• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Introduction
 The sawgrass peat area
 Necessary water control
 Climatic factors and growth of...
 Early experiments with grasses
 Mineral composition of grasses
 Influence of fertilizers upon yield...
 Protein, fat and fiber of pasture...
 Fertilizer requirements for dallis...
 Response to nitrogen
 Muriate versus sulfate of...
 Greenhouse experiments with dallis...
 Yields of carpet grass on fertilizer...
 Discussion and summary
 Literature cited














Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 338
Title: Yield and composition of Everglades grass crops in relation to fertilizer treatment
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00015117/00001
 Material Information
Title: Yield and composition of Everglades grass crops in relation to fertilizer treatment
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 30 p. : ill., charts ; 23 cm.
Language: English
Creator: Neller, J. R ( Joseph Robert ), 1891-
Daane, A
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1939
 Subjects
Subject: Grasses -- Composition   ( lcsh )
Grasses -- Fertilizers -- Florida -- Everglades   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 29-30.
Statement of Responsibility: by J.R. Neller and A. Daane.
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station)
 Record Information
Bibliographic ID: UF00015117
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000924568
oclc - 18214699
notis - AEN5195

Table of Contents
    Front Cover
        Page 1
    Front Matter
        Page 2
    Introduction
        Page 3
    The sawgrass peat area
        Page 4
    Necessary water control
        Page 5
    Climatic factors and growth of grass
        Page 6
    Early experiments with grasses
        Page 7
    Mineral composition of grasses
        Page 8
    Influence of fertilizers upon yield and phosphorus content
        Page 9
        Page 10
        Page 11
        Page 12
    Protein, fat and fiber of pasture grasses
        Page 13
    Fertilizer requirements for dallis grass hay
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
    Response to nitrogen
        Page 22
    Muriate versus sulfate of potash
        Page 23
    Greenhouse experiments with dallis grass
        Page 23
        Page 24
        Page 25
        Page 26
    Yields of carpet grass on fertilizer plots
        Page 27
    Discussion and summary
        Page 27
        Page 28
    Literature cited
        Page 29
        Page 30
Full Text
[03 F (,56


Bulletin 338


October, 1939


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA
WILMON NEWELL, Director




YIELD AND COMPOSITION OF

EVERGLADES GRASS CROPS

IN RELATION TO

FERTILIZER TREATMENT

By J. R. NELLER and A. DAANE


Fig. 1.-Devon cattle grazing on a Dallis grass pasture of the Everglades Experiment
Station farm.


Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA










EXECUTIVE STAFF

John J. Tigert, M.A., LL.D., President of
the University3
Wilmon Newell, D.Sc., Directors
Harold Mowry, M.S.A., Asst. Dir., Research
V. V. Bowman, M.S.A., Asst. to the Director
J. Francis Cooper, M.S.A., Editor3
Jefferson Thomas, Assistant Editors
Clyde Beale, A.B.J., Assistant Editors
Ida Keeling Cresap. Librarian
Ruby Newhall, Administrative Managers
K. H. Graham, Business Managers
Rachel McQuarrie, Accountants


MAIN STATION, GAINESVILLE

AGRONOMY
W. E. Stokes, M.S., Agronomist'
W. A. Leukel, Ph.D., Agronomists
G. E. Ritchey, M.S., Associates
Fred H. Hull, Ph.D., Associate
W. A. Carver, Ph.D., Associate
John P. Camp, M.S., Assistant
Roy E. Blaser, M.S., Assistant

ANIMAL HUSBANDRY
A. L. Shealy, D.V.M., Animal Husbandman' 3
R. B. Becker, Ph.D.. Dairy Husbandman3
L. M. Thurston, Ph.D., Dairy Technologist3
W. M. Neal, Ph.D., Asso. in An. Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarians
N. R. Mehrhof. M.Agr., Poultry Husbandman8
W. G. Kirk, Ph.D., Asso. An. Husbandman"
R. M. Crown, M.S.A., Asst. in An. Husb.3
P. T. Dix Arnold, M.S.A., Assistant Dairy
Husbandman'
L. L. Rusoff, M.S., Asst. in An. Nutritions

CHEMISTRY AND SOILS
R. V. Allison, Ph.D., Chemist' 3
F. B. Smith, Ph.D., Microbiologists
C. E. Bell, Ph.D., Associate Chemist
H. W. Winsor, B.S.A., Assistant Chemist
J. Russell Henderson, M.S.A., Associates
L. H. Rogers, M.A., Asso. Biochemist
Richard A. Carrigan, B.S., Asst. Chemist

ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agricultural Economist1
Bruce McKinley, A.B., B.S.A., Associate
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Assistant

ECONOMICS, HOME
Ouida Davis Abbott, Ph.D., Specialist,
Ruth Overstreet, R.N., Assistant
R. B. French, Ph.D., Associate Chemist

ENTOMOLOGY
J. R. Watson, A.M., Entomologist'
A. N. Tissot, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant

HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist'
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Horticulturist8
R. J. Wilmot, M.S.A., Specialist, Fumigation
Research
R. D. Dickey, B.S.A., Assistant Horticulturist
J. Carlton Cain, B.S.A., Asst. Horticulturist
Victor F. Nettles, M.S.A., Asst. Hort.

PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist' a
George F. Weber, Ph.D., Plant Pathologist3
L. O. Gratz, Ph.D., Plant Pathologist
Erdman West, M.S., Mycologist
Lillian E. Arnold. M.S.. Assistant Botanist


BOARD OF CONTROL
R. P. Terry, Chairman, Miami
Thomas W. Bryant, Lakeland
W. M. Palmer. Ocala
H. P. Adair, Jacksonville
Chas. P. Helfenstein, Live Oak
J. T. Diamond, Secretary, Tallahassee

BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY
J. D. Warner, M.S., Agronomist Acting in
Charge
R. R. Kincaid, Ph.D., Asso. Plant Pathologist
Jesse Peeves. Farm Superintendent
V. E. Whitehurst, Jr., B.S.A., Asst. An. Husb.

CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Horticulturist in Charge
John H. Jefferies. Superintendent
Michael Peech, Ph.D., Soils Chemist
B. R. Fudge, Ph.D., Associate Chemist
W. L. Thompson, B.S., Asso. Entomologist
W. W. Lawless, B.S., Asst. Horticulturist
R. K. Voorhees, M.S., Asst. Plant Path.

EVERGLADES STATION, BELLE GLADE
J. R. Neller, Ph.D., Biochemist in Charge
J. W. Wilson, Sc.D., Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane
Physiologist
Frederick Boyd, Ph.D., Asst. Agronomist
G. R. Townsend, Ph.D., Plant Pathologist
R. W. Kidder, M.S., Asst, An. Husbandman
W. T. Forsee, Ph.D., Asso. Chemist
B. S. Clayton, B.S.C.E., Drainage Engineer2

SUB-TROPICAL STATION, HOMESTEAD
W. M. Fifield, M.S., Horticulturist Acting in
Charge
S. J. Lynch. B.S.A., Asst. Horticulturist
Geo. D. Ruehle, Ph.D., Asso. Plant Pathologist

W. CENTRAL FLA. STA., BROOKSVILLE
W. F. Ward, M.S., Asst. An. Husbandman
in Charge2

FIELD STATIONS
Leesburg
M. N. Walker, Ph.D., Pant Pathologist in
Charge
K. W. Loucks, M.S., Asst. Plant Pathologist
Plant City
A. N. Brooks, Ph.D., Plant Pathologist
Cocoa
A. S. Rhoads, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist
Monticello
Samuel O. Hill, B.S., Asst. Entomologist2
Bradenton
Jos. R. Beckenbach, Ph.D., Truck Horticul-
turist in Charge
David G. Kelbert, Asst. Plant Pathologist
Sanford
R. W. Ruprecht, Ph.D., Chemist in Charge,
Celery Investigations
W. B. Shippy, Ph.D., Asso. Plant Pathologist
Lakeland
E. S. Ellison, Meteorologist2
B. H. Moore, A.B., Asst. Meteorologist2

'Head of Department.
'In cooperation with U.S.D.A.
3Cooperative, other divisions. U. of F.
'On leave.










YIELD AND COMPOSITION OF EVERGLADES
GRASS CROPS IN RELATION TO

FERTILIZER TREATMENT

By J. R. NELLER and A. DAANE1
CONTENTS
Page
The Sawgrass Peat Area ............... ......................... 4
Necessary W ater Control ............................................ ................ 5
Climatic Factors and Growth of Grass ............................................. 6
Early Experiments with Grasses ......................................... .... ... 7
Mineral Composition of Grasses ........................ .......... ........... 8
Influence of Fertilizers upon Yield and Phosphorus Content ........ 9
Protein, Fat and Fiber of Pasture Grasses ..................................... ... 13
Fertilizer Requirements for Dallis Grass Hay ..............-......... ..... 13
Response to Nitrogen ............. ............................ 22
Muriate versus Sulfate of Potash ........................................................ .... 23
Greenhouse Experiments with Dallis Grass ......................................... 23
Yields of Carpet Grass on Fertilizer Plots ..... ............................. .... 27
Discussion and Sum m ary ........................................ ........................ ... 27
Literature Cited .................................................................................. 29

Early in its history the Everglades Experiment Station began
to investigate the growing of grasses on the organic soils of
the Everglades. In general, peat and muck lands are known
to be favorable for grass crops, but conditions peculiar to the
Everglades precluded the drawing of conclusions from results
that have been obtained in other areas of organic soils as to the
agricultural possibilities of grasses for either forage or pasture.
The subtropical nature of the climate of the, Everglades
pointed to the advisability of utilizing grasses indigenous to
the tropical and south temperate zones. It was known, however,
that frosts may occur here from time to time during the winter
months. The high humidity and the occurrence of frequent
though brief rains during the summer months indicated that
hay making would be limited largely to the possibilities of arti-
ficial drying. Experience has shown this to be true and experi-
ments have not yet been conducted to determine whether the
artificial drying of hay is practical for the region. But experi-
mentation has progressed far enough to demonstrate that the
utilization of grass crops by pasturing has much of promise.
Certain of the grasses have an unusually high carrying capacity,
especially during the summer months, and considerable grazing
can be done throughout the entire year.
This bulletin presents information that has been obtained in
relation to fertilizer requirements, yields and nutritive composi-

1Daane deceased; formerly Agronomist in Charge, Everglades Experi-
ment Station.







Florida Agricultural Experiment Station


tion of grasses as fed to cattle in the form of hay and by pasture
grazing. As mentioned above it remains to be determined
whether the artificial drying of hay may be practical and one
phase of that study is embodied herein;-viz., the yield, quality,
water control and fertilizer requirements of some of the grasses
S that have shown themselves to be adapted culturally to the
I region.
S Since the Everglades are composed of organic soils which
have a low reserve of certain minerals it is essential to know
whether the mineral content of the grasses can be amply main-
tained by a fertilizer practice that is economical. Special atten-
tion is given to the use of phosphates for the reason that a
marked response to phosphates develops early in the history of
most crops grown on the sawgrass peat soil area where these
experiments were conducted. Unless sufficient phosphate fer-
tilizer is used crops of poor feeding value might result because
of too low a content of phosphorus.

THE SAWGRASS PEAT AREA
The Everglades of Florida comprise a region of about
3,000,000 acres of organic soils extending in a southeasterly
direction from Lake Okeechobee, bordered on the east by marine
deposits of sand and calcareous rock and on the west by an
expanse known as the Big Cypress Swamp. The area adjacent
to the lake is classified as custard apple muck, which is com-
prised of plastic layers originating from sedimentation and from
aquatic plants alternating with deposits from the reed-like plant
known as sawgrass, Cladium effusum. This narrow zone of
custard apple muck merges out into a region called sawgrass
peat, formed almost entirely from the sawgrass plant.
The inorganic or mineral content of sawgrass peat averages
above 10 percent in cultivated areas and somewhat below 10
percent in unplowed soils still covered with a growth of saw-
grass. The peat is eight feet or more in depth at points nearest
to Lake Okeechobee and gradually becomes thinner at greater
distances from the lake. The entire region is underlaid with
marl rock, a factor of great importance as the soil waters con-
tain calcium and magnesium in solution (4)2 sufficient to keep
the soil in a condition favorable for plant growth without the
necessity of liming. In areas under water control the pH of
'Italic figures in parentheses refer to "Literature Cited" in the back
of this bulletin.







Yield and Composition of Everglades Grass Crops


the surface soil ranges from 5.5 to 6.0 and increases to about
7.0 at lower depths.

NECESSARY WATER CONTROL
The Everglades comprise an extremely flat expanse with an
elevation adjacent to Lake Okeechobee of about 17 feet above
mean sea level and a very slight slope east of southward. The
water level on the cultivated area is controlled almost entirely
with low lift pumps. Water is conducted to and from the pumps
by means of a system of field ditches that lead to the larger
drainage ditches and canals. Water movement is facilitated
by mole drains 30 to 36 inches below the surface soil from 12
to 18 feet apart leading from the field ditches across the fields.
These mole drains are quickly and cheaply established by means
of a tractor and moving machine and have become an important
part of the water control system on all of the better class farms.
A considerable part of the farmed area is in one of the several
drainage districts whose pumps supply part of the necessary
water control. The remainder comes from privately owned
pumping units. Power for pumping is supplied to a slight
extent by electric motors but mostly by engines of the Diesel
or semi-Diesel type.
The question of sufficient water control for the protection
of crops is one of great importance. For certain crops, espe-
cially some of the vegetables, it is essential that too high a
water level should be reduced with the minimum of delay. Grass.
and sugarcane crops are not so sensitive to temporary periods
of high water levels. And while the rainfall is not extreme it
comes oftentimes in brief heavy downpours that far exceed the
removal rate of a practical pumping system. The problem, there-
fore, is to establish a system with a pumping capacity that is
high enough to offer sufficient protection, but not too expensive
to construct and maintain. At the Experiment Station there
is a maximum removal capacity of three acre inches per 24
hours. This appears to be about the proper capacity and it has
been adopted for several of the successful farms of the region.
This brief summary of water control should not be closed
without mentioning that a system of mole lines, ditches and
canals should serve not only in the removal of excess water, but
also in the conducting of water into the fields during those
periods when there is insufficient rain to keep the water level
high enough in the soil to provide for good growing conditions.








6 Florida Agricultural Experiment Station .

Practically every year during the dry season, which extends
normally from November to May, considerable water has flowed
back into the fields on the Station farm from the Hillsborough
Canal and on a few occasions it has been necessary to pump it
into the field ditches in order to maintain a water level 18 to
22 inches below the soil surface.

CLIMATIC FACTORS AND GROWTH OF GRASS

Except for brief periods of frost, grass and hay crops con-
tinue to grow throughout the entire year in the Everglades.
Table 1, which records the average monthly temperature, rain-
fall and evaporation from an open pan at the Everglades Experi-
ment Station for the years 1924-1937, inclusive, shows that the
heaviest rainfall occurs during June, July, August and Septem-
ber and the least during November, December and January.
These wet and dry seasons roughly parallel changes in length
of day and of temperature and the resultant of these climatic
TABLE 1.-AVERAGE MONTHLY RAINFALL, MEAN MAXIMUM AND MINIMUM
TEMPERATURES, AND EVAPORATION FROM AN OPEN PAN FOR 1924-37 AT
THE EVERGLADES EXPERIMENT STATION.

Rainfall Temperature Evaporation
Month Inches Max. Min. Inches
I Degrees F. Degrees F.
January .......... 1.75 76.0 52.6 3.67
February ....... 1.75 76.9 52.0 4.04
March ............ 3.43 78.1 52.5 5.73
April .......... 3.67 82.2 57.3 6.54
May ................ 4.63 85.7 62.6 7.26
June ..............- 10.23 88.1 66.9 6.14
July ............-...( 6.98 90.6 69.2 6.70
August .......... 8.62 91.0 70.2 6.30
September ...... 9.36 88.6 70.3 5.44
October ........... 4.56 84.5 66.1 5.12
November ........ 2.80 77.8 58.0 3.92
December ........ 1.12 75.6 53.2 3.40

Totals ...-.......... 58.90 64.26







Yield and Composition of Everglades Grass Crops


relations is effective in causing the grasses to grow most pro-
fusely during spring and early summer, followed by slower vege-
tative growth and seed forming tendencies in the late summer
and fall. These characteristics are shown especially by Dallis
grass (Paspalum dilatatum) and to a lesser extent by the carib
(Eriochloa subglabra), carpet (Axonopus compressus) and cen-
tipede (Eremochloa ophiuroides) grasses discussed below. It
is probable that length of day and temperature have more effect
upon growth than rainfall in a perennial crop such as a grass
for the reason that when the water level is maintained in the
soil irrespective of rainfall, as discussed above under water
control, a well established root system is supplied with sufficient
water from below.

EARLY EXPERIMENTS WITH GRASSES
In the fall of 1929 about two and one-half acres of the Sta-
tion farm were seeded to a mixture of Dallis, Bahia and carpet
grasses. This land was first plowed in 1924 and served for a
time as a Para grass pasture until the grass was killed during
the winter of 1925 due to a combination of frost and too close
grazing. The land was planted to Dallis, Bahia and lespedeza
in the early fall of 1928. This stand was killed because of the
prolonged period of high water that resulted from the overflow
of Lake Okeechobee following a hurricane. Flooding of that
nature is no longer likely for the Everglades because of the
construction by the Federal Government of a substantial dike
around the southern end of the lake.
Previous to the planting of this area in the fall of 1929 it
was given a dressing of copper sulfate at the rate of 50 pounds
per acre to conform with the requirement that Allison, et al (1)
had found to be necessary for sawgrass peat lands. The Dallis
and carpet grass seed started well, but Bahia appeared to only
.a slight extent due to poor germination. The Bahia grass has
persisted,: however, but the carpet grass was soon smothered
out. This area has been used continuously as a pasture and
still furnishes good grazing on a firm sod.
This initial success in the establishment of a pasture resulted
in the securing of a herd of purebred Devon cattle for the
Station in the fall of 1931. To provide additional pasturage
for these animals five one-acre areas were planted to carpet,
centipede and Dallis on each of three of these acre lots, and of
a mixture of Dallis and carpet and of Dallis and centipede on







Florida Agricultural Experiment Station


the fourth and fifth acres, respectively. These pastures' are
still in use, but the carpet and centipede grasses have been
largely smothered out by sedge and by Bermuda grass. The
centipede grass also has largely disappeared from the area
where it was planted with Dallis grass. Dallis grass only was
obtained where it was sown with carpet grass.

MINERAL COMPOSITION OF GRASSES
Before the virgin soil of these five acres was planted to these
grasses in the fall of 1931 a fertilizer dressing was disked in;
it consisted of 40 pounds of copper sulfate and 150 pounds of
sulfate of potash per acre. During the spring and summer of
1934 samples of grass were hand plucked monthly from the
carpet, Dallis and centipede acres for the purpose of determin-
ing the mineral composition of the grasses as grazed by the
cattle. This study was prompted by indications of bone weak-
ness in some of the lactating cows and their calves that were
maintained on these and other pastures on the Station farm.
Table 2 records the percentages of phosphorus (P205) that
these grasses contained during the months of April, May, June
and July. Results are also included from Dallis and carib grass
pastures planted in December, 1932. These last two pastures
received a fertilizer dressing before planting of 50 pounds of
copper sulfate and 200 pounds of muriate of potash per acre.

TABLE 2.-PHOSPHORUS CONTENT OF GRASSES PLUCKED FROM FIVE
PASTURES IN 1934.

Percentages of P2O, on Oven-dry Basis
Date Plucked Dallis Dallis1 Carib1 Centipede Carpet
Grass Grass Grass Grass Grass

May 2 ............ 0.90 0.63 0.87 0.84
June 8 ............. 0.98 0.92 1.25 0.73
July 26 ........ 0.81 0.89 0.91 0.59 1.16

Average ........... 0.90 0.81 1.01 0.72 1.16

1These two pastures were planted in December, 1932, and the other three in Septem-
ber, 1931.

In addition to phosphorus the grasses plucked on May 2 and
July 26 were analyzed also for other elements (Table 3). It
is to be expected that the calcium and magnesium contents of








Yield and Composition of Everglades Grass Crops


grass in Everglades peat land should be normal to high at all
times because of the large amounts of these elements that are
present in the soil waters (4) by virtue of the marl substratum
that lies next to the organic soil layer. It is to be expected
also that the available native phosphorus will soon become de-
ficient in sawgrass peat soil and this hypothesis is verified in
the experiments recorded in the following section.

TABLE 3.-MINERAL COMPOSITION OF PLUCKED PASTURE GRASSES.

Given as Percentages of Oven-dry Grass
Ingredient Dallis' Dallis Caribl Centipede Carpet
Grass Grass Grass Grass Grass
Plucked May 2, 1934

Calcium (CaO) .......... 1.20 0.94 0.75 0.74
Magnesium (MgO) 1.12 1.27 1.05 1.17
Phosphorus (P2Os) .... 0.90 0.63 0.87 0.84
Iron (FeOs) ............. 0.027 0.031 0.036 0.026
Silicon (SiO2) ............ 1.25 0.92 1.07 0.72
Ash ........................... 8.86 5.87 8.93 6.20

Plucked July 26, 1934

Calcium (CaO) .......... 0.72 0.97 0.48 0.82 0.88
Magnesium (MgO) .. 0.72 0.99 0.42 0.68 0.63
Phosphorus (P,05) .... 0.89 0.81 0.91 0.59 1.16
Iron (FeOa) .............. 0.014 0.016 0.016 0.019 0.040
Silicon (SiO2) ........... 2.25 1.58 2.33 1.93 1.77
Ash ............................. 7.23 7.24 9.79 5.97 7.45

'These two pastures were planted in December, 1932, and the other three in Septem-
ber, 1931.:

INFLUENCE OF FERTILIZERS UPON YIELD AND
PHOSPHORUS CONTENT

On August 1, 1934, a series of fertilizer plots was laid out
in a fenced area of a Dallis grass pasture that had been planted
in December, 1932, on virgin sawgrass peat. In preparation
for that planting the land received a dressing of 50 pounds of
copper sulfate and 200 pounds of muriate of potash per acre.








10 Florida Agricultural Experiment Station

On the fertilizer plots triple phosphate (44% P205) was used
at the rate of 66 pounds per acre and muriate of potash
(50% KO2) at the rate of 120 pounds per acre (Table 4). The
sulfate forms of copper, zinc and manganese were used also
in one of the treatments at the rates of 40, 12 and 40 pounds
per acre, respectively.

TABLE 4.-TOTAL DRY YIELDS IN POUNDS PER ACRE AND AVERAGE PROTEIN
AND PHOSPHORUS CONTENT OF CLIPPINGS OF GRASS FROM AREAS 1, 2
AND 2A OF A DALLIS GRASS PASTURE.


Treatment


Area 1. Eight C]

N one ..... .................

Potash only ................

Phosphate and potash

Phosphate, potash
and minor elements'


Yields I Phosphorus2 I Total Nitrogen2
Rela- Rela- Rela-
Per tive to As tive to As tive to
Acre Potash P20s Potash Protein Potash
Lbs. Only % Only % Only


clippings, August 1,

5,820 50

11,548 100

14,548 126

13,668 118


1934, to September 6, 1935

0.63 109 14.58
0.58 100 13.97

0.71 122 13.36

0.71 122 14.44


Area 2. Eight Clippings, November 8, 1935, to


None ...........................
Potash only .............

Phosphate and potash
Phosphate, potash
and minor elements'


5,228
10,804

12,820

13,080


September 22, 1936

122 18.23 107
100 17.07 100

136 17.56 103

136 17.47 102


Area 2a. Seven Clippings, November 10, 1936, to October 25, 1937

None ............................ 848 15 0.62 168 17.73 115
Potash only .............. 5,708 100 0.37 100 15.46 100

Phosphate and potash 9,176 161 0.57 154 17.60 114

Phosphate, potash
and minor elements' 8,960 157 0.58 157 18.17 118

'These were the sulfates of copper, manganese and zinc.
2These are simple averages as they represent the concentration of the elements better
than weighted averages from the standpoint of pasture condition.







Yield and Composition of Everglades Grass Crops


The plots were in triplicate for each treatment, 1/400 acre
in size with three and one-half foot borders and the fertilizer
for a given plot was applied to the middle of its borders. Before
cuttings were obtained the borders were removed with a small
power mower which cut a swath the exact width of the borders.
Since the sickle of the mower is in front of the drive wheels
(Fig. 2), the grass in the plots is not run down in the process
of cutting out the borders. And where the growth of grass is
continuous across plot and border there is less of a border effect
than in plots separated from each other by cleanly cultivated
strips.





















Fig. 2.-Harvesting equipment in use on the Dallis grass fertility plots. The sickle of
the power mower is 3% feet wide and the mower is used to cut out borders of that width
between the plots.

Table 4 records the total yields per treatment for the eight
cuttings of grass that were obtained from these plots of Area 1
from August 1, 1934, to September 6, 1935. The data of
Table 4 are based on oven-dry weights which averaged 20%
of the green weights. The phosphorus content was considerably
higher in the grass of the first cutting from the plots that re-
ceived phosphate, but it decreased in succeeding cuttings until
in the fifth it was no higher than in the grass from plots that
received potash only. A reapplication of fertilizer after the
fifth cutting of May 23 caused the phosphorus content of the







Florida Agricultural Experiment Station


next three cuttings to be distinctly higher than those that re-
ceived potash only. The average effect from the eight cuttings
covering a period of 13 months was to increase the phosphorus
content of grass from the phosphate treated plots by 22%
(Table 4), with a corresponding increase in yield of 26%. The
inclusion of the sulfates of copper, manganese and zinc was
without apparent effect. Potash alone more than doubled the
yield.
On October 11, 1935, another area of the pasture was fenced
off and fertilized as given above for Area 1, Table 4. On
December 24, 1934, this pasture received a top-dressing of 50
pounds of triple superphosphate and 100 pounds of muriate
of potash per acre. This was the second fertilizer treatment
for the pasture, the first having been made when the grass was
planted in 1932. Table 4 shows that for the eight clippings
obtained from this second set of plots (Area 2) the effect of
potash alone and of phosphate with potash was about the same
on yields and phosphate content of grass as in Area 1. This
demonstrated that the pasture had not received enough phos-
phorus and potash to render anywhere near its potential yield-
ing capacity and that the higher fertility level also increased
the phosphorus content of the greatly increased yields.
A year after it was fertilized Area 2 was given a second
treatment on October 12, 1936. The seven clippings obtained
during the ensuing year (Table 4, Area 2a) demonstrated in
the check plots how completely grass fails on this sawgrass peat
without additions of potash. It may be observed also that
whereas the use of potash alone will maintain yields for a time
the phosphorus content of the grass will decrease sharply, as
the average of 0.37% P205 was the lowest that was obtained
in these experiments.
This experimental method of studying the fertilizer require-
ment of a pasture by establishing fertilizer plots on new areas
of a pasture from season to season is recognized as not being
ideal for the reason that clipping the growth, even though fre-
quently enough to keep it in the grassy or vegetative stage, is
not strictly comparable to the removal of the grass by grazing.
Ritchey and Henley (6) found this to be true for centipede
grass, which is a creeping, prostrate variety. In the more
upright grasses such as Bahia and Bermuda, however, they
found that the seasonal yields as obtained by clipping were in
close agreement with the seasonal gains in steers feeding in







Yield and Composition of Everglades Grass Crops


the pasture. Dallis grass was used in the present experiments
and it has a more upright type of growth than either Bahia
or Bermuda.
While the experiments recorded above demonstrate the need
for the use of both phosphate and potash early in the manage-
ment of Everglades pastures, they do not determine the best
ratio of these two plant food elements. The marked responses
in yield (Table 4) indicate that larger amounts of fertilizer
might be used with economy. Some indications as to ratios and
fertility levels may be obtained from the Dallis grass hay experi-
ments recorded herein.

PROTEIN, FAT AND FIBER OF PASTURE GRASSES
Samples of Dallis, carib, carpet and centipede grasses that
were plucked from the various pastures during the summer of
1934 and discussed above as to mineral content (Tables 2 and 3)
were analyzed for protein, fat and fiber (Table 5). It may be
noted that the protein contents are high, especially of the Dallis
grass, even though no nitrogen fertilizer was used. This is to
be expected for grasses grown on an organic soil whose reaction
and temperature is favorable for the nitrification of the nitro-
genous material represented by a soil nitrogen content of 3 to
3.5%. Proteins were also determined in the cuttings of Dallis
grass clipped from Areas 1 and 2 (Table 4). It may be observed
that fertilizer treatments that affected yield and phosphate con-
tent to a marked degree have no significant effect upon protein
content. There is apparently no explanation other than that
of change of location and season for the somewhat lower amount
of protein in the eight clippings from Area 1 than from Area 2
for the two years following. In general the plucked grasses
(Table 5) contained about the same percentage of protein as
those that were clipped (Table 4). The crude fat and fiber
contents of the plucked pasture grasses are about normal for
grasses, with little difference between varieties.

FERTILIZER REQUIREMENTS FOR DALLIS GRASS HAY
These experiments are based upon a series of plots 1/400 acre
in size and in triplicate for which different fertilizer mixtures
were made up and used on the basis of formulas ranging from
6-6-123 to 0-12-24 at 500 pounds per acre. The source materials
"All formulas refer to nitrogen.(N), phosphate (PO.) and potash (K.O)
in the order given.







Yield and Composition of Everglades Grass Crops


the pasture. Dallis grass was used in the present experiments
and it has a more upright type of growth than either Bahia
or Bermuda.
While the experiments recorded above demonstrate the need
for the use of both phosphate and potash early in the manage-
ment of Everglades pastures, they do not determine the best
ratio of these two plant food elements. The marked responses
in yield (Table 4) indicate that larger amounts of fertilizer
might be used with economy. Some indications as to ratios and
fertility levels may be obtained from the Dallis grass hay experi-
ments recorded herein.

PROTEIN, FAT AND FIBER OF PASTURE GRASSES
Samples of Dallis, carib, carpet and centipede grasses that
were plucked from the various pastures during the summer of
1934 and discussed above as to mineral content (Tables 2 and 3)
were analyzed for protein, fat and fiber (Table 5). It may be
noted that the protein contents are high, especially of the Dallis
grass, even though no nitrogen fertilizer was used. This is to
be expected for grasses grown on an organic soil whose reaction
and temperature is favorable for the nitrification of the nitro-
genous material represented by a soil nitrogen content of 3 to
3.5%. Proteins were also determined in the cuttings of Dallis
grass clipped from Areas 1 and 2 (Table 4). It may be observed
that fertilizer treatments that affected yield and phosphate con-
tent to a marked degree have no significant effect upon protein
content. There is apparently no explanation other than that
of change of location and season for the somewhat lower amount
of protein in the eight clippings from Area 1 than from Area 2
for the two years following. In general the plucked grasses
(Table 5) contained about the same percentage of protein as
those that were clipped (Table 4). The crude fat and fiber
contents of the plucked pasture grasses are about normal for
grasses, with little difference between varieties.

FERTILIZER REQUIREMENTS FOR DALLIS GRASS HAY
These experiments are based upon a series of plots 1/400 acre
in size and in triplicate for which different fertilizer mixtures
were made up and used on the basis of formulas ranging from
6-6-123 to 0-12-24 at 500 pounds per acre. The source materials
"All formulas refer to nitrogen.(N), phosphate (PO.) and potash (K.O)
in the order given.








Florida Agricultural Experiment Station


were ammonium sulfate, sulfate of potash and superphosphate
containing 44% P205. Copper sulfate at the rate of 80 pounds
per acre was applied to all the plots when fertilizers were added
in 1931 and at one-half that rate once a year thereafter.

TABLE 5.-PROTEIN, FAT, FIBER AND NITROGEN-FREE EXTRACT IN DALLIS,
CARIB, CENTIPEDE AND CARPET GRASSES PLUCKED FROM THE PASTURES
IN 1934.


Date Plucked


Given as Percentages of Oven-dry Weights
Protein | Fat Fiber N. F. Ext. Ash

Dallis Grass Pasture


May 25
June 8.

July 26


June 825 .........
June 8 .... .......- .. -

July 26 ...........

Aug. 1 ........... ..



May 25 ..........

June 8 ...............

July 26 .............



May 25 ..........

June 8 .........

July 26 ..............



June 8 ...............


17.25
15.88

14.25



14.13

19.19

16.37

13.96


3.12

2.60

3.20

Dallis Grass


28.50

30.89

33.22

Pasture'


2.63 29.88

2.63 26.97

2.59 30.68

2.02 31.58

Carib Grass Pasture'


42.27 8.86

43.02 7.61
42.10 7.23


47.49

43.34

43.12

43.92


11.19 1.93 27.73 50.22

14.69 1.69 26.04 45.79

11.25 2.45 29.10 47.41

Centipede Grass Pasture

13.81 2.75 29.31 47.93

10.56 2.36 33.14 48.21

12.63 3.69 28.45 48.56


Carpet Grass Pasture

15.81 2.62 26.94


8.93

11.79

9.79


50.24


'These samples were
were planted in 1931.


plucked from pastures planted in 1932. The other three pastures


During the period 1931-1937, inclusive, 33 cuttings of grass
,were removed and each cutting was taken when the grass was
in the late bloom or hay stage. Moisture determinations from








Yield and Composition of Everglades Grass Crops


2 ~r -- -


1'


-1 '\


Fig. 3.-Growth of Dallis grass just before the cutting of June 29, 1934, on the fertility
plots for which the average annual yields are given in Table 6. Treatment 14 was an
0-12 24 mixture at 500 pounds per acre; Treatment 7 was an 0-6-12 mixture; Treatment 6
consisted of potash and Treatment 5 of phosphate equal to the amounts used in Treatment 7.
Copper sulfate, 40 pounds per acre, was added with all the other treatments, including the
check plot, 13. In the first treatment 80 pounds of copper sulfate were used.











TABLE 6.-EFFECT OF PHOSPHATE AND POTASH UPON YIELDS OF DALLIS GRASS HAY FROM FERTILITY PLOTS.


Pounds Hay Per Acre Per Treatment on Oven-dry Basis
12. Phos- 114. Double
5. Phos- 6. Potash 7. Phos- I11. Potash phate and phosphate
.Check' phate only phate and and double double and double
only I potash phosphate potash potash'

18,701 18,564 20,660 20,908 18,629 20,300 17,778

6,320 6,008 9,306 10,226 9,854 12,266 11,957


................. ........ .........
................. ....................



.............. ..............






s5...... ................*1

age per year ...........

relative to
;ash only treatment


5,573

3,085

2,367

2,153

1,253


39,452

5,633


65


5,207

4,451

4,662

4,059

3,592


46,543

6,649


77


9,233

6,467

5,635

4,072

5,199


60,572

8,653


100


10,993

11,880

10,301

9,563

5,545


79,416

11,345


9,090

13,401

12,017

10,273

5,140


78,404

11,201


129


11,468

13,617

13,367

11,933

9,966


92,917

13,274


153


12,304

16,466

17,868

14,814

10,725


101,912

14,559


168


Year


1931

1932

1933

1934

1935

1936

1937


Total

Aver

Yield
pot


Fertilizer No. of
Applied Cuttings



Feb. 18 6

May 25 5

July 14 4

May 22 5

June 10 5

June 16 5

None 3


33


'Copper sulfate at 80 pounds per acre was applied to all treatments including the check plots with first fertilizer application and at 40 pounds
per acre with each subsequent application. Phosphate and potash were used on a basis of an 0-6-12 formula at 500 pounds per acre except where
the amounts weie doubled.


o
3.
a


;?.
rs
x


a


H
m
3.
m
cc
to
a
a
3







Yield and Composition of Everglades Grass Crops


various cuttings showed that the dry matter content of the
fresh cut hay was always close to 25%. Table 6 shows that
the average annual yields of hay from these plots varied from
5,633 pounds per acre on the oven-dry basis where no fertilizer
was applied (Treatment 1) to 14,559 pounds per acre where
an 0-12-24 mixture was used at the rate of 500 pounds per
acre (Treatment 14). The photographs of Fig. 3 are of the
cutting of June 29, 1934, and illustrate an average type of re-
sponse to the various fertilizers. Growth differences were still
greater at the time of the May 17 cutting, which was just
before a reapplication of fertilizer (Table 6). It may be observed
that in addition to the usual high response to potash the use of
phosphate increased yields to a marked degree over those obtained
when potash only was used. Doubling the amount of phosphate
resulted in no increase in yields (Fig. 4 and Table 6), whereas
doubling the amount of potash caused a considerable increase,
showing that potash was the limiting factor. The still greater
increase in yields obtained when both phosphate and potash were
doubled indicates that phosphate became the limiting factor with
an 0-6-24 formula (Treatment 12) and that the fertilizer for
Treatment 14 though fairly well balanced was probably not
sufficient in quantity for maximum yields.
Table 6 further shows that the omission of fertilizer in 1937
resulted in a marked falling off in yields, which illustrates how
quickly the reserves of available plant food can be depleted in
this soil of high organic content. The average annual yield of
eight tons of hay on a 10% moisture basis from Treatment 14,
in which an 0-12-24 fertilizer at 500 pounds per acre per year
was used, indicates that the fertilizer elements were well utilized.
This series included plots where treatments were identical
with those in Table 6 except that fertilizer applications were
omitted in 1932, 1933, 1935 and 1936. The resulting yields are
given in Table 7 and are compared with those of Table 6: in
Figure 4. This comparison of average annual yields for the
seven-year period shows that the omission of phosphate:or
potash from plots where these were used singly did not have
much effect, whereas the omission of fertilizer containing both
phosphate and potash caused a marked reduction in yields.
From a comparison of the annual yields of comparable treat-
ments such as No. 14 of Table 6 and No. 10 of Table 7, as
illustrated in Fig. 5, it may be seen that the fertilizer treat-
ment of May 22, 1934, caused the 1935 yield for Treatment 10










TABLE 7.-EFFECT OF OMISSIONS OF FERTILIZER UPON YIELD OF DALLIS GRASS AS COMPARED WITH YIELDS WHERE FERTILIZER
WAS NOT OMITTED (TABLE 6).


Year



1931 ..................... ........

1932 .................................

1933 ................ ...............

1934 ................. .................

1935 ... ... ..... ...........

1936 ................ ...............

1937 ................... ...........


Totals ......... ......................

Average per year ............

Yields relative to
Treatment 3 ................


Pounds Hay Per Acre Per Treatment on Oven-dry Basis
S9. Phos- 10. Double
2. Phos- 3. Potash 4. Phos- 8. Potash phate and phosphate
.Check' phate only phate and and double double and double
only __potash phosphate potash Ipotash


18,701

6,320

5,573

3,087

2,367

2,153

1,253


39,454

5,635

77


20,835

5,924

5,823

2,864

2,618

2,432

799


41,295

5,899

80


20,137

5,931

5,405

7,168

6,751

3,603

2,433


51,428

7,347

100


19,510

5,615

5,601

8,770

10,667

4,113

2,392


56,668

8,095

110


20,744

5,156

5,292

10,700

12,318

3,245

3,252


65,707

9,387

128


21,920

5,734

6,464

9,167

13,450

3,081

3,559


63,375

9,053

123


20,295

6,521

7,150

9,867

16,467

3,273

3,552


67,125

9,589

131


Fertilizer N
Applied Cu



Feb. .18

None

None


May 22

None

None

None


o. of
things



6

5

4
tQ
5


5
3


33

Ci.
0


1Copper sulfate at 80 pounds per acre was applied to all treatments, including the check plots, with first fertilizer application and at 40 pounds
per acre with each subsequent application. Phosphate and potash were used on a basis of an 0-6-12 formula at 500 pounds per acre except where
the amounts were doubled.







Yield and Composition of Everglades Grass Crops .19

to be about equal to that of Treatment 14 in which annual
applications of fertilizer had not been omitted. The sharp rise
and drop in yields of Treatment 10 (Fig. 5) illustrate again
that although these organic soils have a low reserve of phos-
phate and potash they are apparently able to retain and make
available to crops a large part of the amounts that are supplied
to them.





Ibs. per | Fertilized only in 1931 mad 1934
acre
oven
dry Fertilized each year except 1937
basis
15,000







5,000 --




Treatments 1 2 5 36 4 7 8 11 9 12 10 14

Fig. 4.-Average annual yields of Dallis grass hay for the seven-year period 1931-37
(Table 6). Treatment 1, check; 5, phosphate: 6, potash; 7, phosphate and potash; 11,
phosphate and double potash; 14, double phosphate and double potash; all applications are
based on an 0-6-12 mixture at 500 pounds per acre per year. Treatments 2, 3, 4, 8, 9 and
10 are of the same nature as Treatments 5, 6, 7, 11, 12 and 14 except that applications
were omitted in 1932, 1933, 1935 and 1936.

Inasmuch as phosphorus is the nutritive element that is most
likely to be deficient in hay grown on Everglades peat land,
phosphorus analyses were made of 12 of the 33 cuttings of
Dallis grass hay for which the yields are recorded in Table 6.
Table 8 shows that hay from the plots receiving potash only
contained the least phosphorus while the highest was in hay
from the treatment that received a double application of phos-
phate (Treatment 11) or an 0-12-12 mixture. The treatment
represented by the 0-6-12 formula at 500 pounds per acre pro-
duced hay having an intermediate content of phosphorus almost
identical with that of hay from Treatment 14, which received
an 0-12-24 mixture at 500 pounds per acre.








Florida Agricultural Experiment Station


Ibs. per
acre
oven
dry
basis

20,000


Treatment 10

EZI Treatment 14


15,000



10,000



5,000




1931 1932 1933 1934 1935 1936 1937
Fig. 5.-Comparison of annual yields of Dallis grass as averaged from plots in triplicate
where an 0-12-21 mixture was used each year except 1937 for Treatment 14 (Table 6) and
in 1931 and 1934 only for Treatment 10 (Table 7).

Comparing these results with the yield responses (Table 6),
it is evident that high yields are associated with a normal
phosphorus content which may be increased somewhat by adding
phosphate in excess of the amount necessary to balance the
potash, as in Treatments 5 and 11. Likewise the use of potash
without phosphate produced hay that was lower in phosphorus
and it is apparent from Treatment 6, Table 8, that this reduction
in the phosphorus content of the hay takes place rather quickly
in a soil of this type. This is evident also with respect to the
pasture plots that received potash only (Table 4). These effects
of phosphates upon the phosphorus content of grass are of
interest in relation to the findings of Blair and Prince (6), with
mineral soils, who report that changes in the phosphorus con-
tent of plants as influenced by phosphate treatments are
relatively small in comparison with the effect of nitrogenous
fertilizer upon nitrogen content. In the organic soils of the
Everglades nitrogenous fertilizers have little effect upon the
nitrogen content of most crops. :




TABLE 8.-PHOSPHORUS CONTENT OF CUTTINGS OF DALLIS GRASS HAY WITH YIELDS RECORDED IN TABLE 6.

Given as Percentage P2Os of Oven-dry Matter for Each Treatment
12. Phos- 14. Double
Date of Cutting 5. Phosphate 6. Potash 7. Phosphate 11. Potash phate and Phosphate
1. Check Only Only and Potash and Double Double and Double
Phosphate Potash Potash
Fertilized February 11, 1931

July 24, 1931 ........ 0.64 0.65 0.59 0.66 0.71 0.67 0.66
October 14 ........... 0.66 0.68 0.71 0.70 0.67 0.74 0.70
May 23, 1932 ...... 0.52 0.36 0.36 0.42 0.43 0.34 0.45
Fertilized May 25, 1932

June 29 ............... 0.35 0.36 0.63 0.78 0.61 0.67
September 14 ...... 0.55 0.86 0.42 0.68 0.71 0.52 0.65 o
May 18, 1934 .... 0.41 0.23 0.27 0.39 0.25 0.28
Fertilized May 22, 1934

June 29 ................ 0.37 0.77 0.21 0.39 0.50 0.37 0.51
Fertilized June 10, 1935

July 9, 1935 .. 0.32 0.72 0.29- 0.52 0.67 0.46 0.61
June 4, 1936 0.40 0.56 0.30 0.41 0.45 0.26 0.31
Fertilized June 16, 1936

July 13 ...... ....... 0.33 0.75 0.23 0.75 0.80 0.66 0.75
September 1 ...... 0.35 0.61 0.27 0.56 0.77 0.59 0.62
May 13, 1937 ........ 0.37 0.55 0.25 0.46 0.67 0.35 0.44

Average .............. 0.45 0.62 0.35 0.54 0.63 0.49 0.52
1Samples were not obtained.








Florida Agricultural Experiment Station


RESPONSE TO NITROGEN

Yields from Treatment 16, Tabe 9, which received ammonium
sulfate as supplied in a 6-6-12 formula at 500 pounds per acre
produced no more grass during the seven years of the experi-
ment than Treatment 17 in which the ammonium sulfate was
omitted. This study of the possible effect of a nitrogenous
fertilizer on grass crops in sawgrass peat may be considered
incomplete, however, for the reason that a treatment including
nitrogen was not used where a heavier fertilizer application
caused heavier yields and the withdrawal of greater quantities
of nitrogen from the soil as in Treatment 14, Table 6. Data
and discussion relating to the nitrogen removed from Treat-
ment 14 may be found in a previous publication (5).

TABLE 9.--EFFECT OF USE OF NITROGEN AND OF THE MURIATE INSTEAD OF
THE SULFATE OF POTASH UPON YIELDS OF DALLIS GRASS.


Year



1931 .......................

1932 .....................


1933 ....................


1934 .....................

1935 ....................
1936 ......................


1937 ......................


Totals .................

Av. per year ......

Yields relative to
Treatment 17


Pounds Per Acre Per Treat-
ment on Oven-dry Basis
16. Nitro- 17. Phos- 25. Phos-
gen, Phos- phate phate and
phate and and Muriate
Potash' Potash of Potash

19,562 19,906 19,497

9,527 8,801 9,242


8,599


5,901

8,420

4,239


5,084


61,332

8,762

96


8,786


6,702

9,594
4,817


5,605


64,211

9,173

100


9,591


6,517

8,822

5,253


4,958


63,880

9,126

i99
1


IThe sulfates of potash were used in Treatments 16 and 17 and applications were on
the basis of a 6-6-12 formula at 500 pounds per acre.


Fertilized


Feb. 18

May 25
except
phosphorus

July 14
except
phosphorus
May 22
June 10

June 16
except
phosphorus
None


I







Yield and Composition of Everglades Grass Crops


MURIATE VERSUS SULFATE OF POTASH
Treatment 25 (Table 9) received its potash in the form of
muriate with the result that yields were no higher than from
Treatment 17 where the sulfate of potash was used. Potash
in the form of muriate might be less satisfactory than the
sulfate form in treatments involving greater quantities. Thus
in the rather large amounts employed in the greenhouse trials
discussed below the mixtures containing muriate caused more
depression of growth than those containing sulfate of potash.
It may be considered quite safe, however, to use muriate in field
treatments on grass crops.

GREENHOUSE EXPERIMENTS WITH DALLIS GRASS
Dallis grass was used as one of the index crops in a series
of treatments on sawgrass peat soil in glazed six-gallon jars
in the greenhouse. This series of 20 treatments in triplicate
was designed primarily to study the effect of varying ratios of
phosphorus and potassium in the fertilizer mixture. Chemically
pure sources of the elements were used except that the phos-
phorus of Treatments 13 and 14 (Table 10) was derived from
superphosphate of 44% P205 grade. Commercial flowers of
sulfur was used in Treatments 16, 17 and 20. Rates of applica-
tion were based upon a 10-10-20 formula at 1,000 pounds per
acre. Sulfur was used at the rate of 1,000 pounds per acre
in Treatments 16, 17 and 20, while in Treatments 13 and 14
where wood ashes were made the source of potassium, enough
extra sulfur was added to take up the alkalinity of the wood
ashes on the basis of all of the sulfur changing to sulfate.
Sulfur oxidation was active as evidenced by the reduction to
pH 5.66 in Treatment 16 from a pH of 6.71 in Treatment 15.
The primary purpose of using Dallis grass in this series of
treatments was to ascertain the effect of varying amounts of
phosphate upon the phosphorus content of the grass and to
correlate these data with those of similar nature in the pasture
and hay lands discussed previously. The cuttings were made
in the late bloom stage and typical growth responses are illus-
trated in Fig 6. Table 10 shows that hay from Treatment 3,
which received no phosphate, and from Treatment 10, to which
a minimum amount of phosphate was added, both contained
0.49% of phosphorus (P205). With increasing amounts of phos-
phate in the soil treatment the phosphorus content of the hay







Yield and Composition of Everglades Grass Crops


MURIATE VERSUS SULFATE OF POTASH
Treatment 25 (Table 9) received its potash in the form of
muriate with the result that yields were no higher than from
Treatment 17 where the sulfate of potash was used. Potash
in the form of muriate might be less satisfactory than the
sulfate form in treatments involving greater quantities. Thus
in the rather large amounts employed in the greenhouse trials
discussed below the mixtures containing muriate caused more
depression of growth than those containing sulfate of potash.
It may be considered quite safe, however, to use muriate in field
treatments on grass crops.

GREENHOUSE EXPERIMENTS WITH DALLIS GRASS
Dallis grass was used as one of the index crops in a series
of treatments on sawgrass peat soil in glazed six-gallon jars
in the greenhouse. This series of 20 treatments in triplicate
was designed primarily to study the effect of varying ratios of
phosphorus and potassium in the fertilizer mixture. Chemically
pure sources of the elements were used except that the phos-
phorus of Treatments 13 and 14 (Table 10) was derived from
superphosphate of 44% P205 grade. Commercial flowers of
sulfur was used in Treatments 16, 17 and 20. Rates of applica-
tion were based upon a 10-10-20 formula at 1,000 pounds per
acre. Sulfur was used at the rate of 1,000 pounds per acre
in Treatments 16, 17 and 20, while in Treatments 13 and 14
where wood ashes were made the source of potassium, enough
extra sulfur was added to take up the alkalinity of the wood
ashes on the basis of all of the sulfur changing to sulfate.
Sulfur oxidation was active as evidenced by the reduction to
pH 5.66 in Treatment 16 from a pH of 6.71 in Treatment 15.
The primary purpose of using Dallis grass in this series of
treatments was to ascertain the effect of varying amounts of
phosphate upon the phosphorus content of the grass and to
correlate these data with those of similar nature in the pasture
and hay lands discussed previously. The cuttings were made
in the late bloom stage and typical growth responses are illus-
trated in Fig 6. Table 10 shows that hay from Treatment 3,
which received no phosphate, and from Treatment 10, to which
a minimum amount of phosphate was added, both contained
0.49% of phosphorus (P205). With increasing amounts of phos-
phate in the soil treatment the phosphorus content of the hay











TABLE 10.-YIELD AND PHOSPHORUS CONTENT OF DALLIS GRASS GROWN IN GREENHOUSE WITH VARIOUS SOIL TREATMENTS
TOGETHER WITH THE REACTION OF THE SOIL (SAWGRASS PEAT).


Treatment



Check ............... .......................
2P ................... ........................
4K -...- .......- ..- ..-.....-..- ..-.......
2PK --.... ........ .....- ....-...
2P2K .. .. ... .... ..... ... ....
2P4K ...... .........- ......- ... .........
2P8K .................... ... .................
2P4K (muriate) .........................
2P8K (muriate) .........................
P4K ................... ......... .. ---........
4P4K ....................... ................. ....
8P4K ...........................................
4P (44% phosphate) .......................
8P (44% phosphate) ......................
2P2K plus wood ashes .................
2P2K plus wood ashes plus sulfur
2P4K plus sulfur ............................
2P4K plus nitrate .......................
2P4K plus iron sulfate ...................
2P4K plus iron sulfate plus sulfur


First Cutting

Yield Phosph
gms.

26.5
31.7
31.5
141.9
111.2
92.1
69.1
85.5
35.4
61.8
104.2
67.0
148.8
104.9
30.4
69.2
134.5
63.8
85.8
128.0


May 21

late (PO)
% |I


).64
1.20
0.49
0.61
0.61
0.76
0.70
0.61


2nd, 3rd, 4th Cuttings
Jan. 18-Aug. 15


Yield
gms.

59.6
45.0
128.8
127.5
143.6
158.7
64.8
74.3
10.8
100.8
127.8
112.3
107.6
155.2
15.6
902
152.7
141.2
128.4
187.2


Phosphate (P0Os)
%

0.67
1.03
0.43
0.62
0.56
0.56
0.55
0.66
0.73
0.48
0.78
0.91
0.77
*1.09
0.48
0.67
0.67
0.64
0.58
0.66


Total
Yield

gms.

86.1
76.7
160.3
259.4
254.8
250.8
133.9
159.8
46.2
162.7
232.0
179.3
256.4
260.1
46.0
159.4
287.2
205.0
214.2
315.2


Soil
Reaction

pH

5.42
5.35
5.14
5.34
5.34
5.19
5.29
5.25
5.43
5.29
5.31
5.21
5.16
5.10
6.71
5.66
4.75
5.33
5.24
4.26







Yield and Composition of Everglades Grass Crops


was increased to 1.06% (Treatment 12). Medium amounts of
phosphate (Treatments 4-7) produced hay containing an average
of 0.62% P205, which is higher than the average of 0.52% P205
of the corresponding field Treatment 14 of Table 8, but lower
than the average of 0.85% P205 (Table 2) for Dallis grass
plucked from the pastures. These field and greenhouse results
indicate that the phosphate-potash ratio of one part of P205 to
two of K20 is about as high as the phosphorus content of fer-
tilizer needs to be raised from the standpoint of yield and quality
of Everglades grass crops.


Fig. 6.-Representative growth of Dallis grass in triplicate greenhouse treatments of
the cutting of May 21, 1934 (Table 10). A-Treatment 1 is 2P4K (phosphorus and potash);
2 is 2PK: 3 is 4K; 4 is 2P; and 5 is a check. B-No. 1 is 2P2K with wood ashes as the
source of potash: 2 is 2P2K with wood ashes plus sulfur; 3 is 2P4K plus sulfur: 4 is 2P4K
plus sodium nitrate; 5 is 2P4K plus ferrous sulfate; and 6 is 2P4K plus ferrous sulfate
plus sulfur.


I (2











TABLE 11.-AVERAGE ANNUAL YIELDS OF CARPET GRASS FROM FERTILIZER PLOTS.


Pounds Per Acre Per Treatment on Oven-dry Basis


Year


193 1 ....................... ..... .....

1932 ... .............. .... .....

1933 ............... ................

19 3 4 ................... ....... ....... ...

1935 .......................... ........

193 6 ....... .............. ..........

193 7 ........................... ..........


Totals .............. ....

Average per year ..............

Yields relative to
those from potash only


Check'

1,804

11,167

8,529

2,439

1,522

1,060

1,746


28,267

4,038


73


Phosphate

1,963

11,301

6,833

2,352

1,638

1,500

1,750


27,337

3,905

70


Potash

2,114

12,753

11,663

3,508

2,917

2,059

3,845


38,859

5,551

100


Phosphate
and Potash

1,770

18,854

16,118

7,758

5,419

5,945

5,913


61,768

8,824

159


Phosphate'
and Potash

1,973

18,145

14,776

7,118

4,868

5,100

5,579


57,559

8,223

148


No. of
Fertilized Cuttings


Feb. 11 3

May 25 5

July 14 4

May 22 7

June 10 4

June 16 5

None 4


32


'All treatments received copper sulfate at the rate of 80 pounds per acre when first fertilized and at the rate of 40 pounds per acre thereafter.
Phosphate and potash were used on the basis of an 0-6-12 formula.
'Basic slag was used as the source of phosphorus.


~~ ----







Yield and Composition of Everglades Grass Crops


The Dallis grass greenhouse series (Table 10) corroborate
those in the field to show that either the muriate or the sul-
fate form of potash may be used. The highest yields were
obtained from Treatments 17 and 20, where the soil reactions
were, as a result of sulfofication, reduced to pH values of 4.75
and 4.26, respectively. There was no response to either an iron
or a nitrogenous fertilizer.

YIELDS OF CARPET GRASS ON FERTILIZER PLOTS
Although carpet grass is generally considered to be of too
prostrate a type to be cut for hay, it is of interest to note that
the average annual yield of 8,824 pounds of grass on the dried
basis (Table 11) as cut with an ordinary sickle type mower
(Fig. 2) compares favorably with the annual average yield of
11,345 pounds of Dallis grass hay (Table 6) from plots that
received the same amount of phosphate and potash as repre-
sented by an 0-6-12 formula, at 500 pounds per acre per year.
A similar marked response to both phosphate and potash is
shown in Table 11 for carpet grass as in Table 6 for Dallis grass.
It may be inferred that the growth of carpet grass was not
limited by any minor element deficiency, as yields were not
increased where basic slag was substituted for 44% super-
phosphate as the source of phosphorus.
Although phosphate analyses were not made of these cuttings
of carpet grass it may be assumed that, since carpet grass tends
to remain in a more leafy or vegetative state than Dallis, the
percent of phosphorus in carpet grass hay would, with the same
fertilizer treatment, be fully as high as or higher than is re-
corded for Dallis grass (Table 8). Carpet grass plucked from
a pasture contained 1.16% of phosphorus as P205 (Table 3),
which was considerably higher than the phosphorus content
of Dallis, carib and centipede plucked on the same date from
adjacent, similarly fertilized pastures.

DISCUSSION AND SUMMARY
After the successful establishment of a pasture in 1929 on
the sawgrass peat of the Station Farm, a series of experiments
was started to determine the influence of fertilizers upon the
yield and composition of grass crops.
Climate, soils and necessary water control are discussed in
relation to the growing of grass crops in the Everglades.







Yield and Composition of Everglades Grass Crops


The Dallis grass greenhouse series (Table 10) corroborate
those in the field to show that either the muriate or the sul-
fate form of potash may be used. The highest yields were
obtained from Treatments 17 and 20, where the soil reactions
were, as a result of sulfofication, reduced to pH values of 4.75
and 4.26, respectively. There was no response to either an iron
or a nitrogenous fertilizer.

YIELDS OF CARPET GRASS ON FERTILIZER PLOTS
Although carpet grass is generally considered to be of too
prostrate a type to be cut for hay, it is of interest to note that
the average annual yield of 8,824 pounds of grass on the dried
basis (Table 11) as cut with an ordinary sickle type mower
(Fig. 2) compares favorably with the annual average yield of
11,345 pounds of Dallis grass hay (Table 6) from plots that
received the same amount of phosphate and potash as repre-
sented by an 0-6-12 formula, at 500 pounds per acre per year.
A similar marked response to both phosphate and potash is
shown in Table 11 for carpet grass as in Table 6 for Dallis grass.
It may be inferred that the growth of carpet grass was not
limited by any minor element deficiency, as yields were not
increased where basic slag was substituted for 44% super-
phosphate as the source of phosphorus.
Although phosphate analyses were not made of these cuttings
of carpet grass it may be assumed that, since carpet grass tends
to remain in a more leafy or vegetative state than Dallis, the
percent of phosphorus in carpet grass hay would, with the same
fertilizer treatment, be fully as high as or higher than is re-
corded for Dallis grass (Table 8). Carpet grass plucked from
a pasture contained 1.16% of phosphorus as P205 (Table 3),
which was considerably higher than the phosphorus content
of Dallis, carib and centipede plucked on the same date from
adjacent, similarly fertilized pastures.

DISCUSSION AND SUMMARY
After the successful establishment of a pasture in 1929 on
the sawgrass peat of the Station Farm, a series of experiments
was started to determine the influence of fertilizers upon the
yield and composition of grass crops.
Climate, soils and necessary water control are discussed in
relation to the growing of grass crops in the Everglades.







Florida Agricultural Experiment Station


Since the organic soils of the Everglades are low in reserves
of phosphorus, special attention was given to that element, since
adequate supplies of it are essential in growth of bone in grazing
animals. In a series of samples of Dallis gr ss plucked from
pastures in 1934 the content of phosphorus was found to be
0.63 percent P20 on the dry basis. The phosphorus content
of material plucked from pastures of carib and carpet grasses
is somewhat higher, while that of centipede grass is slightly
lower. In a study of Florida ranges, Becker et al (12) have
reported that cattle grazing on grasses that averaged 0.19 per-
cent P205 showed decided symptoms of phosphorus deficiency
while those on ranges whose grasses contained an average of
0.31 percent were normal.
The fertility experiments reported herein for Everglades saw-
grass peat soil show that sufficient phosphate to insure good
grass yields also insures a phosphorus content above that found
in the grass of Florida ranges where healthy cattle are raised.
Analyses of the plucked grasses from Everglades pastures
indicated that ample amounts of calcium, magnesium and iron
are present. The sub-surface waters of these organic soils
are well supplied with calcium and magnesium from the under-
lying marl, and grass crops grown on these soils are well supplied
with these elements.
A field plot study of a Dallis grass pasture showed that phos-
phate and potash equivalent to the amounts contained in an
0-6-12 formula at 500 pounds per acre should be applied at
least once a year to keep the pasture at a moderately high point
in its potential productivity as shown by yield records of cut-
tings from these plots. The carrying capacity of the pasture
was very high as may be expected because of its location in a
subtropical environment.
Thirty-three cuttings of Dallis grass hay were cut from a
series of fertility plots during a period of seven years (1931-37
inclusive). These gave an average annual yield on the dry
basis of 5,633 pounds per acre where no fertilizer was applied
and 14,559 pounds where phosphate and potash were used in
amounts equivalent to an 0-12-24 mixture applied at the rate
of 500 pounds per acre per year. With an 0-6-24 mixture the
yield was reduced to 13,274 pounds per acre and the phosphorus
content of the hay was lower. With an 0-12-12 mixture the
yield was reduced to 11,201 pounds per acre and practically the







Yield and Composition of Everglades Grass Crops


same yield was obtained with either an 0-6-12 or a 3-6-12
mixture.
Analyses of cuttings of Dallis grass grown in greenhouse jars
corroborated those of field plots in showing that a phosphate
(P205) potash (K20) ratio of one to two is about as high as
the phosphorus content of a fertilizer needs to be raised, from
the standpoint of yield and of phosphorus content of the grass.
In a parallel series of plots using the same fertilizer mixture
at the same rate per acre but omitted in 1932, 1933, 1935 and
1936 the average yield was reduced by about one-third. In
both series yields were almost identical for 1935 following
similar applications of fertilizer to both in 1934, while the 1936
yields on the unfertilized plots dropped to less than half of
those from the fertilized plots. This shows how completely
the fertilizer was utilized in these sawgrass peat soils.
The average annual yields of Dallis grass hay from plots
that received their potash in the form of muriate were prac-
tically the same as from plots where the sulfate of potash was
used.
In the greenhouse Dallis grass did not respond to soil treat-
ments of iron and nitrogen.
In field fertilizer trials during the seven-year period 1931-
1937, the average annual yield of carpet grass was 8,824 pounds
per acre, on the dry basis, where phosphate and potash were
used in amounts equivalent to an 0-6-12 formula at 500 pounds
per acre. There was a marked response to phosphate as well
as to potash.
ACKNOWLEDGMENTS
The authors wish to acknowledge the counsel and advice of Dr. R. V.
Allison in connection with some of the earlier experiments. R. W. Kidder
took the photograph for the frontispiece and was in charge of the cattle
that grazed the pastures discussed in these experiments. Painstaking
assistance has been rendered by John Newhouse in obtaining field records,
by L. S. Jones and P. M. McIntyre with the laboratory work and by Edward
King, Jr., in the taking of weather records.

LITERATURE CITED
1. ALLISON, R. V., O. C. BRYAN and J. H. HUNTER. The stimulation of
plant response on the raw peat soils of the Florida Everglades
through the use of copper sulfate and other chemicals. Fla. Agr.
Exp. Sta. Bul. 190. 1927.








30 Florida Agricultural Experiment Station

.2. BECKER, R. B., W. M. NEAL and A. L. SHEALY. Stiffs or sweeny
(phosphorus deficiency) in cattle. Fla. Agr. Exp. Sta. Bul. 264.
1933.
3. BLAIR, A. W., and A. L. PRINCE. The influence of phosphates on the
phosphoric acid content of the plant. Jour. Agr. Research, 44: 579-
S590. 1932.
4. NELLER, J. R. Effect of rainfall and of substrata upon composition
and reaction of soil waters of Everglades peat land. Volume B,
Transactions of 6th Comm. of International Society of Soil Science,
Zurich 388-393. 1937. Abstract in Volume A, 31-32.
5. NELLER, J. R. The availability to crops of the nitrogen of Everglades
peat. Transactions of the Third International Congress of Soil
Science. 1: 421-423. 1935.
6. RITCHEY, GEO. E., and W. W. HENLEY. Pasture value of different
grasses alone and in mixture. Fla. Agr. Exp. Sta. Bul. 289. 1936.




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