and are under with it in mapping were areas of Coloso, Fortuna, and
salty water most of the year. These areas are along the Bajura soils
seacoast and inlets. The sandy or clayey soils are light This soil is suited to cultivated crops and can be used
coloredThis soil is suited to cultivated crops and can be used
colored and saline and contain organic material for food crops, sugarcane, grasses, and pasture (fig. 5).
from decaying mangrove trees. They are underlain by It needs ordinary management and practices that help
coral, shells, and marl at varying depths. to maintain fertility and good tilth. Capability unit 1-2.
This land type is not extensive and has no value for to maintain fertility and good tilth. Capability unit -2.
farming, but it serves as a feeding and breeding place
for birds, oysters, and crabs. Some of the mangrove Utuado Series
trees are used for making charcoal. The land type has
very severe limitations for nonfarm uses, and reclama- The Utuado series consists of deep, well-drained soils
tion is expensive. Capability unit VIIIw-1. that have moderately rapid permeability. These soils
formed in moderately fine textured or medium-
textured, highly weathered residuum derived from ig-
Toa Series neous rock. They are on mountain side slopes in the
plutonic uplands. Slopes are 40 to 100 percent. The av-
The Toa series consists of deep soils that are moder- erage annual precipitation is 185 inches, and the
ately well drained and moderately permeable. These average annual temperature is 720 F.
soils formed from moderately fine textured and fine In a representative profile, the surface layer is dark-
textured alluvial sediment of mixed origin. They are on brown, very strongly acid clay loam about 5 inches
river flood plains. Slopes are 0 to 2 percent. The climate thick. Below that is yellowish-brown, very strongly
is humid tropical. The average annual precipitation is acid, friable clay loam 13 inches thick. Yellowish-
82 inches, and the average annual temperature is 780 F. brown, very friable loam is between depths of 18 and
In a representative profile, the surface layer is dark- 23 inches. The underlying material is pale-brown and
brown, medium acid silty clay loam about 10 inches very pale brown, very friable sandy loam that extends
thick. The next layer is dark grayish-brown, mottled to a depth of 72 inches or more.
silty clay loam 6 inches thick. Below this layer is These soils have a moderate to low available water
grayish-brown and dark-brown, friable, mottled clay capacity and medium fertility. Runoff is rapid. The
loam that extends to a depth of 60 inches or more. soils have been in hardwood trees, sierra palms, and
These soils have a moderate available water capacity tree ferns for many years.
and high fertility and are easily worked. They have Representative profile of Utuado clay loam, 40 to 60






42 SOIL SURVEY

from 10 to 20 inches. Reaction is strongly acid or very been in sugarcane and pasture for many years, and
strongly acid. some small areas are in food crops.
The Teja soils are on the same landscape as the Pandura, Re snttiv fil f Ta silty cla loam, 6 me
Mayo, Daguao, and Candelero soils. The Teja soils are shal- Representative profile of Toa silty clay loam, 6 me-
lower and coarser textured than the Pandura soils. They are ters west of railroad bridge and 6 meters south, near
shallower than the Mayo soils and lack their B horizon. The main office of Colonia Santa Rosa, Naguabo:
Teja soils are shallower and coarser textured and have a
thinner solum than the Daguao soils. They are shallower, Ap-0 to 10 inches, dark-brown (10YR 3/3) silty clay loam;
coarser textured, and better drained than the Candelero moderate, medium, granular structure; friable, non-
soils. sticky and slightly plastic; medium acid; clear,
smooth boundary.
TeE-Teja gravelly sandy loam, 12 to 40 percent B-10 to 16 inches, dark grayish-brown (10YR 4/2) silty
slopes. This soil is on side slopes and ridgetops. In- clay loam; common, medium, distinct, yellowish-red
clouded with it in mapping were small areas of Pandura (5YR 5/6) mottles; weak, fine, subangular blocky
structure; friable, slightly sticky and slightly plas-
soils and Rock land. tic; medium acid; clear, smooth boundary.
This soil is not suited to cultivated crops, and it has C1-16 to 60 inches, grayish-brown (10YR 5/2) clay loam;
severe limitations for farming because of slope, shal- many, fine, faint, dark-brown (10YR 4/3) mottles;
lowness, and the hazard of erosion. It is suited to wood- weak, medium, subangular blocky structure; friable,
slightly sticky and slightly plastic; thin lenses of
land and pasture. Capability unit VIIs-1; woodland sand and gravel fragments, 2 to 3 inches in di-
suitability group 4d5. ameter, at a depth of 30 inches; medium acid; clear,
smooth boundary.
C2-60 to 70 inches, dark-brown (7.5YR 4/4) clay loam;
Tidal Flats many, fine, distinct, gray and brown mottles; mas-
sive; friable, nonsticky and slightly plastic; com-
Tidal flats (Tf) consists of low areas, slightly above mon fine sand grains; common gravel fragments.
sea level, that are affected by seawater during high The solum is 12 to 28 inches thick. The A horizon has
tide. Because of the high concentration of salt, only value and chroma of 2 or 3. The B horizon has chroma of
salt-tolerant plants grow in these areas. Occasional 2 to 4 and weak, fine or medium, subangular blocky struc-
ture. The C horizon has hue of 10YR or 7.5YR, value of
barren spots that have visible salt accumulation are 4 or 5, and chroma of 2 to 4. Reaction is slightly acid or
common. The soil material varies widely in texture, medium acid.
This land type has severe limitations for farming The Toa soils occupy the same landscape as the Bajura,
because of salinity. It is suitable for wildlife food and Fortuna, Coloso, and Reilly soils. The Toa soils are better
drained and coarser textured throughout than the Bajura
cover. Capability unit VIIIw-1. and Fortuna soils. They are coarser textured in the lower
horizons and better drained than the Coloso soils. The Toa
soils are finer textured than the Reilly soils and lack their
Tidal Swamp underlying sand and gravel.
l s ( c o a t a c Tt-Toa silty clay loam. This nearly level soil is on
Tidal swamp (Ts) consists of areas that are covered river flood plains in the humid coastal plains. Included
with a thick growth of mangrove trees and are under with it in mapping were areas of Coloso, Fortuna, and
salty water most of the year. These areas are along the Bajura soils
seacoast and inlets. The sandy or clayey soils are light This soil is suited to cultivated crops and can be used
coloredThis soil is suited to cultivated crops and can be used
colored and saline and contain organic material for food crops, sugarcane, grasses, and pasture (fig. 5).
from decaying mangrove trees. They are underlain by It needs ordinary management and practices that help
coral, shells, and marl at varying depths. to maintain fertility and good tilth. Capability unit 1-2.
This land type is not extensive and has no value for to maintain fertility and good tilth. Capability unit -2.
farming, but it serves as a feeding and breeding place
for birds, oysters, and crabs. Some of the mangrove Utuado Series
trees are used for making charcoal. The land type has
very severe limitations for nonfarm uses, and reclama- The Utuado series consists of deep, well-drained soils
tion is expensive. Capability unit VIIIw-1. that have moderately rapid permeability. These soils
formed in moderately fine textured or medium-
textured, highly weathered residuum derived from ig-
Toa Series neous rock. They are on mountain side slopes in the
plutonic uplands. Slopes are 40 to 100 percent. The av-
The Toa series consists of deep soils that are moder- erage annual precipitation is 185 inches, and the
ately well drained and moderately permeable. These average annual temperature is 720 F.
soils formed from moderately fine textured and fine In a representative profile, the surface layer is dark-
textured alluvial sediment of mixed origin. They are on brown, very strongly acid clay loam about 5 inches
river flood plains. Slopes are 0 to 2 percent. The climate thick. Below that is yellowish-brown, very strongly
is humid tropical. The average annual precipitation is acid, friable clay loam 13 inches thick. Yellowish-
82 inches, and the average annual temperature is 780 F. brown, very friable loam is between depths of 18 and
In a representative profile, the surface layer is dark- 23 inches. The underlying material is pale-brown and
brown, medium acid silty clay loam about 10 inches very pale brown, very friable sandy loam that extends
thick. The next layer is dark grayish-brown, mottled to a depth of 72 inches or more.
silty clay loam 6 inches thick. Below this layer is These soils have a moderate to low available water
grayish-brown and dark-brown, friable, mottled clay capacity and medium fertility. Runoff is rapid. The
loam that extends to a depth of 60 inches or more. soils have been in hardwood trees, sierra palms, and
These soils have a moderate available water capacity tree ferns for many years.
and high fertility and are easily worked. They have Representative profile of Utuado clay loam, 40 to 60







HUMACAO AREA OF EASTERN PUERTO RICO 43














..... ---------
V/IV
----'.**4I-7
r- 7-







Figure 5.-A recently plowed field on Toa silty clay loam. This soil has high fertility and is easy to work. It is suited to most
cultivated crops.


percent slopes, in an area of the Utuado-Picacho- has weak or very weak, fine to coarse, subangular blocky
Stony rock land association, very steep, 25 meters structure. The C horizon has hue of 10YR or 7.5YR, value
sof 4 to 7, and chroma of 2 to 6. It ranges from sandy loam
southeast of kilometer marker 21.0 on Highway No. to loam. Quartz grains vary from few to many throughout
191: the profile. Reaction ranges from strongly acid to extremely
acid.
A1-0 to 5 inches, dark-brown (10YR 3/3) clay loam; The Utuado soils are on the same landscape as the Ciales,
moderate, medium, granular structure; friable, Yunque, Los Guineos, and Picacho soils. Unlike the Ciales,
slightly sticky and slightly plastic; many fine, Yunque, and Los Guineos soils, the Utuado soils lack a
medium, and large roots; few fine quartz grains; B2t horizon; they are coarser textured than the Yunque
very strongly acid; gradual, smooth boundary. and Los Guineos soils. The Utuado soils are coarser tex-
B2-5 to 18 inches, yellowish-brown (10YR 5/6) heavy clay tured than the Picacho soils and lack their low-chroma
loam; weak, coarse, subangular blocky structure mottles.
breaking to weak, fine, subangular blocky; friable,
slightly sticky and slightly plastic; common fine UpF-Utuado-Picacho-Stony rock land association,
roots; common fine pores; very thin patchy clay very steep. This mapping unit is on mountains in the
films; few fine quartz grains; few, fine, ark rain forest. It occupies narrow upper side slopes where
boundary, slopes range from 20 to 50 percent, mid side slopes
B3-18 to 23 inches, yellowish-brown (10YR 5/4) loam; where slopes range from 50 to 100 percent, and lower
very weak, coarse, subangular blocky structure; side slopes adjacent to drainageways where slopes
very friable, slightly sticky and slightly plastic; ane from 0 to 100 prnt
few fine and medium roots; common fine pores; range rom 30 to 100 percent.
common fine quartz grains; very strongly acid; The composition of this unit is more variable than
gradual, wavy boundary. that of most other units in the survey area but has
C1-23 to 36 inches, pale-brown (10YR 6/3) sandy loam; been controlled well enough to interpret for the ex-
massive breaking to very weak, coarse, subangular
blocky structure very friable,coase, sucky and nogular pected use of the soils. About 40 percent of this unit is
plastic; many fine quartz grains; many, flaky, shiny Utuado soils, 26 percent is Picacho soils, and 19 per-
minerals; common, fine, dark minerals; very cent is Stony rock land. The remaining area is minor
strongly acid; diffuse, wavy boundary. soils that vary in texture and color.
C2-26 to 52 inches, very pale brown (10YR 7/3) sandy The soils of this unit occur in unifrm patterns; the
loam; common, fine, distinct, dark-brown mottles; The soils of this unit occur in uniform patterns; the
massive breaking to very weak, coarse, subangular Picacho soils are on the upper side slopes and the
blocky structure; very friable, nonsticky and non- Utuado soils are on the mid side slopes. Stony rock
plastic; many fine quartz grains; many, flaky, land is on the lower part of the side slopes adjacent to
shiny minerals; iffmany, fine, dark minerals; very the drainageways. Gray and bluish volcanic rocks
C3-52 to 72 inches+, very pale brown (10YR 7/3) sandy cover 90 to 100 percent of the surface, and loose frag-
loam; many, fine, distinct, dark-brown, brown, and ments that range from 6 to 60 inches in diameter are
yellowish-brown mottles; massive; very friable, at the base of the rock cliffs.
nonsticky and nonplastic; very strongly acid. All of this mapping unit is in hardwood trees. Be-
The solum is 18 to 31 inches thick. The A horizon has hue cause of the very steep slopes, its use is limited to for-
of 10YR or 7.5YR, value of 3 or 4, and chroma of 2 to 4. est, habitat for wildlife, and water catchment. The
It ranges from loam to clay loam. The B horizon has hue soils are dsirable for recreation because of their sce-
of 10YR or 7.5 YR, value of 4 to 6, and chroma of 4 to 8. soils are desirable for recreation because of their sce-
It ranges from clay loam or sandy clay loam to loam and nic value, but they have severe limitations for paths,







44 SOIL SURVEY

trails, and roads because they are continuously wet Cartagena, and Poncena soils. Unlike the Vives soils, they
and are susceptible to slippage in roadbanks. Capabil- are poorly drained and have low-chroma mottles. The Vayas
S soils lack the high shrink-swell potential of the Cartagena
ity unit VIIs-3; woodland suitability group 3r3. and Poncena soils, and unlike the Poncena soils, they are
poorly drained and have a B horizon.
Vayas Series Va-Vayas silty clay loam, occasionally flooded.
This nearly level soil is on alluvial flood plains in the
The Vayas series consists of deep soils that are poorly semiarid part of the survey area. Included with it in
drained and slowly permeable. These soils formed in mapping were small areas of Cartagena soils.
fine-textured sediment of mixed origin. They are on Slow permeability, poor drainage, the hazard of
weakly dissected river flood plains. Slopes are 0 to 2 flooding, and poor workability are moderate limita-
percent. The climate is semiarid tropical. The average tions for farming. If the soil is properly drained and
annual precipitation is 30 to 40 inches, and the average managed, it is suited to sugarcane, cut grasses, and pas-
annual temperature is 790 F. Depth to the water table ture. Capability units IIw-4 nonirrigated and IIw-4
ranges from 30 to 60 inches. irrigated.
In a representative profile, the surface layer is very Vc-Vayas silty clay, frequently flooded. This nearly
dark grayish-brown, neutral silty clay about 8 inches level soil is on river flood plains. It has the profile de-
thick. Below that is very dark grayish-brown, firm, scribed as representative of the series. Included with
mottled silty clay 5 inches thick. Brown, friable, mot- this soil in mapping were areas of Cartagena and
tied silty clay and silty clay loam are between depths of Vives soils.
13 and 30 inches. These are underlain by olive-brown, The hazard of flooding, poor drainage, slow perme-
friable, mottled silt loam and fine sandy loam that ex- ability, and poor workability are moderate limitations
tends to a depth of 54 inches. for farming. If the soil is properly drained and man-
These soils have a high available water capacity and aged, it is suited to sugarcane, cut grasses, and pasture.
high natural fertility. They are difficult to work and Capability units IIw-4 nonirrigated and IIw-4 irri-
have been in sugarcane and pasture for many years. gated
Representative profile of Vayas silty clay, frequently
flooded, 24 meters south of farm railroad track, and
0.2 kilometer west of Josefa Machinery Shop within Vega Alta Series
the Hacienda Josefa:
the Hacienda Josefa: The Vega Alta series consists of deep soils that are
Ap-0 to 8 inches, very dark grayish-brown (10YR 3/2) well drained and moderately permeable. These soils
silty clay; few, fine, faint, very dark gray (5Y 3/1)
mottles; massive parting to weak, coarse, sub- formed in fine-textured, red, brown, and gray coastal
angular blocky structure; friable, slightly sticky plain sediment that is rich in iron. They are on coastal
and slightly plastic; few fine roots; few pores; few plains and terraces. Slopes are 2 to 12 percent. The cli-
pebbles; black stains along root channels; neutral; mate is humid tropical. The average annual precipita-
gradual, smooth boundary.
B-8 to 13 inches, very dark grayish-brown (10YR 3/2) tion is 76 inches, and the average annual temperature
silty clay; common, fine, distinct, dark-gray (5Y is 770 F.
3/2) and dark yellowish-brown (10YR 4/4) mot- In a representative profile, the surface layer is dark
ties; weak, medium and coarse, subangular blocky yellowish-brown, strongly acid silty clay loam about 9
structure; firm, slightly sticky and slightly plastic;
clay coatings along root channels and pores; few inches thick. Below this layer is yellowish-brown and
pores; few pebbles; black stains along root chan- red, firm or very firm clay 19 inches thick. The next
nels; neutral; abrupt, smooth boundary. layer is red, yellowish-brown, and light-gray, firm clay
C1-13 to 21 inches, brown (10YR 4/3) silty clay; many, that extends to a depth of 60 inches.
fine, distinct, olive-gray (5Y 5/2) and dark yellow-
ish-brown (10YR 4/2) mottles; massive; friable, These soils have a moderate available water capac-
slightly sticky and slightly plastic; few pores; dead ity and medium fertility. They are somewhat difficult
roots; black stains and coatings along root chan- to work. Runoff is slow to medium. Most of the acreage
nels; mildly alkaline; clear, smooth boundary. is used for sugarcane, cut grasses, and pasture, but
C2-21 to 30 inches, brown (10YR 4/3) silty clay loam;
many, fine, distinct, olive-gray (5Y 4/2) and dark- there are small areas in food crops and brush.
brown (7.5YR 4/4) mottles; massive; friable, Representative profile of Vega Alta silty clay loam,
slightly sticky and slightly plastic; few pores; few 2 to 5 percent slopes, 15 meters west of trail and 0.3
clay coatings along root channels; mildly alkaline; kilometer north from kilometer marker 2.1 on High-
clear, smooth boundary.
C3-30 to 44 inches, olive-brown (2.5Y 4/4) silt loam; com- way No. 194, municipality of Fajardo:
mon, fine, distinct, olive (5Y 4/3) mottles; massive; -
friable, nonsticky and nonplastic; mildly alkaline; A-0 to 9 inches, dark yellowish-brown (10YR 4/4) silty
clear, smooth boundary. clay loam, light yellowish brown (10YR 6/4), dry;
C4-44 to 54 inches, olive-brown (2.5Y 4/4) fine sandy weak, medium, subangular blocky structure; firm,
loam; common, fine, distinct, olive (5Y 4/3) mot- nonsticky and slightly plastic; common fine roots;
ties; massive; friable, nonsticky and nonplastic; strongly acid; clear, smooth boundary.
mildly alkaline. B21t-9 to 20 inches, mixed yellowish-brown (10YR 5/4)
The solum is 12 to 18 inches thick The A horizon has valand red (2.5YR 4/6) clay; weak, fine to medium,
The solum is 12 to 18 inches thick. The horizon has value subangular blocky structure; firm, slightly sticky
and chroma of 2 or 3. The B horizon has value of 3 or 4 and slightly plastic; common pores; common fine
and chroma of 2 or less. It has gray, dark-gray, and dark roots; common clay films on ped surfaces and
yellowish-brown mottles. It is silty clay or clay and has pores; about 5 percent, by volume, is plinthite; few
weak, fine to coarse, subangular blocky structure. The C black concretions; very strongly acid; clear, smooth
horizon has hue of 10YR or 2.5Y, value of 4 or 5, and boundary.d; clear, smooth
chroma of 3 or 4. Reaction is neutral to moderately alka- B22t-20 to 28 inches, mixed red (10YR 4/8) and yellowish-
line. brown (10YR 5/4, 5/6) clay; moderate, medium,
The Vayas soils are on the same landscape as the Vives, subangular blocky structure; very firm, slightly
s angular blocky structure; very firm. slightly







HUMACAO AREA OF EASTERN PUERTO RICO 45

sticky and plastic; many clay films on ped surfaces; slightly plastic; slightly acid; abrupt, wavy bound-
about 5 percent, by volume, is plinthite; few shale ary.
fragments; few pores; very strongly acid; clear, B2t-12 to 23 inches, dark grayish-brown (10YR 4/2) silty
wavy boundary, clay; common, medium, distinct, brownish-yellow
B23t-28 to 60 inches, mixed red (10R 4/8), yellowish- (10YR 6/6) mottles and few, distinct, red (2.5YR
brown (10YR 5/8), and light-gray (10YR 7/1) 4/8) mottles; weak, medium, subangular blocky
clay; weak, medium, subangular blocky structure; structure; firm, slightly sticky and slightly plastic;
firm, slightly sticky and slightly plastic; few clay common black concretions; medium acid; abrupt,
films on ped surfaces; about 5 percent, by volume, wavy boundary.
is plinthite; few shale fragments; very strongly C1-23 to 30 inches, yellowish-brown (10YR 5/8) clay;
acid. common, medium, distinct, gray (2.5Y 5/0) mot-
The solum is more than 60 inches thick. The A horizon tles; few, fine, distinct, red (2.5YR 4/6) mottles;
has hue of 10YR or 7.5YR and value and chroma of 4 to and common, fine, prominent, dark-gray (2.Y 4/0)
6. The B2t horizon has hue of 2.5YR, 7.5YR, 10R, or 10YR, mottles; massive; firm, slightly sticky and plastic;
value of 4 to 7, and chroma of 1 to 8. It has weak or common black concretions; slightly acid; abrupt,
moderate, fine or medium, subangular blocky structure. wavy boundary.
Plinthite makes up 5 to 10 percent of the B2t horizon. C2-30 to 48 inches, yellowish-brown (10YR 5/8) clay; com-
Reaction is strongly acid or very strongly acid. mon, medium, prominent, greenish-gray (5BG 6/1)
The Vega Alta soils occupy the same landscape as the mottles; massive; firm, slightly sticky and slightly
Vega Baja and Fajardo soils. The Vega Alta soils are better plastic; few gravel fragments; few black con-
drained than those soils, and they contain plinthite. cretions; medium acid.
The solum is 14 to 32 inches thick. The A horizon has
VeB-Vega Alta silty clay loam, 2 to 5 percent value and chroma of 3 or 4. The B horizon has chroma of
slopes. This soil is on coastal plains and terraces in 2 or 3. Black concretions range from few to many. Reaction
the humid part of the survey area. It has the profile is slightly acid or medium acid.
described as representative of the series. Included with The Vega Baja soils are on the same landscape as the
this soil in mapping were areas of Vega Baja and Fa- Vega Alta, Coloso, Bajura, and Toa soils. Unlike the Vega
this soil in mapping were areas of Vega Baja and Fa- Alta soils, the Vega Baja soils are somewhat poorly drained
jardo soils. and lack red colors. They have a B2t horizon that the Coloso
This soil has moderate limitations for farming be- soils lack. The Vega Baja soils are not so poorly drained
cause of the hazard of erosion. If it is properly man- as the Bajura soils and lack their high shrink-swell po-
tential. They are finer textured than the Toa soils, and
aged, the soil is suited to food crops, sugarcane, and unlike those soils, they are somewhat poorly drained.
pasture. Capability unit IIe-4.
VeC-Vega Alta silty clay loam, 5 to 12 percent VgA-Vega Baja silty clay loam, O to 3 percent
slopes. This soil is on coastal plains and terraces in the slopes. This soil is on coastal plains and alluvial fans
humid part of the survey area. Included with it in map- in the humid part of the survey area. Included with it
ping were small areas of Fajardo and Vega Baja soils. in mapping were small areas of Coloso, Bajura, and
This soil has moderate limitations for farming be- Toa soils.
cause of slope and the hazard of erosion. If proper This soil has moderate limitations for farming be-
management and conservation practices are used, the cause it is somewhat poorly drained and is susceptible
soil is suited to sugarcane, cut grasses, and pasture, to flooding. If it is properly drained and managed, the
Capability unit IIIe-8., a soil is suited to sugarcane, cut grasses, and pasture.
S- Capability unit IIw-1.

Vega Baja Series Via Series
Via Series
The Vega Baja series consists of deep soils that are
somewhat poorly drained and slowly permeable. These The Via series consists of deep soils that are well
soils formed in fine-textured, mixed sediment. They drained and moderately permeable. These soils have
are on coastal plains and alluvial fans. Slopes are 0 to 3 formed in moderately fine textured sediment that is
percent. The climate is humid tropical. The average an- underlain by coarse-textured, gravelly or cobbly sedi-
nual precipitation is 76 inches, and the average annual ment. They are on terraces. Slopes are 3 to 10 percent.
temperature is 770 F. The climate is humid tropical. The average tempera-
In a representative profile, the surface layer is ture is 780 F.
brown to dark-brown, slightly acid silty clay loam In a representative profile, the surface layer is dark
about 12 inches thick. Below that is dark grayish- grayish-brown, strongly acid silty clay loam about 8
brown, firm, mottled silty clay 11 inches thick. The inches thick. Below that layer is reddish-brown and
underlying material is yellowish-brown, firm, mottled yellowish-red, firm clay loam 39 inches thick. The un-
clay that extends to a depth of 48 inches. derlying material is dark-brown, firm gravelly clay
These soils have a high available water capacity and loam that extends to a depth of 62 inches.
medium fertility. Runoff is slow. The soils are difficult These soils have a moderate available water capac-
to work and have been in sugarcane and pasture for ity, and high fertility. They are easy to work. Runoff
many years, is slow. Most of the acreage is used for sugarcane and
Representative profile of Vega Baja silty clay loam, pasture, but some areas are used for food crops.
0 to 3 percent slopes, 0.9 kilometer west from kilometer Representative profile of Via silty clay loam, 3 to 10
marker 0.8 on Highway No. 976, 90 meters southwest percent slopes, 0.7 kilometer west of kilometer marker
from Land Authority Office, Colonia San Pedro, Fa- 21.9 on Highway No. 3 and 1,050 meters east of school-
jardo, and 38 meters south from junction of farm house:
roads: Ap-0 to 8 inches, dark grayish-brown (10YR 4/2) silty
Ap-0 to 12 inches, brown to dark-brown (10YR 4/3) silty clay loam, brown (10YR 5/3), dry; weak, fine, sub-
clay loam; weak, fine, subangular blocky structure angular blocky structure; hard, friable, slightly
parting to granular; friable, slightly sticky and sticky and slightly plastic; many fine roots; fine







HUMACAO AREA OF EASTERN PUERTO RICO 45

sticky and plastic; many clay films on ped surfaces; slightly plastic; slightly acid; abrupt, wavy bound-
about 5 percent, by volume, is plinthite; few shale ary.
fragments; few pores; very strongly acid; clear, B2t-12 to 23 inches, dark grayish-brown (10YR 4/2) silty
wavy boundary, clay; common, medium, distinct, brownish-yellow
B23t-28 to 60 inches, mixed red (10R 4/8), yellowish- (10YR 6/6) mottles and few, distinct, red (2.5YR
brown (10YR 5/8), and light-gray (10YR 7/1) 4/8) mottles; weak, medium, subangular blocky
clay; weak, medium, subangular blocky structure; structure; firm, slightly sticky and slightly plastic;
firm, slightly sticky and slightly plastic; few clay common black concretions; medium acid; abrupt,
films on ped surfaces; about 5 percent, by volume, wavy boundary.
is plinthite; few shale fragments; very strongly C1-23 to 30 inches, yellowish-brown (10YR 5/8) clay;
acid. common, medium, distinct, gray (2.5Y 5/0) mot-
The solum is more than 60 inches thick. The A horizon tles; few, fine, distinct, red (2.5YR 4/6) mottles;
has hue of 10YR or 7.5YR and value and chroma of 4 to and common, fine, prominent, dark-gray (2.Y 4/0)
6. The B2t horizon has hue of 2.5YR, 7.5YR, 10R, or 10YR, mottles; massive; firm, slightly sticky and plastic;
value of 4 to 7, and chroma of 1 to 8. It has weak or common black concretions; slightly acid; abrupt,
moderate, fine or medium, subangular blocky structure. wavy boundary.
Plinthite makes up 5 to 10 percent of the B2t horizon. C2-30 to 48 inches, yellowish-brown (10YR 5/8) clay; com-
Reaction is strongly acid or very strongly acid. mon, medium, prominent, greenish-gray (5BG 6/1)
The Vega Alta soils occupy the same landscape as the mottles; massive; firm, slightly sticky and slightly
Vega Baja and Fajardo soils. The Vega Alta soils are better plastic; few gravel fragments; few black con-
drained than those soils, and they contain plinthite. cretions; medium acid.
The solum is 14 to 32 inches thick. The A horizon has
VeB-Vega Alta silty clay loam, 2 to 5 percent value and chroma of 3 or 4. The B horizon has chroma of
slopes. This soil is on coastal plains and terraces in 2 or 3. Black concretions range from few to many. Reaction
the humid part of the survey area. It has the profile is slightly acid or medium acid.
described as representative of the series. Included with The Vega Baja soils are on the same landscape as the
this soil in mapping were areas of Vega Baja and Fa- Vega Alta, Coloso, Bajura, and Toa soils. Unlike the Vega
this soil in mapping were areas of Vega Baja and Fa- Alta soils, the Vega Baja soils are somewhat poorly drained
jardo soils. and lack red colors. They have a B2t horizon that the Coloso
This soil has moderate limitations for farming be- soils lack. The Vega Baja soils are not so poorly drained
cause of the hazard of erosion. If it is properly man- as the Bajura soils and lack their high shrink-swell po-
tential. They are finer textured than the Toa soils, and
aged, the soil is suited to food crops, sugarcane, and unlike those soils, they are somewhat poorly drained.
pasture. Capability unit IIe-4.
VeC-Vega Alta silty clay loam, 5 to 12 percent VgA-Vega Baja silty clay loam, O to 3 percent
slopes. This soil is on coastal plains and terraces in the slopes. This soil is on coastal plains and alluvial fans
humid part of the survey area. Included with it in map- in the humid part of the survey area. Included with it
ping were small areas of Fajardo and Vega Baja soils. in mapping were small areas of Coloso, Bajura, and
This soil has moderate limitations for farming be- Toa soils.
cause of slope and the hazard of erosion. If proper This soil has moderate limitations for farming be-
management and conservation practices are used, the cause it is somewhat poorly drained and is susceptible
soil is suited to sugarcane, cut grasses, and pasture, to flooding. If it is properly drained and managed, the
Capability unit IIIe-8., a soil is suited to sugarcane, cut grasses, and pasture.
S- Capability unit IIw-1.

Vega Baja Series Via Series
Via Series
The Vega Baja series consists of deep soils that are
somewhat poorly drained and slowly permeable. These The Via series consists of deep soils that are well
soils formed in fine-textured, mixed sediment. They drained and moderately permeable. These soils have
are on coastal plains and alluvial fans. Slopes are 0 to 3 formed in moderately fine textured sediment that is
percent. The climate is humid tropical. The average an- underlain by coarse-textured, gravelly or cobbly sedi-
nual precipitation is 76 inches, and the average annual ment. They are on terraces. Slopes are 3 to 10 percent.
temperature is 770 F. The climate is humid tropical. The average tempera-
In a representative profile, the surface layer is ture is 780 F.
brown to dark-brown, slightly acid silty clay loam In a representative profile, the surface layer is dark
about 12 inches thick. Below that is dark grayish- grayish-brown, strongly acid silty clay loam about 8
brown, firm, mottled silty clay 11 inches thick. The inches thick. Below that layer is reddish-brown and
underlying material is yellowish-brown, firm, mottled yellowish-red, firm clay loam 39 inches thick. The un-
clay that extends to a depth of 48 inches. derlying material is dark-brown, firm gravelly clay
These soils have a high available water capacity and loam that extends to a depth of 62 inches.
medium fertility. Runoff is slow. The soils are difficult These soils have a moderate available water capac-
to work and have been in sugarcane and pasture for ity, and high fertility. They are easy to work. Runoff
many years, is slow. Most of the acreage is used for sugarcane and
Representative profile of Vega Baja silty clay loam, pasture, but some areas are used for food crops.
0 to 3 percent slopes, 0.9 kilometer west from kilometer Representative profile of Via silty clay loam, 3 to 10
marker 0.8 on Highway No. 976, 90 meters southwest percent slopes, 0.7 kilometer west of kilometer marker
from Land Authority Office, Colonia San Pedro, Fa- 21.9 on Highway No. 3 and 1,050 meters east of school-
jardo, and 38 meters south from junction of farm house:
roads: Ap-0 to 8 inches, dark grayish-brown (10YR 4/2) silty
Ap-0 to 12 inches, brown to dark-brown (10YR 4/3) silty clay loam, brown (10YR 5/3), dry; weak, fine, sub-
clay loam; weak, fine, subangular blocky structure angular blocky structure; hard, friable, slightly
parting to granular; friable, slightly sticky and sticky and slightly plastic; many fine roots; fine







46 SOIL SURVEY

dark concretions; few worm casts; few cobbles trial from Al horizon; common rock fragments
and pebbles at contact with B horizon; strongly that vary from 2 to 5 millimeters in size; neutral;
acid; abrupt, smooth boundary, gradual, wavy boundary.
B21t-8 to 23 inches, reddish-brown (5YR 4/4) clay loam; C-15 to 38 inches, yellowish-brown (10YR 5/4) gravelly
weak, medium, subangular blocky structure; very coarse sand, 60 percent coarse fragments of par-
hard, firm, slightly sticky and slightly plastic; com- tially weathered plutonic rocks.
mon fine roots; few, thin, patchy clay films on R-38 inches, consolidated granitic rock.
vertical ped surfaces; many, fine, dark mineral The solum is 12 to 20 inches thick. The A horizon has
grains; common fine rock fragments; slightly acid; hue of 10YR or 7.5YR, value of 2 or 3, and chroma of 3
clear, smooth boundary. or 4. The B horizon has hue of 10YR or 7.5YR, value of
B22t-23 to 47 inches, yellowish-red (5YR 4/8) clay loam; 4 or 5, and chroma of 3 or 4. It has weak, medium or coarse,
weak, medium, subangular blocky structure; very subangular blocky structure. The C horizon has value of
hard, firm, slightly sticky and slightly plastic; few 4 or 5 and chroma of 4 to 6. Depth to consolidated granitic
fine roots; thin patchy clay films; common, fine, rock is 32 to 50 inches. Reaction is slightly acid to mildly
dark minerals; many fine and medium rock frag- alkaline.
ments; slightly acid; gradual, wavy boundary. The Vieques soils are on the same landscape as the
IIC-47 to 62 inches, dark-brown (7.5YR 4/4) gravelly clay Descalabrado, Coamo, and Guayama soils. The Vieques soils
loam; structureless; hard, firm, slightly sticky; are deeper to rock than the Descalabrado soils, and they are
more than 70 percent, by volume, coarse frag- coarser textured than the Coamo soils. The Vieques soils
ments; medium acid. lack the red colors of the Guayama soils.
Thickness of the solum and depth to the gravelly horizons VmCVieques loam, 5 to 12 percent slopes. This
range from 30 to 60 inches. The Ap horizon has hue of VmC-Vieques loam 5 to 12 percent slopes. This
10YR or 5YR, value of 4 or 5, and chroma of 2 or 3. The soil is on side slopes on the island of Vieques. Its pro-
B horizon has hue of 7.5YR or 5YR and chroma of 4 to 8. file is similar to the one described as representative of
It has weak, fine or medium, subangular blocky structure, the series, but its surface layer is 1 or 2 inches thicker.
Reaction in the B2t horizon is slightly acid or medium Included with this soil in mapping were areas of Gua-
The Via soils occupy the same landscape as the Rio yama and Descalabrado soils.
Arriba, Mabi, and Junquitos soils. They are coarser tex- This soil has severe limitations for farming because
tured than the Rio Arriba and Mabi soils and lack their of low rainfall and the hazard of erosion. It is not irri-
high shrink-swell potential. Unlike the Junquitos soils, the g T si i r and ast that
Via soils lack low-chroma mottles in the B horizon, gated. The soil has been in sugarcane and pasture that
has low carrying capacity. Capability unit IVe-9;
VIC-Via silty clay loam, 3 to 10 percent slopes. woodland suitability group 3d5.
This soil is on terraces in the humid part of the survey VmE2-Vieques loam, 12 to 40 percent slopes,
area. Included with it in mapping were small areas of eroded. This soil is on side slopes and ridgetops on the
Rio Arriba, Junquitos, and Mabi soils. island of Vieques. It has the profile described as repre-
This soil is suited to food crops, sugarcane, and pas- tentative of the series. Most of the original surface
ture. Good management and conservation practices layer has been eroded. Included with this soil in map-
should be used to control erosion. Capability unit ping were small areas of Guayama and Descalabrado
IIIe-9. soils.
This soil has severe limitations for farming because
Vieques Series it is steep and susceptible to erosion. It is suited to pas-
ture and wildlife habitat. Capability unit VIe-5;
The Vieques series consists of moderately deep, well- woodland suitability group 3d5.
drained soils that have moderately rapid permeability.
These soils formed in partly weathered granitic rocks.
They are on side slopes and ridgetops in the dry up- Vives Series
lands. Slopes are 5 to 40 percent. The climate is semi-
arid tropical. The average annual precipitation is 35 The Vives series consists of deep soils that are well
inches, and the average annual temperature is 78 F. drained and moderately permeable. These soils formed
In a representative profile, the surface layer is dark- in moderately fine textured sediment of mixed origin.
brown, slightly acid loam about 5 inches thick. Below They are on river flood plains and on alluvial fans and
that layer is brown to dark-brown, friable sandy clay terraces above the present river flood plains. Slopes are
loam 10 inches thick. The underlying material is 0 to 7 percent. The climate is semiarid tropical. The
yellowish-brown, loose gravelly coarse sand 23 inches average annual precipitation is 25 to 45 inches, and the
thick. Consolidated granitic rock is at a depth of 38 average annual temperature is about 790 F.
inches. In a representative profile, the surface layer is
These soils have a low available water capacity and very dark grayish-brown, neutral, mottled clay about
medium fertility, and they are susceptible to erosion. 9 inches thick. The next layer is yellowish-red and
They have been in native pasture and brush, but some reddish-brown clay loam that has fine rock fragments
areas are used for sugarcane. and is 23 inches thick. The underlying material is
Representative profile of Vieques loam, 12 to 40 per- brown, friable clay loam that extends to a depth of 50
cent slopes, eroded, 30 meters southwest from kilome- inches.
ter marker 1.6 on Highway No. 993, island of Vieques: These soils have a high available water capacity and
S to 5 inches dark-rown ( 3/3) loam ea high natural fertility. They are easily worked, and they
A1-0 to 5 inches, dark-brown (10YR 3/3) loam; weak, have been in sugarcane for many years.
fine, granular structure; soft, friable, nonsticky e en m gar e fo a ea
and nonplastic; common fine roots; slightly acid; Representative profile of Vives clay, 2 to 7 percent
clear, smooth boundary. slopes, 1.4 kilometers north of kilometer marker 150.8
B-5 to 15 inches, brown to dark-brown (7.5YR 4/4) sandy on Highway No. 3:
clay loam; weak, coarse, subangular blocky struc-
ture; slightly hard, friable, nonsticky and slightly Ap-0 to 9 inches, very dark grayish-brown (10YR 3/2)
plastic; few fine roots; krotovinas filled with ma- clay; few, medium, prominent, reddish-brown (5YR







46 SOIL SURVEY

dark concretions; few worm casts; few cobbles trial from Al horizon; common rock fragments
and pebbles at contact with B horizon; strongly that vary from 2 to 5 millimeters in size; neutral;
acid; abrupt, smooth boundary, gradual, wavy boundary.
B21t-8 to 23 inches, reddish-brown (5YR 4/4) clay loam; C-15 to 38 inches, yellowish-brown (10YR 5/4) gravelly
weak, medium, subangular blocky structure; very coarse sand, 60 percent coarse fragments of par-
hard, firm, slightly sticky and slightly plastic; com- tially weathered plutonic rocks.
mon fine roots; few, thin, patchy clay films on R-38 inches, consolidated granitic rock.
vertical ped surfaces; many, fine, dark mineral The solum is 12 to 20 inches thick. The A horizon has
grains; common fine rock fragments; slightly acid; hue of 10YR or 7.5YR, value of 2 or 3, and chroma of 3
clear, smooth boundary. or 4. The B horizon has hue of 10YR or 7.5YR, value of
B22t-23 to 47 inches, yellowish-red (5YR 4/8) clay loam; 4 or 5, and chroma of 3 or 4. It has weak, medium or coarse,
weak, medium, subangular blocky structure; very subangular blocky structure. The C horizon has value of
hard, firm, slightly sticky and slightly plastic; few 4 or 5 and chroma of 4 to 6. Depth to consolidated granitic
fine roots; thin patchy clay films; common, fine, rock is 32 to 50 inches. Reaction is slightly acid to mildly
dark minerals; many fine and medium rock frag- alkaline.
ments; slightly acid; gradual, wavy boundary. The Vieques soils are on the same landscape as the
IIC-47 to 62 inches, dark-brown (7.5YR 4/4) gravelly clay Descalabrado, Coamo, and Guayama soils. The Vieques soils
loam; structureless; hard, firm, slightly sticky; are deeper to rock than the Descalabrado soils, and they are
more than 70 percent, by volume, coarse frag- coarser textured than the Coamo soils. The Vieques soils
ments; medium acid. lack the red colors of the Guayama soils.
Thickness of the solum and depth to the gravelly horizons VmCVieques loam, 5 to 12 percent slopes. This
range from 30 to 60 inches. The Ap horizon has hue of VmC-Vieques loam 5 to 12 percent slopes. This
10YR or 5YR, value of 4 or 5, and chroma of 2 or 3. The soil is on side slopes on the island of Vieques. Its pro-
B horizon has hue of 7.5YR or 5YR and chroma of 4 to 8. file is similar to the one described as representative of
It has weak, fine or medium, subangular blocky structure, the series, but its surface layer is 1 or 2 inches thicker.
Reaction in the B2t horizon is slightly acid or medium Included with this soil in mapping were areas of Gua-
The Via soils occupy the same landscape as the Rio yama and Descalabrado soils.
Arriba, Mabi, and Junquitos soils. They are coarser tex- This soil has severe limitations for farming because
tured than the Rio Arriba and Mabi soils and lack their of low rainfall and the hazard of erosion. It is not irri-
high shrink-swell potential. Unlike the Junquitos soils, the g T si i r and ast that
Via soils lack low-chroma mottles in the B horizon, gated. The soil has been in sugarcane and pasture that
has low carrying capacity. Capability unit IVe-9;
VIC-Via silty clay loam, 3 to 10 percent slopes. woodland suitability group 3d5.
This soil is on terraces in the humid part of the survey VmE2-Vieques loam, 12 to 40 percent slopes,
area. Included with it in mapping were small areas of eroded. This soil is on side slopes and ridgetops on the
Rio Arriba, Junquitos, and Mabi soils. island of Vieques. It has the profile described as repre-
This soil is suited to food crops, sugarcane, and pas- tentative of the series. Most of the original surface
ture. Good management and conservation practices layer has been eroded. Included with this soil in map-
should be used to control erosion. Capability unit ping were small areas of Guayama and Descalabrado
IIIe-9. soils.
This soil has severe limitations for farming because
Vieques Series it is steep and susceptible to erosion. It is suited to pas-
ture and wildlife habitat. Capability unit VIe-5;
The Vieques series consists of moderately deep, well- woodland suitability group 3d5.
drained soils that have moderately rapid permeability.
These soils formed in partly weathered granitic rocks.
They are on side slopes and ridgetops in the dry up- Vives Series
lands. Slopes are 5 to 40 percent. The climate is semi-
arid tropical. The average annual precipitation is 35 The Vives series consists of deep soils that are well
inches, and the average annual temperature is 78 F. drained and moderately permeable. These soils formed
In a representative profile, the surface layer is dark- in moderately fine textured sediment of mixed origin.
brown, slightly acid loam about 5 inches thick. Below They are on river flood plains and on alluvial fans and
that layer is brown to dark-brown, friable sandy clay terraces above the present river flood plains. Slopes are
loam 10 inches thick. The underlying material is 0 to 7 percent. The climate is semiarid tropical. The
yellowish-brown, loose gravelly coarse sand 23 inches average annual precipitation is 25 to 45 inches, and the
thick. Consolidated granitic rock is at a depth of 38 average annual temperature is about 790 F.
inches. In a representative profile, the surface layer is
These soils have a low available water capacity and very dark grayish-brown, neutral, mottled clay about
medium fertility, and they are susceptible to erosion. 9 inches thick. The next layer is yellowish-red and
They have been in native pasture and brush, but some reddish-brown clay loam that has fine rock fragments
areas are used for sugarcane. and is 23 inches thick. The underlying material is
Representative profile of Vieques loam, 12 to 40 per- brown, friable clay loam that extends to a depth of 50
cent slopes, eroded, 30 meters southwest from kilome- inches.
ter marker 1.6 on Highway No. 993, island of Vieques: These soils have a high available water capacity and
S to 5 inches dark-rown ( 3/3) loam ea high natural fertility. They are easily worked, and they
A1-0 to 5 inches, dark-brown (10YR 3/3) loam; weak, have been in sugarcane for many years.
fine, granular structure; soft, friable, nonsticky e en m gar e fo a ea
and nonplastic; common fine roots; slightly acid; Representative profile of Vives clay, 2 to 7 percent
clear, smooth boundary. slopes, 1.4 kilometers north of kilometer marker 150.8
B-5 to 15 inches, brown to dark-brown (7.5YR 4/4) sandy on Highway No. 3:
clay loam; weak, coarse, subangular blocky struc-
ture; slightly hard, friable, nonsticky and slightly Ap-0 to 9 inches, very dark grayish-brown (10YR 3/2)
plastic; few fine roots; krotovinas filled with ma- clay; few, medium, prominent, reddish-brown (5YR







HUMACAO AREA OF EASTERN PUERTO RICO 47

4/4) mottles; weak, fine, subangular blocky struc- The climate is humid tropical. The average annual pre-
ture; firm, slightly sticky and plastic; many fine cipitation is 80 to 90 inches, and the average annual
roots; many fine rock fragments; many fine char-
coal pieces; neutral; abrupt, wavy boundary, temperature is 780 F.
B2-9 to 23 inches, yellowish-red (5YR 4/6) clay loam; In a representative profile, the surface layer is very
weak, medium, subangular blocky structure; firm, dark grayish-brown, very strongly acid loam about 7
slightly sticky and plastic; common fine roots; few inches thick. The next layer is dark grayish-brown,
fine pores; many fine rock fragments; many dark
coating in root chan ne rock utral; clean war friable loam 7 inches thick. Below this layer is dark-
boundary. brown, dark grayish-brown, and very dark grayish-
B3-23 to 32 inches, reddish-brown (5YR 4/4) clay loam; brown, friable to loose very fine sandy loam, loam,
weak, fine, subangular blocky structure; friable, coarse sand, and sandy loam that extends to a depth of
slightly sticky and slightly plastic; few fine roots;
few fine pores; few fine rock fragments; neutral; 60 inches.
clear, wavy boundary. These soils have a moderate available water capacity
C1-32 to 43 inches, brown (7.5YR 4/4) clay loam; mas- and are easily worked. Runoff is slow. The soils have
sive; friable, nonsticky and slightly plastic; many, been in sugarcane for many years, and some areas are
fine, subrounded rock fragments; neutral; clear,
smooth boundary. in pasture.
C2-43 to 50 inches, brown (7.5YR 4/4) clay loam; mas- Representative profile of Vivi loam, 300 meters north
sive; friable, nonsticky and slightly plastic; many of kilometer marker 4.3 on Highway No. 901:
lime splotches; calcareous; moderately alkaline.
S m sp 2 t 0 nces eat hi Ap-0 to 7 inches, very dark grayish-brown (10YR 3/2)
The solum is 20 to 40 inches thick. The A horizon has loam; weak, fine, granular structure; very friable,
hue of 10YR or 7.5YR and value and chroma of 2 to 4. nonsticky and nonplastic; many fine roots; many
The B2 horizon has hue of 5YR or 7.5YR and chroma of fine quartz crystals; very strongly acid; clear,
4 to 6. It ranges from clay loam to clay and has weak, smooth boundary.
fine or medium, subangular blocky structure. Clay films are B-7 to 14 inches, dark grayish-brown (10YR 4/2) loam;
few and patchy. The C horizon has hue of 7.5YR or 5YR weak, medium, subangular blocky structure; fri-
and chroma of 4 to 6. Reaction is slightly acid to moderately able, nonsticky and nonplastic; common fine roots;
alkaline. many fine quartz crystals; strongly acid; clear,
The Vives soils are on the same landscape as the Machete smooth boundary.
and Amelia soils. They lack the B2t horizon of the Machete C1-14 to 20 inches, dark-brown (10YR 3/3) very fine
soils. Unlike the Amelia soils, the Vives soils lack the large sandy loam; massive; friable, nonsticky and non-
amount of gravel in the profile. plastic; few fine roots; many fine quartz crystals;
Vs-Vives silty clay loam, high bottom. This nearly strongly acid; clear, smooth boundary.
level soil is on river flood plains in the semiarid part of 2-20to 30 inches, very dark grayish-brown (YR /2)
loam; massive; friable, nonsticky and nonplastic;
the survey area. Included with it in mapping were many fine quartz crystals; strongly acid; clear,
areas of Arenales and Guamani soils, smooth boundary.
This soil has moderate limitations for farming be- C3-30 to 36 inches, dark grayish-brown (10YR 4/2) coarse
cause rainfall is low. Most of the acreage is in sugar- sand; single grained; loose, nonstick and non-
cause rainfall is low. Most of the acreage is in sugar- plastic; many fine quartz crystals; strongly acid;
cane. If the soil is properly irrigated and managed, it clear, smooth boundary.
is suited to many kinds of crops and to sugarcane and C4-36 to 60 inches, dark grayish-brown (10YR 4/2) sandy
pasture. Capability units IIc-1 nonirrigated and I-3 loam; common, medium, distinct, dark-brown
(7.5YR 4/4) mottles; massive; very friable, non-
irrigated. sticky and slightly plastic; many fine quartz grains;
VvA-Vives clay, 0 to 2 percent slopes. This soil is strongly acid.
on alluvial fans and terraces in the semiarid part of The solum is 10 to 22 inches thick. The Ap horizon has
the survey area. Included with it in mapping were value and chroma of 2 or 3. The B horizon has chroma
small areas of Machete soils and other Vives soils. of 2 or 3 and has weak, fine or medium, subangular blocky
This soil has moderate limitations for farming be- structure. The C horizon has hue of 10YR or 7.5YR, value
of 3 or 4, and chroma of 2 or 3. Reaction is strongly acid
cause rainfall is low. Most of the acreage is planted to or very strongly acid.
sugarcane. The soil is suited to sugarcane, food crops, The Vivi soils are on the same landscape as the Maunabo,
and pasture. Capability units IIc-1 nonirrigated and Coloso, Talante, and Reilly soils. They are coarser textured
I-3 irrigated, and better drained than the Maunabo, Coloso, and Talante
S soils. The Vivi soils are deeper to sand and gravel than
VvB-Vives clay, 2 to 7 percent slopes. This soil is the Reilly soils, and unlike those soils, they have a B
on alluvial fans and terraces in the semiarid part of horizon.
the survey area. It has the profile described as repre- Vw-Vivi loam. This nearly level soil is on river
tentative of the series. Included with this soil in map- flood plains in the humid part of the survey rea. Small
ping were small areas of Machete and Amelia soils, areas of Reilly and Coloso soils were included with it
This soil has moderate limitations for farming be- areas of Reilly and Coloso soils were included with it
cause of low rainfall, slope, and the hazard of erosion. This soi has moderate limitations for farming be-
If it is irrigated, the soil is suited to many kinds of cause it is rapidly permeable. It has been planted to
food crops and to sugarcane Capability units IIIc-2 sugarcane. If the soil is properly managed and irri-
nonirrigated and Ile-1 irrigated. gated, it is suited to food crops and sugarcane. Capa-
bility unit IIs-3.
Vivi Series
The Vivi series consists of deep soils that are well Wet Alluvial Land
drained and rapidly permeable. These soils formed in
moderately coarse textured and medium-textured, Wet alluvial land (Wa) consists of lagoonlike areas
stratified sediment derived from plutonic rocks. They or depressions on the flood plains of the river and
are on the river flood plains. Slopes are 0 to 2 percent. streams that drain the humid part of the survey area.







HUMACAO AREA OF EASTERN PUERTO RICO 47

4/4) mottles; weak, fine, subangular blocky struc- The climate is humid tropical. The average annual pre-
ture; firm, slightly sticky and plastic; many fine cipitation is 80 to 90 inches, and the average annual
roots; many fine rock fragments; many fine char-
coal pieces; neutral; abrupt, wavy boundary, temperature is 780 F.
B2-9 to 23 inches, yellowish-red (5YR 4/6) clay loam; In a representative profile, the surface layer is very
weak, medium, subangular blocky structure; firm, dark grayish-brown, very strongly acid loam about 7
slightly sticky and plastic; common fine roots; few inches thick. The next layer is dark grayish-brown,
fine pores; many fine rock fragments; many dark
coating in root chan ne rock utral; clean war friable loam 7 inches thick. Below this layer is dark-
boundary. brown, dark grayish-brown, and very dark grayish-
B3-23 to 32 inches, reddish-brown (5YR 4/4) clay loam; brown, friable to loose very fine sandy loam, loam,
weak, fine, subangular blocky structure; friable, coarse sand, and sandy loam that extends to a depth of
slightly sticky and slightly plastic; few fine roots;
few fine pores; few fine rock fragments; neutral; 60 inches.
clear, wavy boundary. These soils have a moderate available water capacity
C1-32 to 43 inches, brown (7.5YR 4/4) clay loam; mas- and are easily worked. Runoff is slow. The soils have
sive; friable, nonsticky and slightly plastic; many, been in sugarcane for many years, and some areas are
fine, subrounded rock fragments; neutral; clear,
smooth boundary. in pasture.
C2-43 to 50 inches, brown (7.5YR 4/4) clay loam; mas- Representative profile of Vivi loam, 300 meters north
sive; friable, nonsticky and slightly plastic; many of kilometer marker 4.3 on Highway No. 901:
lime splotches; calcareous; moderately alkaline.
S m sp 2 t 0 nces eat hi Ap-0 to 7 inches, very dark grayish-brown (10YR 3/2)
The solum is 20 to 40 inches thick. The A horizon has loam; weak, fine, granular structure; very friable,
hue of 10YR or 7.5YR and value and chroma of 2 to 4. nonsticky and nonplastic; many fine roots; many
The B2 horizon has hue of 5YR or 7.5YR and chroma of fine quartz crystals; very strongly acid; clear,
4 to 6. It ranges from clay loam to clay and has weak, smooth boundary.
fine or medium, subangular blocky structure. Clay films are B-7 to 14 inches, dark grayish-brown (10YR 4/2) loam;
few and patchy. The C horizon has hue of 7.5YR or 5YR weak, medium, subangular blocky structure; fri-
and chroma of 4 to 6. Reaction is slightly acid to moderately able, nonsticky and nonplastic; common fine roots;
alkaline. many fine quartz crystals; strongly acid; clear,
The Vives soils are on the same landscape as the Machete smooth boundary.
and Amelia soils. They lack the B2t horizon of the Machete C1-14 to 20 inches, dark-brown (10YR 3/3) very fine
soils. Unlike the Amelia soils, the Vives soils lack the large sandy loam; massive; friable, nonsticky and non-
amount of gravel in the profile. plastic; few fine roots; many fine quartz crystals;
Vs-Vives silty clay loam, high bottom. This nearly strongly acid; clear, smooth boundary.
level soil is on river flood plains in the semiarid part of 2-20to 30 inches, very dark grayish-brown (YR /2)
loam; massive; friable, nonsticky and nonplastic;
the survey area. Included with it in mapping were many fine quartz crystals; strongly acid; clear,
areas of Arenales and Guamani soils, smooth boundary.
This soil has moderate limitations for farming be- C3-30 to 36 inches, dark grayish-brown (10YR 4/2) coarse
cause rainfall is low. Most of the acreage is in sugar- sand; single grained; loose, nonstick and non-
cause rainfall is low. Most of the acreage is in sugar- plastic; many fine quartz crystals; strongly acid;
cane. If the soil is properly irrigated and managed, it clear, smooth boundary.
is suited to many kinds of crops and to sugarcane and C4-36 to 60 inches, dark grayish-brown (10YR 4/2) sandy
pasture. Capability units IIc-1 nonirrigated and I-3 loam; common, medium, distinct, dark-brown
(7.5YR 4/4) mottles; massive; very friable, non-
irrigated. sticky and slightly plastic; many fine quartz grains;
VvA-Vives clay, 0 to 2 percent slopes. This soil is strongly acid.
on alluvial fans and terraces in the semiarid part of The solum is 10 to 22 inches thick. The Ap horizon has
the survey area. Included with it in mapping were value and chroma of 2 or 3. The B horizon has chroma
small areas of Machete soils and other Vives soils. of 2 or 3 and has weak, fine or medium, subangular blocky
This soil has moderate limitations for farming be- structure. The C horizon has hue of 10YR or 7.5YR, value
of 3 or 4, and chroma of 2 or 3. Reaction is strongly acid
cause rainfall is low. Most of the acreage is planted to or very strongly acid.
sugarcane. The soil is suited to sugarcane, food crops, The Vivi soils are on the same landscape as the Maunabo,
and pasture. Capability units IIc-1 nonirrigated and Coloso, Talante, and Reilly soils. They are coarser textured
I-3 irrigated, and better drained than the Maunabo, Coloso, and Talante
S soils. The Vivi soils are deeper to sand and gravel than
VvB-Vives clay, 2 to 7 percent slopes. This soil is the Reilly soils, and unlike those soils, they have a B
on alluvial fans and terraces in the semiarid part of horizon.
the survey area. It has the profile described as repre- Vw-Vivi loam. This nearly level soil is on river
tentative of the series. Included with this soil in map- flood plains in the humid part of the survey rea. Small
ping were small areas of Machete and Amelia soils, areas of Reilly and Coloso soils were included with it
This soil has moderate limitations for farming be- areas of Reilly and Coloso soils were included with it
cause of low rainfall, slope, and the hazard of erosion. This soi has moderate limitations for farming be-
If it is irrigated, the soil is suited to many kinds of cause it is rapidly permeable. It has been planted to
food crops and to sugarcane Capability units IIIc-2 sugarcane. If the soil is properly managed and irri-
nonirrigated and Ile-1 irrigated. gated, it is suited to food crops and sugarcane. Capa-
bility unit IIs-3.
Vivi Series
The Vivi series consists of deep soils that are well Wet Alluvial Land
drained and rapidly permeable. These soils formed in
moderately coarse textured and medium-textured, Wet alluvial land (Wa) consists of lagoonlike areas
stratified sediment derived from plutonic rocks. They or depressions on the flood plains of the river and
are on the river flood plains. Slopes are 0 to 2 percent. streams that drain the humid part of the survey area.






48 SOIL SURVEY

The water table is at or near the surface most of the Yunque Series
year. During rainy periods the areas are covered with
water. The soils range from loam to clay in texture. The Yunque series consists of deep soils that are
Because of the high water table, lack of outlets, and moderately well drained and moderately permeable.
high cost of reclamation, this land type is not suited to These soils formed in fine-textured, highly weathered
cultivated crops and is of little value for pasture, but it residuum of volcanic rocks. They are on upper side
provides good habitat for wildlife. Capability unit slopes and ridgetops in strongly dissected uplands.
VIIIw-2. Slopes are 10 to 35 percent. The average annual pre-
cipitation is 185 inches, and the average annual tem-
Yunes Series perature is 720 F.
In a representative profile, the surface layer is dark
The Yunes series consists of shallow soils that are yellowish-brown, very strongly acid silty clay about
well drained, strongly acid, and moderately permeable. 8 inches thick. Yellowish-brown, firm and friable clay
These soils formed in very gravelly residuum of shaly is between depths of 8 and 51 inches. Below this layer
sedimentary rocks. They are on side slopes and ridge- is yellowish-red, friable clay that has red and reddish-
tops in strongly dissected uplands. Slopes are 20 to 60 yellow mottles and extends to a depth of more than 68
percent. The climate is humid tropical. The average inches.
annual precipitation is 76 inches, and the average an- These soils have a high available water capacity and
nual temperature is 770 F. medium fertility. Runoff is medium. The soils have
In a representative profile, the surface layer is dark been in hardwood trees and tree ferns for many years.
reddish-brown silty clay loam about 2 inches thick. Be- In this survey area, the Yunque soils are mapped
low this layer is dark-brown, friable gravelly silty clay only in an association with Los Guineos soils and
loam that extends to a depth of 16 inches. It is under- Stony rock land.
lain by bedded, fragmental shale. Representative profile of Yunque silty clay, 12 to 20
These soils have a low available water capacity, are percent slopes, in an area of the Los Guineos-Yunque-
susceptible to erosion, and are difficult to work. They Stony rock land association, steep, 25 meters southeast
have been in native pasture and brush for many years. from kilometer marker 11.9 on Highway No. 186:
Representative profile of Yunes silty clay loam, 20 to A1-0 to 8 inches, dark yellowish-brown (10YR 4/4) silty
60 percent slopes, eroded, 1 kilometer east of District clay; weak, fine, subangular blocky structure;
Hospital, Bermudez Farm, municipality of Fajardo: friable, slightly sticky and slightly plastic; many
fine roots; few fine pores; few, fine, dark minerals;
A1-0 to 2 inches, dark reddish-brown (5YR 3/2) silty clay few fine rock fragments; few krotovinas; very
loam; moderate, medium, granular structure; strongly acid; clear, smooth boundary.
slightly hard, friable, slightly sticky and slightly B21t-8 to 20 inches, yellowish-brown (10YR 5/6) clay;
plastic; many fine roots; common fine shale frag- few, fine, faint, yellowish-red mottles; weak,
ments; strongly acid; abrupt, smooth boundary, medium, subangular blocky structure; firm, sticky
B2-2 to 11 inches, dark-brown (7.5YR 3/2) gravelly silty and slightly plastic; common fine roots; few fine
clay loam; weak, medium, subangular blocky struc- pores; thin continuous clay films; few, fine, coated
ture; slightly hard, friable, slightly sticky and rock fragments; few krotovinas; very strongly
slightly plastic; many fine roots; 60 percent, by acid; gradual, smooth boundary.
volume, is shale fragments; strongly acid; abrupt, B22t-20 to 38 inches, yellowish-brown (10YR 5/8) clay;
smooth boundary. few, fine, faint, yellowish-red mottles; weak,
B3-11 to 16 inches, dark-brown (7.5YR 4/4) gravelly medium, subangular blocky structure breaking to
silty clay loam; weak, medium, subangular blocky weak, fine, subangular blocky; firm, sticky and
structure; friable, slightly sticky and slightly plas- slightly plastic; few fine roots; few fine pores; thin
tic; 80 percent, by volume, is shale fragments; continuous clay films; few, fine, coated rock frag-
strongly acid; abrupt, smooth boundary, ments; few krotovinas; few dark minerals; very
C-16 inches, bedded, fragmental, mixed light-red (2.5YR strongly acid; gradual, smooth boundary.
6/8), strong-brown (7.5YR 5/8), and pink (7.5YR B23t-38 to 51 inches, yellowish-brown (10YR 5/8) clay
7/4) shale; thickness of beds is from 1 to 4 inches; many, medium, distinct, red (2.5YR 4/8) mottles;
this material can be dug with difficulty with a spade weak, medium, subangular blocky structure; friable,
when moist. sticky and slightly plastic; few pores; few, thin,
patchy clay films; few dark concretions; very
Thickness of the solum and depth to fragmental shale patchrongly acid; clear, smooth boundary.etions; very
range from 10 to 20 inches. The A horizon has hue of 5YR strongly acid; clear, smooth boundary.
or 7.5YR and value and change from 10 to 20 inches. The B horizon has hue of B3-51 to 68 inches+, yellowish-red (5YR 4/8) clay; com-
or 7.5YR value and chroma of 2 or 3. The B horizon has mon, distinct, red (2.5YR 4/8) and reddish-yellow
hue of 5YR or 7.5YR, value of 3 or 4, and chroma of 2 to (7.5YR 6/8) mottles weak, fine, subangular
4. It ranges from gravelly silty clay loam to gravelly clay blocky structure; friable, slightly sticky and
loam. Reaction is strongly acid or very strongly acid. stc ; fries y ti an
The Yunes soils occupy the same landscape as the Ca- slightly plastic; few pores; very few, thin, patchy
guabo soils. Unlike the Caguabo soils, the Yunpe soils are clay films; few dark minerals; strongly acid.
strongly acid and lack hard rock. The solum is more than 60 inches thick. The A horizon
has hue of 10YR or 7.5YR, value of 3 or 4, and chroma of
YuF2-Yunes silty clay loam, 20 to 60 percent 2 to 4. It is silty clay loam or silty clay. The B2 horizon
slopes, eroded. This soil is on side slopes and ridge- has dominant hue of 10YR or 7.5YR, value of 5 or 6, and
tops in the humid, mountainous part of the survey chroma of 4 to 8. It is silty clay or clay and has weak or
area. moderate, fine or medium, subangular blocky structure. Clay
films vary from thick continuous to thin patchy. The B3
This soil is not suited to clean-cultivated crops, horizon has hue of 5YR, 7.5YR, or 2.5YR, value of 4 to 6,
Slope, shallowness, and the hazard of erosion are se- and chroma of 6 to 8. It is silty clay or clay. Mean annual
vere limitations that limit its use for pasture and wild- soil temperature at a depth of 20 inches is 66 to 72 F.,
life. Capability unit VIIs-1; woodland uitability and the difference between mean summer and mean winter
group 4d5. soil temperatures is less than 90 F. Reaction is very strongly
acid or strongly acid.






48 SOIL SURVEY

The water table is at or near the surface most of the Yunque Series
year. During rainy periods the areas are covered with
water. The soils range from loam to clay in texture. The Yunque series consists of deep soils that are
Because of the high water table, lack of outlets, and moderately well drained and moderately permeable.
high cost of reclamation, this land type is not suited to These soils formed in fine-textured, highly weathered
cultivated crops and is of little value for pasture, but it residuum of volcanic rocks. They are on upper side
provides good habitat for wildlife. Capability unit slopes and ridgetops in strongly dissected uplands.
VIIIw-2. Slopes are 10 to 35 percent. The average annual pre-
cipitation is 185 inches, and the average annual tem-
Yunes Series perature is 720 F.
In a representative profile, the surface layer is dark
The Yunes series consists of shallow soils that are yellowish-brown, very strongly acid silty clay about
well drained, strongly acid, and moderately permeable. 8 inches thick. Yellowish-brown, firm and friable clay
These soils formed in very gravelly residuum of shaly is between depths of 8 and 51 inches. Below this layer
sedimentary rocks. They are on side slopes and ridge- is yellowish-red, friable clay that has red and reddish-
tops in strongly dissected uplands. Slopes are 20 to 60 yellow mottles and extends to a depth of more than 68
percent. The climate is humid tropical. The average inches.
annual precipitation is 76 inches, and the average an- These soils have a high available water capacity and
nual temperature is 770 F. medium fertility. Runoff is medium. The soils have
In a representative profile, the surface layer is dark been in hardwood trees and tree ferns for many years.
reddish-brown silty clay loam about 2 inches thick. Be- In this survey area, the Yunque soils are mapped
low this layer is dark-brown, friable gravelly silty clay only in an association with Los Guineos soils and
loam that extends to a depth of 16 inches. It is under- Stony rock land.
lain by bedded, fragmental shale. Representative profile of Yunque silty clay, 12 to 20
These soils have a low available water capacity, are percent slopes, in an area of the Los Guineos-Yunque-
susceptible to erosion, and are difficult to work. They Stony rock land association, steep, 25 meters southeast
have been in native pasture and brush for many years. from kilometer marker 11.9 on Highway No. 186:
Representative profile of Yunes silty clay loam, 20 to A1-0 to 8 inches, dark yellowish-brown (10YR 4/4) silty
60 percent slopes, eroded, 1 kilometer east of District clay; weak, fine, subangular blocky structure;
Hospital, Bermudez Farm, municipality of Fajardo: friable, slightly sticky and slightly plastic; many
fine roots; few fine pores; few, fine, dark minerals;
A1-0 to 2 inches, dark reddish-brown (5YR 3/2) silty clay few fine rock fragments; few krotovinas; very
loam; moderate, medium, granular structure; strongly acid; clear, smooth boundary.
slightly hard, friable, slightly sticky and slightly B21t-8 to 20 inches, yellowish-brown (10YR 5/6) clay;
plastic; many fine roots; common fine shale frag- few, fine, faint, yellowish-red mottles; weak,
ments; strongly acid; abrupt, smooth boundary, medium, subangular blocky structure; firm, sticky
B2-2 to 11 inches, dark-brown (7.5YR 3/2) gravelly silty and slightly plastic; common fine roots; few fine
clay loam; weak, medium, subangular blocky struc- pores; thin continuous clay films; few, fine, coated
ture; slightly hard, friable, slightly sticky and rock fragments; few krotovinas; very strongly
slightly plastic; many fine roots; 60 percent, by acid; gradual, smooth boundary.
volume, is shale fragments; strongly acid; abrupt, B22t-20 to 38 inches, yellowish-brown (10YR 5/8) clay;
smooth boundary. few, fine, faint, yellowish-red mottles; weak,
B3-11 to 16 inches, dark-brown (7.5YR 4/4) gravelly medium, subangular blocky structure breaking to
silty clay loam; weak, medium, subangular blocky weak, fine, subangular blocky; firm, sticky and
structure; friable, slightly sticky and slightly plas- slightly plastic; few fine roots; few fine pores; thin
tic; 80 percent, by volume, is shale fragments; continuous clay films; few, fine, coated rock frag-
strongly acid; abrupt, smooth boundary, ments; few krotovinas; few dark minerals; very
C-16 inches, bedded, fragmental, mixed light-red (2.5YR strongly acid; gradual, smooth boundary.
6/8), strong-brown (7.5YR 5/8), and pink (7.5YR B23t-38 to 51 inches, yellowish-brown (10YR 5/8) clay
7/4) shale; thickness of beds is from 1 to 4 inches; many, medium, distinct, red (2.5YR 4/8) mottles;
this material can be dug with difficulty with a spade weak, medium, subangular blocky structure; friable,
when moist. sticky and slightly plastic; few pores; few, thin,
patchy clay films; few dark concretions; very
Thickness of the solum and depth to fragmental shale patchrongly acid; clear, smooth boundary.etions; very
range from 10 to 20 inches. The A horizon has hue of 5YR strongly acid; clear, smooth boundary.
or 7.5YR and value and change from 10 to 20 inches. The B horizon has hue of B3-51 to 68 inches+, yellowish-red (5YR 4/8) clay; com-
or 7.5YR value and chroma of 2 or 3. The B horizon has mon, distinct, red (2.5YR 4/8) and reddish-yellow
hue of 5YR or 7.5YR, value of 3 or 4, and chroma of 2 to (7.5YR 6/8) mottles weak, fine, subangular
4. It ranges from gravelly silty clay loam to gravelly clay blocky structure; friable, slightly sticky and
loam. Reaction is strongly acid or very strongly acid. stc ; fries y ti an
The Yunes soils occupy the same landscape as the Ca- slightly plastic; few pores; very few, thin, patchy
guabo soils. Unlike the Caguabo soils, the Yunpe soils are clay films; few dark minerals; strongly acid.
strongly acid and lack hard rock. The solum is more than 60 inches thick. The A horizon
has hue of 10YR or 7.5YR, value of 3 or 4, and chroma of
YuF2-Yunes silty clay loam, 20 to 60 percent 2 to 4. It is silty clay loam or silty clay. The B2 horizon
slopes, eroded. This soil is on side slopes and ridge- has dominant hue of 10YR or 7.5YR, value of 5 or 6, and
tops in the humid, mountainous part of the survey chroma of 4 to 8. It is silty clay or clay and has weak or
area. moderate, fine or medium, subangular blocky structure. Clay
films vary from thick continuous to thin patchy. The B3
This soil is not suited to clean-cultivated crops, horizon has hue of 5YR, 7.5YR, or 2.5YR, value of 4 to 6,
Slope, shallowness, and the hazard of erosion are se- and chroma of 6 to 8. It is silty clay or clay. Mean annual
vere limitations that limit its use for pasture and wild- soil temperature at a depth of 20 inches is 66 to 72 F.,
life. Capability unit VIIs-1; woodland uitability and the difference between mean summer and mean winter
group 4d5. soil temperatures is less than 90 F. Reaction is very strongly
acid or strongly acid.






HUMACAO AREA OF EASTERN PUERTO RICO 49

The Yunque soils are on the same landscape as the neutral, fine textured and moderately fine
Utuado, Ciales, Picacho, and Los Guineos soils. The Yunque textured soils; on stream terraces and allu-
soils are finer textured than the Utuado soils, and unlike vl fs in t s a .
those soils they have a B2t horizon. They lack the low- vial fans in the semiarid area.
chroma mottles in the B2t horizon of the Ciales and Picacho Class II. Soils that have moderate limitations that re-
soils. The Yunque soils have a thicker B2t horizon than duce the choice of plants or require moderate conser-
the Los Guineos soils. vation practices.
Subclass IIe. Soils subject to moderate erosion if
they are not protected.
Use and Management of the Soils Unit IIe-1. Deep, gently sloping, well-
drained, neutral and slightly acid, fine tex-
In this section the system of capability grouping tured and moderately fine textured soils;
used by the Soil Conservation Service is explained and on stream terraces and alluvial fans in the
the capability units in the Humacao Area are described, semiarid area.
Estimated yields for the principal crops and pasture Unit IIe-2. Deep, gently sloping, well-
grasses under two levels of management are given, drained, strongly acid, medium-textured
Management of the soils for woodland is also dis- soils; on stream terraces in the humid area.
cussed. Information about the soil properties and limi- Unit IIe-3. Deep, gently sloping, well-
tations that affect engineering practices and recreation drained, strongly acid, medium-textured
uses is given, mainly in tables. soils; on stream terraces and alluvial fans
in the semiarid area.
Ca y Gro g Unit IIe-4. Deep, gently sloping, well-
Capability Grouping drained, strongly acid, moderately fine tex-
Some readers, particularly those who farm on a tured soils; on coastal plains and terraces
large scale, may find it practical to use and manage in the humid area.
alike some of the different kinds of soil on their farm. Subclass IIw. Soils that have moderate limitations
These readers can make good use of the capability because of excess water.
classification system, a grouping that shows, in a gen- Unit IIw-1. Deep, nearly level to gently slop-
eral way, the suitability of soils for most kinds of ing, somewhat poorly drained, slightly
farming. acid, moderately fine textured and fine tex-
The grouping is based on limitations of soils when tured soils; on river flood plains, coastal
used for field crops, the risk of damage when they are plains, and alluvial fans in the humid area.
farmed, and the way the soils respond to treatment. Unit IIw-2. Deep, gently sloping to strongly
The grouping does not take into account major and sloping, somewhat poorly drained, medium
generally expensive landforming that would change acid, fine-textured soils; on alluvial fans
slope, depth, or other characteristics of the soils; does and terraces in the humid area.
not take into consideration possible but unlikely major Unit IIw-3. Deep, nearly level to gently slop-
reclamation projects; and does not apply to horticul- ing, somewhat poorly drained, very strongly
tural crops or other crops that require special manage- acid, fine-textured soils, on alluvial fans,
ment. foot slopes, and terraces in the humid area.
Those familiar with the capability classification can Unit IIw-4. Deep, nearly level, poorly
infer from it much about the behavior of soils when drained, neutral, fine textured and moder-
used for other purposes, but this classification is not a ately fine textured soils; on river flood
substitute for interpretations designed to show suit- plains in the semiarid area.
ability and limitations for forest trees or for engineer- Unit IIw-5. Deep, nearly level, somewhat
ing. poorly drained, slightly acid, moderately
In the capability system, soils are grouped at three coarse textured soils that are underlain by
levels; the class, the subclass, and the unit. The classes, sand; in the humid area.
subclasses, and units in the Humacao Area are de- Subclass IIs. Soils that have moderate limitations
scribed in the list that follows. The capability unit for because of tilth or low available water capacity.
each soil is listed in the "Guide to Mapping Units" and Unit IIs-1. Deep, nearly level to gently slop-
at the end of the mapping unit description in the ing, moderately well drained and somewhat
section "Descriptions of the Soils." poorly drained, mildly alkaline to slightly
acid, fine-textured soils that have expansive
Class I. Soils that have few limitations that restrict clays; on coastal plains, alluvial fans, and
their use. terraces in the semiarid area.
(No subclasses) Unit IIs-2. Deep, gently sloping, moderately
Unit I-1. Deep, nearly level, well-drained, well drained, very strongly acid, fine-
strongly acid, medium-textured soils; on textured soils; on alluvial fans and terraces
stream terraces and alluvial fans in the in the humid area.
semiarid area. Unit IIs-3. Deep, nearly level, well-drained,
Unit 1-2. Deep, nearly level, moderately well very strongly acid, medium-textured soils;
drained, medium acid, moderately fine tex- on river flood plains in the humid area.
tured soils; on river flood plains in the hu- Subclass IIc. Soils limited by lack of water.
mid area. Unit IIc-1. Deep, nearly level, well-drained,
Unit 1-3. Deep, nearly level, well-drained, neutral, moderately fine textured soils; on






HUMACAO AREA OF EASTERN PUERTO RICO 49

The Yunque soils are on the same landscape as the neutral, fine textured and moderately fine
Utuado, Ciales, Picacho, and Los Guineos soils. The Yunque textured soils; on stream terraces and allu-
soils are finer textured than the Utuado soils, and unlike vl fs in t s a .
those soils they have a B2t horizon. They lack the low- vial fans in the semiarid area.
chroma mottles in the B2t horizon of the Ciales and Picacho Class II. Soils that have moderate limitations that re-
soils. The Yunque soils have a thicker B2t horizon than duce the choice of plants or require moderate conser-
the Los Guineos soils. vation practices.
Subclass IIe. Soils subject to moderate erosion if
they are not protected.
Use and Management of the Soils Unit IIe-1. Deep, gently sloping, well-
drained, neutral and slightly acid, fine tex-
In this section the system of capability grouping tured and moderately fine textured soils;
used by the Soil Conservation Service is explained and on stream terraces and alluvial fans in the
the capability units in the Humacao Area are described, semiarid area.
Estimated yields for the principal crops and pasture Unit IIe-2. Deep, gently sloping, well-
grasses under two levels of management are given, drained, strongly acid, medium-textured
Management of the soils for woodland is also dis- soils; on stream terraces in the humid area.
cussed. Information about the soil properties and limi- Unit IIe-3. Deep, gently sloping, well-
tations that affect engineering practices and recreation drained, strongly acid, medium-textured
uses is given, mainly in tables. soils; on stream terraces and alluvial fans
in the semiarid area.
Ca y Gro g Unit IIe-4. Deep, gently sloping, well-
Capability Grouping drained, strongly acid, moderately fine tex-
Some readers, particularly those who farm on a tured soils; on coastal plains and terraces
large scale, may find it practical to use and manage in the humid area.
alike some of the different kinds of soil on their farm. Subclass IIw. Soils that have moderate limitations
These readers can make good use of the capability because of excess water.
classification system, a grouping that shows, in a gen- Unit IIw-1. Deep, nearly level to gently slop-
eral way, the suitability of soils for most kinds of ing, somewhat poorly drained, slightly
farming. acid, moderately fine textured and fine tex-
The grouping is based on limitations of soils when tured soils; on river flood plains, coastal
used for field crops, the risk of damage when they are plains, and alluvial fans in the humid area.
farmed, and the way the soils respond to treatment. Unit IIw-2. Deep, gently sloping to strongly
The grouping does not take into account major and sloping, somewhat poorly drained, medium
generally expensive landforming that would change acid, fine-textured soils; on alluvial fans
slope, depth, or other characteristics of the soils; does and terraces in the humid area.
not take into consideration possible but unlikely major Unit IIw-3. Deep, nearly level to gently slop-
reclamation projects; and does not apply to horticul- ing, somewhat poorly drained, very strongly
tural crops or other crops that require special manage- acid, fine-textured soils, on alluvial fans,
ment. foot slopes, and terraces in the humid area.
Those familiar with the capability classification can Unit IIw-4. Deep, nearly level, poorly
infer from it much about the behavior of soils when drained, neutral, fine textured and moder-
used for other purposes, but this classification is not a ately fine textured soils; on river flood
substitute for interpretations designed to show suit- plains in the semiarid area.
ability and limitations for forest trees or for engineer- Unit IIw-5. Deep, nearly level, somewhat
ing. poorly drained, slightly acid, moderately
In the capability system, soils are grouped at three coarse textured soils that are underlain by
levels; the class, the subclass, and the unit. The classes, sand; in the humid area.
subclasses, and units in the Humacao Area are de- Subclass IIs. Soils that have moderate limitations
scribed in the list that follows. The capability unit for because of tilth or low available water capacity.
each soil is listed in the "Guide to Mapping Units" and Unit IIs-1. Deep, nearly level to gently slop-
at the end of the mapping unit description in the ing, moderately well drained and somewhat
section "Descriptions of the Soils." poorly drained, mildly alkaline to slightly
acid, fine-textured soils that have expansive
Class I. Soils that have few limitations that restrict clays; on coastal plains, alluvial fans, and
their use. terraces in the semiarid area.
(No subclasses) Unit IIs-2. Deep, gently sloping, moderately
Unit I-1. Deep, nearly level, well-drained, well drained, very strongly acid, fine-
strongly acid, medium-textured soils; on textured soils; on alluvial fans and terraces
stream terraces and alluvial fans in the in the humid area.
semiarid area. Unit IIs-3. Deep, nearly level, well-drained,
Unit 1-2. Deep, nearly level, moderately well very strongly acid, medium-textured soils;
drained, medium acid, moderately fine tex- on river flood plains in the humid area.
tured soils; on river flood plains in the hu- Subclass IIc. Soils limited by lack of water.
mid area. Unit IIc-1. Deep, nearly level, well-drained,
Unit 1-3. Deep, nearly level, well-drained, neutral, moderately fine textured soils; on







50 SOIL SURVEY

flood plains, alluvial fans, and terraces in drained, very strongly acid, moderately
the semiarid area. fine textured soils that are underlain by
Unit IIc-2. Deep, nearly level, well-drained, sand; on flood plains in the humid area.
strongly acid, medium-textured soils; on Unit IIIw-4. Deep, nearly level, poorly
stream terraces and alluvial fans in the drained, strongly acid, fine-textured soils;
semiarid area. on flood plains in the humid area.
Class III. Soils that have severe limitations that reduce Subclass Ills. Soils that have severe limitations
the choice of plants, require special conservation because of poor workability, gravel, shallowness
practices, or both. to rock, or low available water capacity.
Subclass IIIe. Soils subject to severe erosion if Unit IIIs-1. Deep, gently sloping, well-
they are cultivated and not protected, drained, medium acid, moderately fine tex-
Unit IIIe-1. Deep, strongly sloping, well- tured, gravelly soils; on foot slopes and
drained, very strongly acid, fine-textured alluvial fans in the semiarid area.
soils; on terraces and foot slopes in the Unit IIIs-2. Deep, nearly level, well-drained,
humid area. moderately fine textured, slightly acid, fri-
Unit IIIe-2. Deep, strongly sloping, some- able soils that are underlain by cobbles,
what poorly drained, strongly acid, moder- gravel, and sand; on flood plains in the
ately coarse textured soils; on foot slopes semiarid area.
and side slopes in the humid area. Unit IIIs-3. Moderately deep, gently sloping,
Unit IIIe-3. Moderately deep, gently sloping well-drained, medium acid, fine-textured
to strongly sloping, well-drained, strongly soils; on foot slopes in the semiarid area.
acid, moderately fine textured soils; on foot Subclass IIIc. Soils severely limited by lack of
slopes in the humid area. water.
Unit IIIe-4. Moderately deep, gently sloping Unit IIIc-1. Deep, nearly level to gently slop-
to strongly sloping, well-drained, strongly ing, moderately well drained to somewhat
acid, moderately fine textured soils; on foot poorly drained, mildly alkaline to slightly
slopes in the semiarid area. acid, fine-textured soils that have expansive
Unit IIIe-5. Moderately deep, strongly slop- clays throughout; on coastal plains, ter-
ing, moderately well drained, strongly acid, races, and alluvial fans.
moderately fine textured, gravelly soils; on Unit IlIc-2. Deep, gently sloping, well-
foot slopes in the humid area. drained, moderately alkaline to slightly
Unit IIIe-6. Deep, gently sloping to strongly acid, fine textured and moderately fine tex-
sloping, well-drained, very strongly acid, tured soils; on alluvial fans and terraces.
moderately fine textured soils; on hilltops Unit IIIc-3. Deep, gently sloping, well-
and foot slopes in the humid area. drained, strongly acid, medium-textured
Unit IIIe-7. Deep, strongly sloping, moder- soils; on stream terraces and alluvial fans.
ately well drained to somewhat poorly Class IV. Soils that have very severe limitations that
drained, very strongly acid, and extremely restrict the choice of plants, require very careful
acid, fine-textured soils; on foot slopes, al- management, or both.
luvial fans, and terraces in the humid area. Subclass IVe. Soils subject to very severe erosion
Unit IIIe-8. Deep, strongly sloping, well- if they are cultivated and not protected.
drained, strongly acid, moderately fine tex- Unit IVe-1. Deep, strongly sloping, some-
tured soils; on coastal plains and terraces what poorly drained, extremely acid,
in the humid area. medium-textured soils; on alluvial fans and
Unit IIIe-9. Deep, gently sloping to strongly foot slopes in the humid area.
sloping, well-drained, strongly acid, mod- Unit IVe-2. Deep, moderately steep, some-
erately fine textured soils that are under- what poorly drained, strongly acid, moder-
lain by gravelly clay loam; on terraces in ately coarse textured soils; on foot slopes
the humid area. in the humid area.
Unit IIIe-10. Deep, gently sloping to strongly Unit IVe-3. Deep, strongly sloping, well-
sloping, well-drained, very strongly acid, drained, very strongly alkaline to slightly
medium-textured soils that are underlain acid, moderately fine textured soils that are
by coarser textured material; on stream underlain bSy gravel or secondary lime; on
terraces and alluvial fans in the humid alluvial fans, terraces, and foot slopes in
area. the semiarid area.
Subclass IIIw. Soils that have severe limitations Unit IVe-4. Moderately deep, strongly slop-
because of excess water. ing, well-drained, medium acid, fine-
Unit IIIw-1. Deep, nearly level, poorly textured soils; on foot slopes and low
drained, slightly acid, fine-textured soils; rolling hills in the semiarid area.
on flood plains in the humid area. Unit IVe-5. Deep, moderately steep and
Unit IIIw-2. Deep, gently sloping, somewhat steep, well drained and moderately well
poorly drained, extremely acid, medium- drained, very strongly acid and extremely
textured soils; on terraces and alluvial fans acid, fine textured and moderately fine tex-
in the humid area. tured soils; on uplands in the humid area.
Unit IIIw-3. Deep, nearly level, poorly Unit IVe-6. Moderately deep, moderately






HUMACAO AREA OF EASTERN PUERTO RICO 51

steep, well-drained, medium acid, moder- tured, gravelly soils; on foot slopes and
ately fine textured soils; on side slopes in alluvial fans in the semiarid area.
the humid area. Class V. Soils that are subject to little or no erosion but
Unit IVe-7. Deep, moderately steep, well- that have other limitations, impractical to remove,
drained, strongly acid, moderately fine tex- that limit their use largely to pasture, woodland, or
tured soils; on uplands in the humid area. wildlife habitat.
Unit IVe-8. Deep, strongly sloping, well- Subclass Vs. Soils that have severe limitations be-
drained, medium acid, moderately fine tex- cause of excess stones.
tured, gravelly soils; on foot slopes in the Unit Vs-1. Nearly level, medium-textured,
semiarid area. stony soils that contain about 70 percent,
Unit IVe-9. Strongly sloping, well-drained, by volume, stones that range from 3 to 10
slightly acid, medium-textured soils that inches in diameter; on flood plains of
are shallow to sand and are underlain by streams and rivers.
hard rock at a depth of 32 to 50 inches; on Class VI. Soils that have severe limitations that make
semiarid uplands. them generally unsuitable for cultivation and that
Unit IVe-10. Deep, moderately steep, some- limit their use largely to pasture, woodland, or wild-
what poorly drained, very strongly acid, life food and cover.
fine-textured soils; on foot slopes in the Subclass VIe. Soils severely limited, chiefly by risk
humid area. of erosion if a protective cover is not main-
Unit IVe-11. Deep, steep, well-drained, very tained.
strongly acid, medium-textured soils on Unit VIe-1. Moderately deep, steep, well-
humid uplands. drained, strongly acid to extremely acid,
Subclass IVw. Soils that have very severe limita- fine textured and moderately fine textured
tions because of excess water. soils; on humid uplands.
Unit IVw-1. Deep, nearly level, poorly Unit VIe-2. Deep, steep and very steep, well
drained, very strongly acid, fine-textured drained and moderately well drained, mod-
soils that are underlain by organic mate- erately fine textured, very strongly acid
rial at a depth of 15 to 30 inches; on soils; on uplands where rainfall is high.
coastal lowlands in the humid area. Unit VIe-3. Deep, moderately steep to steep,
Unit IVw-2. Deep, nearly level, poorly well-drained, strongly acid, medium-
drained, mildly alkaline, fine-textured soils textured to moderately fine textured soils;
that are underlain by organic material at a on humid uplands.
depth of 12 to 22 inches; on coastal low- Unit VIe-4. Moderately deep, steep, well-
lands in the semiarid area. drained, medium acid, moderately fine tex-
Subclass IVs. Soils that have very severe limita- tured soils; on humid uplands.
tions because of shallowness, gravel, poor tilth, Unit VIe-5. Moderately steep to steep, well-
low available water capacity, or permeability, drained, medium-textured soils that are
Unit IVs-1. Deep, nearly level, moderately shallow to sand and are underlain by rock at
alkaline, very friable, excessively drained, a depth of 36 to 50 inches; on semiarid up-
moderately coarse textured soils that are lands.
underlain by sand and gravel at a depth of Subclass VIs. Soils generally unsuitable for culti-
8 to 10 inches, and have a low available vation and limited for other uses by their low
water capacity; on flood plains and alluvial available water capacity or shallowness to gravel
fans in the semiarid area. or hard rock.
Unit IVs-2. Strongly sloping, well-drained, Unit VIs-1. Deep, nearly level, excessively
neutral, moderately fine textured soils that drained, moderately alkaline, coarse-
are shallow to hard rock; on side slopes in textured soils that have a very low available
the semiarid area. water capacity; along the coast.
Unit IVs-3. Nearly level, excessively Unit VIs-2. Moderately steep, well-drained,
drained, medium acid, moderately coarse slightly acid, moderately fine textured soils
textured soils that are shallow to sand and that are shallow to hard rock; on humid up-
gravel; on flood plains in the humid area. lands.
Subclass IVc. Soils very severely limited by lack Unit VIs-3. Deep, nearly level, excessively
of water, drained, very strongly acid, coarse-
Unit IVc-1. Deep, nearly level, well-drained, textured soils that have a low available
moderately fine textured, slightly acid, fri- water capacity; along the coast.
able soils that are underlain by cobbles, Subclass VIc. Soils severely limited by the lack of
gravel, and sand at a depth of 12 to 20 rainfall.
inches; on flood plains in the semiarid area. Unit VIc-1. Deep, nearly level, excessively
Unit IVc-2. Moderately deep, gently sloping drained, mildly alkaline, friable, moder-
to strongly sloping, strongly acid to neu- ately coarse textured soils that are under-
tral, well-drained, fine-textured and moder- lain by gravel and sand at a depth of 8 to 10
ately fine textured soils; on foot slopes. inches and have a low available water ca-
Unit IVc-3. Deep, gently sloping, well- pacity; on flood plains.
drained, medium acid, moderately fine tex- Class VII. Soils that have very severe limitations that







52 SOIL SURVEY

make them unsuitable for cultivation and restrict Subclass VIIIw. Extremely wet soils or marshes.
their use largely to pasture, woodland, or wildlife Unit VIIIw-1. This unit consists of extremely
food and cover. wet areas on coastal lowlands that are pe-
Subclass VIIe. Soils very severely limited, chiefly riodically flooded by seawater. Texture of
by risk of erosion unless protective cover is the soil material ranges widely and in-
maintained. cludes organic material. Only mangrove
Unit VIIe-1. Deep and moderately deep, very trees and other salt-tolerant vegetation
steep, well drained and moderately well grow in these areas. Cost of reclamation is
drained, extremely acid, moderately fine high.
textured soils; on humid uplands. Unit VIIIw-2. This unit consists of low la-
Unit VIIe-2. Very steep, strongly acid, well- goonlike areas on the flood plains of the
drained, medium-textured soils that are rivers and streams that drain the humid
moderately deep to weathered rock; on hu- part of the survey area. The water table is
mid uplands. at or near the surface most of the year.
Unit VIIe-3. Shallow and deep, steep and very Texture of the soils ranges from loam to
steep, poorly drained and moderately well clay.
drained, strongly acid to extremely acid, Subclass VIIIs. Very shallow, stony or sandy soils,
moderately fine textured soils; in rain for- rock, or soil material that has no potential for
est. There are rocks in some mapping units. agriculture.
Subclass VIIw. Soils that have very severe limita- Unit VIIIs-1. This unit consists of narrow
tions because of excess water. strips of light-colored beach sands along
Unit VIIw-1. Deep, nearly level, slightly the coast. The sands are excessively
acid, poorly drained, fine-textured, saline drained, and saltwater is at variable depths.
soils; on coastal lowlands. Unit VIIIs-2. This unit consists of the high,
Subclass VIIs. Soils very severely limited by shal- jagged mountain peaks and long, very steep
lowness, stoniness, or a low available water ca- side slopes in the rain forest and in the
pacity. mountains. Rock outcrops, loose stones, and
Unit VIIs-1. Moderately steep to very steep, boulders cover about 50 to 90 percent of the
well-drained, moderately coarse textured to surface.
moderately fine textured soils that are shal-
low and moderately deep to hard rock; on
humid uplands. Stones on the surface are
common. Estimated Yields
Unit VIIs-2. Deep, very steep, well-drained, The estimated average yields per acre of principal
very strongly acid, fine-textured soils; onyields p acre of p
vehu d ustpan Aboutcid, fine-texred soi unot crops grown in the Humacao Area are shown in table 2,
consists of areas covered with stones and and those of the principal grasses are shown in table 3.
boulders covered wth stones and In columns A are yields expected under management
Unit VIIs-3. Deep and moderately deep, common in the survey area, and in columns B are yields
steep and very steep, well drained and mod- to be expected under improved management.
erately well drained, very strongly acid The yields are based on research data, on long-term
moderately fine textured soils; in rain for- records compiled at the sugarmills, and on information
est. A large percent of the unit consists of obtained from farmers and other agricultural workers.
stony rock land. The yields under management common in the area
Unit VIIs-4 Steep to very steep, well-drained are the average of yields obtained during the period of
neutral moderately fine textured soils that the survey. They include those obtained by a few farm-
are shallow to rock; on semiarid uplands. ers practicing improved management, a few practicing
Unit VIIs-5. Shallow and moderately deep, poor management, and many practicing average man-
very steep, well-drained, strongly acid to agement.Average yields mainly reflect common man-
slightly acid, medium-textured soils; on hu- Improved management includes the following prac-practices.
mid uplands. Boulders cover 40 to 50 per- tices:
cent of the surface.
Unit VIIs-6. Steep, poorly drained, very 1. Application of fertilizer according to the re-
strongly acid, moderately fine textured sults of soil tests.
soils that are shallow to hard rock; on humid 2. Adequate preparation of the seedbed, including
uplands. leveling and smoothing, if feasible.
Unit VIIs-7. Deep, nearly level to gently 3. Drainage and control of water if needed.
sloping, excessively drained, neutral soils 4. Use of improved crop varieties.
that are sandy throughout and have a very 5. Effective use of irrigation water.
low available water capacity; along the 6. Cultivation within the proper moisture content
coast. and to the proper depth.
Class VIII. Soils and landforms that have limitations 7. Control of weeds, insects, and other pests and of
that preclude their use for commercial crop produc- plant diseases.
tion and restrict their use to recreation, wildlife 8. Harvesting crops at the proper time.
habitat, water supply, or esthetic purposes. 9. Management of crop residue so that the burn-







HUMACAO AREA OF EASTERN PUERTO RICO 53

ing of sugarcane residue and other crop residue survey area, r is used if slopes are greater than 40
is avoided. percent.
10. Protection from overgrazing. The last part of the symbol, another number, dif-
ferentiates woodland suitability groups that have iden-
tical first and second parts in their identifying symbol.
Use of the Soils for Woodland Soils in woodland suitability group 3wl, for example,
require somewhat different management than soils in
When Puerto Rico was colonized in the early 1500's, group 3w2.
the island was completely covered by forests, but land In the Humacao Area, many thousands of acres of
clearing for farms was soon begun. By 1880, most of soils that can produce forest trees are not placed in
the forests had been cut. Some areas were not suitable woodland suitability groups, because they are prime
for permanent cultivation and were abandoned when areas for growing sugarcane and for other farm uses
their fertility was lost. Later some of these areas were and they are not likely to be planted to forest.
again cleared, cultivated, and abandoned. Land thus Land types are not placed in woodland suitability
abandoned generally was taken over by inferior volun- groups, because they are not suitable for commercial
teer trees. forest. They are too rocky, too exposed to wind and sun,
At present, about 15 percent of the Humacao Area is too steep, or infertile. Among these are Rock land,
covered by forest, both commercial and noncommer- Rough stony land, Tidal swamp, Tidal flats, Cobbly
cial. This includes the Caribbean National Forest. alluvial land, Wet alluvial land, Coastal beaches,
Nearly half of this total requires timber stand improve- Leveled clayey land, and Salt water marsh. These
ment or reforestation. areas are not suitable for planting trees, but the'exist-
Forest is an excellent use of the soils in the Humacao ing woodland cover should be protected.
Area for the protection of soil and water resources. Table 4 gives a brief description of the woodland suit-
Forest cover can minimize floods, reduce the amount of ability groups in the Humacao Area and lists suitable
soil material lost as sediment in rivers, and hold runoff tree species and their potential productivity for each
into periods of dry weather. In using the soils for forest group. Also, each woodland suitability group is rated
in the Humacao Area, some natural noncommercial for various hazards and limitations that affect man-
forests need to be converted to commercial, other non- agement. These ratings are slight, moderate, and
commercial forests need to be protected and left in severe, and they are explained in the following para-
their natural state, and trees need to be planted in some graphs.
nonforested areas. Seedling mortality refers to the expected degree of
The soils of the Humacao Area have been placed in mortality of naturally occurring or planted tree seed-
woodland suitability groups to assist owners in plan- lings as influenced by kinds of soil or topographic con-
ning the use of their soils for wood crops. Each group is editions. Plant competition is assumed not to be a factor,
made up of soils that are suited to the same kinds of and seed supplies are assumed to be adequate. A rating
trees, that need about the same management where the of slight indicates a loss of 0 to 25 percent of the
vegetation on them is similar, and that have the same seedlings; moderate indicates a loss of 25 to 50 percent;
potential production. and severe indicates a loss of more than 50 percent.
Each woodland group is identified by a three-part Erosion hazard refers to the potential erodibility of
symbol, such as lol, 2wl, or 3w3. The potential pro- the soil and the hazard it causes. A rating of slight
ductivity of the soils in the group is indicated by the means that no special techniques in management are
first number in the symbol: 1 indicates very high required. Moderate means that some provision in man-
potential productivity; 2, high; 3, moderately high; 4, agement must be made to control accelerated erosion.
moderate; and 5, low. These ratings are based on esti- Roads, skid trails, fire lanes, and landing construction
mates of the productivity in board feet per acre per require some special techniques. Severe means that
year of suitable tree species, special techniques in management and special atten-
The second part of the woodland suitability group tion to roads, skid trails, fire lanes, and landing con-
symbol is a lowercase letter. In this survey area, the struction and maintenance are necessary to minimize
letters c, d, r, and o are used. Except for the o, the accelerated erosion.
letter indicates an important soil property that imposes Equipment limitations depend on soil characteristics
a hazard or limitation in managing the soils of the that restrict or prohibit the use of harvesting equip-
group for trees. The letter o shows that the soils have ment, either seasonally or continually. A rating of
few limitations that restrict their use for trees. The slight means that there are no restrictions in the kind
letter c means that the soils have limitations because of of equipment or the time of year it is used. Moderate
the kind or amount of clay in the upper part of the soil means that the use of equipment is restricted for 3
profile. The letter d stands for soils that have a re- months of the year or less. Severe means that special
stricted rooting depth. Soils that are shallow to hard equipment is needed and that its use is severely re-
rock or to layers in the soil that restrict roots are stricted for more than 3 months of the year.
examples. The letter r shows that the main limitation is
steep slopes and that there is a hazard of erosion and
possibly limitations to the use of equipment. In this Engineering Uses of the Soils3
This section is useful to planning commissions, town
2 By ROBERT W. NOBLES, project leader, Cooperative Forestry-
Institute of Tropical Forestry, Forest Service, U.S. Department :'PEDRO CATONI, engineer, Soil Conservation Service, helped
of Agriculture. prepare this section.




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