• TABLE OF CONTENTS
HIDE
 Title Page
 Table of Contents
 Introduction
 Island surveyed
 Climate
 Agriculture
 Soil-survey methods and defini...
 Soils and crops
 Agrologia (suelos y cosechas)
 Productivity ratings
 Clasificacion a base de produc...
 Alkali and saline soils
 Morphology and genesis of...
 Summary
 Literature cited
 Index
 Map






Title: Soil survey of Puerto Rico, series 1936, no. 8
CITATION PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00016128/00001
 Material Information
Title: Soil survey of Puerto Rico, series 1936, no. 8
Physical Description: Book
Creator: Roberts, R. C.
Publication Date: 1942
 Notes
Funding: U.S. Department of Agriculture Soil Surveys
 Record Information
Bibliographic ID: UF00016128
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: notis - AAA8647

Table of Contents
    Title Page
        Title 1
        Title 2
    Table of Contents
        Page 1
    Introduction
        Page 1
    Island surveyed
        Page 2
        Physiographic and geologic features
            Page 3
            Page 4
            Page 5
            Page 6
            Page 7
            Page 8
            Page 9
            Page 10
            Page 11
            Page 12
            Page 13
            Page 14
        Mineral resources
            Page 15
            Page 16
        Vegetation
            Page 17
            Page 18
            Page 19
            Page 20
            Page 21
            Page 22
            Page 23
            Page 24
            Page 25
            Page 26
            Page 27
            Page 28
        Animal life
            Page 29
            Page 30
            Page 31
        Population
            Page 32
            Page 33
            Page 34
            Page 35
        Towns
            Page 36
            Page 37
        Transportation
            Page 38
            Page 39
        Education
            Page 40
        Water supply
            Page 41
        Farm buildings
            Page 42
            Page 43
            Page 44
            Page 45
            Page 46
    Climate
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
    Agriculture
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
        Sugarcane (cana de azucar)
            Page 67
            Page 68
            Page 69
            Page 70
            Page 71
            Page 72
            Page 73
            Page 74
            Page 75
            Page 76
            Page 77
            Page 78
            Page 79
            Page 80
            Page 81
            Page 82
            Page 83
        Tobacco (tabaco)
            Page 84
            Page 85
            Page 86
            Page 87
            Page 88
            Page 89
            Page 90
            Page 91
            Page 92
            Page 93
        Coffee (cafe)
            Page 94
            Page 95
            Page 96
            Page 97
            Page 98
            Page 99
            Page 100
            Page 101
            Page 102
        Grapefruit (toronja)
            Page 103
            Page 104
            Page 105
            Page 106
            Page 107
        Pineapples (pinas)
            Page 108
            Page 109
            Page 110
            Page 111
            Page 112
            Page 113
            Page 114
            Page 115
            Page 116
        Coconuts (cocos)
            Page 117
            Page 118
            Page 119
        Bananas (guineos) and plantains (platanos)
            Page 120
            Page 121
            Page 122
            Page 123
            Page 124
            Page 125
            Page 126
        Corn (maiz)
            Page 127
            Page 128
        Sweetpotatoes (batatas)
            Page 129
            Page 130
            Page 131
        Yautia, dasheen, or tania (yautia)
            Page 132
            Page 133
        Name, or yam
            Page 134
            Page 135
            Page 136
        Pigeonpeas (gandules)
            Page 137
            Page 138
            Page 139
            Page 140
        Yuca (cassava)
            Page 141
            Page 142
        Beans (habichuelas) and cow peas (frijoles)
            Page 143
            Page 144
        Cotton (algodon)
            Page 145 (MULTIPLE)
            Page 146
        Mango
            Page 147
            Page 148
        Avocado (aguacate)
            Page 149
        Miscellaneous crops
            Page 149
            Page 150
            Page 151
            Page 152
        Livestock
            Page 153
            Page 154
            Page 155
            Page 156
            Page 157
            Page 158
            Page 159
            Page 160
            Page 161
            Page 162
            Page 163
            Page 164
            Page 165
    Soil-survey methods and definitions
        Page 166
        Page 167
        Page 168
        Page 169
        Page 170
    Soils and crops
        Page 171
        Page 172
        Page 173
        Page 174
        Page 175
        Page 176
        Page 177
        Page 178
        Page 179
        Page 180
        Page 181
        Page 182
        Soils of the uplands
            Page 183
            Page 184
            Page 185
            Page 186
            Page 187
            Page 188
            Page 189
            Page 190
            Page 191
            Page 192
            Page 193
            Page 194
            Page 195
            Page 196
            Page 197
            Page 198
            Page 199
            Page 200
            Page 201
            Page 202
            Page 203
            Page 204
            Page 205
            Page 206
            Page 207
            Page 208
            Page 209
            Page 210
            Page 211
            Page 212
            Page 213
            Page 214
            Page 215
            Page 216
            Page 217
            Page 218
            Page 219
            Page 220
            Page 221
            Page 222
            Page 223
            Page 224
            Page 225
            Page 226
            Page 227
            Page 228
            Page 229
            Page 230
            Page 231
            Page 232
            Page 233
            Page 234
            Page 235
            Page 236
            Page 237
            Page 238
            Page 239
            Page 240
            Page 241
            Page 242
            Page 243
            Page 244
            Page 245
            Page 246
            Page 247
            Page 248
        Soils of the inner plains
            Page 249
            Page 250
            Page 251
            Page 252
            Page 253
            Page 254
            Page 255
            Page 256
            Page 257
            Page 258
            Page 259
            Page 260
            Page 261
            Page 262
            Page 263
        Soils of the terraces and alluvial fans
            Page 264
            Page 265
            Page 266
            Page 267
            Page 268
            Page 269
            Page 270
            Page 271
            Page 272
            Page 273
            Page 274
            Page 275
            Page 276
            Page 277
            Page 278
            Page 279
            Page 280
            Page 281
            Page 282
            Page 283
            Page 284
            Page 285
            Page 286
            Page 287
            Page 288
            Page 289
            Page 290
        Soils of the costal plains
            Page 291
            Page 292
            Page 293
            Page 294
            Page 295
            Page 296
            Page 297
            Page 298
            Page 299
            Page 300
            Page 301
            Page 302
            Page 303
            Page 304
            Page 305
            Page 306
            Page 307
            Page 308
            Page 309
            Page 310
            Page 311
        Soils of the river flood plains
            Page 312
            Page 313
            Page 314
            Page 315
            Page 316
            Page 317
            Page 318
            Page 319
            Page 320
            Page 321
            Page 322
            Page 323
            Page 324
            Page 325
            Page 326
            Page 327
            Page 328
            Page 329
            Page 330
            Page 331
            Page 332
            Page 333
            Page 334
            Page 335
            Page 336
            Page 337
            Page 338
            Page 339
            Page 340
            Page 341
        Soils of the costal lowlands
            Page 342
            Page 343
            Page 344
            Page 345
            Page 346
            Page 347
            Page 348
            Page 349
            Page 350
            Page 351
            Page 352
            Page 353
            Page 354
            Page 355
            Page 356
            Page 357
    Agrologia (suelos y cosechas)
        Page 358
        Suelos de la altura
            Page 359
            Page 360
            Page 361
            Page 362
            Page 363
            Page 364
            Page 365
            Page 366
            Page 367
            Page 368
            Page 369
        Suelos de las llanuras interiores
            Page 370
            Page 371
            Page 372
        Suelos anbancalados y de aluvion en abanico
            Page 373
            Page 374
            Page 375
            Page 376
            Page 377
        Suelos de las llanuras costaneras
            Page 378
            Page 379
            Page 380
            Page 381
            Page 382
            Page 383
        Suelos de los valles de aluvion
            Page 384
            Page 385
            Page 386
            Page 387
        Suelos de los bajos costaneros
            Page 388
            Page 389
        Glosario
            Page 390
    Productivity ratings
        Page 391
        Page 392
        Page 393
        Page 394
        Page 395
        Page 396
        Page 397
        Page 398
        Page 399
        Page 400
        Page 401
        Page 402
        Page 403
        Page 404
        Page 405
        Page 406
        Page 407
        Page 408
        Page 409
        Page 410
        Page 411
    Clasificacion a base de productividad
        Page 412
        Page 413
    Alkali and saline soils
        Page 414
        Page 415
        Page 416
        Page 417
        Page 418
        Page 419
        Page 420
        Plate
    Morphology and genesis of soils
        Page 421
        Page 422
        Page 423
        Page 424
        Page 425
        Page 426
        Page 427
        Page 428
        Page 429
        Page 430
        The 20- to 25-inch rainfall belt
            Page 431
            Page 432
            Page 433
        The 25- to 35-inch rainfall belt
            Page 434
            Page 435
            Page 436
            Page 437
            Page 438
            Page 439
        The 35- to 45-inch rainfall belt
            Page 440
            Page 441
            Page 442
            Page 443
            Page 444
        The 45- to 60-inch rainfall belt
            Page 445
            Page 446
            Page 447
            Page 448
            Page 449
            Page 450
        The 60- to 75-inch rainfall belt
            Page 451
            Page 452
            Page 453
            Page 454
            Page 455
            Page 456
            Page 457
            Page 458
            Page 459
            Page 460
            Page 461
            Page 462
            Page 463
            Page 464
            Page 465
            Page 466
        The 75- to 95-inch rainfall belt
            Page 467
            Page 468
            Page 469
            Page 470
            Page 471
            Page 472
            Page 473
            Page 474
            Page 475
            Page 476
            Page 477
            Page 478
            Page 479
            Page 480
        The 95- to 160-inch + rainfall belt
            Page 481
            Page 482
            Page 483
    Summary
        Page 484
        Page 485
        Page 486
        Page 487
        Page 488
        Page 489
        Page 490
        Page 491
    Literature cited
        Page 492
        Page 493
        Page 494
        Page 495
        Page 496
    Index
        Page 497
        Page 498
        Page 499
        Page 500
        Page 501
        Page 502
        Page 503
    Map
        Page 1
        Page 2
        Page 3
        Page 4
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Series 1936, No. 8 Issued January 1942

SOIL SURVEY OF PUERTO RICO
By R. C. ROBERTS, Division of Soil Survey, Bureau of Plant Industry, United States Department
of Agriculture, and party I
Area Inspected by MARK BALDWIN, Inspector, District 1

United States Department of Agriculture in cooperation with the
University of Puerto Rico Agricultural Experiment Station



CONTENTS
Page Page
Introduction...- ---.------------ 1 Agriculture-Continued.
Island surveyed-..----------------.... ..-. 2 Livestock.....--------------------- 153
Physiographic and geologic features------. 3 Soil-survey methods and definitions -------. 166
Mineral resources ..--------------------- 16 Soils and crops..............------------- 171
Vegetation...----. ... .---------------. 17 Soils of the uplands.. ---------------- 183
SAnimal life......----------------------- 29 Soils of the inner plains..---------------- 249
Population.-----... -----. --------------- 32 Soils of the terraces and alluvial fans ---- 264
Towns ...--.--------.. -------------- 36 Soils of the coastal plains..---.--... ---. 291
Transportation-..----------------------- 38 Soils of the river flood plains..---- -----. 312
Education----- _~..----.-. ----------- 40 Soils of the coastal lowlands.----------. 342
Water supply..------------------------- 41 Agrologla (suelos y cosechas)...--------------- 358
Farm buildings-.. .------------------ 42 Suelos de la altura .------------------- 359
Climate ......... -----------....-------- 47 Suelos do las llanuras interiores.---------. 370
Agriculture--... ....------------------- 69 Suelosabancaladosydealuvl6nenabanico. 373
Sugarcane (cafia de azfcar)..-------------- 67 Suelos de las llanuras costaneras....---------- 378
Tobacco (tabaco).--.-------------------- 84 Suelos de los valles de aluvi6n.----------- 384
Coffee (caf6)---...-..---...-.. ---------- 94 Suelos de los bajos costaneros......------------ 388
Grapefruit (toronja)..---.------------ 103 Glosario -....---..---....------...-... 390
Pineapples (pifias).------..... --------- 108 Productivity ratings-.---------------....... 391
Coconuts (cocos).----------.----------- 117 Clasiflcaci6n a base de productividad--------. 412
Bananas (guineos) and plantains (plA- Alkgli and saline soils....----------.......----------. 414
tanos) ---.----. ------ --..-------.. 120 Morphology and genesis of soils---...-------- 421
Corn (maiz) --------- ......-------- 127 The 20- to 25-inch rainfall belt----------. 431
Sweetpotatoes (batatas).... ..------. 129 The 25- to 35-inch rainfall belt.......----------- 434
Yautia, dasheen, or tania (yautia)-.... 132 The 35- to 45-inch rainfall belt.----------- 440
Name, or yam....-----------------.... 134 The 45- to 60-inch rainfall belt..----------- 445
Pigeonpeas (gandules) ----- ---- --- 137 The 60-to 75-inch rainfall belt....----------- 451
Yuca (cassava) --------........... 141 The 76- to 95-inch rainfall belt----------- 467
Beans (habichuelas) and cowpeas (frijoles). 143 The 95- to 160-inch +rainfall belt--------- 481
Cotton (algod6n).....-----..... -------- 145 Summary----------.. ......----------------. 484
Oranges (chinas)---...----------- .-- 145 Literature cited----......--...- ----------- 492
Mango ......-------- ----------------. 147 Index ..------------------ ----------------- 495
Avocado (aguacate)-----.........------------ 149 Map.
Miscellaneous crops..........----------------.... 149

INTRODUCTION

The detailed soil survey of Puerto Rico was started during the winter
of 1928 and was continued each winter until its completion in 1936.
The survey parties included from one to eight Federal men and from
one to three insular men. The yearly average was a party of six.
Usually the winter season started in January and finished in June.
A soil survey (16) 2 of an area between Arecibo and Ponce was made in
1902, but since that time much additional knowledge of soils has been
acquired, and it was deemed desirable to remap that area, in order
that the map of the island might be consistent throughout. The
original survey was neither so detailed nor so complete as the recently
finished survey.
I The party included the following: James Thorp, L. R. Smith, C. C. Nikiforoff, A. E. Shearin, S. R,
Bacon, 0 C. Rogers, A. T. Sweet, Robert Wildermuth, Z. C. Foster, W. H. Buckhannan, T. E. Beesley.
M. M. Striker, M. B. Marco, Ralph Leighty, Juan JuArez, Alfonso Reboyras, and V. M. Alexandrino.
Division of Soil Survey, Bureau of Plant Industry, United States Department of Agriculture; and
J. A. Zalduondo, D. A. Rodriguez, Jorge Landron, F. A. Villamil, G. A. Torruella, Octavio Reyes,
Rafael Bird, and Ferdinand Mendez, University of Puerto Rico. The field workfor this survey was done
while the Division of Soil Survey was a part of the Bureau of Chemistry and Soils.
2 Italic numbers in parentheses refer to Literature Cited, p. 492.
1









Series 1936, No. 8 Issued January 1942

SOIL SURVEY OF PUERTO RICO
By R. C. ROBERTS, Division of Soil Survey, Bureau of Plant Industry, United States Department
of Agriculture, and party I
Area Inspected by MARK BALDWIN, Inspector, District 1

United States Department of Agriculture in cooperation with the
University of Puerto Rico Agricultural Experiment Station



CONTENTS
Page Page
Introduction...- ---.------------ 1 Agriculture-Continued.
Island surveyed-..----------------.... ..-. 2 Livestock.....--------------------- 153
Physiographic and geologic features------. 3 Soil-survey methods and definitions -------. 166
Mineral resources ..--------------------- 16 Soils and crops..............------------- 171
Vegetation...----. ... .---------------. 17 Soils of the uplands.. ---------------- 183
SAnimal life......----------------------- 29 Soils of the inner plains..---------------- 249
Population.-----... -----. --------------- 32 Soils of the terraces and alluvial fans ---- 264
Towns ...--.--------.. -------------- 36 Soils of the coastal plains..---.--... ---. 291
Transportation-..----------------------- 38 Soils of the river flood plains..---- -----. 312
Education----- _~..----.-. ----------- 40 Soils of the coastal lowlands.----------. 342
Water supply..------------------------- 41 Agrologla (suelos y cosechas)...--------------- 358
Farm buildings-.. .------------------ 42 Suelos de la altura .------------------- 359
Climate ......... -----------....-------- 47 Suelos do las llanuras interiores.---------. 370
Agriculture--... ....------------------- 69 Suelosabancaladosydealuvl6nenabanico. 373
Sugarcane (cafia de azfcar)..-------------- 67 Suelos de las llanuras costaneras....---------- 378
Tobacco (tabaco).--.-------------------- 84 Suelos de los valles de aluvi6n.----------- 384
Coffee (caf6)---...-..---...-.. ---------- 94 Suelos de los bajos costaneros......------------ 388
Grapefruit (toronja)..---.------------ 103 Glosario -....---..---....------...-... 390
Pineapples (pifias).------..... --------- 108 Productivity ratings-.---------------....... 391
Coconuts (cocos).----------.----------- 117 Clasiflcaci6n a base de productividad--------. 412
Bananas (guineos) and plantains (plA- Alkgli and saline soils....----------.......----------. 414
tanos) ---.----. ------ --..-------.. 120 Morphology and genesis of soils---...-------- 421
Corn (maiz) --------- ......-------- 127 The 20- to 25-inch rainfall belt----------. 431
Sweetpotatoes (batatas).... ..------. 129 The 25- to 35-inch rainfall belt.......----------- 434
Yautia, dasheen, or tania (yautia)-.... 132 The 35- to 45-inch rainfall belt.----------- 440
Name, or yam....-----------------.... 134 The 45- to 60-inch rainfall belt..----------- 445
Pigeonpeas (gandules) ----- ---- --- 137 The 60-to 75-inch rainfall belt....----------- 451
Yuca (cassava) --------........... 141 The 76- to 95-inch rainfall belt----------- 467
Beans (habichuelas) and cowpeas (frijoles). 143 The 95- to 160-inch +rainfall belt--------- 481
Cotton (algod6n).....-----..... -------- 145 Summary----------.. ......----------------. 484
Oranges (chinas)---...----------- .-- 145 Literature cited----......--...- ----------- 492
Mango ......-------- ----------------. 147 Index ..------------------ ----------------- 495
Avocado (aguacate)-----.........------------ 149 Map.
Miscellaneous crops..........----------------.... 149

INTRODUCTION

The detailed soil survey of Puerto Rico was started during the winter
of 1928 and was continued each winter until its completion in 1936.
The survey parties included from one to eight Federal men and from
one to three insular men. The yearly average was a party of six.
Usually the winter season started in January and finished in June.
A soil survey (16) 2 of an area between Arecibo and Ponce was made in
1902, but since that time much additional knowledge of soils has been
acquired, and it was deemed desirable to remap that area, in order
that the map of the island might be consistent throughout. The
original survey was neither so detailed nor so complete as the recently
finished survey.
I The party included the following: James Thorp, L. R. Smith, C. C. Nikiforoff, A. E. Shearin, S. R,
Bacon, 0 C. Rogers, A. T. Sweet, Robert Wildermuth, Z. C. Foster, W. H. Buckhannan, T. E. Beesley.
M. M. Striker, M. B. Marco, Ralph Leighty, Juan JuArez, Alfonso Reboyras, and V. M. Alexandrino.
Division of Soil Survey, Bureau of Plant Industry, United States Department of Agriculture; and
J. A. Zalduondo, D. A. Rodriguez, Jorge Landron, F. A. Villamil, G. A. Torruella, Octavio Reyes,
Rafael Bird, and Ferdinand Mendez, University of Puerto Rico. The field workfor this survey was done
while the Division of Soil Survey was a part of the Bureau of Chemistry and Soils.
2 Italic numbers in parentheses refer to Literature Cited, p. 492.
1







2 U. S. DEPARTMENT OF AGRICULTURE
The purpose of the survey has been to take an inventory of all the
land, determine the apparent productivity of the different soil types,
and make a map of the island showing such cultural features as roads,
trails, houses, schoolhouses, towns, railroads, bridges, canals, reser-
voirs, and cemeteries, and such natural features as soil types, streams,
mountain peaks, lakes, and rock outcrops.
It was thought that, with a careful study of the soil types, better
procedures for soil and crop management could be worked out in rela-
tion to the many soil types, so that higher yields could be obtained or
production costs reduced. Most soil types have individual capabilities
and requirements for fertilizers, kinds and varieties of crops, and cul-
tivation practices; in fact, in many instances. a special system of crop
management is required for each soil, in order to obtain the maximum
yields. By having a map showing the different soil types, the results
of fertilizer experiments and the experiences of farmers can be classified,
and the best crop and management can be found for each soil type.
This publication gives a brief description of Puerto Rico, its physiog-
raphy, mineral resources, vegetation, climate, transportation, indus-
tries, agricultural statistics, soils, crops and their managements, and
also the future possibilities of the crops now grown. A section on
soils and crops, written in the Spanish language, also is included. For
persons interested in the scientific aspects of the soils and their genesis,
more detailed descriptions of the soils and a discussion of the soil-
forming processes are made.
ISLAND SURVEYED

Puerto Rico is the smallest and farthest east of the four islands-
Cuba, Jamaica, Hispaniola, and Puerto Rico-known as the Greater
Antilles. It lies in the Torrid Zone between 17055' and 18031' north
latitude and 65039/ and 67015' west longitude. The latitude is about
the same as that of the Sahara Desert and Bombay, India, and is
slightly farther south than the southern tip of the island of Hawaii,
The north-central coast of Puerto Rico is 1,400 nautical miles (1,610
statute miles) southeast of New York City, and the western part of
the island is about 450 miles from the eastern point of Cuba. Ponce,
on the south coast, is about 525 miles due north of Caracas, Venezuela.
The island is bounded on the north and east by the Atlantic Ocean,
which attains its maximum depth, 27,922 feet, about 75 miles to the
north. On the south is the Mar Caribe (Caribbean Sea), which attains
a depth of about 12,000 feet a short distance offshore. Canal de la
Mona (Mona Passage) separates Puerto Rico on the west from the
Dominican Republic, which occupies the eastern part of the island of
Hispaniola.
Puerto Rico is nearly rectangular, as shown by figure 1. The
greatest dimension, 113 miles (182 kilometers), is east and west, and
the average width north and south is about 41 miles (66 kilometers).
Including all the small islands under its jurisdiction, Puerto Rico has
an area of approximately 3,435 square miles (8,896 square kilometers).
The soil survey includes all the larger islands except Mona, which lies
about 45 miles southwest of the mainland and has an area of about 20
square miles (52 square kilometers). The most important 2 of the 28
or more smaller islands belonging to Puerto Rico are Vieques and







SOIL SURVEY OF PUERTO RICO 3

Culebra. They have an area of approximately 57 square miles
(148 square kilometers) and 11 square miles (28 square kilometers),
respectively, and extend directly eastward from the mainland to


F, OR-O 0.


0 -




C- PUERTO C
$ A-'-'- a .s o



LZ S 0 A MN'N^








PHYSIOGRAPHIC AND GEOLOGIC FEATURES



FIographic divisions, each having its own geologicadjacent relations, showing location. 2).

whCroquis de las Indias Occidentales y regiones adyto an oldies, demostrando peneplan,
stage of opographic development. The total area of there soilthen submergedis3,383 and
were overlapped during Tertiary time by terse second divisionthe
PHYSIOGRAPHIC AND GEOLOGIC FEATURES



Purcoastal plains. Thmaybe sea ledivided roughly into that period fluctuated to suchysi-
anThe most extensive division consists oftht the complastal plains were exposed, eroded, and submeranged,
which were eroded durig Cretaceous time\ to an old, or peneplain,










only to be exposed again and further dissected. The third division-
the playa plains-includes land formed by sediments accumulated
on the lower elevations during Quaternary time.

THE COMPLEX MOUNTAIN RANGES
If Puerto Rico were viewed from the air at a high elevation one
would readily observe that it is divided into a northern and a southern
part by an east-west mountain range, the crest of which is far to the
south of a latitude duina e passing through the center of the island.
south of a latitudinal line passing; through the center of the island.








I-P






SIMPLIFIED GEOLOGIC MAP OF PUERTO RICO



ISABELA
A'""'"ECI80 "- -I .----























T-1- -o v.E -- 1 = s A111-11 ,.FS, U... R.. .. SERP-1. 1 -, s-1.6S
L E G E N D







FIGURE 2.-The unconsolidated recent alluvial and old alluvial deposits largely comprise the playa plains. The areas occupied by Tertiary
limestone comprise the northern and part of the southern coastal plains. The remainder of the island consists of complex mountain
ranges and dissected plateaus of various rock types indicated in the legend.
Los llanos de la playa incluyenla mayor parte de los dep6sitos de aluvi6n recientes y viejos. Los llanos de la costa incluyen la mayor parte
del area ocupada por la caliza terciaria. El resto de la isla constitute las cadenas montafiosas complejas.























-4
0








0




FIGURE 3.-Rain-forest vegetation in the Sierra de Luquillo; average annual rainfall about 130 inches. Soils are shallow and
grayish brown on steep slope; on undulating areas they are grayish brown, underlain by light-red fairly permeable clay.
Vegetaci6n en los bosques de las montafias de Luquillo; promedio annual de l1uvia es alrededor de 130 pulgadas. Los suelos son
poco profundos, de un color pardogrisaceo y en un declive escarpado. En Areas ondulantes el suelo es pardogrisiceo sobre
una arcilla permeable de color rojo claro.







6 U. S. DEPARTMENT OF AGRICULTURE

To the south of the crest the relief is rugged and is characterized by
many steep-walled rock cliffs, abrupt high waterfalls, and jagged
peaks. On the north side of the crest and extending to the coastal
plain, the relief gradually becomes less rough, although there are many
small waterfalls, cascades, rapids, and high mountain peaks. The
main mountain range is known as the Cordillera Central in the west
and Sierra de Cayey in the east. This chain extends in a north-
westerly direction from Punta Yeguas (Yeguas Point) along the south-
eastern coast to a point near the Represa de Carite (Carite Reservoir)
where the peaks attain a height of nearly 3,000 3 feet. Thence the
chain extends westward, skirting Cayey on the south, to the high
rolling agricultural plateau at Aibonito. From Aibonito to a point


















FIGURE 4.-Soil-covered slopes, A-shaped grass-covered ridges, and V-shaped
forested ravines. The wind-protected southern and western concave slopes
are better adapted to coffee, bananas, and oranges than are the wind-exposed
ridges and the eastern and northern convex slopes.
Laderas cubiertas de suelo, montes en forma de A cubiertos de yerba, y barrancas
en forma de V cubiertas de bosques. Las laderas c6ncavas al sur y al oeste
protegidas del viento estan mejor adaptadas para la siembra de caf6, guineos
y chinas (naranjas) que aquellas convexas hacia el este y el norte, expuestas
al viento.

west of Oroco.vis the peaks are numerous, steep, brush covered, and
range in elevation from 3,000 to 3,300 feet. West from Orocovis to
Monte Guilarte (Mount Guilarte) the range becomes more rugged,
heavily forested, and more sparsely populated. Cerro de Punta, the
highest peak (4,398 feet above sea level), is about 4 miles south of
Jayuya and is near the center of this rugged area. From Monte
Guilarte to sea level at Mayagiiez the elevation gradually decreases,
the relief becomes less rough, and more agricultural crops, especially
coffee and oranges, are grown.
The less extensive chains of the complex mountain ranges consist
of the prominent rocky, steep, sparsely populated, forest-covered Sierra
' All elevations are taken from a map (Porto Rico and Contiguous Islands under its Jurisdiction) pub-
nshed by U. S. Dept. Agr. Forest Service, R-8. (Revised by L. I. Neiman, 1935.)






SOIL SURVEY OF PUERTO RICO 7

de Luquillo (Luquillo Mountains) 2,500 to 3,500 feet high(fig., 3), in
the eastern end of the island, and the less conspicuous lower highly
eroded thickly populated grass- and minor-crop Atalaya range,
culminating in Pico Atalaya (Atalaya Peak) in the northwestern
part. In addition to these ranges, there are many smaller ranges
separated'by agricultural valleys and hills.
This extensive physiographic division is characterized by steep
soil-covered slopes (fig. 4), A-shaped ridges, and V-shaped ravines
that gradually change toward the coastal plains and interior valleys
to gently rolling hills and
sloping ravines. The hills and
mountain ranges do not have
a uniform definite trend as do
the hills in the coastal plain
along the northern coast, but
they have been deeply dis-
sected by a dendritic system
of stream development, and
many of the divides are sepa-
rated by gorgelike valleys
ranging from 500 to 1,000 feet
in depth. Many excellent
dam sites for hydroelectric
plants occur along the rapid-
flowing rock-bottom mountain
streams (fig. 5).
Practically all of the streams
head in the area occupied by
this physiographic division.
Some of the rivers are very
large, but none is navigable
except for small boats. The
largest waterways are the Rio
Grande de Loiza- (Loiza River),
Rio de la Plata (Plata River),
and Rio Grande de Arecibo
(Arecibo River). All these flow
north to the ocean. The Rio
Culebrinas (Culebrinas River)
flows west, following the lime-
stone escarpment from a point FIGURE 5.-Rapid-flowing mountain stream,
near Lares to the western which affords excellent sites for dams for
near Lares to the western hydroelectric plants.
coast; and the Rio Grande de
coast; and the Ro Grandede Torrente en un monte; sitio excelente para
Aflasco (Afiasco River) drains una presa de plant hidroel6ctricas.
a large part of the west-central
area. The streams flowing to the southern coast resemble the streams
in the western plains of the United States, as they generally are dry
many months of the year. Those flowing to the eastern coast are
short but flow continuously. The beds of the larger streams, both in
the humid and arid sections range from 100 to 175 feet in width, and
the height of the banks ranges from 4 to 20 feet. Most of the stream
beds through the uplands are strewn with large boulders, but only in
the arid southern section are large boulders abundant in the stream
channels throughout the river flood plains. During floodtime some
of the streams discharge (49, p. 26) from 10,000 to 20,000 second-feet






8 U. S. DEPARTMENT OF AGRICULTURE

of water. Even during the dry seasons, some of the streams in the
humid area discharge from 250 to 1,500 second-feet.
Geologically, the complex mountain ranges are of volcanic origin,
but not in the same- degree as the ranges on the volcanic islands of
Hawaii and Martinique. Meyerhoff (31) has written an extensive
description of the geology of Puerto Rico. The most abundant and
widely distributed rocks are volcanic tuffs and shales, many of which
contain some igneous intrusive, generally andesitic in composition.
The tuffs and shales contain a very small quantity of quartz. There-
fore, the weathering of these rocks produces a soil that is high in clay,
medium low in silt, and low in sand. The rocks have weathered to a
depth ranging from 20 to 60 feet on level or rolling relief in areas of
high rainfall. The development of the soil and the weathering of the
rocks depend to a great extent on the character of the soil climate,
which is the product of air climate and local conditions. The more














FIGURE 6.-Granite boulders strewn over the surface of Pandura loam, smooth
phase. Making charcoal to the right on typical Pandura loam. Mdcara soils
in background.
Rocas graniticas regadas por la superficie del Pandura 16mico, fase lisa.
A la derecha haciendo carb6n en un Pandura 16mico tfpico. Suelos Mdcara
al fondo.

water and heat that penetrate to the rock, the greater the weathering
process and the thicker the soil. Even in areas having very high
rainfall, if the slopes are so steep that only a small quantity of water
remains in contact with the rocks for any length of time, the soil is
shallow. In fairly dry areas, if the surface is level or slightly depressed,
the rock in general is weathered to a greater depth than on slopes in
areas having a higher rainfall.
Granite ranks next in extent to tuffs and shales in the composition
of the complex mountain ranges. It is localized chiefly in two rather
large areas, one covering nearly 100 square miles in the vicinities of
Juncos, Yabucoa, and Patillas, the other including about 30 square
miles between Utuado and Jayuya. The larger area is characterized
by two distinct separations, as follows: (1) Steep, eroded slopes with
numerous smooth hard granite boulders, some of which are 20 feet
in diameter, strewn over the surface (fig. 6). Some of the peaks in
this area are nearly 2,000 feet high, but most of the land is below the







SOIL SURVEY OF PUERTO RICO 9

1,500-foot contour line. (2) The more rolling areas, which range in
elevation from 250 to 1,000 feet and are rock-free, moderately eroded,
but intensively cultivated. The small granite area near Utuado is
characterized by short steep severely eroded stone-free cultivated
hillsides and grass-covered knife-edged ridges, very few of which
attain an altitude of more than 1,500 feet. Most of the granite
rock in Puerto Rico is a coarse-grained quartz diorite that weathers
into a friable well-drained and well-aerated soil that requires yearly
fertilization. In most granite areas, the drainageways are U-shaped
rather than V-shaped, as is characteristic in other areas of the island.
Houses are numerous in these areas, especially so on those of more
rolling relief.
In addition to the tuff, shale, and the granite igneous intrusions,
a fairly large area of serpentine rock occurs in the west-central part
of the island, extending from a point northwest of Yauco to the coast
near Mayagiiez. This rock produces soils that are less erodible than
the products of other rocks, and most of the hills are conspicuous in
that they extend above the surrounding land, forming high rounded
ridges. Where soils from this rock occur, vegetation is scanty and
there are very few houses. Extensive landslips and pronounced
creeping occur on the steep slopes. The rock is smooth, like talc,
and platy, and when an unusual quantity of rain falls, the rocks
slide easily over the surface of each other, causing a part of the hill-
side to tumble down.
Another rock of the complex mountain ranges is the Cretaceous
limestone which is conspicuous in the few areas in which it occurs,
owing to the steep or precipitous relief and lack of stream channels.
Water readily penetrates the limestone to underground streams.
Soils derived from this rock are not well adapted to agriculture because
they are rocky, shallow, and have unfavorable relief. The largest
areas of this kind are east of Juana Diaz, near Lajas, in the vicinities
of Cayey and Orocovis, and near La Muda.
Besides the above-mentioned rocks, conglomerates and agglom-
erates are associated with the tuffs and shales in many parts of the
island.
COASTAL PLAINS

The coastal plains parallel nearly the entire coast line. They range
in width from a maximum of 13 miles (21 kilometers) at Lares to nil at
several points along the eastern and western coasts. On the north
coast they include most of the area north of the towns of Lofza, Rio
Piedras, Corozal, Ciales, Lares, San Sebastian, Moca, and Aguadilla.
On the south coast they are much less extensive. Here, they include
a part of the area south of Boquer6n, Lajas, Yauco, Guayanilla,
Pefiuelas, Juana Diaz, Baios de Coamo (Coamo Springs), and
Guayama. On the east and west coasts they cover but a few square
miles. Most of the coastal plains are confined to areas that were
submerged during Tertiary time and covered by a thick deposit of
limestone. Since that time there have been several fluctuations in
sea level, causing the landscape to have a belted appearance.
The outstanding characteristic of the northern coastal plain is the
horizontal east-west deposit of limestone, which develops into dis-
tinct topographic belts according to the composition of the limestone.
This limestone area is a plateau in a youthful stage of dissection, so









10 U. S. DEPARTMENT OF AGRICUL'rURE





































































FIGURE 7.-See legend on page 11.
^______or







SOIL SURVEY OF PUERTO RICO 11

far as stream erosion is concerned, but the relief in some of the lime-
stone belts is the roughest of the island, because the underground
solution has caused sinkholes, caves, and numerous precipitous cliffs,
making some areas nearly impossible to penetrate, even by foot.
Both surface and subterranean erosion are still active. From a
maximum elevation of about 1,500 feet near Lares, the northern
coastal plain gradually slopes to sea level along the northern coast.
The most southerly belt of the northern coastal plain occupies an
almost continuous narrow strip from a point near Corozal to a point
near San Sebastian. This belt is characterized by comparatively
pure calcium carbonate rocks and massive reef beds that have open
porous textures, making it possible for the forces of erosion to form
conspicuous high cone-shaped mogotes (haystacks) and long narrow
pepino (cucumber-shaped) hills (fig. 7). Almost all of the pepino
hills have a northeast-southwest trend and are about two-tenths of a
mile long; none of them is very flat or broad on the top. Between
the hills are numerous small long narrow undulating valleys. Drain-
age water makes its way to the small alleys and sinkholes, thence
along underground passages to the few streams that have cut deep
gorgelike valleys across this formation. Houses are fairly numerous
in the small valleys, but only a few dot the hilltops. Trees are scarce
except near dwellings and along the drainageways.
The southern limit of this belt has a very definite escarpment
several hundred feet high (fig. 7). It is characterized by a nearly
uniform east-west unbroken line, except where rivers flowing from the
mountains have cut through the limestone formation, forming large
triangular-shaped indentations with the apex pointing downstream
and terminating in a gorge. The Rios Guajataca, Camuy, Tanamh,
Grande de Arecibo, Manatf, and Cibuco have cut through in this
manner. The Rio de la Plata terminates in a flood plain. Directly
back of the escarpment, occurring from one end of the limestone
areas to the other, and also in lowland valleys within the limestone
section, are inner plains that range in width from a few feet to a mile
or more. The soil contains considerable basal gravels and probably
is derived from lower Tertiary shale. Wherever this material occurs
there are many surface drainageways which abruptly sink where the
material joins the limestone hills. In this area some of the land is
nearly level, but most of the hills are dissected by drainageways.
North of the southernmost limestone belt is another limestone
formation extending from the Rio Guajataca eastward to a point south
of Esperanza, thence from a point east of the Rio Manati to a point
near Corozal. In this formation the steep mogotes are absent and the
relief is rolling or undulating (fig. 8). The limestone is white and semi-
crystalline, with some chalky seams. All the rain water drains to nu-
merousdeep sinkholes, thence into the subsurface streams. Throughout

FIGURE 7.-Vertical aerial view of the southern escarpment of the north-coast
limestone area along the Rio Grande de Arecibo. The conspicuous long narrow
pepino (cucumber-shaped) hills are gradually weathering into many cone-
shaped hills. (Photograph taken by U. S. Navy.)
Vista area vertical de ]a escarpa sur del area caliza de la ccsta norte a lo
largo del Rio Grande de Arecibo. Las colinas largas y estrechas llamadas
pepinos (en forma de pepinos), se estAn gradualmente convirtiendo en muchas
colinas c6nicas. (Fotografia tomada por la Marina de los EE. UU.)







12 U. S. DEPARTMENT OF AGRICULTURE




















































FIGURE 8.-See legend on page 13.







SOIL SURVEY OF PUERTO RICO 13

this limestone belt, houses are numerous and farms are small, few of
them more than 10 acres in extent. There are very few trees through-
out this area, except along fence lines.
Adjacent to this limestone belt on the north and extending to the
west and east is another distinct limestone belt which extends from a
point near Aguada north almost to Aguadilla, thence eastward in a
narrow strip to the Represa de Guajataca (Guajataca Reservoir),
thence in wider areas to Florida, Corozal, Toa Alta, and Central'
Can6vanas. This belt is similar in relief and drainage to the south-
ernmost belt, but it does not include so high a proportion of steep
land and most of the hills have longer and more gentle slopes that are
better suited for cultivated crops. Houses dot the hilltops and the
narrow valleys.
The next hmestone belt on the north, which extends from Aguadilla
to Toa Alta, is characterized by spectacular, rugged, brush-covered
mogotes and sinkholes. The general trend of the individual hills, or
mogotes, is northeast to southwest. Drainage is effected through the
numerous sinks, which in time may become united by the caving and
dissolving of the adjacent limestone. Small dwellings are fairly
numerous on the hills and valleys; they are located in many places
without much regard to accessibility or nearness to the limited water
supply. Foot and horse trails are the only means of travel through
most of this country, and some of the rougher parts are hardly pas-
sable for the sure-footed small horses and mules.
The most northern of the large limestone belts is characterized by
uniformly stratified beds of hard flinty limestone alternating with soft
gray limestone. Most of the limestone rock of the mogotes in this
belt is pitted with holes and has many irregularities (fig. 9); it is very
dense and hard and will ring when hit with a hammer. Characteris-
tic features of this belt are the long east-west chains of saw-toothed,
jagged, tree-covered mogotes and the nearly level, densely populated
rather wide valleys. This belt extends from the northwestern
corner of the island to a point east of Loiza. From Bayam6n to a
point near Loiza only a few limestone hills are exposed. Some of them
rise abruptly above the alluvial land and muck areas, where weather-
ing of the limestone has been complete. In the northwestern part of
the island this limestone belt terminates abruptly, forming high
sea-girt cliffs. Most of this area has subterranean drainage, and
consequently water for domestic purposes is scarce.
Fringing the northern coast at low elevations is another narrow
intermittent belt of limestone. It is characterized by scattered ridges
of calcareous sandstone that probably have been formed by a com-

FIGURE 8.-Vertical aerial view of the smooth grass-covered limestone hills in
the foreground and the fields of sugarcane on the soils of the lower Tertiary
plains, which abruptly join along the small stream. Land on one side of the
stream is valued at $175 an acre and on the other side at $5. (Photograph
taken by U. S. Navy.)
Vista area vertical; las colinas calizas cubiertas de yerba al frente y los campos
de cafla en suelos de los llanos Terciarios, se juntan abruptamente a lo largo
del riachuelo. La tierra a un lado del liachuelo esta valorada a $175 por
acre y al otro lado a $5. (Fotograffa tomada por la Marina de los EE. UU.)
4 Central refers to a large surgarcane mill and adjacent land.






14 U. S. DEPARTMENT OF AGRICULTURE

bination of a slight uplift of the shore line and the drifting action of
the trade winds.
The coastal plain on the south side of the island has no definite
limestone belts, but. a large
percentage of its area overlies
Tertiary limestone, and it has
a much higher proportion of
old alluvial-fan material than
the northern coastal plain.
Most of the alluvial fans are
in the east-central part or
between Ponce and Patillas.
The limestone hills range
from gently rolling to steep,
and the many intervening
plains or valleys are undulat-
ing and fairly wide. Most of
the drainage of the limestone
section is subterranean. The
elevation of this area ranges
from a few feet to more than
500 feet above sea level.
The largest area of the
coastal plains in the eastern
part of the island is near
FIGURE 9.-Hard dense Tertiary limestone Ceiba. This is a broad nearly
which weathers slowly, producing acid red flat or undulating plain which
soils of the Tanamd, Bayam6n, and re- is crossed by very few drain-
lated series. ageways. Similar topographic
Piedra caliza Terciaria s6lida y densa; esta positions occur in the inter-
piedra se desintegra lentamente y produce mountain valley east from
suelos rojos Acidos de las series TanamA,
Bayam6n, y otras series relacionadas. Caguas, as well as in small
areas on the west coast near
Faro Cabo Rojo (Cabo Rojo Lighthouse), Boquer6n, Puerto Real, and
Joyuda. These areas range from a few feet to 100 or more feet above
sea level. Most of them are densely populated.
PLAYA PLAINS
The playa plains include the level alluvial flood plains, the lagoon
deposits, and the elevated beach sands. The flat alluvial flood plains
occupy the largest area and comprise the most valuable agricultural
land. They occur along all the streams but are most extensive near
the mouths of the larger rivers. In a great many places the shape of
the plain is triangular, with the apex pointing upstream. The alluvial
deposits terminate abruptly against the upland hills. The soils are
developed from transported material and, therefore, range in texture
from coarse sands to clay. They occur at low elevations, generally
not more than 10 feet above sea level. The-land is so valuable that
few houses are built on it. In most places natural drainage is supple-
mented by artificial drainage systems.
Nearly the entire coast line is fringed by a low, almost level, sandy
beach, which ranges in width from a few feet to more than a mile.
The coastal beach material consists of shells, coral, lime carbonate,
and sand. In places sand dunes, a few of which are 20 feet high, occur






SOIL SURVEY OF PUERTO RICO 15

at or near the beach. In many places, depressions or lagoons, slightly
below sea level, containing salt water or salt-marsh vegetation, occur
inland a short distance from the dunes. Adjacent to the lagoons are
old estuary clay or silty clay deposits which gradually merge, toward
the rivers, with well-drained alluvial land. Many of the estuary
deposits are only slightly above sea level and unless drained are under
water several months of the year. The mouths of most of the streams
emptying into the ocean are choked by sand bars, and these have
helped to form the adjacent swamp areas.
Puerto Rico has several small natural lakes and a few large reser-
voirs. The lakes occur within the coastal lowland, and the reservoirs
are located on the upland, most of them in the high mountains. The
larger lakes are Lago Tortuguero, Laguna Cangrejos (Torrecilla),
and Lago San Jose along the northern coast; Laguna de Guanica near
the southern coast; and Lago Joyuda on the west coast. Lago
Tortuguero, a fresh-water lake embracing an area of about 2 square
miles, is the largest. All the other lakes are shallow and contain
salty water, except Laguna de Guanica, in which the water is only
brackish. As they have outlets to the nearby -waters of the ocean,
most of the lakes are affected by the tides.
Represa de Guajataca, the largest reservoir, is situated between the
limestone hills of the coastal plains, and its waters are used to irrigate
the land near Isabela. The water from all other reservoirs used for
irrigation purposes is diverted to the south coast.
The island has many bays, some of which are well protected from
the waves and have very quiet waters, with mangrove swamps
extending to the water's edge. Puerto de San Juan (San Juan Bay)
offers the finest harbor for ships.
MINERAL RESOURCES
Mineral resources seem to be limited in extent and value. Some of
the rocks, especially the Cretaceous limestone, have high value as
road-building material. This rock is hard, yet crushes fairly easily
and has binding qualities superior to those of most of the other rocks.
The semicrystalline Tertiary limestones are good for road material,
but they are generally interbedded with chalky lime which is soon
worn away when placed on a road and subjected to heavy traffic.
The tuffs crumble too readily for road material, and the other volcanic
rocks are either too hard for crushing or are not sufficiently indurated.
Some andesites are used for road material.
Some of the chalk lime is used commercially for the liming of acid
soils. Many thousands of acres in the interior could be greatly im-
proved by an application ranging from 2 to 4 tons of lime to the acre.
The addition of lime not only helps the physical condition of the soils,
but it increases the yield of crops and probably improves the nutritive
value of the grains and grasses produced. Almost any of the lime-
stones occurring on the island is effective if it is finely ground.
Some limestone, however, contains a fairly high content of phosphorus
and therefore is more valuable as a soil amendment than are other
calcareous rocks. The lime most commonly used comes from Cayo
Icacos (Icacos Island), northeast of Fajardo. It is used on soils and
for the sedimentation of impurities in the manufacture of sugar.






16 U. S. DEPARTMENT OF AGRICULTURE

Some of the Tertiary limestone should make good building stone as it
is rather easily worked into blocks and is fairly resistant to weathering.
The white silica sand, which occurs in large quantities near the line
of the American Railroad Co. of Puerto Rico south and east of Lago
Tortuguero, and in other areas along the northern coast from San-
turce to the Rio Camuy, may at some future time be used in the
manufacture of glassware or sodium silicate.
The deep soils derived from serpentine rocks should have good
possibilities for the mining of iron, chromium, and nickel, as they are
very high in the first and moderately high in the other two minerals.
This kind of land (Nipe clay and Rosario silty clay) occupies 27,904
acres southeast of Mayagiiez and near Punta Guanajibo.
Northeast of Juana Diaz, a deposit of manganese ore in Cretaceous
limestone yields an annual production (10, p. 5) of about 2,500 tons.
















FIGURE 10.-Salt pans and piles of salt in the arid region along the south coast.
Montones de sal y cristalizadores en la region arida a lo largo de la costa sur.
Other manganese deposits are south of Aguada, Adjuntas, and Corozal.
Some magnetite has been found near Las Piedras. A few thin veins
of lignite outcrop near San Sebastian, but they are not being developed.
Some copper is mined south of Aguada, and placer gold mining has
been carried on near Corozal for a number of years. Some gold has
been found near Hacienda Catalina, Lares, Sabana Grande, and
Guayama. A total of $100,000 worth of gold was mined between 1900
and 1932 (10, p. 7).
Sea water is evaporated to produce salt in fairly large quantities on
the south coast adjacent to the sea. The quantity obtained annually
depends on the size of the pans and the length of the rainless periods.
The working season is during the winter and spring. In most places
the water is pumped into the pans by large fan windmills (fig. 10).
When the water has evaporated the salt is scooped into wheelbarrows
and then dumped into piles until hauled by truck to local markets.
This industry has been profitable during recent years, and the area
devoted to it has greatly increased.
* Chemical analysis of a sample of Nipe clay appears on p. 475.







SOIL SURVEY OF PUERTO RICO 17

A small quantity of bat guano fertilizer is obtained from some of the
caves in the Tertiary limestone, especially on Mona Island.
Several of the soil types, especially Catalina clay and Alonso clay,
should make very good bricks. Indian pottery found on Las Mesas
near Mayaguiez is of good quality, indicating that Nipe clay also
should be good for making bricks and pottery. The granite boulders
in the Pandura soils should make very good building stone.
VEGETATION

Most of the present native vegetation undoubtedly is different from
the plant life that existed during Cretaceous or even Tertiary periods.
The introduction of plants into Puerto Rico, through the aid of man,
probably was started by the Caribs and the Arawaks long before
Columbus landed in 1493, and it has continued to the present time.
The ever-changing environment has had its effect on the different
species, as also has the destruction of the original forest, which exposed
the soil, increased evaporation, and tended to make a drier soil
climate. The second-growth vegetation was slightly different from
the virgin trees, as it has had to be more drought-resistant in order to
survive.
The native vegetation is very closely related to the soil climate.
On drought land, such as coarse sands, very steep hills, shallow soils,
or very permeable soils, the vegetation in many places is more typical
of a drier climate than that of the surrounding air climate. On the
other hand, slight depressions, poorly drained soils, or swamps, even
in arid regions, have a plant growth characteristic of a moist climate.
The names of the plants generally used throughout this report are
those in most common use-some are English, and some are Spanish.
The botanical names and the corresponding English and Spanish
common names (taken mostly from Otero and Toro (33)) of nearly all
of the plants mentioned are listed in table 1.

TABLE 1.-Important plants growing in Puerto Rico

Botanical name English name Spanish name

Acaciafarnesiana .----------.------.. Casha-.....---------------------. Aroma casha.
Achras zapota.------.. ------------.. Naseberry; sapodilla----------.. Nispero.
Acrocomia aculeala .-------- ------. Corozo palm ----------------.. Palma de corozo.
Acrostichum aureum --- --------- Acrostichum fern------------- Helecho.
Agati grandiflora ...--------- ----.----.---------..------------- Gallito.
Agave americana. ----------------- Centuryplant....--------------- Maguey.
Agave sisalana .. ..-------..---.----- Sisal hemp--..---------.------ Sisal.
Amomis caryophyllata -...--------- ..Bay rum tree _-------..-.---- Malagueta.
Anacardium occidentale ------------- Cashew nut .----------------- Pajuil.
Ananas sativu- ....----------------- Pineapple .-----.--.----------. Pifia.
Andira inermis- .------_----------- Angelin tree; cabbage tree -..-- Mcca.
Andropogon virgatus.---------- ... ------------------------------ Rabo de rat6n.
Annons reticulata. ..---------------- Custard-apple ------..------. Coraz6n.
Annona muricata.---------------- Soursop.- -------------------- Guandbana.
Arachis hypogaea -------------------- Peanut --......------------------ Mani.
Artocarpus communism .------------- Breadfruit--..--------------- Palo de pan.
Athyrocarpus persicariaefolius --------------------------------- Cohitre blanco
Avicennia nitida -.-----. -----------. Black mangrove --------------. Mangle bobo.
Bambusa vulgari- ..----------------- Bamboo ----.....-------.------- Bambi.
Bats naritinma ....------------------ Saltwort..-------------------.. Barilla.
Bromelia pinguin ...-------.-------- ----.----.--------------- Maya.
Buchenavia capitata --------------- Yellow sanders .--------------- Granadilla.
Bucida buceras .._------------.------ Black olive....----------------- Hfcar; iear.
Cactus intortu -..-----------. ---- Turkscap....------------------- Mel6n de costa.
Cajanus cajan .--------- _-------- --- Pigeonpea.--... .---------.. ---- Gandul.
Callisia monandra ---....------------.. --.---------..----------- Cohtre morado.
Calophyllum antillanum _----------. Galba....-------.......---------- Santa Maria; MarIa.
Calotropis procera------..-..--------- Giant milkweed--------..... ----- Algod6n de seda.
144035-41 2









18 U. S. DEPARTMENT OF AGRICULTURE


TABLE 1.-Important plants growing in Puerto Rico-Continued

Botanical name English name Spanish name

Caesalpinia sepiaria-------------- Wait a bit ...------------------. Zarzade cereas
Capparis coccolobifolia ----.------- Broad-leaved caper tree....----- Burro.
Capparisfleuosa.. ---------------- Caper tree...-- ....-------...--- Palo de burro.
Carica papaya- ------------------ Papaya.---.----------------- Lechoza.
CaryophyllusJambos(Eugenia jambos). Rose apple ------------------ Poma rosa.
Castalia ampla. ---------------------- Waterlily ------------------- Flor de agua.
Casuarina equisetifolia ------------Australian pine .------------- Pino Australiano.
Cecropia peltata_ ------------------- Trumpet tree.---------------- Lagrumo.
Cedrela odorata ...- ---------------. Spanish cedar --------------- Cedro.
Ceiba pentandra. _. ------------- Silk-cotton tree_ --------------. Ceiba.
Cenchrus echinatus. -------------- Sandbur ------------------ Abrojo.
Cephalocereus royeni ---.-----S-----. ----_----------------- Sebucdn; dildo.
Chloris inflata ------------------Mexican bluegrass -----.------- Horquetilla morada.
Chrysobalanus icaco -----. ------- Coco-plum ---. ------------. Icaco.
Citrus grandis_ _--------------------- Grapefruit ------------------ Toronja.
Citrus medical ------_ ------------- Citron ---------------------- Cidra.
Citrus sinensis- ------- ---------- Orange --------------------------China.
Cladiumjamaicense --------------- Sawgrass------- ------------ Serrucho.
Clusia rosea ---- --------------- Balsam fig ------------------Cupey.
Coccoloba uvifera -------------- Seagrape -------------------Uva de playa.
Cocos nucifera -------------------Coconut ---------------------- Palma de coco.
Colocasia esculenta -----------------. Elephant ear ---. ------------ Malanga.
Colubrina reclinata.---------------- Nakedwood -----------------Mabi.
Conocarpus erecta_ ------------------ Buttonwood ---------------- Mangle boton.
Cordia alliodora -.------------------ Spanish elm ------------------Caph prieta.
Cordia sulcata --------------- -. ------- -------.. ------------- Moral.
Crescentia cujete----------------- Calabash ------_-. -------------H igiiero.
Crotalariajuncea ---------------- Crotalaria ...-----------------Crotalaria.
Cucurbita mochata ------------------Squash------------------------- Calabaza.
Cyathea arborea ....--------------- Treefern H------------------- elecbo arborescente.
Cynodon dactylon._---------------- Bermuda grass ....------------- Grama; yerba Bermuda.
Cyperus giganteus- -. -------------------- -_ Junco de cienaga.
Cyperus rotundus -.-------------- Nutgrass.------------------- Coqul.
Dacryodes excelsa .---------------- Candlewood-------------- Tabonuco.
Delonix regia. ---. --------.------- Flametree (royal poinciana) --._ Flamboyant.
Dendropogon usneoides ------------ Spanish-moss _-----------..---- Barbas de fear.
Dioscorea cayenensis ------------- Yellow yam ------------------ Name de Guinea.
Dioscorea esculenta --------------- Potato yam--.. --------------- Name papa.
Dioscorea rotundata ------------- White Guinea yam----._____- Name de Guinea blanco.
Dioscorea trifida ------------------- Indian yam ---------------.. Mapuey.
Cassia occidentalis ----------------- Coffee senna ----------------- IHedionda.
Elaphrium simaruba -----.. --------Gum tree. ----------------- Almbcigo.
Erythrina corallodendrum -----_-. Red-bean tree ------B------ Bucare.
Euterpe globosa --...----- ---. -- Mountain palm..------------ Palma de sierra.
Fieus laevigata ----- _------------ -- Wild fig -------------- Jagiey.
Fimbristylis diphylla.. ---------- ------------------------- Junquillo.
Gaussia attenuata--- ------------ --- ---------Llume.
Gossypium barbadense.---.----------- Cotton.-------------------- Algod6n.
Guaiacum officinale------------------ Lignumvitae --------- ..------- Guayacn.
Guaiacum sanctum__ --------------.. _- ---_---_----------- Guayacfn blanco; guayacanillo
Guarea guara --------------------- Muskwood------- .------- Guaraguao.
Hymenaea courbaril -. ------------ West Indian locust---..---- Algarrobo.
Inga rera ---------------------_. .--.---..---------- .-------. Guaba.
Inga laurina -------------------- Pomshock ------------------ Guama.
Ipomoea batatas ----------------- Sweetpotato ------------------ Batata.
Laguncularia racemosa -------------- White mangrove------------- Mangle blanco.
Lantana involucrata-_ --------------. Button sage---------------- Santa Maria.
Laplacea portoricensis --------- ----- -----____--------------------... Maricao.
Leptocereus quadricostfatus --- --. ..------..----- --------------- Sebucbn; pitajaya.
Leptoglottis portoricensis _------- ------------- -------------- Zarzarilla.
Magnolia splendens ------- -----------__ ------------------- Sabino.
Mammea americana ......-------- Mammee apple -------------- Mamey.
Mangifera indica. .----------------- Mango ------------------------ Mango.
Manihot esculenta. .....-..--------- Cassava ..-------------------- Yuca.
Marcgravia rectiflora ..----.... -- -.----.- -....--.... -------... -------- Bejuco de palma.
Marcgravia sintenisii Be-eiuco de rana.
Melinis minutiflora --------------- Molasses grass -------------- Yerba melado; yaraguA.
Meliosma obtusifolia ------.. -----------------------.._--_--.-- _--_ Cerrillo.
Mimosa pudica ---------------- Sensitiveplant------..... -------- Sensitiva; morivivi.
Mimusopsnitida ...--.-.---------- Bulletwood ..------------- JAcana.
Musa paradisiaca ---....----------- Plantain .------------.. -- .. Platano.
Musa paradisiaca sapientum ------- Banana --. ------------------Guineo.
Nicotiana tabacum---_------------- Tobacco -. ------------------Tabaco.
Ocotea spathulata -------... --_ .---------------------------- Granadillo.
Olyra latifolia .. .---.----- ----.-- ------..._.------------_. ---. Carrucillo.
Opuntia dillenii--. ----------_-- Pricklypear ---.----_-----.---- Tuna brava.
Panicum purpurascens--..---------- Para grass ------------------Malojillo.
Panicum maximum.- ------------ Guinea grass -------------- Yerba de Guinea.
Paspalum virgatum ------------------------ ------------------ Cortadero.
Pennisetum purpureum ----------- Napier grass; elephant grass --- Yerba elefante.
Persea americana --- --------.--- Avocado (alligator pear) _-.... Aguacate.
Phaseolus vulgaris. ------ -Bean --------- ------------ Habichuela.
Philoxerus vermicularis..---.....----- Saltweed-----.. ------------- Yerba de sal.








SOIL SURVEY OF PUERTO RICO 19

TABLE 1.-Important plants growing in Puerto Rico-Continued

Botanical name English name Spanish name

Phragmites communism .---- Common reed .-- ----- Caila de indio.
Pithecolobium unguis-cati .. Blackbead.. .- Escambr6n colorado.
Prosopis chilenis s -...--- Mesquite -- Mezquite.
Psidium ajaa ----------------- Guava Guayaba.
Pterocarpus officinalis ------ -- Palo de polo.
Quercus thompsonii ----------- ---- Oak --. Roble.
Randia mitis .--. ----------_------. Box brier .------ -----.--- Tintillo; escambr6n.
Rhizophora mangle -------------- Mangrove -------------. Mangle.
Roystonea borinquena.------- --- .. Royal palm-- Palma real.
Rubus rosaefolius---------------- Mountain raspberry Fresa.
Saccharum officinarum ---------- Sugarcane--- Calia de azfcar.
Schizachyrium brevifolium.-- ---- Serrillo dulce.
Sechium edule -----------------Chayote ----Tayote.
Sesuvium portulacastrum--- Verdolaga rosada.
Sideroxylon foetidissimum ----- Ausubo.
Solanum tuberosum ..------ Potato ---------------- -- Papa.
Spathodea campanulata__-- African tuliptree...-. ---- Tulipfn africano.
Spondias mombin --------------- g plum -------- ---... Jobo.
Sporobolus indicus---------- West Indian rush grass --------- Matojo.
Sporobolus virginicus.----------- ----- ------- Matojo de playa.
Stenotaphrum secundatum -....- St. Augustine grass; running Grama blanca.
crabgrass.
Swietenia mahagoni. -- -- Mahogany----------- Caoba.
Tabebuia rigida _..--- .. i--.. Roble de sierra.
Tamarindus indica ------------- Tamarind -.. Tamarindo.
Terminalia catappa--------- ---- Tropical almond (West Indian Almendro.
almond).
Theobroma cacao ---------------- Chocolate tree Caco.
Tragus berterionanus Pricklegrass ----- lincadora.
Typha angustifolia ------------ Cattail ---------------- ----- Aneas.
Tillandsia recurvata-------------- Air plant Nidos de gungul]ln.
Tripsacum laum----------------- Guatemala grass-------- Yerba Guatemala.
Triumfetta lappula--------------------------------- Cadillo.
Vigna unguiculata _----- --- Cowpea; black-eyed pea ...--.. Frijol.
Xanthosoma atrovrens ------ Yautia; dasheen; tania --------- Yautiaamarilla.
Zea mays-. --.----------- --- Indian corn ....-- Maiz.


Some of the most common plants that grow throughout nearly all
parts of the island are flamboyant, maya, almendro, hedionda, Aus-
tralian pine, bamboo, and such commercial crops as bananas, plan-
tains, oranges, grapefruit, pineapples, sugarcane, tobacco, corn,
beans, yuca, yautia, sweetpotatoes, mangoes, pigeonpeas, avocados,
breadfruit, and papaya.
Among the tropical trees, flamboyant is one of the most beautiful.
Its gorgeous firelike scarlet or purple flowers bloom from May to July.
It grows readily from the dry sea-level areas of the south coast to the
wet high areas of the mountain ranges. The maya, a barbed pine-
applelike plant, often planted as a fence or as a boundary between
small farms, thrives equally as well on the fairly strong "alkali"6
soils as on the tropical rain-forest areas. The almendro is an orna-
mental deciduous tree which grows along most of the main highways.
The nuts (Malabar almonds) ripen from July to August; they are
edible. The hedionda is a low leguminous weed which seems to thrive
throughout the island. Its seeds sometimes are mixed with coffee
berries in preparing a hot beverage. It has not been long since the
Australian pine was introduced, but it seems to be a tree as well
adapted to the soils and climate of Puerto Rico as the maya. It is a
fast-growing slender densely branched evergreen that is used as an
ornamental tree along roadways and around houses, as well as a hedge
which acts as a windbreak for fruit trees or other crops. It will grow
on alkali land, if the concentration of salt is not much greater than 2
6 The term "alkali" is used to indicate any harmful salt in the soil. Black alkali refers to sodium carbon-
ate, and white alkali refers principally to sodium chloride.







20 U. S. DEPARTMENT OF AGRICULTURE

percent, but none has been seen growing in the water-covered swamps.
Many varieties of bamboo grow throughout the island. In the arid
districts bamboo grows only along the edges of small ponds, and in the
semiarid districts only along stream banks. Many of the bamboos
are cut and used for fence posts, and some are used in the manufacture
of furniture. The growing plant is used as a windbreak in some of the
citrus groves, and it is also used on hillsides to help in the prevention
of erosion. The commercial crops are discussed more fully under the
section entitled "Agriculture."
Some plants are confined to rather narrow limits of environment,
owing to the physical or chemical characteristics of the soil, to soil
climate, or to elevation. Along the sandy beach, which fringes nearly
the entire island, is a plant association consisting of matojo de playa,
a low weedlike grass that migrates along the seaward side of the beach
by means of rhizomes; yerba de sal, a prostrate fleshy red-stemmed
plant tolerant to white alkali; and uva de playa which has broad
leaves and an extensive root system. The height of the uva de playa












FIGURE 11.-Uva de playa and matojo de playa struggling desperately to stabilize
the shifting sand dunes along the north coast.
Uva de playa y matojo de playa en lucha para estabilizar las dunas de la
costa norte.
ranges from that of a nearly prostrate plant to that of a tall tree 8
inches in diameter. Generally, however, the plant is small, and its
leaves are almost in contact with the soil. This helps to keep the
sand moist and prevents the soil from blowing (fig. 11).
Closely associated with these drought-resistant sand-loving plant
associations are plants that are resistant to salt water. In many
places inland and parallel to the sandy coast are salt-water marshes
and, in a few places, fresh-water swamps. The environment in these
areas restricts vegetation to the water-loving or hydrophytic plants
and alkali-resistant species. In some places the swamps extend to the
quiet bays. In such places the plant nearest to the sea and that in
the most salty water is the common mangrove, which has numerous
strong aerial roots (fig. 12) that help to stop the agitation of the silt-
laden water that pours into the swamps from the adjacent and far-
away countryside. The silt and clay soon settle and thus build a
mineral soil over the fast-decaying lower roots of the mangrove.
Associated with the common mangrove but growing in areas having
less concentration of salt, are the white mangrove, black mangrove,







SOIL SURVEY OF PUERTO RICO 21

and mangle bot6n. The last-named plant generally grows in dry
climates and may be a considerable distance from the swamp, on
alkali land. All the varieties of mangroves are important sources of
wood for charcoal making. They quickly reestablish themselves and
ordinarily are cut when 5 years old. At this age they produce from
15 to 20 cords of wood to the acre. Associated with the mangroves
in wet open areas is a tall fern which grows to a height of 6 feet or more,
and in many places the growth is so dense that it is impossible to pene-
trate it to any great distance. This fern is of little value, and it may
crowd out stands of mangroves that have been cut over too frequently.
Associated with this fern but now occurring in only a few places, such



















FIGURE 12.-Mangrove with its characteristic stiltlike aerial roots.
Mangles, n6tese las races areas.
as in the swamp a mile west of Humacao playa, is the palo de pollo
tree, a tree very similar to the common mangrove except that each
stump has many slender trunks and an exceptionally large buttress.
This tree also is used as a source ot wood for charcoal making. Malo-
jillo grows in many of the more open spaces in association with the
palo de polio, indicating that there is little or no harmful salt in the
soil.
On the south and east coast, as well as on the coasts of the small
islands, inland from the mangrove swamps, are two plants which indi-
cate the presence of salt, namely, barilla and verdolaga rosada. Both
are low bushlike shrubs; the former has pale-yellow stems and the
latter dark-green or reddish-brown thick leaves. These plants nearly
everywhere indicate that the land has about 3 percent of white alkali
within the topmost foot of soil. These plants grow on better drained
soils than do mangroves. They may grow even on well-drained sand
if there is sufficient spray from the sea to maintain a high content of
salt in the soil. In many places they grow in clusters adjacent to but
slightly higher than the barren areas very high in alkali (fig. 13).







22 U. S. DEPARTMENT OF AGRICULTURE



















FIGURE 13.-Salt flats near Parguera. Barren areas have in excess of 3 percent
of sodium chloride; barilla in foreground is on soil containing from 2 to 3 percent
of salt; the tuna brava, or pricklypear (left), is growing on soil containing about
1 percent of sodium chloride.
Llanos salados cerca de La Parguera. Los eriales tienen mds de 3 por ciento de
cloruro de sodio; barilla crece al frente en suelo que contiene de 2 a 3 por ciento
de sal; la tuna brava, a la izquierda, crece en suelo que contiene como 1 por
ciento de cloruro de sodio.



















FIGURE 14.-Lignumvitae, or guayacan, trees, with a dense growth of Mexican
bluegrass, or horquetilla morada. Note the effect of trade winds on the trees.
Picture taken along the southern coast.
Arboles de guayac6n o lignumvitae y horquetilla morada. N6tese el efecto del
viento en los Arboles. Fotograffa tomada en la costa sur.

In general the salt content of the soil becomes less and less as the
distance from the mangrove swamps increases, and the character of
the vegetation changes accordingly. The most important plants a
short distance from the mangrove associations are junquillo, a round-
stemmed sedge, which nearly always grows on black-alkali land and







SOIL SURVEY OF PUERTO RICO 23

is therefore restricted to calcareous soils receiving a rainfall of less
than 50 inches, and horquetilla morada (fig. 14), a fairly nutritious
grass, which grows on both alkali and nonalkali land, as does the next
important plant, Bermuda grass. These plants are associated on the
wetter areas with junco de ci6naga, a tall coarse grass of little value.
Cattail, sawgrass, caria de indio, and waterlily grow in brackish-water
swamps in many parts of the island.
I Associated with the Bermuda and horquetilla grasses in the arid
sections are xerophytes, such as cacti and other drought-resistant
plants (fig. 15). The most widely propagated cactus is the prickly-
pear. It grows on Cabo
Cabezas de San Juan near
the Fajardo lighthouse, along
the northwestern coast, and
on Isla de Vieques (Island of
Vieques), Isla de Culebra
(Island of Culebra), and other
dry islands, as well as in the
large dry area extending from
Guayama to the southwestern
coast. In arid sections it
grows on almost any soil, but
in semiarid sections it grows
either on very shallow per-
meable soils or on very sandy
soils.
Other cacti worthy of note
are sebucn, or pitajaya, a
many-branched bushlike wide-
spreading cactus; sebuctn, or
dildo, a cactus shaped like a
baseball bat; and the mel6n
de costa which is nearly round
(fig. 16). These cacti are
numerous on the shallow soils FIGURE 15.-Xerophytic vegetation on a
of the limestone hills east of steep limestone hill near Guinica quarry.
Faro Cabo Rojo to a point Average annual rainfall about 30 inches.
east of Ponce. They also Vegetaci6n xerofftica en una colina caliza
grow on other hills in th escarpada cerca de la canter de Guinica.
grow on other hills in the Promedia annual de Iluvia-30 pulgadas.
semiarid sections, if they have
not been removed in order to allow better grazing. Associated with
the cacti are other thorny shrubs and small trees, such as escambr6n
colorado, tintillo, palo de burro, Santa Maria, mesquite, aroma casha,
zarzarilla, and others. These are all of little value and are cut when
the land is prepared for planting guinea grass, which is the most
important pasture grass of the arid section. Several trees are more
or less confined to the drier sections having calcareous soils. They are
hcar (or ficar), algarrobo, tamarindo, almicigo, jagiley, lignumvitae,
ceiba, and many species of acacia.
The hdcar tree is confined to drier areas than are the other trees.
It is used for building purposes, especially as sills, and also for fence
posts. It is a gray-barked, spreading tree, often attaining a height
of 30 feet. Many of these trees are nearly covered with Spanish-
moss, especially in areas near Parguera and south of Bafios de







24 U. S. DEPARTMENT OF AGRICULTURE

Coamo. The algarrobo and tamarindo are conspicuous because of
their dense spreading tops which make desirable shade for range
cattle in the dry-land pastures. The tamarindo produces a substance
around its podded seeds which is used in making a refreshing drink;
it is also eaten raw or used as a dessert. The algarrobo produces a
sausagelike pod which contains an ill-smelling but palatable substance
that surrounds the seed.
The almAcigo is conspicuous
by its shiny reddish-brown
bark, wide open branches,
and smooth limbs. It may
grow in moist regions but is
seldom seen in places where
the annual rainfall is more
than 65 inches. It is nearly
valueless, even for charcoal.
The j agiiey, which has aerial
twining roots, and the legu-
minous acacias have about
the same climatic require-
ments as the almocigo; they
grow in the eastern end of the
island, in the northwestern
part, on drought soils in the
more moist sections, and on
the south coast. The lig-
numvitae at present is con-
fined mostly to the drier parts
of the island. It is a valuable
and exceedingly hard wood.
Unfortunately nearly all of
these trees, as well as the
other valuable trees, have
been marketed, and few
remain to propagate. The
ceiba is common throughout
the arid and semiarid see-
FIGURE 16.-Mel6n de costa, or turkscap, tions. It is conspicuous, with
growing on Ensenada clay, a shallow red its huge buttresses and
soil derived from limestone. Annual rain- sparsely branched giantlike
fall about 25 inches, trunk (fig. 17). The legu-
Mel6n de costa, en Ensenada arcilloso, un suelo ominous acacias are conspic-
rojo poco profundo derivado de piedra caliza. uous along almost all the
Precipitaci6n annual promedia alrededor de fence lines throughout the
arid and semiarid sections.
The air plant, with its ball-shaped matted structure, grows only in
the arid or semiarid sections. It is prominent on many insulated
wires, as well as on trees, cacti, and other vegetation of the south coast.
Inland from the arid or semiarid plant associations and below the
rain forest, the vegetation consists for the most part of mesophytic
plants or those that require a moist climate. This association includes
the largest number of plants on the island, partly because there is a
larger area involved. Growing within this area is the royal palm
(fig. 18)-a magnificent symmetrical sentinellike' palm that prefers







SOIL SURVEY OF PUERTO RICO 25

alkaline to acid soils but will grow on nearly every kind of soil, pro-
vided it has sufficient moisture. In some localities various parts of
the royal palm are used. Its matured nutlike seeds (palmiche) are

















FIGURE 17.-Giant ceiba tree growing on San Ant6n loam, one of the most pro-
ductive soils in Puerto Rico. Sugarcane on this field produces from 70 to 90
tons an acre when the land is properly managed and irrigated.
Enorme ceiba en San Ant6n 16mico, uno de los suelos mAs productivos de Puerto
Rico. Este predio produce de 70 a 90 toneladas de cafia de azdcar por acre,
cuando se riega y se trabaja bien.



















FIGURE 18.-The symmetrical royal palm that is used for many purposes.
La sim6trica palma real se usa para muchas cosas.
nutritious and a favorite feed for hogs, as they contain nearly 6 per-
cent of fat. Its bark is stripped off in long, narrow lengths (listones
de la cortezas) and used as siding for the native houses. Its lustrous
green leaves are used in the thatching of roofs or for covering coffee







26 U. S. DEPARTMENT OF AGRICULTURE

seedbeds; some leaves are shredded and used in the making of chair
seats. The racemes are used in the making of the locally used brooms.
The leaf sheath, which is about 3 feet long and 20 inches wide, is used
to cover roofs and walls, and it makes fairly good washtubs for the
cleaning of clothes. The tigiiero, or canoe-shaped palm sheath, is
used as a convenient grain container, and, when the tree is cut, the
cogollo, or bud, is used as a delicate salad which tastes very much
like raw cabbage.
The lagrumo thrives in all moist areas and is very conspicuous on
the abandoned coffee farms, on account of its ungainly stems and its
large leaves, with white undersurfaces, floating in the breeze. It has
a hollow fragile stem and is of very little value even for charcoal. The
poma rosa, a bushlike tree which generally grows in moist acid soils, is
used in basket weaving, for fence posts, for charcoal, and for roof tops
for coffee seedbeds and nurseries. Its fruits are eaten by people and
sometimes are fed to hogs. Associated with the mesophytic plants are
many tropical fruit trees, such as jobo, coraz6n, guayaba, mabi, nis-
pero, cacao, mamey, guanabana, citron, icaco, and cashew nut. The
jobo is a deciduous tree that loses its leaves during winter, when it
then presents a naked appearance, as all the limbs are nearly straight,
smooth, and bare. It produces a plum-sized insipid yellow fruit
during the summer and fall, which is relished by hogs and sometimes
eaten by people. The coraz6n is a large tree having many branches,
which, during the winter, produces heart-shaped grapefruit-sized solid
reddish-colored slightly acid fruit. The guayaba, or guava, a semi-
cultivated tree or bush, produces the pink-centered many-seeded
walnut-sized fruit that is eaten raw or made into guava jelly or paste,
some of which is exported to the United States. This bush becomes
an obnoxious weed in many abandoned pastures. It readily develops
a vigorous root system, and within 5 years, if not cut, an expenditure
of about $5 an acre would be required to clear it from the fields. It
grows on poor land nearly as well as on good land.
The mabi tree does not produce an edible fruit, but the bark is used
in the preparation of a fermented drink. Sweetened water is added
to an extract of the bark and allowed to ferment overnight. The
nispero tree produces a fruit that is small, brown, sweet, and very high
in sugar. It is relished by most people. The cacao tree was at one
time important commercially, but at present a very small quantity
of the seeds of the large ovate pods is gathered and prepared for mar-
ket. The mamey is a dual-purpose tree; the thick smooth oblong
leaves are used, especially in sandy soil, to protect young tender plants,
such as tobacco, from the mole cricket, or change. The fruit is sweet,
yellow, and about the size of a coconut. The pulp is used raw, and
some is made into a paste and consumed as a dessert. The guanabana
produces a large somewhat pear-shaped fruit with soft rind, white
fibrous pulp, and large black seeds; it is slightly acid; and the rind has
many short fleshy spines. The fruit is eaten raw or as a dessert, and
the pulp is made into drinks or sherbet. The citron grows in only a
few groves, but it seems to be capable of producing a profitable com-
mercial crop and in time probably will occupy a larger acreage than at
present. Its requirements for soil and climatic conditions are similar
to those of the grapefruit tree. The fruit is used in making candy.
The icaco is a bushlike tree producing black, white, or purple plumlike
fruit which has a large dark seed and a small quantity of sweet white







SOIL SURVEY OF PUERTO RICO 27

pulp that is eaten raw. This bush will thrive on drought unproduc-
tive soils. The cashew tree grows in semiarid sections on drought
soil as well as within mesophytic plant associations. The nut is
kidney-shaped and about one-fourth inch thick. The roasted kernel
of the seed is of good quality and delicious, but it is seldom sold on a
commercial scale. The pulp of the sour fruit is sometimes cooked for
dessert. Some of the other associated forest trees are higiiero, llume
palm, cupey, jacana, bay rum tree, bucare, African tuliptree, many
kinds of robles, moca, guamh, and guaba. The last three are used ex-
tensively as shade trees on the coffee plantations. The higiiero pro-
duces a large oval gourdlike fruit (calabash) that is picked, dried,
seeded, and used locally for water containers and cups. The llume
palm presents an interesting sight when its tall thin cylindrical trunk
and large pinnate leaves are fanned by the breeze. This palm prefers
alkaline soils, and it grows only in the rugged limestone hills and in the
rough land of Isla de Vieques. The cupey tree is conspicuous in the
limestone section, as its long aerial roots resembling black ropes, swing
far down over the cliffs. This tree usually grows as a parasite on other
trees until its aerial roots become anchored m the soil. The jAcana is a
hardwood and is used for building purposes. The bay rum tree grows
in moist as well as in semiarid sections. Its leaves are often gathered,
brewed, and distilled, and the product is sold for making bay rum. The
buicare, African tuliptree, and roble have striking blossoms which give
the landscape added attraction. The leaves of the bicare, especially
of the dwarf variety, make nutritious forage for livestock. The leaves,
which are very high in protein, may be fed green or may be ground.
This tree is used also as a support for the climbing vanilla plants.
The more common small plants in the moist sections are the many
common ferns, sensitiveplant, fresa, and cohitre morado. The com-
mon ferns are very abundant along road banks and on idle land. Some
species are very good indicators of strongly acid soil, low in plant
nutrients. Ferns also extend into the rain-forest plant association.
The sensitiveplant grows in many pastures and on many plantations.
It is regarded as a weed. The fresas are more abundant at elevations
of more than 1,500 feet than at the lower levels. The fresa berries are
similar to raspberries, and they ripen throughout most of the year.
They are gathered, and many of them are sold locally from the road-
side. They are eaten fresh and used as dessert. Cohitre is similar
to wandering-jew. Some varieties are used for hog feed. The cohitre
morado is effective on the densely shaded coffee farms as a soil binder,
thus helping in the control of erosion.
The most important grasses growing in the moist-climate areas are
matojo, cerrillo, and St. Augustine grass. Matojo is a rank-growing
bunchgrass that is eaten by livestock, but it seems to be low in nu-
tritious constituents. The mountain matojo is used in thatching
some of the bohios, or mountain houses (fig. 19). Cerrillo ranks as a
fair grass for livestock. It grows on many kinds of well-drained soils
throughout the moist and semiarid sections. St. Augustine grass is
considered the best upland grass. It not only is very nutritious, but
it is one of the best plants for the control of erosion on the island, as it
readily forms a thick mat and its long rhizome-stemmed foliage
creeps over banks and over the sides of gullies, thereby helping to
hold the soil in erodible places. It is used also on lawns.







28 U. S. DEPARTMENT OF AGRICULTURE

As the rainfall increases there is a gradual change from the moist-
climate plant association to the rain-forest vegetation, and thence to
the moss vegetation of the areas having the highest rainfall, which are


















FIGURE 19.-A bohio, or mountain home. Generally some subsistence crops,
such as bananas, beans, yautias, yuca, pigeonpeas, and sweetpotatoes, are
planted in the dooryard or nearby.
Un bohfo. En general se encuentra algunos cultivos como guineos, habichuelas,
yautfas, yuca, gandules y batatas alrededor de la casa.




















FIGURE 20.-Dense vegetation in the rain forest-treeferns, mountain palms,
bananas, and many other plants-all striving for existence.
Exhuberante vegetaci6n en un bosque-helechos arborescentes, palmas de sierra,
guineos y muchas otras plants.

the high wind-swept cool fog-laden peaks. Some of the most impor-
tant plants of the rain-forest vegetation are (figs. 3 and 20) palma de
sierra, or mountain palm, treefern, tabonuco, granadillo, sabino,







SOIL SURVEY OF PUERTO RICO 29

maricao, mahogany, and Spanish cedar. The mountain palm is
similar to the royal palm, but it does not have so symmetrical an
appearance and is more slender. It is used to some extent in building,
the trunk being split into narrow strips for siding. The treefern is of
value only in helping to prevent erosion, as it has a good root system
and its leaves help to break the force of the rain. The tabonuco tree
is valuable for its timber, and its resin is sometimes used in making
torches. The granadillo, sabino, and maricao are used for building
purposes. The mahogany and Spanish cedar are valuable woods for
cabinetmaking. Neither tree is attacked by termites. Both grow in
the moist sections as well as in the rain forest.
The moss association is confined mostly to the high peaks of the
Sierra de Luquillo, where the precipitation is heavier than elsewhere on
the island. The most common trees of this mossy plant association
are roble de sierra and granadillo. On the high wind-swept peaks the
trees, although mostly virgin, have a dwarfed appearance. They
gradually increase in size with decreasing elevation. Those growing
on the summits of the highest peaks range from 2 to 6 feet in height,
but at the lower elevations theymnay attain a height of 30 feet. At
the high elevations the branches are crooked and are so dense and
interlaced that only a small amount of sunlight penetrates to the moss
and sedge-covered shallow and nearly saturated rocky soil below.
Many species of mosses and ferns are abundant. Most of the mosses
grow on the branches of dead trees and on rocks. The bejuco de
palma and bejuco de rana, two clinging vines, are abundant in moist
climates and in the areas of highest rainfall. Orchidlike plants are
conspicuous on the tree trunks in the high elevations and in the lower
part of the rain forest. Many other plants grow throughout Puerto
Rico, such as ornamental shrubs and flowers. Although many of them
are very beautiful, most of them lack pleasing fragrance. Mushrooms
and toadstools are rarely seen anywhere.
A valuable descriptive account of the plant ecology and plant dis-
tribution in Puerto Rico is given by Cook and Gleason (12).
ANIMAL LIFE
According to Danforth (14, p. 18), Puerto Rico does not have any
indigenous land mammals; squirrels, skunks, minks, coyotes, alliga-
tors, or similar animals do not inhabit any part of the island. The
most common animal is the mongoose (Herpestes birmanicus), which
was imported from Cuba in 1877 for the purpose of destroying rats
and snakes. The rats have not been controlled, there never were
many snakes, and now the mongooses have increased so rapidly that
they have become a nuisance. They inhabit all parts of the island
and are destructive to chickens, lizards, and ground-nesting birds.
Roof rats, house rats, and house mice are fairly numerous, especially
in the congested parts of towns. The rats do considerable damage to
sugarcane stalks and coconuts. Many of the coconut groves are pro-
tected with a 10- or 12-inch metal band placed around each palm at a
height ranging from 4 to 8 feet above the ground (fig. 25). Bubonic
plague, which is spread to human beings from infected rats, has
appeared twice in San Juan and nearby cities.
Lizards are both prevalent and beneficial. They range in size
from the 15- or 20-inch lagarto (Ameiva exul) to the 3-inch lagartija







30 U. S. DEPARTMENT OF AGRICULTURE

(Anolis poncemesis). All the lizards are insectivorous and do incalcu-
lable good by destroying millions of flies, mosquitoes, and other
insects. The lizards run about at will from the houses to the fields in
all parts of the island. Several kinds of frogs have been imported
and may be found in the wet areas adjacent to the coast as well as in
the tropical rain-forest areas. The importation of the toad (Bufo
marinus) has been one of the greatest benefits to the south-coast cane
growers, as the toads have multiplied rapidly and have the white grub
nearly under control by eating the May beetle (Lachnosterna porto-
ricensis), the adult of the white grub.
Birds are not so plentiful as might be expected, owing in part to the
destruction of the nests and young birds by hurricanes and in part to
the density of the population, as boys and young men destroy the
eggs and kill the birds. The greatest number of birds seem to be
in the most sparsely populated areas, such as the arid southwest.
Some of the most conspicuous birds (14) are the reinita, or Puerto
Rican honey creeper; the mozambique, or grackle, that follows plows,
catching grubs and other insects; the gorri6n, or carib grassquit; the
ruisenor, or mockingbird; the pitirre, or gray kingbird; the golondrina,
or barn swallow; the putilla, or killdeer; and the aura, or southern
turkey vulture. Several species of doves and ducks are hunted and
are relished by sportsmen. Herons are very numerous in the lagoons
and mangrove thickets.
Bats are fairly numerous in the caves of the limestone section,
especially on Mona Island. Bat guano is used as a fertilizer, but the
quantity obtained now is much less than formerly.
There are many crabs along the coast. The most conspicuous are
the large blue land crabs, or cangrejos (Cardisoma quanhumi), which
are very numerous along the wet poorly drained coastal lowland soils.
After the first few rains following a long dry season, thousands of
crabs are caught and eaten by the people. These crabs do consider-
able damage to sugarcane, and poisoned bran must be placed near
their holes in order to reduce their number as much as possible.
More than 1,400 different species of insects (50) have been identi-
fied on the island. These include many that are destructive to crops,
such as the change, or mole cricket (Scapteriscus vicinus), which does
much damage in loose sandy soils, especially on level coastal plains,
to the young tender crops, such as tobacco and minor crops; the white
grub which causes much loss in the sugarcane fields on alluvial lands;
the giant rhinoceros beetle, which attacks and kills young coconut
palms; the sugarcane rhinoceros beetle, which at times feeds on
sugarcane; the coffee-leaf miner, a small caterpillar that is very destruc-
tive to the coffee leaves; and the hormiguilla, a small ant that makes
tunnels in living trees, especially the guam6 one of the best shade
trees for coffee. The damage caused by the pink bollworm has been
one of the reasons for the small acreage devoted to cotton. The
West India fruitfly has been a serious handicap to the fruit grower.
Flea beetles do much damage to the tobacco plants in areas receiving
less than 65 inches of annual rainfall. The corn earworm is a serious
pest in both sweet corn and field corn.
Other important insects are the various species of termites, the
polilla being very destructive to buildings of imported lumber. The
comejen's large black "niggerhead" nest is very conspicuous on fence
posts, trees, and even on the ground throughout the island. The







SOIL SURVEY OF PUERTO RICO 31

termite has social habits similar to the bee; its brittle vesicular nest,
1 foot or more in diameter, contains workers, soldiers, and a single
royal pair.
Flies are not so numerous as might be expected, and very few enter
the houses, although the windows and doors are usually open during
the day. Mosquitoes are seldom seen during the daytime, except in
a few swamps, but they are very numerous at night, and certain
parts of the lowlands are infested with a fairly high proportion of
malaria-carrying mosquitoes.
The number of deaths from malaria has decreased rapidly, owing
to the work of the Department of Health of Puerto Rico and to the
drainage work and studies on malaria by the Rockefeller Foundation.
Bees are not so common as might be expected. According to the
1935 census of the Puerto Rico Reconstruction Administration (34),
19,160 colonies were reported from 1,466 farms. The largest numbers
of apiaries are in the mountainous sections, especially in the coffee
districts. The exportation of honey during 1938-39 was 1,115,785
pounds, valued at $42,272, according to the Annual Book on Statistics
of the Puerto Rico Department of Agriculture and Commerce.
The principal parasites affecting livestock are ticks, lice, flukes,
tapeworms, and roundworms. The ticks and tick fever caused by
the microparasites do incalculable damage to livestock. The loss of
life is not great, but the vitality is sapped from the animals. A
systematic tick-eradication program is now under way. Lice are
prevalent among all animals in all parts of the island. Flukes are
particularly obnoxious in the arid sections and in areas of calcareous
or neutral soils, as their host, the snail (Lymnaea cubensis) (48, p. 18),
is more prevalent on alkaline than on acid soils. The most favorable
location for the snail is in wet or moist lowlands where the soils are
neutral or calcareous. The flukes enter the livers of both man and
beast. Tapeworms and roundworms are very common and serious
parasites in many sections.
Visible effects of microfauna activity are noticed throughout all
the soils. There seems to be more earthworm activity in the humid
sections than in the nonirrigated arid or semiarid sections. The
surface soils of the irrigated lands contain an abundance of worm
casts, indicating the activity of numerous worms. However, the
casts are not so plentiful as in the upland soils in the humid sections,
especially in the Cialitos, Catalina, and related soils. The principal
visible microfaunas are termites, white grubs, ants, fishworms, and
nematodes, all of which play a very important role in mixing the plant
residues and mineral part of the soil as it passes through their bodies.
The aquatic animal life in the waters near the coast, in the mangrove
swamps, and in fresh-water streams includes fish, oysters, lobsters,
corals, many kinds of mullusks, and sponges, The principal fish are
el pargo, or lane snapper; macarela espafiola, or Spanish mackerel;
pargo rojo, or red snapper; el arenque, or herring; pompano, or pom-
pano; and salmonete blanco, or white mullet, of the salt-water and
el dajao of the fresh-water streams. A large number of people make
their living by seining fish along the coast. At times they catch barra-
cuda, sharks, and manatees (or sea cows) in their nets.
The oysters are small and are gathered, not from beds but from
the numerous mangrove roots. The lobsters are fairly numerous
and are delicious. The principal corals along the beach are the fan







32 U. S. DEPARTMENT OF AGRICULTURE

and brain corals. Many kinds of edible mollusks are gathered and
eaten by the coast dwellers. The sponge most commonly seen is the
finger sponge. Neither the sponge nor the mollusk industry is very
important.
Domestic animals are discussed in the section on Agriculture.
POPULATION
Puerto Rico was discovered and named by Christopher Columbus
in November 1493, or 127 years before the landing of the Pilgrims
at Plymouth Rock. At that time the inhabitants were Indians, who
have since disappeared. Puerto Rico remained Spanish territory
until it was ceded to the United States by Spain in 1898. The present
political status is that of a territory with certain legal limitations.
The island is divided for governmental purposes into 77 municipal
districts,7 and these again into barrios.8 The present inhabitants are
for the most part either descendants of Spanish settlers or of Negroes
brought in for work on the plantations. They are American citizens
and have a right to vote at elections on the island and for Federal
officials when residing in the United States.
According to the Federal census, the total population in 1930 was
1,543,913, or 454 people to the square mile. Of this number, in
addition to the native-born Puerto Ricans, 3,585 were born in Spain,
2,160 in the United States, 367 in Central America and South Amer-
ica, 342 in France, and a few in other countries. Preliminary data of
the 1940 census show an increase of 21.1 percent, to a total of 1,869,245,
or 549.7 people to the square mile. The density of the population,
which varies greatly from place to place, creates the most serious
social and economic problems confronting the insular government.
Few people build their homes on the good alluvial lands paralleling
the larger streams, on the forest-covered soils of the high elevations,
or on the pasture lands of the south coast.
The most densely populated parts of rural Puerto Rico (fig. 21) are
on the shallow brown hill-land soils near Trujillo Alto and Rinc6n and
south of Cabo Rojo, also from Hatillo (Hatillo) to Aguadilla on the
soils derived from limestone (fig. 22), and on the soils along the north
coast. In these areas there are more than 600 people to the square
mile. This is a very grave situation, because most of the people
depend almost entirely on agriculture for their support. A high pro-
portion of the area of Puerto Rico consists of shallow, stony, steep, or
submarginal land, and it is doubtful whether agriculture can support
such a dense population and give the people a reasonable standard of
living. Many people obtain part-time work in sugar centrals, tobacco-
stripping shops, needlework shops, and other industries; but, even with
this additional income, families are able to obtain only the bare necessi-
ties of life. Thousands of people of all ages are undernourished.
The large population has had its effect on the natural resources of
the island, such as forests, soils, and fish. The great increase in popu-
lation, which began more than 100 years ago, naturally has led to the
removal of forests and the planting of both subsistence and major
crops. Most of the timber has either been sold or is rapidly being
7 The municipal district, or municipality, is an unsurveyed but somewhat definite land area averaging
44.6 square miles, or slightly larger than a township.
I The barrios are unsurveyed but fairly well recognized land areas about one-tenth the size of a munici-
pality, or about 4 square miles.












/. / ) ( l
.. .\ .- .f "

4 N S ,-1 : ,
...i' ./ : ..T .
..' /:.. ....I ..' .:: \,,,,

.r- / . -..) "- '" '
C/ILI





.. stric'.,, de l" p a .' \ rural en 13 C d t rep re.e t -1 00 -.0 p -
"" *.. .- .-- .-. /"
-- -^ /* ^ *.. *. *.. / .* ..* .. .. ^^ ** .* i : ^ \ ." -



i. -i
FIGURE 21.--Distribution of rural population in 1935. Each dot represents 1,000 people.
Distribucion de la poblaci6n rural en 1935. Cada punto represents 1,000 personas.








34 U. S. DEPARTMENT OF AGRICULTURE


















































FIGURE 22.-Aerial photograph of about 600 acres in the irrigated district near
Isabela. Approximately 800 people live in the 150 or more houses seen in this
picture. Most of the soils are deep permeable red or yellowish-red Matanzas
and Coto clays which are fairly well adapted to nearly every crop grown on the
Island. (Photograph taken by U. S. Navy.)
Fotograffa area de cerca de 600 acres en el distrito de riego de Isabela. Aproxi-
madamente 800 personas viven en las 150 6 mds casas que se ven en la foto-
graffa. Muchos de los suelos son arcillas Matanzas y Coto, profundas, rojas o
amarillo rojizas y permeables y son bastante adaptables a casi cualquier cultivo
de la isla. (Fotografia tomada por la Marina de los EE. UU.)







SOIL SURVEY OF PUERTO RICO 35

used for the making of charcoal, and this exploitation of the forest
resources over a long period of years has nearly depleted the timber.
According to Gill (19, p. 133), "probably 50 percent of Puerto Rico,
or 1,000,000 acres, may be classified as true forest soil, but of all this
only 110,000 acres still remains uncut. Eighty percent has been
devastated." One reason so much of the land has been cut over is
because the cutting has been unrestricted, with no provision made for
reforestation. Fires never have and probably never will be a menace
to either the forest or grass. A comprehensive and intensive forest
program is needed immediately to make Puerto Rico self-supporting
in wood requirements. Rapid progress in this direction has been
made during the last 2 years, owing to activities of both the Federal
and insular governments. At present (1940) about 186,155 acres are
in forest, of which 26,010 acres are in the Federal forest reserve
(Caribbean National Forest) and 40,000 acres are in insular forest
land. The largest areas include some of each of the following: The
rough, rugged mountainous areas, the mangrove swamps, and the
shallow soils derived from serpentine and limestone in humid and
arid regions, respectively.
The pressure of the increasing population forces the people to culti-
vate steeper and steeper land and a greater and greater acreage to the
person, because returns to the acre are becoming less. With the ex-
ception of the soils of the alluvial lands, most of the cultivated land in
humid Puerto Rico has been leached to such an extent that a deficiency
of calcium, phosphorus, and magnesium seems to exist. A very low
percentage of the owners of small farms 9 use fertilizer or manure to
offset the loss of these necessary mineral elements. The plants pro-
duced, whether grain plants or grasses, do not have the maximum food
value for the development of bones, teeth, and the physical well-being
of the animals and people. Rickets, poor teeth, and poor health are
common among some of the natives in the humid districts.
Livestock that have been grazed on grasses of the alkaline and semi-
arid districts have larger bone development, smoother hair, and better
general appearance than those pastured in the moist mountainous
districts where acid leached soils are dominant and the grass is tall
and dense.
Sheet erosion has been reducing crop yields year after year on im-
properly used hill land (fig. 23). The combined destructive effects
of leaching and erosion, in addition to the constantly increasing popu-
lation, make an acute problem in land utilization. Probably one of
the most effective measures for better land use is through the Puerto
Rico Extension Service in directing the jibaros,'0 through their
conuco n agriculture, to plant more strip crops with the contour of
their land. Increasing quantities of fertilizer and lime must be used
each year to restore the fertility that is lost by cropping and erosion,
in order to increase or maintain the same yearly production of agri-
cultural crops.
Few of the fresh-water fish become large before they are caught and
used for food, and the only wild game left includes a few doves and
ducks. Neither fish nor game is protected by strict game laws.
According to the 1935 census of the Puerto Rico Reconstruction Administration (34), 27.9 percent of the
improved land was in farms less than 50 acres in size.
10 Jibaros refer to the tillers of small patches of land.
11 Conuco agriculture refers to garden farming of small patches of several kinds of minor crops, such as
pigeonpeas, beans, corn, yautia, yuca, bananas, and others.







36 U. S. DEPARTMENT OF AGRICULTURE

Within the last few years the insular forest service has been stock-
ing some of the streams with suitable kinds of fish. This should prove
beneficial, but, owing to the large numbers of people, game laws cannot
be made very effective, and it is doubtful whether fish or game ever
will be very plentiful.





4f




























FIGURE 28.-Severe erosion on an improperly farmed hillside of Descalabrado
silty clay, eroded phase, where the annual rainfall is sufficient to encourage
the planting of crops, yet is not sufficient for the plants to make rapid growth
which would check the force of tropical showers. The gardens to the right are
properly farmed.
Fuerte erosion en una ladera de Descalabrado limo-arcilloso, fase erosiva, mal
trabajada. La lluvia annual en este sitio es suficiente para la siembra de cultivos,
pero no lo bastante para que las plants crezcan rapidamente, y sirvan de re-
sistencia a la fuerza de las lluvias tropicales. Los huertos hacia la derecha estAn
bien trabajados.
TOWNS
San Juan, the capital and largest city, is on the north coast in the
east-central part of the island. It is the location of the United States
Army and Navy radio stations; other Army stations are at Borinquen









SOIL SURVEY OF PUERTO RICO 37

(near Aquadilla), near Vega Baja, and at Cayey. In 1940 the popu-
lation of San Juan was 169,247. The business section and a part
of the residential section are on an island connected to the mainland
by bridges. Ponce, which is located near the center of the south
coast, is the second largest city, with a population of 65,182 in 1940.
Mayagiiez, which is centrally located on the west coast, is the third
city, with a population of 50,376 in 1940. Caguas, the fourth largest
city, had a population of 24,377. It'is situated in a mountain valley
about 35 kilometers south of San Juan. The populations, elevation
above sea level, approximate location, and principal crops and indus-
tries of the cities and larger towns are given in table 2.

TABLE 2.-Data regarding principal cities and towns in Puerto Rico

Population t In- Eleva-
crease tion
City or town or de- above Location Principlcr and in-
crease a dustries
1940 1930 in op- le1
elation

San Juan-...--.- 169,247 114,715 47. 5 224:7 Northern coast ----- Commercial.
Ponce---------- 65,182 53, 430 22.0 51.5 Southern coast -. Commercial, sugarcane.
Mayagiez-------- 50, 36 37,060 35.9 7.3 Western coast ------ Needlework, coffee, sugar-
cane.
Caguas..--------- 24, 377 19,791 23.2 3232.9 Mountain valley --- Tobacco, sugarcane, subsist.
ence crops.
Arecibo.---------. 22,134 12,863 (4) '27.3 Northern coast ----- Sugarcane, grapefruit, com-
mercial, subsistence crops.
RioPiedras --. 19,935 13,408 48.7 78.7 ---do- ------- Sugarcane, fruits.
uayama-------- 16,913 10,953 54.4 244.5 Southern coast --- Sugarcane, livestock.
Bayam6n ---- 14,696 12,986 12.4 253.7 Northern coast---- Sugarcane, grapefruit, pine-
apples.
Aguadillaa-.. ---- 13,468 10,962 23.0 '13.9 Western coast ------ Sugar cane, coconuts, com-
mercial, needlework.
Yauco -------- 9,985 8,607 16.0 '104.1 Southern slope --- Sugarcane, coffee, livestock.
Coamo -------. 8, 691 5,831 49.0 3354.3 Southern valley--.. Livestock.
Catafio ...------- 7,924 7,044 12.5 520.0 Northern coast ----- Commercial.
Humacao ..---- 7,624 7, 937 6-3.9 3 52.5 Eastern coast ------ Sugarcane.
-Fajardo -------- 7,108 7,322 6-2.9 '32.8 .-- do ..----------- Do.
Manat ----- 6, 771 7,449 --9. 1 291.2 Northern coast.-- Sugarcane, fruits.
San German------ 6,446 5,636 14.4 244.3 Southern valley ---- Sugarcane, coffee, subsist-
ence crops.
Cayey... .------- 5,622 5,953 --5.6 '1,300.0 Mountain valley--- Tobacco, subsistence crops.
Vega Baja- _-- 5, 409 4,784 13.1 228.9 Northern coast --- Sugarcane, fruits.
Carolina .------- 5,368 4,454 20. 5 339.3 -----do ------------ Sugarcane, subsistence crops.
Cabo Rojo---...- 5,303 4,605 (7) 52.3 Western valley-..- Do.
San Lorenzo -...- 5,181 4,916 5.4 5200.0 Interior plain --- Tobacco, sugarcane, subsist-
ence crops.
Juncos-------..... 5,009 5,297 --5:4 3446.0 ---- do--..---------- Sugarcane, tobacco, subsist-
ence crops.
Sabana Grande._ 4, 783 3,778 26.6 5 289. 0 Southern valley-- Sugarcane.
Yabucoa .--.----. 4,542 3,841 18.3 3 52.5 Eastern coast ------- Do.
Utuado.---..----. 4,430 4,758 '-6.9, 2442.6 Mountain valley-._ Coffee, tobacco, subsistence
crops.

I Population data from the United States census.
2 Elevations from U. S. Geological Survey.
3 Barometric elevations by insular department of interior.
SBarrios Buenos Aires, Miramar, and San Luis were annexed to Arecibo town in 1937. The figure for
1930 is not, therefore, comparable.with that for 1940.
5 Approximate elevation.
6 Minus sign indicates decrease.
7 Pueblo Nuevo was organized from part of Miradero and annexed to Cabo Rojo town in 1932. The figure
for 1930 is not, therefore, comparable with that for 1940.

Most of the larger cities are near the coast and adjacent to land that
is well adapted to the production of sugarcane. Most of the inland
mountain towns are small and generally have but one improved road
leading to and from the town (fig. 24).







38 U. S. DEPARTMENT OF AGRICULTURE














FIGURn 24.-The small inland town of Pueblito del Rio which has but one auto-
mobile road and one oxcart road. Sugarcane is grown both on the alluvial
lands and on the sloping hills.
Pueblito del Rio, solamente tiene una carretera para autom6viles y un camino
para carretas. La cafia se siembra en las tierras de aluvi6n y en las colinas.
TRANSPORTATION
Among the United States ports from which goods may be shipped
to Puerto Rico are New York, Baltimore, New Orleans, Mobile,
Tampa, Galveston, Houston, and San Francisco. Boats from other
countries stop in San Juan harbor at frequent intervals. Ponce,
Mayagiiez, Aguirre, Fajardo, Arecibo, and other seacoast towns also
have harbors where freighters pick up exports and leave imports.
Passenger boats stop at Ponce, Mayagfiez, and, at times, at some other
ports. San Juan has connections with the United States by regular
boat and airplane transportation, also by cable and telephone.
According to the Annual Book on Statistics for 1938-39, 22,607
motor cars are registered, of which 12,608 touring cars, 2,287 light
trucks, and 2,073 heavy trucks, a total of 16,968 vehicles, are privately
owned. There were 4,327 touring cars, 38 light trucks and 1,274
heavy trucks, or a total of 5,639 vehicles, under public ownership.
This represents about 1 car for every 83 persons. Very few horse-
drawn buggies and carriages are seen, and only a very small propor-
tion of the rural inhabitants have saddle horses. Walking is the
principal means of travel by day laborers and their families. Pedes-
trians throng the highways throughout the day and most of the night.
Lines of the American Railroad Co. of Porto Rico and other com-
panies, subsidiaries of sugar mills, such as the Fajardo Development
Co., or the Ferrocarriles del Este (Eastern Railroad), Fortuna Rail-
road Co., and Ponce & Guayama Railroad connect nearly all the coast
towns, except those in the southeastern part of the island, from Arroyo
to Yabucoa. Most of the lines have single tracks and are 1 meter
wide. Owing to the rough terrain, the railroads do not cross the inte-
rior. They carry first- and second-class passengers, freight, and express,
but most people travel by either bus or public cars, which ply between
all towns, picking up and discharging passengers at any place along
the road. The fare is about 1 cent a kilometer. All sugar centrals
have a network of railroads throughout their holdings. Most of the
railroads are very narrow gaged, and some of the tracks are removed
/







SOIL SURVEY OF PUERTO RICO 39

as soon as the crop is taken off the land. The towns-and sugar cen-
trals are connected by telephone and telegraph, but very few rural
residences have telephones or free'delivery of mail. During warnings






































FIGURE 25.-A 15-foot highway along the coast. Note the metal bands on the
coconut palms to keep the rats from climbing them.
Carretera de 15 pies de ancho a lo largo de la costa. N6tese las bandas metAlicas
en las palmas de coco para evitar que las ratas suban a las palmas.

of an approaching hurricane, news spreads surprisingly fast by verbal
communication.
Hard-surfaced roads, or carreteras,1' connect all the towns. Many
of the secondary roads, or caminos, leading into the mountains or
hilly country are impassable except by oxcart, saddle horse, or on
foot. Thousands of the country homes,,or bohios, are reached only
:2 In Puerto Rico carretera' is used to designate a hard-surfaced main-traveled automobile road; a callej6n
refers to an oxcart road, especially in the sugarcane fields; a camino refers to a second-class road; and a vereda
refers to a footpath.







40 U. S. DEPARTMENT OF AGRICULTURE

by foot and horse trails, which penetrate to all parts of the island.
The trails zigzag up the steep rocky mountainsides then generally
follow the ridge tops. The pack animals carrying coffee, tobacco,
charcoal, bananas, and other crops on their way to towns, and re-
turning with rice, beans, canned fish, and other provisions, have
great difficulty in carrying comparatively light burdens through mud
ankle deep or over the steep rock-strewn mountain slopes. Trans-
portation in the mountainous districts is slow and expensive. Most
of the first-class roads have the hard limestone as a base and a top
dressing of tar, and, as there is no freezing or thawing to heave the
underlying soil, the roads last for a number of years. Most of the
roads, however, are only 15 feet wide (fig. 25), and, as a high percent-
age of all merchandise and products is moved with large trucks, they
soon become uneven and require continual maintenance. Many of
the secondary roads are made from crushed soft limestone which is
soon worn away by the tropical downpours. On the large holdings
of the sugar centrals, roads are numerous, and generally there is an
oxcart road (callej6n), around every 10 or 20 acres. Only the most
important callejones are shown on the soil survey map, and many of
the trails (veredas) are not shown.
EDUCATION
Every community has some public schools, but most of the isolated
rural districts are very much handicapped by inadequate schools,
both as regards number and size. Most of the schools in these dis-
tricts have only four grades. In most of them the first-grade pupils
attend for one-half of the day and the second-, third-, and fourth-
grade pupils for the other half. Each teacher has about 60 children
during the day. The 1935 census of the Puerto Rico Reconstruction
Administration (34) shows that the average number of persons in a
family is 5.4. Of the children between the ages of 7 and 13 years,
61.7 percent attend school, and of those between the ages of 14 and
15 years, 40.7 percent attend school. The census figures show that
35.1 percent of the people over 10 years old are illiterate.
The 54 districts that have established second-unit schools are very
fortunate, as the schools under this system equal or are superior to
schools in the United States, especially in regard to local needs, for
instance, educating the children's taste for beneficial vegetables not
commonly used by the families but which can be and are grown by
the boys of the school on the 4- to 25-acre tracts of school land.
Several teachers are employed at each of these rural schools. Do-
mestic science, agriculture, manual training, and ceramics are some
of the subjects taught besides the regular graded-school studies.
Spanish is the language of the people, but English is understood
and spoken by all high-school students and many pupils in the graded
schools. The University of Puerto Rico is located in Rio Piedras.
The enrollment for 1936-37 (first semester) was 4,306 students, of
whom 1,492 were men and 2,814 women. The School of Tropical
Medicine is in San Juan. The College of Agriculture and Mechanic
Arts is near Mayagiiez, where the enrollment in agriculture is about
200 and in engineering about 300 students. The Polytechnic Institute
is at San German, and there are several denominational schools on
the island.
Most of the municipalities have a county agricultural agent, and
at present there are nine agricultural extension demonstrations farms,







SOIL SURVEY OF PUERTO RICO 41

locally called granjas. The average size is about 16 cuerdas.'3 The
Agricultural Experiment Station of the University of Puerto Rico,
having 185 cuerdas for agricultural purposes, is located near Rio
Piedras, and the irrigation substation, located west of Isabela, covers
a total of 80 cuerdas in 3 farms on different soil types. The Federal
Experiment Station has a total of 410 cuerdas in 2 separate farms and
is located near Mayagiiez. Valuable information in agriculture is
obtained from all these stations and farms.
Every town has at least one church, which generally joins the plaza
on the east, and a few churches have been built in the rural districts.
As a rule, each town has only one cemetery, and there are very few
in the rural districts. Less than 500 cuerdas are occupied by ceme-
teries in Puerto Rico. Several daily newspapers are published in
San Juan and one or two in Ponce and Mayagiiez. The papers are
printed in the Spanish language, with the exception of one or two
that have an English supplement. There are also several magazines
published on the island, one of which is a scientific agricultural
magazine. San Juan has two radio broadcasting stations, and
broadcasting programs are heard from both Europe and the United
States. The larger cities have public libraries, and nearly every
town has a municipal hospital. San Juan has many clinics and
hospitals and one Young Men's Christian Association building, the
only one on the island.
WATER SUPPLY
In many places, especially in the rural districts, the water supply is
insanitary and inadequate. In the northwestern part of the island, in
the limestone area, underground drainage forces the people to use
water caught in mudholes and depressions, especially after the limited
supply of rain water caught from the eaves of the metal-roofed houses
has been used. In irrigated districts the people use irrigation water.
In the mountain areas any stream or spring water is used, regardless
of its state of sanitation. The quality and quantity of water varies
considerably from place to place. Probably the best water comes
from springs originating in the serpentine rocks, such as those east of
Mayagilez on Las Mesas. Within areas where granite rocks are
dominant, surface water for drinking purposes is scarce during the dry
seasons, and throughout all limestone areas most of the domestic
water is obtained from the eaves of the metal-roofed houses. In areas
where the dominant rocks are tuff and shale, the water supply is fairly
good and usually abundant. Municipal water hydrants are located
along many of the roads in the thickly populated rural districts where
natural water is scarce. Most of the household water is carried in
5-gallon cans by the women, and often the water supply is from one-
eighth to one-fourth of a mile down the mountainside from the house.
Practically the only windmills or pumps in use are in pastures in the
arid and semiarid districts. These wells provide water for people and
for livestock. Water for the towns generally is piped from mountain
streams through aqueducts, and in the larger cities it is chemically
filtered with aluminum sulfate and treated with chlorine, but in the
smaller towns it is filtered by settling and is treated only with chlorine.
Typhoid fever and other water-borne diseases are disseminated by the
insanitary water supply. Most of the household washing is done
along the stream banks (fig. 26).
13 A cuerda is equivalent to 0.9712 acre, or 42,105 square feet.







42 U. S. DEPARTMENT OF AGRICULTURE

According to the data of the commissioner of health of Puerto Rico
for 1937, the death rate per 100,000 population from diarrhea and
enteritis was 482.4 people; from tuberculosis, 287.1; from pneumonia,




















FIGURE 26.-Washing clothes along one of the shallow streams.
Lavando ropa en una quebrada.
187.8; and from malaria, 129.5. These five diseases accounted for
1,086.8 deaths per 100,000 out of a total death rate of 2,094.

FARM BUILDINGS
Many of the dwellings, or bohios, are small and flimsy. Some
are constructed with palms (fig. 19), either the leaves or sections of
the outer trunk, and many are built from boxes and scraps of metal

















FIGURE 27.-A hurricane shelter which could accommodate from 10 to 15 people,
and a thatch-roofed house in right background.
Una tormentera para 10 6 15 personas y una casa techada de yaguas a la derecha.







SOIL SURVEY OF PUERTO RICO 43

roofing. In general the dwelling has one or two rooms, with a lean-to
for cooking. These homes afford only the bare necessities. The more
well-to-do landowners have modern homes substantially built to with-
stand hurricanes, but at times even these are destroyed. Among the
smaller dwellings there are a few hurricane shelters (fig. 27), but ex-




























FIGURE 28.-Modern sugar central where both raw and refined sugar are manu-
factured. In the right foreground sugarcane is being loaded on oxcarts. Light
streaks in sugarcane indicate areas of soil very high in lime, which condition
causes chlorosis in the cane. Level soils are mostly Mercedita clay. Hills
in background are used only for pasture.
Moderna central azucarera donde se fabric azdicar cruda y refinada. A la
derecha se carga azdcar en carretas. Los sitios claros en la cafia indican Areas
de alto contenido en cal, lo que causa clorosis en la cafia. Los suelos llanos son
principalmente Mercedita arcilloso. Los cerros al fondo se usan solamente
para pasto.
perience has taught that their numbers are far too few to care for all
the people during a storm.
The sugar centrals have many more modern buildings and equip-
ment, the valuation of which ranges between $2,000,000 and $3,000,000
-- I




















for the larger centrals (fig. 28). They have their own stores (tiendas),
warehouses (arlac6n), and hospitals. The grapefruit growers have
warehouses (almac~n), and hospitals. The grapefruit growers have







44 U. S. DEPARTMENT OF AGRICULTURE
-U





















FIGURE 29.-Typical coffee finca. The concrete floors are glacis for drying the
coffee. Building to right is the warehouse. The plants in the foreground are
yautias.
Finea de cafe tfpica. Los pisos de concrete son glacis para secar cafe. Elalmac6n
estt a la derecha. Yautfas al frente.
















FIGURE 30.-Open-sided modern dairy barn.
Lecheria modern.
modern American homes, and many have a grading shed and possibly
a packing plant. Most of the coffee growers have two-story square
frame houses each with several additional small buildings for prepara-








SOIL SURVEY OF PUERTO RICO 45



















FIGURE 31.-Large cattle ranch in the arid southwest near Faro Cabo Rojo.
The cows are milked once a day and also suckle their calves. About 1 gallon
of milk is obtained from each cow. The feed consists entirely of guinea grass
and a few other grasses.
Rancho de ganado en el suroeste Arido de la isla, cerca del Faro Cabo Rojo. Las
vacas se ordefian una vez al dia y tambi6n alimentan sus becerros. Solamente
como 1 gal6n de leche se obtiene de cada vaca. La alimentaci6n del ganado
consiste de yerba de guinea y otras yerbas.



















FIGURE 32.-Small tobacco farm in a limestone valley south of Isabela, on Sabana
Seca sandy clay loam. Note the thatch-roofed tobacco barn and the small
house.
Pequefia finca de tabaco en un valle calizo al sur de Isabela en Sabana Seca areno-
arcilloso 16mico. N6tese el rancho para tabaco techado de yaguas y la csita.

tion of the coffee (fig. 29). Many of the dairy farmers have modern
dairy barns (fig. 30). The cattle ranches have substantial corrals but
very few buildings (fig. 31). The tobacco growers have large tobacco
barns but small houses averaging two rooms and a lean-to for cooking
(fig. 32).







46 U. S. DEPARTMENT OF AGRICULTURE

Charcoal is universally used for cooking and ironing. One seldom
sees any outbuildings around the small farm dwellings. At night
chickens and pigs stay under the houses which are elevated off the
ground (fig. 33). Very few of the jibaros have storage sheds, and
the crops grown are either consumed or sold immediately to the small
rural stores nearby, which frequently sell some of these products back
to the original seller at a later date. This does not apply to the
more enterprising farmers, such as owners of sugarcane, citrus, coffee,
or tobacco farms. Most of the commercial crops are sold a few months


















FIGURE 33.-Well-built farm dwelling elevated 1 or 2 feet from the ground for
better ventilation. At night the doors and windows are closed. Poultry and
small livestock stay under the house during rains and at night. Storage sheds
are rarely seen. The 5-gallon cans are used as water containers. The water
supply may be a mile or more away.
Casa de campo bien construida, elevada como dos pies de la tierra para mejor
ventilaci6n. De noche se sierra las puertas y ventanas. En tiempo Iluvioso
y de noche las aves de corral y otros animals pequefios duermen debajo de la
casa. Rara vez se v6 un almacen. Las latas de 5 galones se usan como recipi-
entes de agua y la fuente de abastecimiento puede estar a una milla o mas de
distancia.

after they are harvested. Some of the centrals may store a part of
their sugar in the hope of obtaining higher prices.
Most of the fences around grapefruit orchards, pineapple fields, and
pastures are good; those around sugar central holdings range from fair
to good; and those of most of the other farms are poor or lacking. The
type of fence in most common use among the small landowners is
formed by the maya, a thorny spreading plant from 3 to 4 feet tall.
Many of these plants have a spread ranging from 6 to 9 feet. They
make a very effective fence; but if allowed to grow unpruned, they
cover too much of otherwise valuable land. Boundaries between the
farms in the sugarcane, grapefruit, tobacco, and pasture lands generally
are definite and distinct, but in the coffee and forest lands they are
indefinite and hard to determine.







SOIL SURVEY OF PUERTO RICO 47

CLIMATE
Puerto Rico is less than 200 north ofthe Equator, rather small in
area, and far from any large land masses. It has, as may be expected,
a tropical, uniform, oceanic climate, and nearly ideal conditions exist
for a heavy precipitation over most of its area. The moisture-laden
northeast trade winds, over the warm waters of the ocean, blow
almost continuously during the day and strike Sierra de Luquillo at
right angles. The air is diverted upward where it expands because of
less pressure at the higher elevations and is cooled below the dew
point. Condensation then takes place, and generally it is followed by
rain. As a general rule, the higher the elevation, the less the pressure,
the cooler the atmosphere, and, therefore, the greater the precipita-
tion, to a maximum at elevations ranging from 4,500 to 6,000 feet,
but these high elevations do not occur in Puerto Rico. As the rain
clouds move southwest across the island they gradually give up their
moisture.
The highest peaks and the northern and eastern sides of the moun-
tain ranges receive the greatest rainfall; the small islands, the southern
side of the main island, the northwestern corner, the eastern shore
line, and the interior valleys receive the least. The reason for the
low rainfall on the small islands and the low eastern coast line is
because such obstacles as mountain ranges are not present to lower
the temperature of the wind as it passes. Often the weather will be
clear on the eastern coast, yet clouds will form at about 9 a. m. on
Sierra de Luquillo, from 3 to 5 miles away, and rain will fall through-
out most of the day.
The southern coast is dry for two reasons: (1) The wind usually
has given up much of its moisture before it passes the high mountain
crest and there is none to fall on the low southern side; (2)-which is
also the reason the mountain valleys near Caguas, Cayey, Adjuntas,
Rinc6n, Jayuya, and Utuado are drier than the nearby hills-after the
wind passes the high northern mountain ridges it blows down the steep
southern slopes and becomes compressed and denser at the lower
levels and so is warmed. It then can hold not only all the moisture
it has, but can take up some through evaporation. The greater the
evaporation, the drier the soil and the more sparse the vegetation.
The northwestern corner of the island is drier than the interior
because this area is to the north of the winds that have been cooled
by any of the mountain ranges or peaks and the wind is warm and
holds most of its moisture. Inland, for a mile or more, the entire
north coast is dry for the same reason.
The average annual precipitation ranges from less than 30 inches in
the southwestern part of the island to nearly 200 inches on the highest
peaks in Sierra de Luquillo. Table 3 gives the rainfall, by months,
at most of the United States Weather Bureau stations on the island.
Table 4 gives the normal monthly, seasonal, and annual temperature
and precipitation, as recorded by the Weather Bureau stations, at
Fajardo, Rfo Piedras, and Isabela along the north coast; San Lorenzo,
Aibonito, and Marica6, in the interior; and Maunabo, Ponce, and
Ensenada along the south coast. These tables show that there are
no definite seasons, but rather a rainy period from May 1 to November
1, inclusive, and a dry period the other 6 months. Throughout the
winter, however, many showers occur, but the heavy torrential rains
take place in the summer.









48 U. S. DEPARTMENT OF AGRICULTURE

TABLE 3.-Mean monthly and annual rainfall at a number of places in Puerto Rico
based on all available records (1899-1928)
SOUTH COAST AND ISLANDS



Station .



Yrs. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins. Ins.
Ensenada-.... .-----. 27 0.72 1.17 1.22 1.98 2.78 2.17 1.75 2.70 3.75 4.02 3.34 1.11 26.71
Potala --....------- 21 .86 1.27 1.04 2.21 2.65 2.10 2.42 3.79 4.61 4.88 3.42 .99 30.24
Santa Isabel..---------- 28 1.04 1.01 1.11 1.62 3.45 2.62 2.85 3.52 4.46 5.93 4.10 1.97 33.68
IsladeMona--------- 11 1.05 2.32 2.44 2.09 3.15 2.75 3.36 2.97 4.38 4.22 4.06 2.14 34.93
Ponce ------------- 28 1.01 .99 1.44 2.08 3.06 3.46 2.97 4.16 4.97 6.45 4.05 1.22 35.86
IsladeCulebra .----- 7 2.88 2.15 2.10 1.77 4.54 2.72 2.73 4.70 5.15 4.28 5.53 2.62 41.17
Aguirre ..-...------ 30 1.38 1.57 1.52 1.88 3.76 4.74 4.48 4.65 6.22 6.46 4.13 1.86 42.65
Isla de Vieques------ 30 2.95 2.53 2.21 2.68 3.53 3.96 4.24 4.55 6.12 6.26 5.77 3.35 48.15
Josefa...........--- 28 1.74 1.95 1.86 2.04 4.16 5.18 5.13 4.52 6.95 7.62 5.36 2.12 48.63
Guayama............ 18 2.11 2.37 2.04 2.17 4.34 5.11 5.19 4.52 6.91 7.23 5.52 2.46 49.97
Juana Diaz-....--- 30 1.07 1.71 2.10 3.50 4.63 4.51 3.87 6.08 7.24 8.65 5.08 1.80 50.24
Coamo...------ 8 3.43 1. 48 1.77 3.80 4.26 5.60 3.60 5.97 5.26 6.81 6.43 4.04 52.45
Pefluelas............ 21 1.58 2.69 2.04 4.19 4.90 4.15 4.82 6.10 6.99 8.56 5.85 2.07 53.94

NORTH COAST

Camuy.............. 16 4.03 2.92 3.25 3. 3. 74 2.49 3.53 3.78 4.56 4.67 6.85 4.36 47.50
Isabela-_. .---.. 30 3.43 2. 2. 58 3.53 .27 3.89 3.49 4.82 5.05 4.94 7.41 4.62 51.72
Arecibo............ 26 5.44 4.07 4.05 4.50 5.50 3.32 5.01 4.52 4.83 4.73 8.52 6.07 60.56
Barceloneta ...----. 14 5.77 4.64 3.52 3.75 5.50 3.17 5.88 4.31 5.47 5.03 8.40 5.36 60.80
SanJuan-............ 30 4.14 2.76 3.10 4.24 5.37 5.21 6.02 6.12 6.17 5.74 6.99 5.47 61.33
Cangrejo.-------.-- 8 4.67 3.78 2.39 3.98 5.83 5.59 6.47 4.54 6.34 7.28 7.86 4.99 63.72
Fajardo.----------- 30 3.50 3.01 3.11 3.71 5:40 4.96 5.88 5.54 7.30 8.34 8.64 4.86 64.25
Manati.............. 30 5.14 4.22 4.68 5.26 5.89 4.16 6.03 5.00 6.45 5.68 8.27 6.75 67.51
Dorado............... 21 5.45 4.19 3.94 4.67 5.69 4.65 6.68 5.95 6.15 5.38 8.92 6.21 67.88
RIo Piedras.... -...- 28 4.69 3.47 3.78 4.96 6.65 6.16 7.85 7.54 8.05 6.54 7.30 6.47 73.46
Bayam6n .......- 30 4.89 3.21 3.82 5.00 7.33 7.44 8.38 8.40 7.76 6.57 7.54 6.24 76.58

PROTECTED VALLEYS OF THE INTERIOR

Cayey.............. 30 3.21 2.83 2.90 3.47 4.44 5.64 6.22 6.58 6.60 6.37 6.26 4.13 58.65
Caguas....-- 30 3.86 2.44 2.97 3.84 5.03 5.92 7.10 6.43 6.90 7.32 6.37 4.79 62.97
San Getrmdn.... -- 30 1.96 2.65 3.52 6.49 5.59 4.31 5.79 7.45 7.39 9.05 6.86 3.19 64.25
Juncos...............19 3.24 2.78 2.88 3.61 5.59 5.70 7.55 7.49 8.02 8.20 7.35 3.02 65.43
CaboRojo............ 22 2.15 2.98 3.84 5.36 5.55 4.57 7.64 7.94 9.04 8.75 5.73 2.80 66.35
Jayuya ........... 20 2.25 2.20 5.53 7.26 6.38 3.95 6.02 5.89 10.37 8.10 7.02 2.45 67.42
Maunabo ......... 30 3.70 3.27 3.45 3.24 5.86 8.22 7.15 7.10 9.50 9.81 8.55 5.00 74.85
Comerfo Falls.- 22 6.63 4.53 4.85 5.78 5.70 4.52 7.91 8.29 7.69 6.70 8.57 7.11 78.28
Orocovis............. 11 5.63 3.1 5.89 4.93 9.37 4.13 7.35 4.58 8.34 '8.93 8.98 7.68 78.96
Yabucoa-...-... 24 3.98 4.04 3.04 3.73 7.10 7.08 7.75 7.55 10.24 9.82 9.20 4.92 78.45
Utuado ......... 15 3.72 1.85 3.64 6.94 8.19 7.86 6.47 7.68 12.75 10.24 7.66 3.89 80.89

INTERIOR

Oidra ......_ ----- 23 6.67 4.14 4.32 5.14 7.49 7.20 8.33 10.16 7 351 5.90 6.86 6.89 80.45
Coloso.-..-.......- 30 2.13 2.09 2.97 4.90 9.9212.20 9.37 9.99 10.30 8.32 6.79 2.60 81.58
Mayagiiez .....-....- 30 1.89 2.20 3.31 5.52 7.94 9.00 11.23 11.26 10.78 9.99 6.42 2.62 82.16
CariteCamp .......-- 18 4.79 4.94 4.73 4.70 6.57 7.55 9.63 7.61 9.12 10.38 8.17 4.71 82.90
Humacao ....-......- 30 4.08 3.48 3.56 4.54 8.54 8.62 8.36 8.54 9.92 9.90 9.03 4.92 83.49
Guajataca..-.......... 8 4.00 4.47 4.32 7.86 7.97 8.58 6.80 8.07 11.42 8.87 6.59 5.17 84.12
Aflasco ..........-... 21 1.52 2.90 2.82 5.63 8.71 10.15 11.63 12.21 11.05 10.47 6.26 2.84 86.19
Morovis.. --------. 9 5.25 3.38 6.38 5.74 8.35 5.63 6.46 11.06 8.61 10.01 8.62 7.70 87.19
Toro Negro.-..- ..... 18 3.88 4.39 4.67 8.43 9.02 6.64 7.48 7.54 13.01 14. 50 10.90 4.64 95.00
Lares-................ 24 3.26 3.60 4.39 9.1611.74 9.99 8.46 9.26 12.23 12.32 8.79 5.03 98.23
Las Marfas.---------- 17 2.75 2.61 4.72 6.49112.3710.66 9.34 12.14 13.24 12.37 8.97 3.72 99.38
San SebastiAn ...... 17 3. 64 2.45 4.94 8.24 13.29 12.47 9.58 11.01 12.59 11.91 9.01 3.96 103.09
Maricao -......---. 18 1.92 3.14 4.65 8.36 10.77 9.18 12.75 13.40 13.26 15.80 9.37 3.68106.28
Luquillo (La Perla) e 9 8.21 3.37 6.54 11.27114.94 13.75 14.56 11. 14 12.24 13.94 16.23 9.36135.55









SOIL SURVEY OF PUERTO RICO 49


TABLE 4.-Normal monthly, seasonal, and annual temperature and precipitation
at 9 Weather Bureau stations -

FAJARDO, P. R. ELEVATION 30 FEET

STemperature Precipitation


Month Total Total
amount amount
Mean Absolute Absolute Mean for the for the
maximum minimum driest wettest
year year

SF. F. o F. Inches Inches Inches
December----.... ----- 77. 5 90 60 4.88 2. 67 3.06
January ------ --------- 76.4 89 57 3. 55 3.93 1.75
February.--------------- 76.2 92 59 2.97 2.25 6.63
Winter -------------------. 76. 7 92 57 11.40 8.85 11.44
March ------------- 76.8 92 60 2.94 2.97 2.70
April ------.---.. ------------- 78.3 93 61 3.80 1.23 6.52
May -- ------------------ 80.3 93 60 6.32 2.99 9.14
Spring -------------------- 78. 5 93 60 13.06 7.19 18.36
June..-------.------------- 81.3 93 68 5.28 1.58 11.92
July..-.......---------------- 81.8 93 69 5.87 6.14 5.62
August----....------------------. 82.2 95 64 6.05 5. 40 8.81
Summer ------------------ 81.8 95 64 17.20 13.12 26. 35
September-..---------------- 81.6 96 68 7.79 3.20 14.28
October -..-.. ---------------- 80.8 98 65 8.30 10.95 12.20
November..----------.-- --- -- 79.3 93 63 8.25 3.31 15. 34
Fall.. ---------------.. 80.6 98 63 24.34 17.46 41.82
Year------------------- 79.4 98 57 66.00 146.62 297.97

RIO PIEDRAS, P. R. ELEVATION 75 FEET

December ----73.9 90 54 5.03 4.67 5.16
January.----.-----.-------------- 7 .1 89 54 4.73 10.51 7.45
February ---------------------- 73.3 91 55 3.59 5.08 1.54
Winter ---------------- 73.4 91 54 13. 3 20.26 14.15
March -- ----------------- 73.8 91 57 2.85 2.29 8.32
April...-------------------- 75. 5 92 58 6.38 .69 4.82
May ------------------- 77.7 93 62 8.87 3.96 12.20
Spring----. ------------- 75.7 93 57 18. 10 6.94 25.34
June -------- ----- 78,8 93 63 5.76 3.17 9.86
July -------------78.8- 94 63 7.08 4.04 17.38
August .------.--------- 79. 95 58 6.13 6.33 6.56
Summer ------ ------- 78 9 95 58 18.97 13. 54 33.80
September.--------------------- 79.6 /95 57 7.59 4.46 8.82
October------------------------ 78.9 95 64 6.91 4.10 11.82
November--- --------- 77.0 94 62 7.89 4.84 12.89
Fall.----..... ---------- 78.5 95 57 22.39 13.40 33.53
Year-------------------- 76.6 95 54 72.81 3 54.14 106.82

ISABELA, P. R. ELEVATION- 275 FEET

December --------------------- 76.2 94 57 4.61 5. 10 6.41
January ------------- 75. 1 92 58 3.34 4.30 6.70
February ---------------------- 74.8 94 59 2.81 1.10 .29
Winter---------------- 75.3 94 57 10.76 10.50 13.40
March------------------------- 75.7 94 59 2.87 1.50 2.64
April -...... ------------.--- 77.0 96 60 3.36 3.00 4.70
May------------- 78.5 97 62 6.40 1.95 15.89
Spring-------------------- 77.1 97 59 12.63 6.45 23.23

See footnotes at end of table.
144038-41----4










50 U. S. DEPARTMENT OF AGRICULTURE

TABLE 4.-Normal monthly, seasonal, and annual temperature and precipitation
/ at 9 Weather Bureau stations-Continued
ISABELA, P. R. ELEVATION 275 FEET-Continued

Temperature Precipitation


Month Total Total
amount amount
Mean Absolute Absolute Mean for the for the
maximum minimum driest wettest
year year

SF. o F. F. Inches Inches Inche
June-................- ............ 79.6 98 63 4.78 .85 5.67
July......-----------------------..80.4 96 65 3.97 3.30 11.87
August...------.--..--------..------- 80.5 99 65 5.15 1.90 9.17
Summer ...-- --...-------- 80.2 99 63 13.90 6.05 26.71
September .----.-----.--------- 80.3 99 63 5.60 3.00 16.80
October.-------------.. -------.-- 79.7 97 60 5.42 6.80 7.14
November..-----.------------.. -- 78.4 96 60 7.02 3.10 6.22
Fall...---------------------- 79.5 99 60 18.04 12.90 30.16
Year.---....-----.--------. 78.0 99 57 55.33 3 35.90 6 93.50

SAN LORENZO (VALDES FARM), P. R. ELEVATION 203 FEET

December _-----------.-------. 74.6 92 53 4.95 0.95 3.29
January 72.9 90 54 3.51 2.70 2.45
February-- -------------- -- 72.9 92 53 2.39 2.75 4.88
Winter -------------- 73.5 92 53 10.85 6.40 10.62
March-.--.--.-------------------. 73.6 93 53 3.14 2.48 2.74
April.-------.. ----- 76. 2 93 57 3.43 2.06 11.25
May -------------------------- 78.0 95 53 9.23 3.89 17.77
Spring ----------- 75.9 95 53 15.80 8.43 31.76
June.---.....-- ---.......-------.. 78.8 94 60 6.55 2.66 10.23
July ..-..-------.. ---- --..--- -.. 78.8 94 64 6.76 9.78 9.10
August .....--------.------..- 79.4 103 63 7.56 6.00 4.81
Summer ------------------- 79.0 103 60 20.87 18.44 24.14
September..---------.. L-------- 79.0 101 60 10.00 6.47 20.97
October-...-.....- ------.-----. 78.1 96 60 8.06 5.28 15.27
November---..--....-----.------ 76. 3 97 58 7.93 3.08 18.97
Fall--....--- -------.-------- 77.8 101 58 25.99 14.83 55.21
Year-.......-----.------- 76. 6 103 53 73.51 48.10 2 121.73

AIBONITO, P. R. ELEVATION 2,000 FEET

December--..------ 69.4 85 49 4.44 2.40 2.64
January-- ------------- 67.9 89 43 3.74 3.65 5.51
February------------------------ 67.8 88 43 3.13 1.05 2.21
Winter-----------.-------- 68.4 89 43 11.31 7.10 10.36
March .-------.---- .-------- 68.6 89 40 3.45 2.95 1.95
April .. ---------.. ------------ 69. 9 88 45 3.82 2.95 3.45
May ......-----------------.- 71.9 92 48 6.00 5.15 6.10
Spring-------------------- 70.1 92 40 13.27 11.05 11.50
June........-------------. --- 73.4 90 49 4.16 1.05 3.72
July..------------------------ 74.4 90 52 5.21 2.40 16.62
August---.......-------.-------- 74.8 90 52 6.10 2.47 15.47
Summer ------------------- 74. 2 90 49 15.47 5.92 35.81
September-------------------- 74.1 90 51 6.54 5.20 8.34
October.......--.---...--- ---- 73.2 92 50 7.53 3.09 19.43
November....-------.---. ----. 71,6 91 50 6.43 4.05 8.18
Fall --...---... .----------. 73.0 92 50 20.50 12.34 35.95

Year ....---..... ---------- 71.4 92 40 60. 55 36.41 893.62

See footnotes at end of table.









SOIL SURVEY OF PUERTO RICO 51


TABLE 4.--N rmal monthly, seasonal, and annual temperature and precipitation
at 9 Weather Bureau stations;-Continued
MARICAO, ELEVATION 1,500 FEET

Temperature Precipitation


Month Total Total
amount amount
Mean Absolute Absolute Mean for the for the
Meanmaximum minimum
maximum minun driest wettest
year year

SF. F. O F. Inches Inches Inches
December--....----. ------..... 70.9 89 50 3.72 3.05 1.60
January.----------- -------. 70.1 88 50 2.20 2.30 2.80
February--...-----------------... 69.7 90 48 3.02 .40 1.75
Winter....----------------- 70.2 90 48 8.94 5.75 6.15
March -- .. .- ------------- 69.9 92 48 5.05 1.78 15.65
April ------ 71.1 90 50 8.10 5.40 10.65
May ...--.. -------.-.-------- --- 72.1 93 60 12.18 9.50 13.80
Spring -------------- 71.0 93 48 25.33 16.68 40.10
June-------------.--- 73.3 95 54 8.11 12.40 9.50
July.----------- 74.0 92 55 11.70 8.52 19.95
August ..----------------------- 74.7 92 55 14.62 8.38 16.45
Summer ------------------ 74.0 95 54 34.43 29.30 45.90
September------ -------------- 73.4 90 55 15.93 10.28 8.45
October ...-------.. -------- 72.7 90 50 15.32 13.74 28.85
November ------------------ 72.1 90 50 8.77 5.27 11.15
Fall.---------------------- 72.7 90 50 40.02 29.29 48.45
Year------------------ 72.0 95 48 108.72 781.02 4140.60

MAUNABO, ELEVATION 50 FEET

December..---------------------- 78.0 93 61 5.48 2.30 8.47
January ----- ------------- 76.3 90 59 4.53 8.14 1.60
February -----.-------------._ 76.7 93 58 3.33 3.89 2.62
Winter --------------.----- 77. 93 58 13.34 14.33 12.69
March -.....----------.-- ---.- 77.0 93 57 3.26 1.10 .70
April ..------------------------ 78.8 94 61 3.29 .60 5.50
May .-..------..----- --------- .79.8 95 62 7.27 3.39 13.93
Spring ..-------------.--.- 78.5 95 57 13.82 5.09 20.13
June......------------------------- 81.1 96 62 8.31 4.68 17.70
July.-..---.......------------..82.2 95 68 7.35 4.15 9.55
August-..----.. ...--- --------- 82.7 96 62 7.56 4.60 14.90
Summer .....------------- 82.0 96 62 23.22 13.43 42.15
September-....------------------ 81.8 95 66 9.58 3.82 13.95
October ..---------------------- 81.1 96 65 9.86 10.75 15.15
November------. --.---------.. 79.6 94 61 8.31 5.20 9.55
Fall--------------------- 80.8 96 61 27.75 19.77 38.65
Year..------..... ---------. 79.6 96 57 78.13 52.62 2113.62


See footnotes at end of table.










52 U. S. DEPARTMENT OF AGRICULTURE


TABLE 4.-Normal monthly, seasonal, and annual temperature and precipitation
at 9 Weather Bureau stations-Continued

PONCE, ELEVATION 80 FEET

Temperature Precipitation


Month Total totall
Mean Abolt Ab t amount amount
Mean Absolute Aolute Mean for the for the
maximum minimum driest wettest
year year

F o F. o F. Inches Inches Inches
December-.......---.--..--..... 77.0 91 57 1.17 0.97 0.10
January .---.---... -----..... ... 75.4 90 57 1.05 .05 1.34
February......------------------ 75.4 90 55 1.23 .56 .86

Winter--~.-..-- .......---- 75.9 91 55 3.45 1.58 2.30
March.-----...-.---..--------.--- 76.0 91 58 1.29 .54 .45
April -----..------------------ 77.4 93 59 1.87 1.67 2.62
May---------------....... -------- 79.5 95 61 3.62 2.03 3.69

Spring -----------....--- 77.6 95 58 6.78 4.24 6.76
June-------------.--------------. 80.7 96 58 3.60 .89 7.74
July.---......----- ------. .. ----- 81.0 95 58 2.73 .20 3.14
August-...-.------------..------- 81.6 96 64 4.20 2.52 17.20
Summer ......----------..- 81.1 96 58 10.53 3.61 28.08

September...-------------------. 81.3 98 68 5.14 7.75 3.19
October ------------.. --...------ 80.5 95 61 5.70 1.74 8.20
November ..-----.--------------. 79.0 94 60 3.84 .87 10.20
Fall-----.. --..------- ----- 80.3 98 60 14. 68 10.36 21.59

Year---.------. .-----...... 78.7 98 55 35.44 10 19.79 1 58.73

ENSENADA, ELEVATION 50 FEET

December ------------ 75.4 95 51 1.27 0.53 3.85
January -------------------- 74.3 95 53 .84 .10 2.10
February----- -------- ------... 74.3 92 51 1.49 .18 .80

Winter.----.---------.----. 74.7 95 51 3.60 .81 6.75
March ..-- .---------.---.----- 75.1 100 52 1.43 .54 2.25
April.....------__---------------- 76.2 100 56 1.82 .93 .00
May ....--- ---------.......- 77.5 94 58 3.41 .32 7.70

Spring----------------- 76.3 100 52 6.66 1.79 9.95
-- -- --
June..-----------.. --------.----. 79.0 99 58 2.40 2.00 3. 0
July-.-------------------- 79.3 95 60 1.71 .06 .70
August..------------..--------- -- 79.6 98 60 3.01 .82 3.30
Summer--- ------ -- 79 3 99 58 7.12 2.88 7.90
September.---.-----. --- .------ 79.7 98 56 4.37 1.29 10.80
October-.------- --------- 78.6 97 59 3.94 3.27 9.72
November---------------------- 77.1 96 58 3.66 1.30 7.95
Fall---. -- --- ----78.5 98 56 11.97 5.86 28.47

Year .-----.------.------ 77.2 100 51 29.35 1211.34 1353.07

I For 1926. 6 For 1932. 0o For 1929.
2 For 1931. 7 For 1913. 11 For 1909.
3 For 1920. 8 For 1916, 12 For 1922.
4 For 1927. For 1930. 13 For 1933.
5 For 1923.






SOIL SURVEY OF PUERTO RICO 53

A rainfall of 30 inches in Puerto Rico is equivalent in effectiveness
to about 15 inches in the United States. The high evaporation com-
bined with high temperatures, low relative humidity, and constant
winds tends to cause semiarid conditions even where the average
annual rainfall is 45 inches. In San Juan the evaporation from a
free water surface exceeds the precipitation, but in the moist moun-
tain districts the precipitation probably far exceeds the evaporation.
The evaporation' is much higher in comparison to the rainfall during
the dry winter than at other seasons, and, as crops grow throughout
the year, irrigation is sometimes necessary even in areas having an
average annual rainfall of 65 inches. Some of the soils, because of'
their permeable physical characteristics, require water at frequent
intervals in order to insure maximum crop production. This is
especially true with the red soils derived from limestone, which occur
from Bayam6n to Aguadilla. Extensive irrigation systems are in
operation in most cultivated areas having less than 50 inches of rain-
fall, and some pumping plants have been installed for the irrigation
of sugarcane and grapefruit in areas receiving an average annual
rainfall of 68 inches.
The temperature, although tropical, is cooled during the day by
the moisture-laden trade winds and at night by the land breezes that
blow from the cool mountains to the coast. Mean monthly tempera-
tures along the warmer dry coast towns range from about 750 F. in
the winter to about 800 during the summer. Throughout the. year
the moist mountain'areas are about 50 cooler than those along the
coast. Extremes of temperature within 24 hours are very rare,
except during hurricanes. The temperature seldom rises higher than
900, and even in the highest, coolest parts of the island it seldom falls
below 500; at least there are no records of very low temperature.
Fire is not needed in any of the homes, except for cooking and ironing.
Frost is unknown, and rarely does one hear of sunstroke. Dense fogs
occur only in the mountain valleys and on peaks.
The mild uniform temperature, low relative humidity combined
with invigorating breezes, and the mountainous character of most of
the island make it a very agreeable place in which to live. Sunshine
occurs daily over most of the island, with the exception of a few days
each year, and the ultraviolet rays of the Tropics are beneficial to
'plants, animals, and mankind. The high precipitation, however, has
caused destructive leaching in many soils, and they are acid, low in
bases, and lacking in plant nutrients. The plants produced from the
leached soils do not seem to be so nutritious as those grown on neutral
.or alkaline soils high in bases.
The climate (45, pp. 4-12) is nearly ideal for a 12-month growing
period for such tropical crops as coffee, sugarcane, pineapples, bananas,
mangoes, coconuts, yautia, and yuca, but it is not so good for alfalfa
and berries. Such crops as wheat, oats, barley, apples, and peaches
are not grown. The imported dairy cattle, hogs, goats, and chickens
suffer somewhat because of the climate, but oxen, horses, and mules
seem to thrive. Sheep and beef cattle do much better in cooler
climates. The climate has had very little direct effect on the dis-
tribution of most of the livestock and poultry, except turkeys which
are much more prevalent in the dry hot areas than in the moist
districts, because the drier areas are less favorable for the many
harmful diseases that beset turkeys.







54 U. S. DEPARTMENT OF AGRICULTURE

During the progress of the soil survey a rainfall map (fig. 34) of the
island was compiled from rainfall data furnished by the United States
Weather Bureau, owners of sugar centrals, and other landowners, as
well as from information obtained from the correlation that exists
between soil climate and the following: Plant species, growth of vege-
tation, soil erosion, soil color, soil development, elevation, and, to
some extent, rural population.
There is very little noticeable correlation between the temperature
and plant species, because there is only about 10' or 15 F. difference,
for any length of time, between the coolest and warmest parts of the
island. Such plants as wild raspberries, many kinds of flowers, and
coffee grow better and produce higher yields in the cool mountains
than on the warm coastal plain, but they are not limited to the cool
mountains. Some of the mosses and vegetation on the highest peaks
probably are restricted to the cool districts, but they are of minor
importance. The quantity of rainfall, however, is the limiting factor
for the distribution of many plant species. The sudden change in
amount of precipitation is reflected so much in the native vegetation,
that within a distance of a very few miles and a descent of a few hun-
dred feet, one may pass from a luxuriant tropical rain forest to a shrub-
covered desert.
The correlation that exists between plants and rainfall is in reality
the relationship between plants and soil moisture, as is shown by the
royal palms, which seldom grow on steep hillsides if the annual rainfall
is less than 60 inches; but they will grow on level land if the annual
rainfall is 50 or more inches; and they grow along drainageways if the
annual rainfall is greater than 35 inches. Cacti and many of the
thorny plants are confined mostly to sections having less than 40 inches
of annual rainfall, but they grow abundantly in areas of higher rain-
fall if the soil is very permeable, drought, and the relief steep, for
instance, on some of the Rosario soils which are derived from serpen-
tine and occur northwest of Yauco in a belt where the annual rainfall
is more than 65 inches. The drought-resistant guinea grass grows
abundantly in the valleys, but it ceases to grow on the adjacent hill-
sides having an annual rainfall of less than 30 inches, unless it has ex-
ceptionally good care. Coconuts will grow along the low coast regard-
less of the low rainfall, but they do not thrive on the hillsides unless
the annual rainfall is greater than 40 inches. The hlfcar, or icar,
trees thrive either on hills or level land if the annual rainfall is 45 inches
or less. The almAcigo, tamarindo, algarrobo, and jagiiey are con-
spicuous in almost all areas having an annual rainfall of 60 inches or
less. This is also about the rainfall limit of barrilla and horquetilla
grasses. The treeferns do not seem to grow in areas having less than
80 inches of annual rainfall, and generally with that rainfall they grow
in the concave drainageways. The sierra palms are seldom con-
spicuous unless the annual rainfall is 100 or more inches. The char-
acteristic moss vegetation of high peaks of Sierra de Luquillo requires
more than 150 inches of rainfall annually.
Plant growth also is correlated with soil moisture. Sugarcane
generally will be a failure when planted on steep hillsides, level sandy
soils, or very impervious soils, in areas having less than 60 inches of
annual rainfall. Low yields of sugarcane may be expected on level
alluvial land in areas having less than 40 inches of annual rainfall,
unless the land is irrigated. The valley south of Lajas, which has




























6 -o 4 -





0


FIGURE 34.-Rainfall map of Puerto Rico, compiled from data furnished by the United States Weather Bureau, owners of sugar centrals,
and other landowners, and from information obtained from the correlation that exists between soil climate and the following: Plant
species, growth of vegetation, soil erosion, soil color, soil development, elevation, and, to some extent, rural population.
Mapa de precipitaci6n pluvial de P. R. compilado de los datos suplidos por el Negociado del Tiempo de los EE. UU., las centrales y
otros agricultores, tambien de informaci6n obtenida de la correlaci6n que existe entire el clima del suelo y lo siguiente: species de
plants, vegetaci6n, erosi6n, color del suelo, desarrollo del mismo. elevaci6n, y hasta cierto punto, poblaci6n rural.



<^r






56 U. S. DEPARTMENT OF AGRICULTURE

an average annual rainfall of 45 inches, produces fair yields of sugar-
cane on the low level lands, but the adjacent hills to the south will
produce only such crops as corn, beans, grass, and pasture, which
require less water. In the eastern part of the island, near Ensenada
Honda de Fajardo, where the annual rainfall is about 60 inches, much
of the sugarcane planted on the hillside will be a failure, unless the
rainfall is above the average; but sugarcane generally will range from
fair to good on the adjacent level alluvial lands, where the sugarcane
roots can penetrate deeply and obtain a much greater supply of
moisture than on hillsides.
The amount of rainfall varies greatly within short distances, espe-
cially in sections having mountain barriers and where the mean annual
precipitation is less than 70 inches. The north side of a high or
medium-high east-west ridge may receive 10 inches more rainfall
annually than the south side. In many areas receiving annually from
50 to 60 inches of rainfall, the north side of a hill will be cultivated to
corn, beans, tobacco, and gandules, or pigeonpeas, and the south side
will be in pasture. It is of the utmost importance for the agriculturist
as well as for money-lending agencies to know as nearly as possible
the boundaries of the areas receiving less than 60 inches of rain annu-
ally, as this is more or less the critical moisture zone. The success or
failure of many hundreds of people depends on whether or not they
attempt hillside farming in areas having less or more than 60 inches
of annual precipitation. A person may be deceived greatly by the
general appearance of the drier country, if he visits it during the rainy
season.
It is noticed that in sections having from 50 to 60 inches of annual
rainfall, there is more serious soil erosion than in any other part of
Puerto Rico. (See fig. 23, p. 36.) There may not be so much erosion
within this area as in more mountainous areas, but the harm resulting
from erosion is more lasting. Erosion is more serious within this belt
than elsewhere mainly because the rainfall is sufficient to encourage
hillside farming by small farm owners who plant clean-cultivated crops,
such as beans, corn, tobacco, and pigeonpeas, yet not sufficient for
plants to make a quick dense growth as in more moist areas. One of
the main reasons that soil erosion is not more destructive on the steep
hillside farms in the areas of high rainfall is because vegetation grows
so quickly and densely that the force of the water is checked and the
soil granules are bound together by the plant roots. The areas
receiving less than 50 inches of rainfall annually support a sparse
growth of vegetation, but the farmers do not attempt to cultivate the
steeper slopes nor do they overgraze their pastures to such an extent
as do farmers in the areas of slightly more rainfall. Erosion in the
dry areas is due mostly to sudden, intense showers that fall at the
termination of long dry periods, when the grass is short, or sparse, and
much of the ground is exposed. Within a week's time after the spring
rains start, however, the grass reestablishes itself so that destruction
from rains during the rest of the rainy season is greatly reduced.
Very few data are obtainable on the intensity of the rains in different
parts of Puerto Rico. The intensity of rainfall and wind as recorded
by the Weather Bureau station at San Juan is presented in tables 5
and 6. These tables show that the greatest amount of rain falling
in 24 hours was 10.55 inches and the heaviest downpour in 2 hours
was 4.67 inches. This high intensity of rainfall is one of the serious








SOIL SURVEY OF PUERTO RICO 57

factors in causing soil erosion on the sloping lands. The intensity of
rainfall is greater in some other, cities than at San Juan.

TABLE 5.-Extremes of precipitation and wind at San Juan (1899-1935)

Precipitation Wind
*Month Greatest
Date Year in 24 Date Year Direction vHigest
hours velocity 1

Miles
Inches per hour
January...........----- 3 1934 4. 52 21 1921 Northeast---..-------..- 43
February.......----.. 23-24 1918 ,4. 84 6 1931 North-.-------------. 40
March---...........-- .. -- 1927 3.64 12 1921 East~--------.-----~ 38
April -----..-------.- 7-8 .1915 6.72 10 1915 .....do.....---------------- 35
May-----------..... 1-2 1902 4.81 6 1928 Northeast--------.. ---- 34
June....-----..---------.... 11-12 1919 5. 26 16 1908 Southeast...-------------- 40
July--.......... -------- 6-7 1901 4.05 23 ,1926 East .---- -------------. 51
August -......------ 8-9 1899 6.26 .22 1916 Northeast.-------------. 70
September..---------- 13-14 1928 8.50 13 1928 -- do-------------- 2149
October.-------------- 30-31 1927 3.87 9 1916 North ...--------------- 41
November...------------ 11-12 1931 8.06 28 1917 Northeast..------------. 40
December------------. 13-14 1910 10.55 3 4 1934 ---do --..--.. --------. 40

1 Corrected to true velocity. 8 Also in 1935, March 10, from the northeast.
2 Estimated. 4 Also in 1935. December 7, from the northeast.
TABLE 6.-Excessive precipitation at San Juan, 1899-1935
[Maximum amounts for short periods]

Dpurmationuo n- Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Mm-
pour (minutes) mum

In. In. In. In. In. In. In. ,In. In. In. In. In. In.
5 ..------------- 0.48 0.45 0.56 0.58 0.79 0.50 0.44 0.57 0.56 0.48 0.44 0.60 0.79
10...------...----- .88 .83 .98 1.01 1.02 .76 .72 .89 .91 .80 .82 .89 1.02
15..-------------- 1.17 1.10 1.20 1.32 1.08 1.05 .96 1.28 1.31 1.05 1.19 1.19 1.32
30.--------------. 1.77 1.26 1.50 2.06 1.80 1.62 1.60 2.16 2.09 2.00 2.23 1.47 2.23
60----....---------. 3.19 2.00 1.55 2.46 3.03 2.13 2.10 3.18 3.43 3.01 3.48 2.67 3.48
120..------------- 4.26 2.35, 1.79 3.57 3.46 2.98 2.60 3.58 4.21 3.30 4.67 3.55 4.67


The correlation between soil climate and soil color and development
is very obvious. In the driest part of the island, or the part receiving
less than 25 inches of annual rainfall, the mature soils are brown, and
they would be classified with the Brown soil group in the United States.
The areas receiving from 25 to 35 inches of annual rainfall have chest-
nut-colored soils and are classified as Chestnut or Reddish Chestnut
soils. The soils in a moister belt are very dark grayish brown and
are classified with the Chernozem. This area has an annual rainfall
ranging from 35 to 45 inches. Within the areas having an annual
rainfall ranging from 45 to 60 inches, the soils having nearly black
surface soils are classified as Prairie or Reddish Prairie soils. Most of
the nearly level soils occurring within the area having an annual
rainfall ranging from 60 to 75 inches have grayish-brown surface soils
and leached layers above the subsoil. These soils are classified as
podzolic soils. Most of the soils occurring on the level or undulating
areas having an annual rainfall ranging from 75 to 90 inches are red
and deep, and are classified as lateritic, but the soils on the slopes are
shallow and brown. The soils in belts where the annual rainfall
ranges from 90 to 110 inches are deep and red, even on 80-percent
slopes, and are considered lateritic. In areas where the annual rain-
fall exceeds 110 inches, the surface soil has a gray cast, and the color







58 U. S. DEPARTMENT OF AGRICULTURE

is similar to that of Podzol soils. Soils produced from limestone or
rocks high in bases may be exceptions to the above; for example, the
soils north of San Sebastian and Lares are nearly black, although the
annual rainfall is nearly 100 inches. These soils are derived from a
medium soft limestone and are classified as Rendzina. In the extreme
northwestern and the southwestern parts of the island, the average
annual rainfall is 50 and 30 inches, respectively, but the soils are red
because they are derived from rather hard limestone.
In most areas a correlation exists between the rainfall and the acid-
ity of the soils. If the average annual rainfall is below 40 inches the
soils are strongly alkaline, they generally effervesce at the surface
when treated with dilute hydrochloric acid, and they have a pH value
of 8 or more. Within this rainfall limitation are most of the "black
alkali" areas. This rainfall belt, as shown on the map, includes only
a small percentage of the island. Most of the soils receiving from 40
to 50 inches of rainfall annually range from neutral to alkaline in the
surface soil and have free lime in the subsoil. Most soils having from
50 to 60 inches of annual rainfall are neutral or slightly acid in the sur-
face soil and slightly alkaline in the subsoil. Most of the soils receiv-
ing from 60 to 70 inches of rainfall annually are acid in the surface soil
and neutral in the subsoil. In most areas receiving more than 70
inches of annual rainfall the soils are acid in both the surface soil and
subsoil. In most places the more poorly drained soils are the most
alkaline, as the calcium carbonate does not leach readily under satur-
ated soil conditions. Muck and peat soils are exceptions, as they are
generally strongly acid. In some places in the arid districts, the soils
are acid because they are derived from exceptionally acidic rocks and
are low in soluble bases; for example, the soil mapped as Mariana clay
loam near Lajas. Other soils are acid in dry areas because they are
very old and probably were leached of their carbonate under a more
moist climate than now exists. In general, soils derived from soft
limestone will be alkaline even if the annual rainfall is more than 100
inches, but if the limestone is very hard and weathers slowly the soil
might be acid if the annual rainfall ranges from 40 to 50 inches.
There is no uniform correlation between elevation and rainfall, but
throughout the island the heaviest precipitation occurs on the high
peaks. Southward from the east-west mountain ranges, the rainfall
decreases with decreasing elevation, but on the north, east, and west
sides the total amount of precipitation at the same elevation varies.
Climate, especially the two extremesYof rainfall, seems to be a
factor in the distribution of rural population. In the arid islands and
along the southern coast of the mainland, few crops, except the
drought-resistant grasses, can be grown without irrigation. Such
areas that are not irrigated are sparsely populated, because only a few
people to the square mile can obtain a living. Subsistence crops are
not grown successfully in the areas of high rainfall, which occur in
the rough, rugged, fog-swept mountains at an elevation above 2,000
feet. Therefore, such areas are sparsely populated. The rural popu-
lation is most dense in those municipalities that have the average
climate, combined with soils, such as those of the Micara and
Catafio series, that are better adapted to subsistence crops than to
other crops.
Climate probably has had some effect on the distribution of the
races. On the hot sandy coast the proportion of Negroes is much







SOIL SURVEY OF PUERTO RICO 59

higher than that of whites, but in the cool high mountains there are
very few Negroes.
Puerto Rico is in the region of the eastern Caribbean Sea where
tropical cyclones take place, and these storms are dreaded from one
season to the next. Between 1825 and 1935, 22 hurricanes caused
great destruction on the island. The hurricanes generally occur be-
tween August and October, and the more severe ones have caused
nearly $50,000,000 worth of damage and the loss of nearly 3,000 lives.
The wind velocity may be moretthan 120 miles an hour, and the rain-
fall may exceed 20 inches for a 24-hour period. Some of the most
destructive storms were: San Narciso, in 1867; San Ciriaco, in August
1899; San Felipe, in September 1928; and San Ciprian, in 1932.14
The crops most affected by storms are coffee, grapefruit, and sugar-
cane. The coffee growers suffer the greatest loss, as it requires 6 or 7
years after the shade trees have been destroyed before the coffee trees
become profitably productive again. The loss of several successive
crops, as well as the expense of planting new shade and coffee trees, is
extremely heavy on the one-crop coffee grower. The grapefruit grow-
ers may lose 80 percent or more of their year's crop and possibly from
10 to 20 percent of their trees, but the next year the crop may be as
large as the average. The sugar centrals undergo heavy losses of
buildings, machinery, and railroads, in addition to the loss in sugarcane
yields and to the low sucrose content of the cane, caused by the rapid
growth of suckers as soon as the cane is blown over by the wind. After
a storm the sugarcane is much harder to cut, as it is usually in a tangled
mass.
In addition to the damage to property, loss of life, and loss in crop
yields, the torrential rains occurring during and following the hurri-
canes do unestimable damage in washing the soil from the hills and
either depositing it on alluvial flats or carrying it far out into the sea.
Floods cause considerable damage to property, crops, and human life.
Occasionally parts of the islands are affected by earthquakes.

AGRICULTURE

Puerto Rico always has been and probably always will be an agri-
cultural island. When Columbus landed there nearly 450 years ago,
some of the native Indians were gardeners and produced root crops to
be used for a part of their diet. Today more than 50 percent of the
farms are less than 9 acres each in area and are made up of small
garden patches. The majority of the people have been gardeners for
a long time, and, doubtless, with the rapidly increasing population, a
much larger proportion of them will obtain a part of their living in
the future by growing subsistence crops. For several hundred years
the principal crops grown by the jibaro farmers or gardeners have
been bananas, corn, sweetpotatoes, beans, yautia, pigeonpeas, yuca,
and flames. These subsistence crops are relished by all the native
people and, supplemented with rice, fish, and coffee, constitute the
main diet of the masses.
Although these crops are of vital importance to many thousands of
people, the commercial prosperity of the island depends on the pro-
duction and selling price of three main cash crops-sugarcane, tobacco,
and coffee. These crops have been grown for many years, mostly by
14 It is customary to name the hurricanes after a saint whose birthday is nearest to the day of the storm.








60 U. S. DEPARTMENT OF AGRICULTURE

farmers owning large tracts of land. Table 7 gives the acreage of
the principal crops grown, and figure 35 shows the types of farming
practiced throughout the island.

TABLE 7.-Acreage of the principal crops grown in Puerto Rico, in stated years

Crop 1899 1 19031 19092 1901 2 1929 2 19353

Acres Acres r Acres Acres Acres Acres
Sugarcane .------------------- 72, 146 112,416 145,433 227,815 237,758 245, 154
Coffee---------------------- 197, 031 177,754 186,875 193,561 191,712 182,316
Bananas ---69, 380 _-......- ----- 4 52,206 4128,339 61,786
Corn------------------- 18,093 --....---- 56,640 58,785 70, 217 49.820
Tobacco----------------- 5,963 18,414 22,142 39,068 52,947 45,720
Sweetpotatoes ------------ 37,109 -.--. ---- -- -------. 31,457 47,616 36,947
Beans ..---.--.------------------- ------ 20, 652 34,907 40,902 31,470
Yautia ..------. .. 12, 256 -.. --- .. 16,683 17,596
Coconuts -----------5,447 2,931 17,555 526,307 530,357 23,227
Pigeonpeas --- --- --------15,954
Grapefruit --- ----------------------- ---- --- -63,379 4,763 9,485 6 11,429
Rice--- ---------------- 8,667 ------------ 16,138 11,749 5,244 9,386
Names -------------- 2,098 ------------ -.-------- --------- 5, 186 7,966
Plantains- ...... --------- ------ ----- ----6,449 47,729 4 7,436
Yuca ... ..- ----- ------- ----------- -------- --- ---------. 6,072 6,846
Cowpeas---- .------- --------- ------------ ------- 3,379
Vegetables --------- -- -------- ------------ ----------- ------------ 11,962 3,616
Pineapples -------- ------------ --------- 2,530 7946 1,827 7 1,487
Cotton ------------- ------- ---------- 1,425 2,760 10,282 934
Minor crops ------- -------- 49,836 8201,036 ------------ ----

I See (46, p. 17).
2 Federal census.
3 From Puerto Rico Reconstruction Administration special census (34).
4 Calculated on the basis of 625 plants to the acre. Many acres of these crops are interplanted with coffee.
The same is true of oranges, which have not been included in this table.
5 Calculated on the basis of 30 trees to the acre.
SCalculated on the basis of 70 trees to the acre.
7 Calculated on the basis of 10,000 plants to the acre.
8 The minor crops have not been separated.

Sugarcane was introduced 25 years after Columbus landed, and coffee
plants were taken to the island about two centuries later. Tobacco
has been grown for a long time but was not grown on a commercial
scale until about 1880. The raising of cattle was an important enter-
prise during the early days. Pineapples and grapefruit were of little
importance until occupation by the Americans. During the last 200
years there have been many fluctuations, both in the acreage and in
the importance of the different crops, which will be fully discussed,
crop by crop, in the latter part of this section.
The history of early land tenure in Puerto Rico, as in nearly all
newly settled countries, is vague. Undoubtedly the island once was
covered with dense forests which varied in density and in the size of
trees from place to place according to the climate and soil. The clear-
ing of the forests by Indians, in preparation of the land for their root
crops, was confined mostly, but not entirely, to the land along the
coast. The more peaceful Arawak Indians seldom dared cultivate
land in full view from the sea, but confined their farming to concealed
places along inland valleys and along the river flood plains a short
distance from the coast. The early Spanish settlers practiced agri-
culture only on the coastal lowlands and river flood plains near the
small settlements. Later, most of the land held by the Spaniards
was in large grants, many of which included the good level alluvial
lands that were soon planted to sugarcane. Now, with few excep-
tions, cane occupies all the best soils. Coffee and tobacco were
planted on the steeper, more acid, and less fertile land.



























2










93
8 I








0


FIGURE 35.-Map of Puerto Rico, showing the different types of farming: 1, Coconuts; 2, sugarcane; 3, pasture and some subsistence crops;
trees and some subsistence crops; 5, pineapples; 6, tobacco; 7, grapefruit; 8, subsistence crops; and 9, coffee.
Mapa de los siguientes cultivos en Puerto Rico: 1, Cocos; 2, cafia de azdcar; 3 pastos y algunos cultivos de subsistencia; 4 arboles y
algunos cultivos de subsistencia; 5, pifias; 6, tabaco; 7, toronjas: 8, cultivos de subsistencia; y 9, caf6.
CTS







62 U. S. DEPARTMENT OF AGRICULTURE




















































FIGURE 36.-See legend on page 63.







SOIL SURVEY OF PUERTO RICO 63

Within the last 30 years most of the sugarcane estates and haciendas
have been enlarged, and now many are owned by sugar centrals, many
of which control from 1,000 to 10,000 acres. The best and most pro-
ductive lands, therefore, are under the control of a comparatively few
individuals or corporations. These lands, however, are efficiently and
scientifically managed and now produce much higher yields than they
did when they were held in small holdings and managed by the owners.
The coffee fincas always have been in large tracts, compared with
the size of the minor truck farms. The tobacco farms range from very
small to rather large. Tobacco is mostly grown by small farmers; 80
percent have less than 3 acres. From the beginning, the livestock
ranches have included large tracts and probably will continue to do so.
Owing to irrigation projects on the south coast, many large cattle
ranches have been converted into checkerboard-patterned fields occu-
pied exclusively by sugarcane (fig. 36). The average size of the com-
mercial pineapple and grapefruit farms is about 200 and 100 acres,
respectively, and their size has changed but little since they were
started about 30 years ago. Many small farms have a few acres in
pineapples or grapefruit.
The minor truck farms or gardens have changed considerably since
the early days. At one time the most common practice of the jibaros
was to cut the virgin trees, probably sell some timber but burn most of
the limbs and branches on the land, then plant subsistence crops.
This practice prevailed not only in the mountains but also on the
better lands. In the olden times the jibaros had as large an acreage
as they cared to cultivate even on the good alluvial lands. Later,
when land became more valuable and sugarcane more important, the
owners of the haciendas bought almost all of the level alluvial land,
and the owners of the small tracts had to work for wages or buy other
places on less desirable land. The owners of the haciendas, however,
allowed the peon helper to have a small garden on the rich alluvial
land. Gradually the alluvial land became too valuable for the produc-
tion of subsistence crops, and the population increased so rapidly that
the jibaros were crowded farther and farther into the steep mountain-
ous country. As the jibaro family increased and married, the farm
was divided and a part given to the sons or the farm products were
shared with all members of the family.
At present these small gardeners live on steep hills where the soi
is shallow or on very sandy level areas near the coast. In both situa-
tions the soils are poorly adapted for any of the' main commercial
crops, but, fortunately for the jibaro, they are fairly well adapted to
subsistence crops. The hill land is steep, and, owing to much erosion,
which is accelerated when clean-cultivated crops are planted, the
surface soil becomes thin or is entirely washed away, but, as the sub-
soil and parent rock are soft and fairly rich in bases and plant nutrients,


FIGURE 36.-Checkerboard-patterned irrigated sugarcane fields on Machete clay
loam and Machete clay, which formerly were range land for livestock. Note
the modern sugar central in the lower left-hand corner and the old hacienda in
the upper right-hand corner. (Photograph taken by U. S. Navy.)
Campos de cafa en forma de tablero de damas, bajo riego en Machete arcilloso
16mico y Machete arcilloso, y que antiguamente eran pastos. N6tese la
modern central en la parte baja a la izquierda y la antigua hacienda en la
parte de arriba a la derecha. (Fotograffa tomada por la Marina de los EE. UU.)







64 U. S. DEPARTMENT OF AGRICULTURE

the crops produced are of a better quality and more abundant than
those grown on the deeper, less eroded, more leached acid soils such
as occur in the coffee districts. The shallow young soils can maintain
their productivity better under the jibaros' system of farming than
can most of the older soils. The jibaros rarely use fertilizer, and they
frequently plant three or four crops on the same land year after year.
When viewed from the air, these small irregular-shaped garden
patches give the landscape an appearance of an intricate mosaic pattern.
Nearly all of the sandy soils along the coast that are used extensively
by the jibaros for gardens are fairly good for root crops and other
subsistence crops. Yields are seldom high unless fertilizers are used,
but fair crops are obtained and help in keeping the people from
starvation.
According to the 1935 census of the Puerto Rico Reconstruction
Administration (34), the average-sized farm is 36.2 cuerdas. The
average farm for each municipality ranged from 15.6 cuerdas in
Aguada, where most of the land is in subsistence crops, to 1,001.1
cuerdas in Santa Isabel where most of the cultivated land is in sugar-
cane and the uncultivated land in cattle ranches. There are 52,790
farms on the island, 25,326 of which are between 3 and 9 cuerdas in
size and only 335 are 500 cuerdas or more.
The average value of land and buildings per cuerda was $81.69 in
1935 and in 1920 was $74.80. Land values range from nearly $1,000
a cuerda for the very best irrigated land on the south coast to less
than $5 for that on rough limestone hills in either the dry district on
the south coast or in the haystack hill area on the north coast.
According to the 1935 census, 18.7 percent of the farms are operated
by tenants, 4.6 percent by managers, and 76.7 percent by owners or
part owners. Most of the tenant farms are rented on a cash basis,
and some of the good sugarcane land rents at prices ranging from $10
to $30 an acre. The planter usually pays the taxes, which may be
more than $5 an acre. Many leases of the cane land are for a period
ranging from 10 to 20 years.
Very often sugar centrals advance money to the nearby colonos, or
small farmers, who send their cane to be ground at the central's fac-
tory. The transaction is in the form of a contract. The sugar central
agrees to grind the colono's cane and may advance him $20 or more an
acre for the first year's planted crop and less for the ratoon crops.
The centrals charge interest and usually exercise some control over
the cultivation and management of the crop. The price paid to the
colono usually depends on the percentage of sucrose in the cane.
Many contracts specify that the cane grown by the colono must have at
least the minimum sucrose content and purity required. If the cane
does not reach the minimum requirement, the grower is not remun-
erated, as the cost of grinding equals or is greater than the value of the
cane.
Buyers of tobacco and cotton often advance money to the planters
of these crops. The Federal Intermediate Credit Bank makes crop
loans for the production of coffee, tobacco, and other crops.
According to the Federal census, the amount of money expended for
fertilizer, including manure, was only $911,412 in 1909, but nearly six







SOIL SURVEY OF PUERTO RICO 65

times that amount, or $5,697,465, was spent in 1919. In 1929, $5,401,-
187 was spent by the 18,540 farmers reporting. This was almost one-
eighth of the total value of all vegetable, field, and orchard crops for
1929. The municipalities expending the largest amount for fertilizers
in 1929, ranking in the order named, are: Salinas, Humacao, Guhnica,
Arecibo, Caguas, Fajardo, Bayam6n, and Cayey. All these munici-
palities, except Cayey, have a very large acreage in sugarcane. Arecibo
and Bayam6n have considerable acreages in fruits, and Cayey has a
large acreage in tobacco.
The use of commercial fertilizer is general for such crops as sugar-
cane, grapefruit, tobacco, pineapples, flames, and some vegetables.
Very little is used for coffee, coconuts, corn, minor crops, and pasture.
The municipalities using the greatest amount of fertilizer are those that
have the largest acreages of sugarcane. Most of the fertilizer is pur-
chased ready mixed, and about 600 pounds to the acre are used for
cane, from 800 to 1,000 pounds for grapefruit and tobacco, and about
1,200 pounds for pineapples. The grades used are discussed under the
agriculture of each crop. The potash salts for the preparation of the
mixed fertilizers are imported directly from Germany, the nitrate of
soda from Chile, and the sulfate of ammonia, calcium cyanamide,
and calcium superphosphate are brought from the United States.
According to the Annual Book on Statistics issued by the Depart-
ment of Agriculture and Commerce of the insular government, Puerto
Rico imported, during the fiscal year 1938-39, a total of $75,684,719
worth of merchandise from the United States and $7,039,563 worth
from foreign countries. Of the amount from foreign countries, more
than $1,000,000 was expended for fish. The value of the most im-
portant items imported from the United States is given in table 8.

TABLE 8.-Most important imports to Puerto Rico from the United States for the
fiscal year ending June 30, 1939 1

Article Value Article Value

Rice....--..----. .--------------------- $5,466,216 Lard, fat, and oils (edible) .-------- $2,381,736
Cotton cloth-.----------------------. 5,292,813 Electrical machinery and apparatus. 1,998, 305
Iron and steel manufactures....------ 4, 838, 742 Silk manufactures ------ ------- 1, 950,952
Cigarettes ....----------------------- 3,491,023 Soap and toilet preparations--------- 1,652,820
Meat products...------------------- 3,442,501 Paper and manufactures ------------- 1,526,952
Leather manufactures (mostly shoes).- 3,214,326 Cotton wearing apparel-------------- 1,468,182
Automobiles and other vehicles-.... 2,827,406 Wheat flour. --------- ---------1,437, 882
Lumber and wood products._-------- 2,805,340 Dairy products --.......------.... 1,344,463
Rayon and other synthetic fabrics-.... 2,611, 164 Fertilizers and fertilizer materials-- -. 1,328,755
Petroleum and products ---.....---- 2,535,032 Dried beans ----...---------------. 1,327,670
Industrial machinery .---------- ----. 2,415,740

I Data taken from the following publication: DIVISION Or STATISTICS. DEPARTMENT OF AGRICULTURE
AND COMMERCE. ANNUAL BOOK ON STATISTICS, FISCAL YEAR 1938-39. 222 pp. [1939]

In 1935 only five countries-United Kingdom, Canada, Japan,
France, Germany-in addition to the Territory of Hawaii, bought
more goods from the United States than did Puerto Rico.
Puerto Rico's position in United States trade is shown in table 9,
taken from data of the United States Department of Commerce.



144038-41- 5








66 U. S. DEPARTMENT OF AGRICULTURE

TABLE 9.-Puerto Rico's place in export and import trade with the United States'
[In thousands of dollars-i. e. 000 omitted]

From the United States in- To the United States in-
Country
1935 1936 1937 1935 1936 1937

United Kingdom..------- --------- -$433, 399 $440,122 $534,564 $155,282 $200,385 $202,771
Canada...-------. -------------------- 323,194 384,151 509,508 286,444 375,832 398.539
Japan---.....----. ------------------ 203,283 204,348 288,378 152,902 171,744 204.202
France---------------------------- 117,013 129,457 164,311 58,107 65,288 75.663
Germany- -------. ------------- 91,981 101,956 124,166 77, 792 79,679 92.644
Hawaii--...-- -------------------- 78. 925 85,744 104,181 98,696 125.537 130.138
Puerto Rico ----------- --------- 70, 052 86.352 90,044 87,726 103.952 102,859
Cuba----------------------------- 60, 139 67,421 92.283 104,303 127,475 148.047
Philippine Islands ------------------- 52, 640 60.350 85, 031 96.999 101,679 126,207
Italy ------ ------------------- 72,416 58, 989 76, 792 38. 674 40. 337 48, 188
Argentina --..---- ------------------ 49,374 56,910 94, 173 65,408 65,882 139. 123
Brazil ----------------------------- 43,618 49,019 68, 631 99,685 102,004 120,639
British Malaya----------------- 4,500 5,021 8,834 131.607 167,997 235,194

I From U. S. Department of Commerce, Summary of United States Trade with World, 1937. except data
on Puerto Rico and Hawaii, which are from Monthly Summary of Foreign Commerce of the United States,
December 1937.

According to the Annual Book on Statistics (1938-39) of the insular
government, Puerto Rico exported a total of $86,486,570 worth of
merchandise in the fiscal year 1939, of which $84,782,650 worth
went to the United States (table 10). Of this amount $53,604,381
was for sugar. In 1936, Puerto Rico ranked seventh (table 9)
among the countries shipping goods to the United States. The
island led such countries as Brazil, Philippine Islands, Argentina,
France, and China, but was led by Canada, United Kingdom, Japan,
British Malaya, Cuba, and Hawaii. The percentage of Puerto Rico's
world commerce that has been shared with the United States has
ranged from 17.8 percent in 1896 to 95.3 percent in 1936.

TABLE 10.-Value of shipments of most important merchandise from Puerto Rico to
the United-States in the fiscal year 19S9 '

Total Total
Product Value value Product Value value

Sugar --------------------------$53,604,381 Oranges... ..---------- $2,041 ---
Unrefined _------ $44,251,614 -----------. Pineapples -..--------. 862,423 -----
Refined-....---------- 9,352,767 -------- Other fresh fruits ---... 1,497----------
Cotton manufactures-----.....----------- 9,511,472 Prepared or preserved:
Tobacco and manufactures ___ __------ 7, 464, 394 Grapefruit- ----------- 170, 466 -----
Unmanufactured: Pineapples ..---------- 142,533------
Leaf, stemmed--..... 6,355,627 .--------.. Other prepared or pre-
Leaf, unstemmed_--.. 217,868 .-- -.. served fruits --------- 15,507 .........
Stems, scrap. andtrim- Orange peel.------------ 1,147 .......
mings ---------- 825,119 ------- Linen manufactures...------ ...-----.-- $2,605,893
Manufactured: Alcohol ..----.------------ --------. 393,504
Cigars and cheroots-. 37,602 .----- --- Coconuts in the shell------ ----------- 306,021
Cigarettes ---- ------- 26,985 ....------. Coffee.--. ----- ----- -.-------. 475,316
Other tobacco manu- Forexport_..---------. 407,771 -----
factures------------ 1,193 --------- For consumption------- 67, 545 ---
Molasses --------.------ .----------- 565,699 Silk manufactures.---------- --------. 2,661,282
Fruits --------------- ------------ 1,352,609 Rum -------------- ------- 3, 194,849
Fresh- Buttons, pearl or shell....-----. ------ 303,145
Citrons --- ------- 6,872 ...------.. Straw hats. .....----.----.---- ----- 235. 634
Grapefruit. -.. ---- 110,612 .........

1 See footnote 15, p. 67.

According to the 1935 census of the Puerto Rico Reconstruction
Administration, the leading enterprises, based on agriculture, and the
number of persons employed in them are as follows: Cigar and tobacco







SOIL SURVEY OF PUERTO RICO 67

factories, 14,712; sugarcane mills, 16,162; and other food industries,
4,737. Agriculture employs 246,976 persons. The number of people,
mostly women and girls, employed in the clothing and embroidery
shops, is 19,857, and needlework and embroidery is done in the home
by 50,371 persons. Although these are not agricultural industries, a
large number of the employees are from the rural districts, as the farm
women do piece work in their homes. The towns employing the
largest number of employees are Mayagfiez, San Juan, Ponce, and
Arecibo.
On the farms visited by officials of the Division of Labor during
1930-31, a total of 30,714 persons were employed on sugarcane plan-
tations, 5,851 on coffee plantations, and 5,202 on tobacco plantations.
Wages are higher in the sugar mills and fruit industries than in the
coffee or tobacco shops. Wages in the embroidery and needlework
shops are slightly less than in the cigar factories. Wages range from
50 cents to $3 a day in the fruit industries and from 12 cents to $1.70
a day for women in the embroidery and needlework shops.
The farm land and buildings were assessed at $156,278,450 in 1935.
Fifteen percent of the farms operated by full owners were mortgaged
for $13,323,869, or 49.9 percent of their assessed value of $26,981,893.
The public debt of the island is high; on June 30, 1933, it was $47,587,-
616.76, of which $17,872,122.22 was municipal debt and $29,715,494.54
was insular debt.
SUGARCANE (CANA DE AZUCAR)
Sugarcane is the most valuable crop, and the manufacturing of
refined and raw sugar is the most important industry. The climate,
soil, and people are adapted to the production of this crop. It might
be said that Puerto Rico is a sugar-bowl island, as nearly $54,000,000
of the $86,486,570 obtained for total exports in 1938-39 was from
sugar, molasses, and alcohol. Generally speaking the yield and
price of sugarcane is the barometer of prosperity for the entire island.
Sugarcane was first brought to the island from Haiti in 1515 (16,
p. 795). For the first 32 years molasses only was manufactured. The
first muscovado mill for the manufacture of sugar was built near
Bayam6n in 1548 (17, p. 541). At that time sugarcane was grown
on the alluvial soils along the rivers Bayam6n and La Plata. These
soils are still producing sugarcane after more than 380 years of cultiva-
tion. They are now producing a higher tonnage than ever before, due
to excellent varieties, good management, constant control of diseases
and insects, fertilizer, and some irrigation. From all indications
these soils will continue to produce good crops, if intelligently
managed, for hundreds of years.
Many fluctuations have taken place in the industry since 1515.
At one time in the seventeenth century, ginger was cultivated, almost
to the exclusion of sugarcane. Later a royal decree prohibited the
growing of ginger, and through governmental aid the sugar industry
was established.
The production (16, p. 795) of sugar in 1581 was about 187 tons, and
in 1828 it had increased to 9,391 tons. For the next 20 years, there
was a gradual increase to 52,089 tons in 1847. During the following
20 years, the production varied between 43,195 and 65,517 tons. In
I The Annual Book on Statistics for 1939-40 gives the yearly production of sugarcane from 1828 to 1939.







68 U. S. DEPARTMENT OF AGRICULTURE

1879, a peak of 170,679 tons was reached. This high production was
not exceeded until 1905, when 214,480 tons were produced. Since
then, the yearly production has never been below 200,000 tons. In
1920, 485,077 tons were produced. With slight variations, production
increased yearly until 1934, when an all-time peak of 1,103,822 tons
was reached. Partly due to curtailment of the acreage, only 773,021
tons were produced in 1935, but an increase to 851,969 tons was made
in 1939. The production in 1934 was almost one-half as great as that
of Cuba and about 6 percent of the world production; in 1939 it was
less than one-third of that of Cuba and 4.1 percent of the world
production.
The value of exported sugar also has varied in different years,
according to the amount exported and the price per ton. The value
of the export sugar increased from $4,715,611 in 1901 to a high of
$98,923,750 in 1920. The value fell to $35,224,038 in 1929 but
increased to $53,604,381 in 1939. In 1935, sugar to the value of
$47,837,144 was exported. Between 1901 and 1935 the price of
exported sugar has ranged from $3.02 to $11.79 per 100 pounds.
The price in 1939 was $2.84, the lowest yet recorded.
The number of sugar mills has varied considerably. In 1581, only
11 were reported on the island, but in 1879, 553 were grinding sugar-
cane (16, p. 795). In 1910 there were 41 modern mills, 14 old steam
mills, and 91 ox mills grinding cane (2, p. 15). At present about 40
mills manufacture all the sugar produced on the island. In remote
areas a few ox mills are still in use for grinding the sugarcane for
locally used molasses.
According to the Puerto Rico Reconstruction Administration census
of 1935 (34), the acreage in sugarcane has increased from 145,433
cuerdas in 1909 to 245,154 cuerdas, or 34.5 percent of the land from
which crops were harvested, in 1935. This crop occupies a larger
total area than any other crop grown on the island.
Figure 37 shows the distribution of sugarcane as recorded by the
Puerto Rico Reconstruction Administration census of 1935. It may
readily be seen that most of the sugarcane grows in the municipalities
bordering the coast. The best soils for the production of sugarcane,
such as those on the nearly level flood plains, terraces, and alluvial
fans, occur within these municipalities. Owing to the good soils and
valuable crops, roads, railroads, and towns are numerous along the
coast. The production of sugarcane is limited largely to areas within a
kilometer of a good road or railroad. Although sugarcane is grown
throughout most of the island, unless the land is irrigated it is not
grown on level areas receiving less than 40 inches of mean annual
rainfall or on very steep land receiving less than 60 inches. In humid
districts, much cane is grown on hills having 50-percent slopes. The
municipalities having the largest acreage in sugarcane, ranking in the
order named, are: Arecibo, Juana Diaz, Cabo Rojo, Loiza, Lajas,
San German, Naguabo, Ponce, Guayama, and Salinas. In these
municipalities the percentage of total crop land in sugarcane ranged
from about 33 percent in Arecibo to 75 percent in Salinas. It is
interesting to note that the acre yield is only three-fourths as great
in the municipality of Arecibo as in the municipality of Santa Isabel.
Most of the soils used for cane in the latter municipality are those of
the San Ant6n, Santa Isabel, Fraternidad, and Aguirre series. In the
Arecibo municipality cane is grown on less productive soils, such as













.. .-.v .. .. .
"" ,' i ,, \ /. : I 7.. ..'
S -1 I .:



''.. \::. < ."
I. ... 0



FIGURE 37.-Distribution of sugarcane in 1935. Each dot represents 100 acres.
Distribuci6n de cafia de azdcar en 1935. Cada punto represent 100 acres.
2"/7rCT>
SO
I s
I~t:- eI/







70 U. S. DEPARTMENT OF AGRICULTURE

the Bayam6n, Vega Alta, Sabana Seca, Espinosa, Coloso, and Toa.16
Soils of the Coloso and Toa series are the most productive for sugar-
cane on the north coast, but they do not return such high yields as
does the best soil along the irrigated southern coast.
Field observations and factory figures indicate that a higher yield
of both sugar and sugarcane is obtained on the irrigated south coast
than in any other large area on the island. This is because the low
relative humidity along the south coast and a sufficiently regulated
irrigation water supply, combined with level, deep, well-drained alka-
line soils, make most favorable conditions for the growth of sugarcane.
In addition, the soils have not been leached of mineral elements to so
great an extent as have those in the areas of higher rainfall. Most of
the soils of the south coast have been farmed for less than 40 years




















FIGURE 38.-Excellent sugarcane.
Cafia excelente.
whereas those in other parts of the island have been under cultivation
nearly 400 years.
The best soils along the south coast, under favorable conditions and
proper management, produce from 80 to 100 tons of sugarcane an
acre, or from 10 to 14 tons of sugar (fig. 38). Here, some of the best
land sells at prices ranging from $600 to $700 an acre. On the north
coast the best land sells at prices ranging from $350 to $400 an acre,
and a few irrigated areas sell for about $500 an acre.
Most of the land used for the production of sugarcane either is
planted to this crop or is in process of preparation for it. The two
planting periods are: Fall planting, or gran cultural, which is from
July to November; and spring planting, or primavera, which is from
January to June. Gran cultural crops grow for a period ranging from
14 to 22 months, averaging about 16 months, and primavera crops
Is The soil series and soil types are defined in the section entitled "Soils and Crops."







SOIL SURVEY OF PUERTO RICO 71

mature within about 13 months. Both plantings will continue to
produce volunteer, or ratoon, 12-month crops year after year, or until
the fields are plowed. The tendency in the last few years is to give
the sugarcane as long a period of growth as possible-that is, long
ratoons and fall plantings rather than primavera plantings.
As gran cultural crops are planted in the rainy summer months and
have a long period of growth, they outyield primavera crops by 15 or
20 percent. Usually prima-
vera crops outfield the first 3 -- -
ratoon crop by 10 or 15 -
percent. The succeeding ra-
toon crop yields from 5 to
10 percent less than the pre- '
vious ratoon crop.
The proportion of each of
these types of planting to the
total area planted varies in
different parts of the island
and with the individual
grower. In general, the farm-
ers having a small acreage of
sugarcane have a much larger
percentage of their land in 2-,
3-, or 4-year ratoon crops
than the large-scale operators.
The sugar centrals on the
south coast have a higher
percentage of gran cultural
plantings than those in any
other, part of the island.
Along the south coast during
average years, about 25 per-
cent of the land is in gran
cultural, about 35 percent is
in primavera, and about 40 FIGURE 39.-The chimney-all that remains
percent is in ratoons. of an abandoned small sugar mill. La
On the level coastal plains, chimenea-todo lo que queda de una pe-
On the level coastal plains, quefia central abandonada.
on such permeable soils as the
Bayam6n, Espinosa, Vega Alta, Coto, and Matanzas, the general
practice is to grow a large proportion of ratoons and very little pri-
mavera plantings. In Isla de Vieques and semiarid districts, where
the tonnage is low and very little fertilizer is used, five or six ratoon
crops are common.
The sugarcane grower is interested primarily in obtaining the
greatest acre yield of sugar at the lowest cost. Two of the most
important factors in reaching this objective are efficient management
and land suited to the growing of sugarcane. Efficient management
includes efficiency in the sugar mills as well as in the canefields, and
efficiency in the mills has increased manyfold since the time of small
muscovado mills. In order to compete with other sugarcane-growing
countries the small mills were abandoned (fig. 39), and large central
mills were constructed (fig. 36). Each of the latter will grind the same
quantity of sugarcane formerly ground by about 20 small mills in less
than one-half of the time and with an increased sugar yield of more
than 50 percent. The modern sugar-central factory is now developed







72 U. S. DEPARTMENT OF AGRICULTURE

to a fine degree of perfection. The grinding capacity of the mills has
increased from a season's grinding ranging from 20 to 1,000 tons of
sugarcane in the first small mills to the 24-hour grinding capacity
ranging from 1,000 to 4,000 tons in the present-day up-to-date mills.
Most of the canefields of the large sugar centrals are scientifically
managed. They seem to be properly fertilized,"7 cultivated, and
drained or irrigated if necessary. Excellent sugarcane varieties are
grown, and continuous effort is being made to combat harmful in-
sects, diseases, and weeds. Many of the owners of small sugarcane
farms are not financially able to weed, fertilize, or manage their
fields in the most efficient manner.
In order to compete successfully with the world's sugarcane-
producing countries, Puerto Rico must economically produce a very
high tonnage to the acre. The best way to do this seems to be on a


















FIGURE 40.-Mdcara silty clay loam on steep hillsides, used for the production of
sugarcane. Yields are less than 18 tons an acre.
Laderas escarpadas de Mdcara limo-arcilloso 16mico sembradas de cafia. El
rendimiento es menos de 18 toneladas por acre.
large-scale production, with sufficient capital to invest in large
quantities of fertilizer, machinery, and irrigation if necessary. Suffi-
cient and contented labor at the proper time is another prerequisite
for success in the sugar business.
Sugarcane can be grown successfully on many soil types, ranging
from calcareous friable fine sandy loams to acid plastic clays and from
medium-shallow steep soils of the uplands to the deep well-drained and
poorly drained level soils of the river flood plains. Even the organic
soils of the coastal lowlands produce fair yields, if the areas are well
drained and fertilized. The acre yields, however, range from about
15 tons on the poorest soils (fig. 40) to more than 100 tons on the best
soils, and the profits vary somewhat accordingly. According to Jensen
17 Many of the large sugar centrals have their own scientifically planned fertilizer experiments and variety
test plots on several of their most important soil types.






SOIL SURVEY OF PUERTO RICO 73

(21, p. 32), more than 50 percent of the sugarcane roots on dry-weight
basis are in the first 8 inches of the soil, but sugarcane growing on soil
having a depth ranging from 12 to 18 inches, such as the Mdcara,
Juncos, and some soils of the Colinas series, produce far lower yields
than sugarcane produced on related but deeper soils, such as those
of the Mabi, Santa Clara, and Camagfiey series. The extensive
development of the root system depends on the physical and chemical
condition of the soil types, and without a healthy, well-developed root
system the normal functions of the entire plant cannot operate at
maximum efficiency.
The best land for sugarcane in Puerto Rico has a friable loam or
silt loam surface soil, high in organic matter, neutral or alkaline in
reaction, brown or very dark grayish brown, free from gravel or harm-
ful salt, and granular, with a slightly heavier but friable alkaline sub-
soil beginning at a depth of 10 or 12 inches and continuing to a depth
below 5 feet before any free water or gravel is reached. The surface
soil is loose and porous and when cultivated forms an ideal seedbed.
It can be worked under a fairly wide range of moisture conditions
without harming its structure. The subsoil has enough silt and clay
to prevent serious leaching of fertilizers or lime, yet it is not too heavy
to interfere with the rapid penetration of roots. Water penetrates
this soil rapidly and does not remain on the surface for any length of
time. Owing to the slightly heavy subsoil, a high proportion of the
percolating water reaching it is retained and is utilized by the lower
roots of the cane. Soils of this description generally are flat. They
allow the use of most kinds of modern machinery, and they are almost
ideal for maximum agricultural utilization. Typical areas of Altura
loam, Altura silt loam, San Ant6n loam, and San Ant6n silt loam have
these characteristics, and when they are fertilized with from 300 to
400 pounds of mixed fertilizer and 300 to 400 pounds of ammonium sul-
fate, are properly managed, and have sufficient water, sugarcane will
yield from 75 to 110 tons to the acre. Some of the other good soils for
sugarcane on the south coast are those of the Machete, Fraternidad,
Santa Isabel, Paso Seco, Vives, Coamo, Aguirre, and Guanica series.
These soils have an acre yield ranging from 40 to 85 tons of gran cultural.
The Poncefia, Moca, Dominguito, and Las Piedras soils occurring in
the inner plains also are good soils for sugarcane. Most of the sugar-
cane on the north and west coasts is grown on the well-drained alluvial
Toa and Estaci6n soils, the imperfectly drained Coloso soils, and the
poorly drained Palmas Altas soils. These soils when properly man-
aged and planted to gran cultural yield from 40 to 60 tons to the acre.
The yield of cane depends to a large extent on the management, fer-
tilizer used, and especially the amount of rainfall during the critical
period of ripening which, according to Davis (15, p. 3), is between
December and February. The Coloso soils in the vicinity of Cabo
Rojo and Filial Amor seem to be much more productive than the
Coloso soils near Central Coloso or along the north coast. The differ-
ence in yields for the same soil in different parts of the island may be
due to better management, more rainfall at the proper time, or to
the fact that the soils have not been under cultivation for so long a
time near Cabo Rojo as they have along the north coast.
A large acreage of the nearly level areas of such soils as Coto,
Bayam6n, Vega Alta, and associated soils in the northwestern part
are in sugarcane. These soils produce from 20 to 45 tons of gran






74 U. S. DEPARTMENT OF AGRICULTURE

cultural cane when they are properly managed. In the eastern end
the best soils for the production of cane are those of the Fortuna,
Vivi, Yabucoa, Josefa, and Maunabo series. When these soils are
planted to gran cultural and properly managed they produce from 30
to 50 tons to the acre. The interior hill lands, such as the Mdcara,
Alonso, Catalina, Rio Piedras, Cayagui, Utuado, and Colinas soils,
produce from 18 to 30 tons of gran cultural. They require nearly as
much fertilizer and weeding as do the soils producing 100 tons to the
acre. It may readily be seen that the greatest profit is made from the
cane grown on the best soils.
Such soils as the Nipe, Rosario, Tanama, Pandura, Teja, Picacho,
Yunes, Aguilita, San German, Descalabrado, JAcana, Guayabo,
Corozo, Algarrobo, St. Lucie, Catafio, Meros, and Jaucas, the steep

















FIGURE 41.-Plowing land for sugarcane with oxen. Note how the yokes are
attached to the animal's poll and forehead.
Arando con bueyes. N6tese los yugos en los animals.
phase of Soller, and coastal beach are not adapted to the production
of a very high tonnage of sugarcane.
The Nipe and Rosario soils lack plant nutrients, and the Rosario
soils are too steep for cultivation, as also are the TanamA soils and
most areas of the Pandura soils. The Pandura and Teja soils are
low in fertility and are drought. The Picacho and Yunes are too
shallow and steep for the production of cane. The Aguilita, San
GermAn, Descalabrado, and JAcana occur in too dry a climate for
the production of cane without irrigation, and the relief of these soils
is unfavorable for irrigation. All except the Jacana soils are very
shallow. The very sandy soils are too loose and low in fertility for
profitable yields of sugarcane.
The method of planting and cultivating sugarcane varies consider-
ably for soils having greatly contrasting characteristics. The clay
soils are handled differently from the sandy soils, and the soils on steep
hillsides are planted differently from those on level land. Poorly
drained soils require more attention than well-drained soils. In







SOIL SURVEY OF PUERTO RICO 75

general the heavy-textured soils of the level river flood plains, alluvial
fans, terraces, and inner plains are plowed twice, to a depth ranging
from 12 to 18 inches. One plowing is at right angles to the other,
and the land is harrowed after each plowing. At present more of the
plowing of the large tracts is done by tractors than formerly. The
use of tractors enables land to be in sugarcane that otherwise would
be in pasture and hay for the work oxen. Most of the small farm
owners still use oxen (fig. 41) and all plowing on hillsides and poorly
drained areas is done by oxen. The rather steep hillsides, the per-
meable clay soils of the uplands, the coastal plains, and the sandy-
textured soils are plowed only once. In some areas near the rivers
the alluvial soils that are subject to overflow are not plowed at all,
but furrows are made in which the sugarcane cuttings are planted.
















FIGURE 42.-A cable-gear plow making furrows in the soils of the alluvial fans
along the irrigated south coast. Cane cuttings 10 or 12 inches long will be
placed in the furrows and covered to a slight depth.
Haciendo surcos en los aluviones bajo riego de la costa sur para sembrar pedazos
de cafla de 10 6 12 pulgadas de largo.

Within the last few years a specially constructed rotating plow-
the gyrotiller-has been used. Foss (18, p. 81) states that, in 1935,
13 of these were in operation on the island. This plow does exception-
ally good work in the churning of the soil to any desired depth not
exceeding 2 feet. The soil is well churned and aerated yet not changed
in position. This type of plowing should be very beneficial for those
soils having heavy nearly impervious subsoils, such as the Sabana
Seca, Santa Isabel, and Candelero soils, and the heavy-subsoil phases
of the Vega Alta soils. Two sizes of gyrotiller are in use. The larger
weighs 24 tons and has a 170-horsepower Diesel motor, and the smaller
weighs 12 tons and has an 80-horsepower Diesel motor. The larger
machine has an 11-foot plow width and the smaller one a 9-foot width.
The cost of plowing with these machines ranges from $4 to $5 an acre.
Other plows and tractors seen in many of the sugarcane fields are the
large steam cable-gear plows (fig. 42) and various types of caterpillars.
On some of the heavy clay soils having compact subsoils, deep
knifing or deep subsoiling is beneficial. This is a costly operation,






76 U. S. DEPARTMENT OF AGRICULTURE
however and should be practiced only in soils that will not run to-
gether after the first few rains. Such soils as those of the Santa Isabel,
Sabana Seca, Candelero, and similar series are greatly benefited by
such treatment. Such plastic soils as those of the Aguirre, Poncefia,
Camagiiey, Coloso, and similar series would be benefited for a short
time only. Shallow knifing has proved beneficial on some of the
shallow hill-land soils, such as the Micara and Teja.
After the land is plowed and harrowed, it is ready to be planted.
The sugarcane is planted either in furrows about 4 feet apart, in
grand bank, or in shallow holes 4 feet apart. On the well-drained
river flood plains soils, such as the San Ant6n, Toa, and Vivi, and on
the alluvial fans and terraces, both in the irrigated arid districts
and in the humid districts, the sugarcane is planted in furrows. In
the humid districts, drainage ditches are dug at intervals of about
every 10 rows, and they are usually dry except during long wet periods.
In the dry nonirrigated districts the furrows are deeper than in ir-
rigated or humid areas, because it is necessary to plant the cuttings
deep enough that they will be in an environment that is sufficiently
moist to start germination. As the roots continue to grow to greater
depth, they have, during droughts, a much larger area to drain than
if the cuttings were planted at a slight depth.
On some of the deep upland soils, such as the Catalina, Cialitos,
and Alonso, sugarcane often is planted in shallow holes 4 feet square
and several sugarcane seed pieces are placed in each hole. The holes
are not entirely filled with earth when the seed is planted, and they
act as catch basins for sheet-erosion waters and help considerably in
checking the speed and force of the flowing water. After sugarcane
becomes a foot or more high, it is a fairly good crop for checking sheet
erosion, even on steep hillsides.
Sugarcane seed for gran cultural planting is obtained from selected
fields of young sugarcane stalks, about 8 months old, that are free
from mosaic. Ratoon cane makes desirable seed. The sugarcane
stalks are cut in pieces from 9 to 12 inches long, and they usually
have two internodes and three nodes, or buds. Generally the leaf
sheath is removed, except when the planting is made in sandy soils
that are infested by the mole cricket, or change. From 14 to 3 tons
of cuttings are required to seed an acre. The price of this seed ranges
from $4 to $10 a ton, and the average price is about $7. Seed for
primavera plantings is much less expensive, as this seed is obtained
from a point near the tops of matured sugarcane stalks during harvest.
The upper parts of the stalks contain every little sucrose; consequently
they are of little value when ground for sugar. Cane seed of this
kind sells at prices ranging from $2.50 to $4 a ton.
All the sugarcane is planted by hand. When planted in furrows,
the seed cuttings are spaced from 6 to 12 inches apart in the bottom
of the furrows in a single row, and one end of the cutting is covered
with a few inches of soil. Some farmers plant two rows of cuttings
about 4 inches apart in the bottom of the furrow and space the cut-
tings from 14 to 18 inches apart. In some parts of the island, as
near Fajardo, entire sugarcane stalks are placed end to end in the
bottom of the furrow and covered with a few inches of soil. The
advantage of this method is (often) better germination and less op-
portunity for infestation by disease germs which may be on the cut







SOIL SURVEY OF PUERTO RICO 77

surfaces of the seed pieces. In the poorly drained river flood plains
and coastal lowlands, on such soils as those of the Coloso, Fortuna,
Palmas Altas, Aguirre, Yabucoa, and similar series, sugarcane is
planted in grand banks. With this system" of planting a ditch is
dug on each side of every two, three, or four rows, depending on the
amount of water to be drained away (fig. 43). Deeper cross ditches
are dug at intervals ranging from about 20 to 40 feet. These ditches
lead to larger drainage ditches and finally to the rivers. Most of the
ditches are dug by hand, but some are made with a No. 90 plow.
They are cleaned with a double moldboard plow or by hand. It is
essential that the ditches be maintained at all times, in order to pre-
vent the soils from becoming waterlogged. During long protracted
droughts, the ditches can be blocked and the water table can be
regulated to the best advantage of the growing crop. As lack of















FIGURE 43.-A modified grand-bank method of planting sugarcane on Coloso
silty clay. None of the ditches is very deep.
M6todo de gran banco modifieado en Coloso limo-arcilloso. Las zanjas no son
muy profundas.

water is not a limiting factor on soils that are planted according to the
grand-bank system, the sugarcane cuttings are planted in shallow
holes.
The muck and peat areas planted to sugarcane require more
complex drainage systems than do the mineral soils; in many places
pumps are installed and dikes are built, in addition to the ditches
necessary for the grand banks. This is because most of the muck
and peat areas are slightly below the level of high tide.
In the permeable well-drained valley coastal plain soils, such as the
Espinosa, Coto, Matanzas, Bayam6n, and Vega Alta, sugarcane is
planted in furrows, generally following the contour of the land,
especially in the irrigated districts near Isabela. These soils are not
only so permeable that drainage ditches are unnecessary, but in many
areas lack of water is a limiting factor in crop production, and it is
essential that the sugarcane cuttings be planted in furrows ranging
from 10 to 15 inches in depth.







78 U. S. DEPARTMENT OF AGRICULTURE

On the inner plains in such plastic soils as the Camagiiey, Santa
Clara, Poncefia, Moca, Mabi, and associated soils, sugarcane is planted
in shallow furrows, although shallow drainage ditches are numerous.
The naturally rolling relief is a very desirable feature for these soils,
as a large proportion of the excess water is drained from the surface.
In the few nearly level areas of these soils it is difficult to drain the
land properly so that the sugarcane cuttings will germinate and
develop a good root system. The character of the sticky plastic
subsoil prevents excess water from percolating through it as fast as
it should or as fast as the water penetrates the plastic but not so
sticky poorly drained soils of the coastal lowlands and river flood
plains. The drainage ditches, made either by hand labor or machines,
are much more expensive than those made on other soils, because
the soil sticks to shovels, plows, and other implements. Laborers
refuse to work in this soil at the same price as in other lands, because
of the harder and slower work.
On the medium deep soils of the uplands, such as those of the Juncos,
Micara, Rio Piedras, Colinas, Cayaguh, and similar series, the
progressive landowners use contour furrows, with numerous drainage
ditches running zigzag down the hill. The bottoms of the ditches
generally rest on rocks, so that gully erosion is arrested and does very
little damage.
When the land is prepared for grand-bank plantings, from two to
four pieces of sugarcane cuttings are planted on the banks in holes
about 18 inches square and 6 inches deep. The holes are spaced from
40 to 60 inches apart, or about 2,000 to an acre. The seed pieces
are planted by hand with a short-handled pick or hoe, and they are
so placed in the ground that about one-half of the seed is exposed
at an angle of about 300.
The principal sugarcane varieties grown vary considerably in differ-
ent parts of the island and on different soil types. B. H. 10 (12) is
the dominant variety grown on soils of the river flood plains, such as
the Toa, San Ant6n, Coloso, Yabucoa, Vivi, and similar soils, regard-
less of the location or climate. If the sugarcane becomes badly
infected with mosaic, however, the acreage of B. H. 10 (12) is reduced
and that of P. O. J. 2878 and Mayagiiez 28 is increased. P. 0. J.
2878 is probably the second most commonly grown variety on these
soils. A much higher proportion of this variety, however, is grown
on the north coast than on the south coast. P. 0. J. 2725 and P. O. J.
2878 are the principal varieties grown on the level permeable acid
coastal plains, on such soils as those of the Vega Alta, Espinosa, Bay-
am6n, and related series. Mayagiiez 28 seems promising for these
soils. P. 0. J. 2878, B. H. 10 (12), and S. C. 12/4 seem to be the main
varieties grown on the soils of the uplands, such as the Catalina,
Colinas, Seller, and Mdcara. Uba and S. C. 12/4 are the principal
varieties grown in arid nonirrigated districts and by the owners of
small tracts of land. In the northeastern part of the island probably
85 percent of the land in cane is planted to B. H. 10 (12) with S. C.
12/4, F. C. 916, and P. O. J. 2878 occupying most of the remaining 15
percent. In this area the average sucrose content is about 18 percent,
the purity about 83 percent, and the yield about 11.5 percent. The
number of tons of sugarcane produced to the acre in this area and on
the alluvial soils of the north coast is about 31. Gran cultural averages
about 40 tons, primavera about 35, and ratoons about 28. In this







SOIL SURVEY OF PUERTO RICO 79

area B. H. 10 (12) outyields S. C. 12/4 by about 10 tons to the acre.
On the south coast on irrigated lands gran cultural averages about
65 tons, primavera about 42, and ratoons about 35. On the north-
western coastal plains the gran cultural plantings yield about 40 tons,
the primavera 30, and the ratoons 25. In arid nonirrigated districts,
such as on Isla de Vieques, most of the cane is ratoon S. C. 12/4, which
yields from 15 to 25 tons to the acre.
Very little machinery is used in cultivation of the growing cane.
The ratoon cane is plowed with a walking single moldboard plow,
usually pulled by a mule. The plowing of the ratoons generally is
completed within 2 weeks after harvest. First, the cane trash, or
paja, is laid in alternating furrows by hand, the clean bank is then
cultivated, and the trash is placed in the plowed furrow. The other
row is plowed. During the plowing dead plants are replaced by new
seed. In some fields that have been ratooned for many years, most
of the growing cane consists of replants. The trash is burned in
irrigation districts, in order to have unobstructed watercourses in
irrigation. It is burned in many other areas also. Plowing is more
difficult when the trash is not removed than when it is burned. Trash
is usually burned in all areas subject to frequent overflow, as, if allowed
to remain in the fields, it may be carried by floodwaters and piled on
young cane, thereby killing the plants.
Almost all the weeding is by hand labor. Usually it is necessary
to weed the cane several times before the plants are large enough to
shade the ground and naturally keep the weeds under control. Some
varieties of cane are far superior to others in this respect. Mayagiiez
28 stools prolifically, and the cost of cultivation is much less than that
of the erect canes with few stools."
Experiments with different fertilizer formulas seem to indicate that
all the soils need a large quantity of nitrogen, less potash, and a small
quantity of phosphorus. The red acid soils of the uplands probably
need a larger quantity of phosphorus than the soils in the arid districts
or the alluvial soils along the north coast. In most of the experiments
with sugarcane, an application of phosphoric acid in excess of 90
pounds to the cuerda apparently lowered the gain in yields. The
more common applications range from 150 to 250 pounds of ammonia
to the acre, 30 to 90 pounds of phosphoric acid, and 100 to 200 pounds
of potash. Fertilizer formulas vary among the different landowners;
the most commonly used formulas contain from 14 to 16 percent of
nitrogen, 8 to 16 percent of potash, and 4 to 8 percent of phosphoric
acid. From 400 to 800 pounds of mixed fertilizer is used to the acre,
and from 400 to 600 pounds of ammonium sulfate is used as a second
application. All the fertilizer is distributed by hand labor, generally
by women. On most farms the complete fertilizer is spread within a
radius of 8 inches of the cane plants, from 1 to 2 months after the
sugarcane is planted. The second application (ammonium sulfate)
is applied in the same way 2 months later. The fertilizers are covered
with a one-horse plow or with hoes.
So much sulfate of ammonia has been applied to the soils that in
the humid districts an application ranging from 2 to 4 tons of finely
ground limestone has given good results, especially in soil having a
pH value of 5.8 or lower. Bonnet (9) states that ammonium sulfate
should not be used as a source of nitrate for plants on Lares clay loam.
Extensive experimental work should be started on the effect of lime







80 U. S. DEPARTMENT OF AGRICULTURE

and the availability of the essential plant elements in the different soil
series. In some soils the effect of lime may make certain fertilizers less
available and thus prove detrimental.
Cowpeas are the principal crop used for green manure in the sugar-
cane fields, but even they are used on only a very small proportion of
the land. Cowpeas grow rapidly and readily on almost all of the
soils, provided the rainfall is sufficient. In general the crop is ready
to be turned under within 3 months from the time of germination.
Filter-press mud, or cachaza, is applied to the soils which produce
poorly. Only a small quantity of this is available during the grinding
season, and, as several tons are applied to the acre, only a small area is
treated each year. Cachaza should be beneficial for land on which
sugarcane is affected with chlorosis. Table 11 shows the composition
of a composite sample of filter-press mud collected from January 22
to February 1, 1912, at the South Puerto Rico Sugar Co.'s plant and
analyzed by their chemists.

TABLE 11.-Chemical composition of filter-press mud, or cachaza

Content Percent Content Percent
Moisture.----------.. ------------------- 61.78 Ash---..--------..... --------------------- 10.89
Organic ---- -------------------- 27.33 Phosphoric acid (PiOj), equivalent
Wax ..----.-------------------. 2.77 to bone phosphate, 3.95 percent.... 1.81
Ammonia (NHs), equivalent to ni- Silica (SiOs) -------- --------.-- .42
trogen (N) 0.774 percent-----....-- .94 FeOs and AlsO ..---------.......... 1.70
Sucrose .---------- --------------. 3.86 Lime (CaO) --...----... -.......-.. 4.13
Invert sugar ...... .-------------- (') Magnesia (MgO)-_.--------------- (1)
Undetermined.---------------. 19.76 Undetermined ----------.------- 2.83

I Trace.

So little stable manure is available that practically none is used in
the sugarcane fields.
The sugarcane is cut exclusively with a machete by hand labor
(fig. 44). The peons are very proficient in this work; they can cut
from 2 to 8 tons a day, depending on the quality of cane and the ambi-
tion of the laborer. Wages for this work range from 50 cents to $1.50

















FIGURE 44.-Cutting sugarcane by hand in the eastern part of the island.
Cortando cara en la parte este de la isla,







SOIL SURVEY OF PUERTO RICO 81

a day or from 20 to 35 cents a ton of cane. After the cane is cut it is
gathered immediately and usually is either loaded on oxcarts or cars on
portable tracks and conveyed to a loading station where derricks are
used to transfer it to railroad cane cars or trucks, and it is then hauled
to the sugar central. Some centrals have the cane hauled directly
from the field to the factory in oxcarts and in small cars (fig. 45)
which hold from 1% to 2% tons and are run on portable tracks. Usually
the portable tracks are connected with a network of permanent tracks
leading to the factory. In a very few of the nearly inaccessible hill
areas, such as near Central Soller and Central Plata, sugarcane is
carried on horses and mules from the field to the factory. Cane is not
carried by water or gravity as in some parts of Hawan.
Sugarcane harvest extends from December to July, and during this
period the factories run day and night with the exception of 1 day a
week, which is devoted to the cleaning and repairing of machinery.
















FIGURE 45.-Hauling sugarcane from the fields to the factory or to loading
stations, where the cane will be transferred to larger cane cars.
Arrastre de cafia de los campos a la factoria o a estaciones de carga para transferirla
a vagones mayors.
During this season of the year, most of the laborers on the island
obtain work, but during the rest of the year a high proportion of the
sugarcane laborers are unemployed. Only a limited number of men
obtain regular work in the canefields because weeding, ditching, and
planting gran cultural cane is about the extent of the available work
during the summer and early fall.
The pests and diseases most prevalent in the canefields are the
sugarcane borer, white grub, mosaic, dry top rot, nematodes, yellow
aphis, mole cricket, land crab, and rat. The sugarcane borer (Dia-
traea saccharalis) probably causes the greatest damage. It has spread
throughout the island, but it is most damaging in gran cultural and
primavera crops in the arid and semiarid districts. The white grub
causes the greatest damage on the south coast but is also prevalent
throughout the island. With the importation of the toad (Bufo
marinus) and continued deep cultivation, the white grubs are not so
144038-41- 6







82 U. S. DEPARTMENT OF AGRICULTURE

abundant as formerly. Mosaic has been brought nearly under con-
trol by the use of mosaic-resistant varieties of cane and the continual
roguing by all progressive landowners, as well as the selection of
good mosaic-free seed. Dry top rot is most severe in the poorly
drained lowlands, and for its control drainage is essential. Nematodes
and other soil organisms cause a small amount of damage to the roots.
The yellow aphis is more noticeable on poor soils in dry areas where
the cane does not have the vitality to resist the attack of the sucking
insects. The mole cricket is destructive in the loose sandy soils, such
as those in the Isabela district. Partial control is effected by leaving
the cane sheath attached to the cane seeds. Land crabs are destruc-
tive to young cane on the coastal lowland soils and poorly drained
river flood plains. These pests are controlled with a poison mixture
of corn meal and phosphorus placed on or near their holes. Rats
do considerable damage near ditches along the coast.
Weeds are not a serious pest to any of the commercial crops. The
principal weeds in the canefields are coqui, cadillo, abrojo, rabo de
rat6n, cohitre blanco, morivivi, and the more common grasses, such
as Bermuda, cerrillo, grama blanca, and malojillo.
Irrigation of sugarcane is very similar to irrigation of corn in the
semiarid section of continental United States. Laterals laid out with
the contours of the land convey the water from the large canals to
the growing plants. The source of water is from mountain streams
that empty into fairly large reservoirs and from deep wells. The
wells used on the south coast for irrigation range from 40 to 750 feet
in depth. Most of the shallower wells are grouped in a series including
from 4 to 10 wells, 6 inches each in diameter, connected to a centrifugal
pump located near the center of the series, in a concrete pit ranging
from 10 to 30 feet in depth. Many of the pumps are operated by
electricity. The deep wells are about 20 inches in diameter, and in
general each one is operated by a motor above ground. The v ells
on the north coast range from 60 to 300 feet in depth. Some farmers
pump the water directly from the river stream. In the Isabela irri-
gation district all the irrigation water comes from Rio Guajataca,
and most of the main-line canal is lined with concrete slabs, owing
to the porous character of the permeable clay soils traversed by the
canal. Along the south coast, the only parts of the canals and laterals
that are lined have a gravelly or rocky substratum near the surface.
In order to eliminate inefficient night irrigation, small overnight
reservoirs have been constructed along the south coast and in the
Isabela irrigation district. The reservoirs range in size from small
circular basins 20 feet in diameter to cisterns 300 feet square and 10
feet deep.
The number of irrigations necessary varies with the season, soil,
and plantings. Along the south coast, in the average alluvial soil,
such as typical San Ant6nloam or San Ant6n silt loam, when the annual
rainfall is about 45 inches, an 18-month gran cultural crop requires
about 25 irrigations, or about 13 acre-feet of water. The primavera
crops require about 8 acre-feet and the ratoons only about 6 acre-feet.
In the Isabela district the permeable Coto clay and related soils require
considerably more water than the soils along the south coast or the
alluvial soils along the north coast. In most parts of the island the cane
is watered as soon as it is planted and is rewatered in a week if the
weather is dry. The frequency of irrigation from then until maturity







BOIL SURVEY OF PUERTO RICO 83

of the cane depends on the rainfall, but the average period between
irrigations is 15 days.
When the cane becomes large, irrigation is very difficult, as it is
hard for the irrigators to penetrate the canefields. Many of the lower
leaves of the cane must be removed, in order that they will not inter-
fere with the flowing water, and such a procedure also makes it easier
for the men to penetrate the rank high cane.
The sugarcane industry in Puerto Rico is more important than any
other of the main commercial crops. The island is naturally ideal for
growing sugarcane. It has a favorable climate, good soil, and good
transportation service to the United States. The laborers are
accustomed to working either singly or in groups in the fields. They
often have to walk several miles over steep mountainous trails to
and from work, sometimes starting on their journey at 3 or 4 a. m.,




















FIGURE 46.-A modern sugar factory with well-managed fields of cane on good
productive Toa soils. Note the bamboo along the streams.
Modern factoria de azdcar con campos de cafia bien administrados en suelos
productivos Toa. VWase el bambd al borde de los rios.
because work means food. The summer, or idle period, is the lean
season for the laborer. However, very few men will work 6 days a
week, even if they are paid by the day or by piece work. They like
to start work on Tuesday and finish the week on Friday.
The Puerto Rican sugar growers, in order to counteract the com-
petition of sugar growers in other countries, have enlarged their
holdings for the purpose of more efficient management. The sugar
industry requires large capital, either from individuals, corporations,
or efficiently managed cooperative associations. To equip a modern
mill, a capital between $1,000,000 and $2,000,000 is necessary. This
includes railroads, livestock, field and factory machinery, and buildings.







84 U. S. DEPARTMENT OF AGRICULTURE

It is unreasonable- to expect a landowner to finance his small farm
and also have a small sugar factory, but it is possible for an energetic
owner of a small farm to plant and harvest a crop of cane and sell it
at a cooperative mill or a sugar central, at a profit, provided he is
able to have his cane ground at the proper time. His acre yield and
profit will be much less than if the same land were operated by a more
efficient landowner having a much larger holding. For the owner of
a small farm to make a success it is essential that he obtain credit
at a very low interest rate.
Most of the best land for sugarcane belongs to large corporations
(fig. 46) or is leased by them. This land is very efficiently managed,
and under the present economic conditions, with the protective tariff
on sugar, such land in cane yields from 15 to 25 percent greater returns
than if it were in the other commercial crops now commonly grown
in Puerto Rico.
The acre yields on the better soils probably can be increased
provided the sugar producers continue their scientific studies in search
of better varieties, better fertilizer practices for specific soil types, more
efficient machinery, and more effective control of insects and diseases.
Additional irrigation, either by pumps or from streams also should
increase the acre yield. Several areas, such as those near Rinc6n,
Aguadilla, Afiasco, Cabo Rojo, the east coast, and a narrow strip
along the northern coast would be greatly benefited by some irrigation.
TOBACCO (TABACO)
According to Barrett (6, p. 254), tobacco (known to the Arawaks
as cohoba) was widely cultivated in the Antilles long before they were
discovered by the Spaniards. It was chewed, smoked, and taken as
snuff by the aborigines. Dorsey (16, p. 796) states:
Tobacco is indigenous to the island, but in the earlier years of settlement its culti-
vation was interdicted, both by papal bulls and royal decrees, the latter issued in
1608. However, its cultivation was permitted by a special law passed in 1614.
By this same law the sale of tobacco to a foreigner was prohibited on penalty of
death and confiscation of property. Other stringent measures were enacted in
1777 and 1784, which by their very severity defeated their own purpose. In
1775 the crop reached 701,750 pounds. Production was large enough to permit
of exportation in 1836 (4,954,200 pounds), but by 1838 had declined to half that
amount. The maximum crop was that of 1880, when 12,000,000 pounds were
produced. The crop of 1897 reached 6,250,000 pounds.
According to the 1938-39 Annual Book on Statistics, the production
between 1921 and 1939 has ranged between 50 million pounds in 1927
and 6 million pounds in 1932, and the acreage has ranged from 81,900
acres in 1927 to 10,079 in 1932. The price received by the farmers
since 1921 has ranged from 39 cents a pound in 1926 to 11 cents a
pound in 1938. The production reported by the 1935 census of the
Puerto Rico Reconstruction Administration was 31,254,288 pounds
(84), or slightly less than that produced in Georgia in 1934, according
to the 1935 Federal census. The area in tobacco as reported by the
1935 census of the Puerto Rico Reconstruction Administration was
45,720 cuerdas, or 6.4 percent of the harvested cropland. This was
considerably less than the total area in tobacco in Georgia. Produc-
tion has dropped since 1934, as the Annual Book on Statistics reports
an area of only 18,688 acres in tobacco and a production of 11,688,384
pounds in 1939.















/ .... :^-./ ) '... y .i .. .. ." --....
) r* *





^^^ ,~~~~-T-\ -^^^
Jy (1 0 \ //
'C '* i .~-.- .. :. '":-.-..'...^ .

'..-.f :'-":'-1" .: ,< 0


1 .



FIGURE 47.-Distribution of tobacco in 1935. Each dot represents 100 acres.
Distribuci6n de tabaco en 1935. Cada punto represent 100 acres.


00
01







86 U. S. DEPARTMENT OF AGRICULTURE

Between 1916 and 1931 the value of the export tobacco ranked
second to that of sugarcane. Before 1916 it was exceeded by the value
of both coffee and cane, and since 1932 it has been exceeded by cane
and needlework. According to the Annual Book on Statistics
(1938-39), $7,621,006 worth of tobacco was exported in the fiscal
year 1939. Nearly the entire export crop is sent to the United
States. Included in this total is $26,985 worth of cigarettes and
$37,602 worth of cigars. The United States received all the ciga-
rettes and almost all of the cigars. Puerto Rico imported $132,517
worth of leaf tobacco during the fiscal year 1939, nearly all of which
came from the United States, with a small quantity from Cuba.
During the same year, Puerto Rico imported $3,491,023 worth of
cigarettes from the United States. The amount of money spent for
imported cigarettes was more than one-third of the total export value
of unmanufactured tobacco.
Compared with citrus or sugarcane, tobacco is a shallow-rooted
crop. Therefore it will grow and produce fair or good yields on shallow















FIGURE 48.-Some of the soils used for tobacco near Cayey. The more rolling
areas are Juncos clay, and the steeper areas are Mdcara silty clay loam. In
the foreground is a hurricane shed, a house, and a tobacco barn.
Algunos suelos sembrados de tabaco cerca de Cayey. Las areas mis ondulantes
son Juncos arcilloso, y las mas escarpadas son Mdcara limo-arciloso 16mico.
Al frente, una tormentera, casa y rancho de tabaco.

soil or on steep hillsides. The best yields and quality are obtained on
friable well-drained well-aerated soils that are neutral or alkaline in
reaction, rich in plant nutrients, and situated at considerable distances
from areas affected by the salt spray of the ocean. Tobacco is not
well adapted to the strongly acid red soils of the uplands, as the
acidity limits the supply of calcium and magnesium, as well as the
availability of the phosphorus, and favors excessive solubility of
aluminum and manganese. Areas of the Toa soils that are seldom
overflowed are the most productive, but probably the largest acreages
of tobacco are grown on the Mdcara, Juncos, and related brown
neutral soils of the uplands.
Figure 47 shows the distribution of the tobacco acreage in 1935,
according to the Puerto Rico Reconstruction Administration census.






SOIL SURVEY OF PUERTO RICO 87

It may readily be seen that there are four tobacco areas. The heart
of the largest is in the vicinity of Cayey. Tobacco in this area is
grown mostly on the neutral friable rolling Juncos soils and on the
neutral friable shallow very steep Micara soils (fig. 48). To the east
of Cayey tobacco is grown on the rolling granitic soils, among which
the Las Piedras and Cayagus are the most important (fig. 49). North-
west from Cayey considerable areas of Naranjito soils are used for the
growing of tobacco. The best tobacco is produced in the vicinity of
Cayey.. The second most important area for the production of this
crop is on the coastal plains in the vicinity of Isabela and eastward
from that place to Vega Baja. The tobacco in the latter section is
grown on the level or undulating soils derived from limestone, such
as the Coto, Maleza, Vega Alta, and Bayam6n soils and their shallow
phases. All these soils occupy valleylike areas between limestone hay-
stack hills. The third largest area is near Utuado, and the tobacco
















FIGURE 49.-CayaguA sandy clay loam near San Lorenzo, used mostly for the
production of tobacco, corn, and beans.
Cayagua areno-arcilloso 16mico cerca de San Lorenzo usado principalmente para
tabaco, maiz y habichuelas.
grown is good-quality cigar-filler tobacco. It is grown on the Utuado
and Jayuya soils which are derived from granite. The fourth largest
area is near Sabana Grande on nonirrigated semiarid lands, and the
tobacco returns low yields. It is grown in small patches, generally
on low slopes or in valleylike positions.
The procedure in growing tobacco is very similar to that followed in
the United States. Carefully selected seed of healthy, vigorous,
good-quality, adaptable varieties is first planted in well-prepared seed-
beds, which, generally, are small, gardenlike, banked beds located on
well-drained alluvial soils or on gentle slopes near the bases of the hills,
where the soil is friable, well drained, and fairly high in organic mat-
ter-all requirements of a good seedbed. About 1 acre of a well-pre-
pared and productive seedbed is required from which to plant from 130
to 140 acres. Selected seeds generally are planted under the protection
of cheesecloth (fig. 50), which helps to protect the young, tender plants






88 U. S. DEPARTMENT OF AGRICULTURE

from insects, intense direct sunlight, and the beating effect of dashing
rains.
The first seeds are planted in the beds during August, and generally
a second planting is made early in September. The seedbeds are well
fertilized. The plants are transplanted to the field during the last of
October, November, and the first of December. They should be well
protected from the sun during transplanting. They are set from 12
to 15 inches apart in rows spaced from 36 to 44 inches apart on well-
prepared, weed-free, well-drained soils. In nearly all of the fields on
slopes ranging from 40 to 100 percent, shallow ditches are dug around
every plot (which includes about 900 square feet), giving the field the
















FIGURE 50.-Tobacco seedbed under cheesecloth near Ciales. Limestone escarp-
ment in the distance.
Semillero de tabaco bajo toldo cerca de Ciales. Escarpa caliza a lo lejos.
appearance of a gridiron (fig. 51). These ditches enable the water to
drain rapidly without causing serious loss of soil from the fields. The
water travels but a short distance before it enters a ditch, and there-
fore it does not have time to develop much force to carry soil particles.
This method seems to be the best of any tried for the prevention of
serious erosion on the steep hillsides. Even with the many ditches,
there is some erosion, but this must be expected when clean cultiva-
tion is practiced on hillsides having 80- to 100-percent slopes. There
is only a small amount of gully erosion, however, as the bottoms of the
ditches are bedrock.
For a good quality of tobacco, it is of utmost importance to use
well-drained soils. Poorly drained soils are referred to by many farm-
ers as "cold" soils for tobacco, and they produce tobacco of poor
quality. Many of the sandy-textured soils produce a better quality
of leaf than do highly fertile clay or silty clay soils. Salt spray as well
as chlorides in the soil affect the quality.
Tobacco requires considerable quantities of readily available nitro-
gen and potash. The first application of fertilizer generally is made a
few days before planting, at the rate of about 400 pounds to the acre
of a 6-7-8 formula,18 and a duplicate application is made about 30
IS Percentages, respectively, of nitrogen, phosphoric acid, and potash.







SOIL SURVEY OF PUERTO RICO 89

days later. The fertilizer requirements for one soil type may or may
not be the same as for another, and only by experience and experi-
mentation can the best formula be obtained. The kind and quantity
of fertilizer used vary somewhat for the different kinds of tobacco.
Land for tobacco is cultivated two or three times, depending on the
weed growth. Generally all cultivation is done by hand, especially
on the steep hillsides. Hoeings should be made with the contour of
the land or up the slope rather than down the slope, as the latter prac-
tice tends to transfer the soil down the slope continually.
About 35 days after transplanting, the lower leaves of the tobacco
plant should be removed, in order to increase the circulation of air
















FIGURE 51.-Tobacco grown on Mdcara silty clay loam having a slope ranging
from 15 to 60 percent. Note the gridiron drainage ditches. The water travels
but a short way before it enters a ditch and therefore does not have time to
develop much force for carrying soil particles.
Tabaco cosechado en Mdcara limo-arcilloso 16mico con un declive que varia de
15 a 60 por ciento. N6tese las zanjas de avenamiento. El agua camina muy
poco antes de entrar a una zanja y por lo tanto no tiene tiempo de desarrollar
fuerza suficiente para transportar particular de suelo.
The terminal bud is pinched off at this time or a week or two later,
except from plants to be used for seed. The plant should be pruned,
leaving from 12 to 16 well-developed healthy leaves. Any suckers
that appear after pruning should be pinched off fairly near the axil.
Two methods are used in harvesting, which is done within about 90
days from the time the plants are transferred to the field. One is to
cut the entire plant when the leaves are yellowish green or yellowish
brown. The cut plants are allowed to wilt in the field, then are
carried to the tobacco shed and hung bottom end up to dry on 6-foot
sticks or bamboo poles that are suspended horizontally in racks one
above the other in six or seven tiers. The drying process is very
gradual, and the leaves and stems become yellowish brown and some-
what tough. The other method is to hand-pick the ripe leaves at
three different periods, starting first with the bottom leaves, then the
middle or best quality leaves, and finally the top ones. When the
leaves are being transported to the barn they should be protected






90 U. S. DEPARTMENT OF AGRICULTURE

from dust and sunlight. In the drying barns the leaves from the
different parts of the stem are kept on separate racks.
The leaves are stored in the drying barn for a period ranging from
20 to 30 days, depending on the weather. The barns or curing sheds
are built to protect the leaves from the sun, air currents, and excessive
humidity. Many different kinds of barns are in use, but the most
common type in the large tobacco-growing section near Cayey is a
wooden well-constructed tight-roofed building from 36 to 120 feet
long, 15 to 30 feet wide, and 15 to 30 feet high, with ventilation on all
sides. The height should equal the width. Many tobacco barns in
other districts, some of which are not more than 10 feet high, are
thatched with palm leaves and covered with matojo grass. On some
of the smaller farms the farmers cure their tobacco in their dwellings
(fig. 52) or in open sheds or barns, most of which seem to be located

















FIGURE 52.-Curing tobacco on the side of a dwelling.
Cirando,tabaco al lado de una casa.
without much regard to prevailing winds or exposure. They should
be so placed that they could have, if necessary, a good draft throughout
the building and should be located convenient to the tobacco fields.
Owing to a high content of moisture in the tobacco leaves, the drying
process must be watched closely, in order that the best chemical
changes may take place. The buildings must be closed during cold
nights and rainy days, and at times charcoal must be burned, to pro-
vide sufficient heat during long wet periods. During clear dry days
sufficient ventilation must be made by opening windows or doors.
When the midribs of the leaves are wrinkled and dry, the leaves have
dried sufficiently to be removed from their supports in the drying barn
and transferred to piles. This operation generally is done in the early
morning when the leaves are moist and flexible and are less likely to be
injured than if moved during the hot afternoon when they are dry
and brittle. The stems, together with the leaves, are put in piles
from 3 to 6 feet high, covered with banana leaves, and weighted with







SOIL SURVEY OF PUERTO RICO 91

rocks so that the plants will undergo a sweat. The length of time for
the first sweat depends on climatic conditions and ranges from 1 to 6
days. The leaves are then stripped from the stem and separated,
according to quality, in three grades and tied into bunches known as
manillas. These are taken to the fermentation house for fermenta-
tion. The fermentation house, which generally is small, should have
a wooden floor and very few windows, as air currents should be
avoided. The different grades of leaves are placed in separate piles
about 5 feet wide, 10 feet long, and 4 feet high, and are covered with
sacks.
If the leaves have been removed from the stems in the field and
classified when put in the tobacco barn, they are tied into packs when
dried and also taken to the fermentation house and put m piles for
fermentation. In order to obtain high-quality tobacco, the fermenta-
tion process must be watched closely, to see that the leaves in the piles
have the proper moisture content and gradually heat to about 132 F.,
then gradually reduce to 800, the temperature of the building. To-
bacco generally is in fermentation for about 3 months, and during this
time the piles may have to be opened, ventilated, and rebuilt many
times, in order to keep the leaves from becoming too hot, glued to
each other, or deteriorated in quality.
Most of the tobacco grown on the island is for cigar filler, although
most of that produced near Isabela is used for chewing. A few years
ago considerable cigar-wrapper tobacco was grown under cheesecloth
cover, but this is not the present practice. Practically no green-leaved
cigarette tobacco is grown, although the sandy-textured soils of the
Bayam6n and Maleza series and many other coastal plains soils
should be adapted for this kind of tobacco if they were properly
fertilized and the proper variety of tobacco planted.
The principal variety grown is Virginia Blanca, which can be har-
vested either by picking the leaf or by cutting the entire plant. It is
used for cigar filler. The Gigante is grown to sdme extent in dry areas.
The Connecticut Round Tip at one time was grown extensively under
cover.
The principal disease affecting the seedbed is salcocho, or damping-
off disease, which is controlled by spraying the soil with bordeaux
mixture. The change is destructive to young tobacco plants, especially
in sandy soils. This pest is controlled by putting paris green and wheat
flour around the tobacco stems or by encasing the young stems with
mamey leaves. Flea beetles and certain worms, such as the gusano,
gusano verde, pega pega, leaf miner, cuerudo, agrimensor verde, and
tijerillas, are pests in the tobacco districts. Flea beetles are controlled
by submerging the tops of the tobacco plants in lead arsenate solu-
tion before they are transplanted in the field. All the worms, except
the leaf miner, are controlled by dusting the plants with lead arsenate.
Tobacco mosaic, black shank, leaf spot, and bacterial wilt are
diseases attacking the plants. Mosaic and black shank are controlled
by destroying the infected plants. There is at present no known
control for leaf spot. Bacterial wilt is controlled by planting wilt-
resistant varieties.
The farms in the tobacco-growing sections are of various sizes.
In the Cayey district the average size probably is about 100 acres,
about 45 acres of which are in pasture, 30 acres in minor crops, such
as corn, beans, sweetpotatoes, and pigeonpeas, ranking in acreage in







92 U. S. DEPARTMENT OF AGRICULTURE

the order named, 20 acres in tobacco, and possibly a small acreage
in rice and coffee. The tobacco farms in the Isabela district are very
small, probably averaging less than 15 acres each, with more than one-
half of their area in pasture and almost valueless brush. Of the 7 or 8
acres in cultivated crops, corn probably occupies about 2Y acres,
beans 1% acres, sweetpotatoes 1 acre, and tobacco 1 acre; and the
remaining acreage is divided among plantains, pigeonpeas, yuca,
flames, yautia, and other subsistence crops. The average size of the
tobacco farms in the Utuado section is about 30 acres. Pasture
probably occupies about 10 acres; corn, coffee, and tobacco about
equal areas, or about 5 acres each; and the remaining 5 acres is used
for the production of subsistence crops, such as sweetpotatoes, beans,
yautia, and pigeonpeas. An average tobacco farm in the semiarid
section along the southern coast includes about 40 acres. Probably
30 acres are in pasture, 5 in tobacco, and the remaining 5 in corn,
beans, and other subsistence crops. At one time considerable cotton
was grown on these farms.
It is rather questionable whether the average size of the tobacco
farms will increase, that is, farms on which much of the income must
be derived from subsistence crops, in order to insure a living. More
net income to the acre is made on large tobacco farms than on small
ones, but a small acreage of tobacco can be planted by nearly every
farmer who plants subsistence crops in the tobacco-growing districts,
and he will continue to do so even though the cash returns may be
small. Subsistence farms undoubtedly will increase in number and
decrease in size as the increasing pressure of the population forces
people to cultivate the steeper hillsides.
The acre yield of tobacco is very similar to that in the United States.
In the vicinity of Isabela, acre yields ranging from 400 to 600 pounds
are common on the nonirrigated areas and from 700 to 900 pounds on
the irrigated lands. This tobacco is used for chewing and is twisted
in long ropelike pieces: It is sold in rolls of 25 or 30 pounds, at a
price ranging from $18 to $24 a hundred pounds. Tobacco does not
need nearly so much water as does sugarcane; therefore the farmers
who grow tobacco are reluctant in using irrigation water, although it
is available and increases the yield considerably, especially during
very dry years. The production in the Cayey section ranges from
2,000 pounds to the acre on the good Toa and Estaci6n soils to
400 pounds on the poorer grades of the Mdcara soils. Most of the
tobacco grown on average Mdcara soils yields about 700 pounds an
acre. The price for this tobacco is about $25 or $30 a hundred
pounds. The yield, price, and quality of the tobacco grown near
Utuado are comparable to those of tobacco grown near San Lorenzo,
which are nearly as good as of that grown near Cayey. Production
is low on the land in the semiarid section along the south coast, and it
probably will continue to be low, owing to the frequency of dry years.
Most of the land in this locality now used for tobacco would not be
very well adapted for tobacco if it were irrigated, but it would be
very good for sugarcane.
The general rotation practiced among tobacco growers is to prepare
the land for such minor crops as corn, beans, or sweetpotatoes soon
after the tobacco crop is harvested (fig. 53). The minor crops derive
some benefit from the fertilizer applied for the tobacco and produce







SOIL SURVEY OF PUERTO RICO '93

an additional income. After these crops are harvested the land is
prepared for the next crop of tobacco. The practice of producing
tobacco on the same land year after year applies to the good level
alluvial lands and the better grades of hill land. The steeper hill-
sides generally are planted to tobacco every 2 or 3 years and during
the other years are in pasture or minor crops. In the vicinity of
San Lorenzo considerable rice is planted after the tobacco has been
harvested.
The future outlook for the production of tobacco is fairly good for
ambitious, efficient young farmers, assuming that tobacco will con-
tinue to be protected by the tariff and that the island will not be forced
to sell on the open market. The ever-changing economic conditions
may in time be such that only small acreages will be devoted to tobacco
in certain districts, but, owing to favorable climate, soils, and a crop
which lends itself to small-scale farming, tobacco should continue















FIGURE 53.-Same area as that in figure 51. Picture taken a few months later.
Corn, beans, and yautia are growing on land that was in tobacco a few months
before.
La misma area de la fig. 51. Fotograffa tomada unos meses mis tarde. Siembras
de mafz, habichuelas y yautia donde meses antes habfa tabaco.
to be the second leading commercial crop, and many thousands of
laborers should obtain employment in the tobacco-stripping shops.
Disputes between employees and employers which terminated in
strikes have resulted in a curtailment of the acreage and a loss both
to the employees and employers.
The quality of the tobacco should be improved, as the market favors
a filler tobacco that has perfect combustibility and an agreeable aroma.
The wrapper tobacco should contain a small quantity of nicotine and
have a light color, fine texture, and small veins. The chewing, or roll,
tobacco should contain considerable glutinous juice and be fairly sweet.
Living conditions could be improved on all the farms producing
tobacco if more livestock were produced to supply a milk, cheese,
butter, and meat diet to the people who now receive a very low per-
centage of protein in their food.







94 U. S. DEPARTMENT OF AGRICULTURE

COFFEE (CAFE)
Coffee is believed to have been introduced into Puerto Rico in the
eighteenth century by the French refugees from Haiti. The crop is
produced on a low, diffusely branched small tree or shrub that is always
green. The coffee tree has a soft gray bark and dark-green glossy




































FIGURE 54.-Coffee berries are produced on the 1%- or 2-year-old growth of the
lateral branches. (Courtesy of Office of Experiment Stations, U. S. Department
of Agriculture.)
La uva del caf6 se produce en las ramas laterales de 1% 6 2 aflos de edad. (Cortesfa
de la Oficina de Estaciones Experimentales.)
oblong leaves. The blossoms are star-shaped, have white petals and
yellow centers, and have both fragrance and beauty. The dull-green
plump olive-shaped berries grow in clusters close to the stem in the
axils of the leaves (fig. 54) and turn red when ripe. Most of them are







SOIL SURVEY OF PUERTO RICO 95

produced on the 1)j- or 2-year-old growth of the lateral branches,
although some are produced on the 3-, 4-, and 5-year-old branches.
At elevations ranging from 1,000 to 1,500 feet above sea level the
coffee berries begin to ripen during September and October, or about
7 months from the time of blossoming. At elevations of about 80 feet,
such as in the vicinity of Mayagiiez, blossoming is advanced at least
a month ahead of that at the higher elevations.
Each coffee berry contains two seeds, or coffee beans. The first
berries picked are of poor quality. The main crop matures in October
or November, depending on the elevation, and it is picked at intervals
of about 15 days until all the berries have been gathered. The sev-
eral ripenings correspond to the several blossomings in the spring.
Only the ripe berries are picked, except at the last picking, when all
the remaining berries are collected. The pickers, mostly women and
children, strip the ripe berries from the branches, allowing them to
drop into baskets, and, in turn, they are emptied into sacks which are
carried when filled to the drying floor, where the berries are spread to
dry overnight. In the morning they are sorted and taken to the
hulling machine, or despulpadora, which consists either of one roller
with many dull-pointed nails or the more modern disk-shaped ma-
chine. The machines may be turned by hand or by power, depend-
ing on their size. They remove the outer hull, or pulp, which falls
to one side and is later used as a fertilizer. The coffee grains fall into
a fairly large bin where they sweat or ferment for a period ranging
from 8 to 12 hours. This process loosens the sweet sticky colorless
substance called baba with which they are covered. The baba must
be removed, and it is more easily washed off after the berries sweat
for a few hours. During the washing process the poorer grains float
and are strained off. After the water is drained away, the berries
are taken to the dryer which usually is either a cement floor, called
glacis, or consists of large shallow boxes, called correderas, that are
mounted on tracks and can be pushed out in the sun during the day
and put under shelter during rams and at night. The coffee is stirred
occasionally, so that all the excess wash water will evaporate. When
this operation is completed the coffee is said to be enjugado, or in a
semidry condition. Every hundred pounds of this semidry coffee
will make 46 pounds of cascara seca, or dry coffee. To obtain the
dry coffee, the natural water in the berry must be evaporated. This
is done, in most places, by putting the berries in toldas, or square
pieces of cloth, and placing them in the sun or directly on the glacis
(fig. 29). It takes from 3 to 5 days to dry the berries. A hundred
pounds of the dry coffee will make only 80 pounds of coffee ready to
be roasted, as the yellow brittle outer covering must yet be removed.
This may or may not be done on the farm. The coffee is sacked in
100-pound bags, and generally two bags are strapped to the back of a
mule or a pony and thus conveyed to town or to the highway and then
loaded into trucks to be taken to town where the coffee is sold or
stored for future market. The wholesale dealer generally hulls, sorts,
sizes, and polishes the coffee before he sells it. The price of coffee on
the farm ranges from $10 to $24 a hundred pounds, depending on the
supply, market demand, and quality. Coffee yields range from less
than 50 pounds to more than 600 pounds an acre, depending on the
soil, location, age and number of trees, condition of shade trees, man-
agement, and climate. The variety most commonly grown is Coffea







96 U. S. DEPARTMENT OF AGRICULTURE

arabica (29, p. 2), and for high yields and long production it must be
protected from the direct sunlight, although a medium amount of
diffused sunlight is essential. Bananas and plantains are planted for
temporary shade or until the permanent shade trees supply the coffee
trees with enough protection from the sun. The trees commonly
planted for permanent shade (fig. 55) are the guamd, on wind-exposed
slopes and on high elevations, and the guaba and moca on medium
elevations. The guam& is an excellent shade tree, but it is suscepti-
ble to injury from the hormigiiilla, a small ant that migrates to the
coffee trees from heavily infested shade trees. This insect bores
tunnels in the coffee trees, thereby weakening the branches, causing
them to be easily broken by the wind and during harvest. The guaba
tree is preferred to the moca, as it is a fast-growing tree, is easily
pruned, and does not scatter hundreds of prolific seeds as does the
moca. Cutting the seedlings of the moca increases the cost of culti-
vation of coffee.
The shade trees should be spaced from 24 to 30 feet apart each way
when they are fully grown, but they must be planted much thicker
and some trees eliminated as they develop. The coffee trees should
be planted about 9 feet apart. The height of the coffee tree should
not be much more than 9 feet, in order that the crop may be gathered
easily and also that many lateral berry-producing branches will be
formed. The height of the coffee trees can be regulated to some
extent by the number of shade trees planted to the acre and by pruning.
Coffee can be grown on the same land for many years. The coffee
trees are fully grown at about 10 years of age, and they will continue
to produce for another 10 years or more if they receive proper care.
Each tree varies in yield in accordance with location, fertility, soil,
shade, moisture, and vigor. Yields range from less than one-fourth
pound to nearly 5 pounds a tree. Under favorable conditions and
proper management the trees start producing 18 months after plant-
ing, but, as a general rule, very few berries are produced before the
third year, and even under favorable conditions most trees do not
produce more than one-half pound of berries each before they are 5
years old. The yields of coffee usually are higher every second year,
partly because after a heavy production the trees have fed so heavily
on the soil nutrients that nearly 2 years are required for the trees to
obtain from the soil sufficient available nutrients to produce another
good crop. The difference in yearly yields is not so noticeable if fer-
tilizer is used each year. The production of coffee is much higher on
concave slopes where the soil is richer and deeper than on the convex
slopes. Coffee that will yield 50 pounds to the acre on convex slopes
will yield from 300 to 500 pounds on concave slopes. Yields of coffee
decrease with an increase in the slope of the land. Fairly high yields
can be grown on 60-percent slopes, however, but yields are low on
slopes ranging from 80 to 100 percent. Some of the best coffee farms
are in Barrios Mameyes Abajo and Tetuan in the municipality of
Utuado and in Barrio Front6n in the municipality of Ciales. Most
of these farms are on slopes of 30 or 35 percent, and the soil is deep, is
well drained, and is high in organic matter. Land values vary with
location, road facilities, elevation, soil, degree of slope, extent to which
erosion has taken place, and climate. At present (1938) land in good
productive coffee trees, yielding about 400 pounds to the acre, is valued
between $125 and $150 an acre. Land producing about 200 pounds









SOIL SURVEY OF PUERTO RICO 97


is valued at $80 or $90, and land producing only 50 pounds is valued
at $40 or $50. Similar land in pasture is valued at about $30 or $40.
The estimated cost of planting an acre of coffee trees is about $50.







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Coffee of the best quality is grown at elevations of more than 1,500
feet above sea level, but, owing to the greater destruction from wind
at high elevations, most of the coffee now grown is below an elevation
144035--41-7




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