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 Title Page
 Board of control and staff
 Experimental procedure
 Results and discussion
 Summary and conclusions
 Literature cited














Group Title: Bulletin University of Florida. Agricultural Experiment Station
Title: Effect of fertilizer on growth and composition of carpet and other grasses
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00026832/00001
 Material Information
Title: Effect of fertilizer on growth and composition of carpet and other grasses
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 31 p. : ill. ; 23 cm.
Language: English
Creator: Blaser, R. E ( Roy Emil ), 1912-
Stokes, W. E ( William Ernest ), 1895-1948
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1943
Copyright Date: 1943
 Subjects
Subject: Grasses -- Fertilizers -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (p. 31).
Statement of Responsibility: by R.E. Blaser and W.E. Stokes.
General Note: Cover title.
 Record Information
Bibliographic ID: UF00026832
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltuf - AEN5841
oclc - 18235182
alephbibnum - 000925195

Table of Contents
    Title Page
        Page 1
    Board of control and staff
        Page 2
        Page 3
        Page 4
    Experimental procedure
        Page 5
        Page 6
    Results and discussion
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
    Summary and conclusions
        Page 29
        Page 30
    Literature cited
        Page 31
Full Text

Bulletin 390 July, 1943



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






EFFECT OF FERTILIZER ON GROWTH

AND COMPOSITION OF CARPET

AND OTHER GRASSES


By R. E. BLASER and W. E. STOKES








TECHNICAL BULLETIN








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










BOARD OF CONTROL ECONOMICS, HOME
H. P. Adair, Chairman, Jacksonville Ouida D. Abbott, Ph.D., Home Econ.1
R. H. Gore, Fort Lauderdale Ruth O. Townsend, R.N., Assistant
N. B. Jordan, Quincy R. B. French, Ph.D., Biochemist
T. T. Scott, Live Oak
Thos. W. Bryant, Lakeland
J. T. Diamond, Secretary, Tallahassee ENTOMOLOGY

EX V STAFF sJ. R. Watson, A.M., Entomologist'
EXECUTIVE STAFF A. N. Tissot, Ph.D., Associate'

John J. Tigert, M.A., LL.D., President of the H. E. Bratley, M.S.A., Assistant
University
Wilmon Newell, D.Sc., Director3
Harold Mowry, M.S.A., Asso. Director HORTICULTURE
L. O. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield. M.S., Asst. Dir., Admin.4 G. H. Blackmon, M.S.A., Horticulturist'
J. Francis Cooper, M.S.A., Editors A. L. Stahl, Ph.D., Asso. Horticulturist
Clyde Beale, A.B.J., Assistant Editors F. S. Jamison, Ph.D., Truck Hort.
Jefferson Thomas, Assistant Editor3 R. J. Wilmot, M.S.A., Asst. Hort.
Ida Keeling Cresap, Librarian R. D. Dickey, M.S.A., Asst. Hort.'
Ruby Newhall, Administrative Manager8 J. Carlton Cain, B.S.A., Asst. Hort.'
K. H. Graham, LL.D., Business Manager3 Victor F. Nettles, M.S.A., Asst. Hort.'
Claranelle Alderman, Accountant3 Byron E. Janes, Ph.D., Asst. Hort.
A. L. Kenworthy, M.S., Asst. Hort.
MAIN STATION, GAINESVILLE F. S. Lagasse, Ph.D., Asso. Hort.2
H. M. Sell, Ph.D., Asso. Horticulturists
AGRONOMY

W. E. Stokes, M.S., Agronomist1
Fred H. Hull, Ph.D.. Agronomist PLANT PATHOLOGY
G. E. Ritchey, M.S., Agronomists
SE. itchey, ., Agronomist W. B. Tisdale, Ph.D., Plant Pathologist' '
W. A. Carver, Ph.D., Associate
Roy E. Blaser, M.S., Associate Phares Decker, Ph.D., Asso. Plant Path.
G. B. Killinger, Ph.D., Associate Erdman West, M.S., Mycologist
Fred A. Clark, B.S., Assistant Lillian E. Arnold, M.S., Asst. Botanist

ANIMAL INDUSTRY
SOILS
A. L. Shealy, D.V.M., An. Industrialist' a
R. B. Becker, Ph.D., Dairy Husbandmans R. V. Allison, Ph.D., Chemist' 8
E. L. Fouts, Ph.D., Dairy Technologists Gaylord M. Volk, M.S., Chemist
D. A. Sanders, D.V.M., Veterinarian F. B. Smith, Ph.D., Microbiologista
M. W. Emmel, D.V.M., Veterinariant C. E. Bell, Ph.D., Associate Chemist
L. E. Swanson, D.V.M., Parasitologist' L. E. Ensminger, Ph.D., Soils Chemist
N. R. Mehrhof, M.Agr., Poultry Hush.8 J. R. Henderson, M.S.A., Soil Technologist
T. R. Freeman, Ph.D., Asso. in Dairy Mfg. L. H. Rogers, Ph.D., Associate Biochemist'
R. S. Glasscock, Ph.D., Asso. An. Hush. R. A. Carrigan, B.S., Asso. Biochemists
D. J. Smith, B.S.A., Asst. An. Husb.' J. N. Howard, B.S., Assistant Chemist
P. T. Dix Arnold, M.S.A., Asst. Dairy Husb. Assistant Chemist
G. K. Davis, Ph.D., Animal Nutritionist
L. Mull, M.S., Asat.in Dairy T t H. W. Winsor, B.S.A., Assistant Chemist
L. E. Mull, M.S., Asst. in Dairy Tech.
0. K. Moore, M.S., Asst. Poultry Husb.3 Geo. D. Thornton, M.S., Asst. Microbiologist
J. E. Pace, B.S., Asst. An. Husbandmans R. E. Caldwell, M.S.A., Asst. Soil Surveyor'
S. P. Marshall, M.S., Asst. in An. Nutrition Olaf C. Olson, B.S., Asst. Soil Surveyor"
C. B. Reeves, B.S., Asst. Dairy Tech.

ECONOMICS, AGRICULTURAL 1 Head of Department.
2 In cooperation with U. S.
C. V. Noble, Ph.D., Agr. Economist' Cooperative, other divisions, U. of F.
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Associate 4 In Military Service.
Max E. Brunk, M.S., Assistant 6 On leave.



Exchiuat. Univ, Pub.














BRANCH STATIONS w. CENT. FLA. STA., BROOKSVILLE

NORTH FLORIDA STATION, QUINCY Clement D. Gordon, Ph.D., Asso. Poultry
Geneticist in Charge2
J. D. Warner, M.S., Agronomist in Charge
R. R. Kincaid, Ph.D., Plant Pathologist RANGE CATTLE STA., ONA
V. E. Whitehurst, Jr., B.S.A., Asst. An. Hush.4
W. C. McCormick, B.S.A., Asst. An. Hush. W. G. Kirk, Ph.D., An. Hush. in Charge
Jesse Reeves, Asst. Agron., Tobacco E. M. Hodges, Ph.D., Asso. Agron., Wauchula
W. H. Chapman, M.S., Asst, Agron.' Gilbert A. Tucker, B.S.A., Asat. An. Hush.'

Mobile Unit, Monticello
R. W. Wallace, B.S., Associate Agronomist FIELD STATIONS

Leesbarg
Mobile Unit, Milton
M. N. Walker, Ph.D., Plant Path. in ChargeO
Ralph L. Smith, M.S., Associate Agronomist

Plant City
CITRUS STATION, LAKE ALFRED A. N. Brooks, Ph.D., Plant Pathologist

A. F. Camp, Ph.D., Horticulturist in Charge Hastings
V. C. Jamison, Ph.D., Soils Chemist A. H. Eddins, Ph.D., Plant Pathologist
B. R. Fudge, Ph.D., Associate Chemist E. N. McCubbin, Ph.D., Truck Horticulturist
W. L. Thompson, B.S., Entomologist
W. W. Lawless, B.S., Asst. Horticulturist' Monticello
R. K. Voorhees, Ph.D., Asso. Plant Path. S. O. Hill, B.S., Asst. Entomologist2s
C. R. Stearns, Jr., B.S.A., Asso. Chemist A. M. Phillips, B.S., Asst. Entomologist2
H. 0. Sterling, B.S., Asst. Horticulturist
T. W. Young, Ph.ID., Asso. Horticulturist Bradenton
J. W. Sites, M.S.A., Asso. Horticulturist J. B. Beckenbach, Ph.D., Horticulturist in

Charge
EVERGLADES STA, BELLE GLADE E. G. Kelsheimer, Ph.D., Entomologist

F. T. McLean, Ph.D., Horticulturist
J. R. Neller, Ph.D., Biochemist in Charge A. L. Harrison, Ph.D., Plant Pathologist
J. W. Wilson, Sc.D., Entomologist' David G. Kelbert, Asst. Plant Pathologist
F. D. Stevens, B.S., Sugarcane Agron.
Thomas Bregger, Ph.D., Sugarcane Sanford
Physiologist R. W. Ruprecht, Ph.D., Chemist in Charge
G. R. Townsend, Ph.D., Plant Pathologist J. C. Russell, M.S., Asst. Entomologist
R. W. Kidder, M.S., Asst. An. Hush.
W. T. Forsee, Jr., Ph.D., Asso. Chemist Lakeland
B. S. Clayton, B.S.C.E., Drainage Eng.2 E. S. Ellison, Meteorologist2 5
F. S. Andrews, Ph.D.. Asso. Truck Hort.4 Harry Armstrong, Meteorologists
R. A. Bair, Ph.D., Asst. Agronomist
E. C. Minnum, M.S., Asst. Truck Hort.
N. C. Hayslip, B.S.A., Asst. Entomologist
1 Bead of Department.
SUB-TROPICAL STA., HOMESTEAD 2 In cooperation with U. S.

s Cooperative, other divisions, U. of F.
Geo. D. Ruehle, Ph.D., Plant Path. in Charge
S. J. Lynch, B.S.A., Asso. Horticulturist *In Military Service.
E. M. Andersen, Ph.D., Asso. Horticulturist 5 On leave.













EFFECT OF FERTILIZER ON GROWTH AND
COMPOSITION OF CARPET AND OTHER GRASSES
By R. E. BLASER and W. E. STOKES

CONTENTS
Page
EXPERMENTAL PROCED RE ...................................... .......... ....... .. ......... .......... ................ 5
RESULTS AND DISCUSSION .............................. -........... ..... .......................... .................... 7
Growth Response to Nitrogen With and Without Superphosphate and Potash 7
Growth Response to Combinations of Fertilizers .............................................. .. 11
Growth Response to Heavy Infrequent and Light Frequent Applications of
Lime, Superphosphate and Potash ............ ................................................... 16
Growth Response to Trace Elements ......................................................................... 18
Chemical Composition as Affected by Lime and Fertilizer Mixtures .............. 18
1937 and 1939 Analyses ................................. .................... ....................... 18
1940 Analyses ..............- --.. ....... ........ ........ ...... .......... ....... .... ....... 23
Chemical Composition of Various Grasses Treated with Phosphorus from Dif-
ferent Sources and Lime with Fertilizer ............................... .................. .... 26
SUMMARY AND CONCLUSIONS ...................... ..................................................................... 29
LITERATURE CITED ....................... ................... .............. ........................... ............ 31

INTRODUCTION
Plant species differ greatly in nutritional value and literature
reviews show that the mineral content of pasture plants is aug-
mented appreciably by fertilization (1, 2, 6),1 by soil types (7),
and by good grazing management (4, 5). The best improved
permanent pastures are made up of adapted and nutritious
plants properly managed and fertilized.
Few data are available which give the effect of liming and
fertilization on chemical composition of carpet and other grasses
which are commonly utilized in Florida. This research was
initiated to measure the effect of different sources of lime and
rates and mixtures of fertilizers on the growth and chemical
composition of carpet grass (Axonopus affinis Chase) grown
on 4 soil types. Chemical analyses of several grasses from
several soil types which were treated with lime and fertilizer
mixtures and phosphorus from different sources on various soil
types are also included.

EXPERIMENTAL PROCEDURE

Thirty-six fertilizer treatments were applied in March 1937
on established carpet grass sods on 4 common soil types. The
soil types were Leon and Plummer fine sands in Alachua County,
Bladen fine sand in Duval County and Fellowship fine sand in

Acknowledgments.-The writers wish to express their appreciation to
Dean Graham who made the chemical analyses under the direction of W. A.
Leukel; to Jeffrey Dawson for assistance in computations; and to R. E.
Billington for assistance with field work.
1Italic figures in parentheses refer to Literature Cited.







6 Florida Agricultural Experiment Station

Hernando County. The Bladen fine sand probably was treated
by the owner with 300 pounds of superphosphate per acre sev-
eral years before these experiments were started and the other
3 soils were once farmed and fertilized.
The fertilizer treatments were designed to study the follow-
ing: (1) rates and time of applying nitrogen as associated with
seasonal yield, (2) frequent light and infrequent heavy applica-
tions of plant nutrients, (3) rates and combinations of lime,
phosphorus, potash and nitrogen, and (4) effect of minor ele-
ments on growth. These treatments in connection with each
of the 4 studies were replicated in 4 randomized blocks. This
experimental design was used to reduce the size of the random-
ized blocks and thereby reduce the soil variance. All fertilizers
were surface broadcast in March 1937 on plots 7 x 20 feet.
Samples of carpet grass for yield data were taken with a
special power lawn mower equipped with a grass catcher. The
grass was mowed at intervals sufficiently frequent to keep it
in a vegetative growth stage, as stressed by Leukel (4) and
others. Intervals between mowing varied from 7 to 40 days,
depending upon rate of growth. The mower was set to cut the
grass at a height of 1/2 inch and a 25-inch strip was mowed
lengthwise through the center of each plot. After the yield
samples were taken the uncut grass on all plots was mowed to
a uniform height. This method of taking yields was satisfac-
tory, as indicated by the coefficient of variation of yields (10
to 15 percent) for the entire season.
The entire 25-inch sample from the center of each plot was
weighed for green weight and subsequently dried at a tempera-
ture of 70-90 C.
Aliquots of the oven-dried grass from the replicated plots
taken during 1937 and 1939 were composite for making mineral
and protein analyses. The analytical data for 1937 and 1939
are the means of triplicate analyses for composite samples.
During the 1940 season only the early season yields of grass
clippings were retained for chemical analysis. A single analysis
of these samples from the replicated plots was made. The 1940
percentages of chemical constituents are means of the single
analysis from 3 of the replicated plots.
To reduce laboratory work in making chemical analyses it
was necessary to select grasses from a limited number of treat-
ments. It was.not possible each season to make analysis of grass
taken from all soils.






Effect of Fertilizer on Carpet and Other Grasses 7

Yields of the plots from these experiments are given as oven-
dried weights in pounds per acre. The yields and chemical data
were analyzed by the analysis of variance method, provided
experimental designs permitted.
A second experiment to study the effect of 4 sources of phos-
phorus (superphosphate, basic slag, rock phosphate and colloidal
phosphate) plus various fertilizer mixtures on clover growth
and chemical composition of carpet grass was established on 8
soil types during October 1938. The design of experiments con-
sisted of plots 15 x 30 feet in size replicated in 2 randomized
blocks. Carpet grass, in a vegetative growth stage, from certain
fertilizer treatments was plucked by hand during June 1939.
Separate pluckings from grass plots were taken from the 2
replicates for making mineral analyses. The chemical composi-
tion of these grasses is used as means of single analysis of the
2 replicates.
In addition to the above, samples of carpet and other grasses
were plucked in June 1940 from various ranches, for the purpose
of obtaining data which would serve as a measure of the effect
of fertilizers on chemical composition.

RESULTS AND DISCUSSION

GROWTH RESPONSE TO NITROGEN WITH AND WITHOUT
SUPERPHOSPHATE AND POTASH
The growth response to different lime and fertilizer mixtures
was somewhat similar for the 4 soil types tested. Thus, yield
data will not be discussed in detail for the individual experiments
on each of the soil types.
Because of the shortage of forage during winter and early
spring, the time of production, particularly early production, is
as important as total yield. Grass yields as augmented by fer-
tilization are thus given as early season yields (April through
June 15) and total yields.
Nitrogen fertilizers, alone and in combination with super-
phosphate and potash, were applied at various rates in March
to measure their effect on early season and total growth. Treat-
ments were also included to measure the relative growth response
when nitrogen applications were made during different periods
of the year; also, to make a comparison of growth between
single and split applications. These data are given in Table 1.









TABLE 1.-EARLY AND TOTAL ANNUAL YIELDS OF CARPET GRASS (POUNDS DRY WEIGHT PER ACRE) FROM FOUR SOIL TYPES 00
AS AFFECTED BY RATES AND DATES OF APPLYING NITROGEN FERTILIZER, WITH AND WITHOUT A FERTILIZER MIXTURE,
DURING THE 4-YEAR PERIOD 1937-40.
Fertilizers (Lbs. per Acre) and Time of
Application* Early Season Yields** TOTAL YIELDS**
N I P206 I KO 1 Portion of N Applied 1 1937 j 1938 | 1939 ( 1940 1Meantll 1937 [ 1938 1 1939 1 1940 I Meant
Bladen Fine Sand, Duval County (untreated soil-pH 4.83) o
0 0 0 369 301 269 272 303 1,430 1,850 1,570 1,370 1,600
72 0 0 635 649 675 544 626 1,980 3,060 3,040 2,810 2,970
72 0 0 % in Sept. 452 709 751 337 562 1,790 3,430 2,920 2,280 2,880
36 0 0 % in Sept. 322 594 662 314 473 1,490 2,950 2,600 2,110 2,550 I
0 144 50 319 290 622 154 346 1,300 1,920 2,550 1,650 2,040 .
72 144 50 % in June 523 764 690 557 634 2,680 4,180 3,670 3,180 3,680
72 144 50 % in August 481 944 837 730 748 2,020 4,430 3,540 3,000 3,660
72 144 50 % in November 387 722 889 515 628 1,820 3,050 3,100 2,510 2,890
72 144 50 1 in May, % in Sept. 316 774 824 625 635 1,790 3,470 3,330 3,040 3,280
36 144 50 421 792 544 507 566 1,710 3,160 2,270 2,510 2,650
72 144 50 667 928 947 886 857 2,200 3,740 3,470 3,500 3,570
Leon Fine Sand, Alachua County (untreated soil-pH 4.80)
0 0 0 220 264 120 204 202 1,210 1,270 1,440 1,600 1,380
72 0 0 481 803 677 764 681 1,650 2,660 2,750 2,550 2,400
72 0 0 '2 in Sept. 489 617 698 476 570 1,750 2,360 2,560 2,110 2,200 r4
36 0 0 % in Sept. 361 426 452 437 419 1,530 1,870 2,230 2,020 1,910 g
0 144 50 377 316 209 238 285 1,760 1,620 1,790 1,740 1,730 .
72 144 50 % in June 458 740 426 515 535 2,570 3,180 2,280 2,790 2,710
72 144 50 % in August 573 805 609 651 660 2,250 3,000 2,910 2,450 2,650
72 144 50 % in November 468 1,220 706 518 728 1,730 3,030 2,660 2,110 2,380
72 144 50 % in May, % in Sept. 471 565 481 782 575 2,290 2,400 2,650 2,750 2,520
36 144 50 442 740 547 541 568 1,810 2,400 2,330 2,240 2,200
72 144 50 _557 1,200 910 973 910 2,120 3,310 3,290 2,890 2,900





TABLE 1.-EARLY AND TOTAL ANNUAL YIELDS OF CARPET GRASS (POUNDS DRY WEIGHT PER ACRE) FROM FOUR SOIL TYPES
AS AFFECTED BY RATES AND DATES OF APPLYING NITROGEN FERTILIZER, WITH AND WITHOUT A FERTILIZER MIXTURE,
DURING THE 4-YEAR PERIOD 1937-40-Concluded.
Fertilizers (Lbs. per Acre) and Time of
Application*I Early Season Yields** TOTAL YIELDS**
N I PO, I KO I Portion of N Applied I 1937 1 1938 j 1939 1 1940 ] Meantl 1937 j 1938 | 1939 | 1940 Meant
Plummer Fine Sand, Alachua County (untreated soil--H 5.08)
0 0 0- 217 233 191 251 223 1,430 1,600 1,660 1;820 1,630 g
72 0 0 594 847 570 659 668 2,440 2,830 2,540 2,810 2,660
72 0 0 % in Sept. 392 638 473 507 503 2,010 2,520 2,280 2,470 2,320
36 0 0 % in Sept. 327 392 424 481 406 1,740 2,030 2,150 2,220 2,040
0 144 50 259 251 180 214 226 1,560 1,540 1,690 1,660 1,610
3I
72 144 50 % in June 397 607 395 452 463 2,660 3,150 2,620 3,010 2,860
72 144 50 % in August 489 706 547 672 604 2,550 2,860 2,890 2,740 2,760
72 144 50 1/ in November 452 1,140 737 567 724 2,280 3,140 2,720 2,460 2,650
72 144 50 % in May, YV in Sept. 358 599 531 858 587 2,430 2,710 2,820 3,080 2,760 ^
36 144 50 468 617 465 541 523 2,120 2,330 2,200 2,370 2,260
72 144 50 748 1,250 850 842 923 2,920 3,560 3,190 3,050 3,180
Fellowship Fine Sand, Hernando County
0 0 0 1,290 1,660 1,980 1,640
72 0 0 1,730 2,270 3,410 2,470
72 0 0 2 in Sept. 1,270 2,380 2,700 2,120
36 0 0 % in Sept. 1,300 2,090 2,740 2,040
0 144 50 1,300 1,690 1,880 1,620
72 144 50 in June 2,210 2,790 3,670 2,890
72 144 50 % in August 1,630 2,900 3,090 2,540
72 144 50 % in November 1,750 2,950 3,730 2,810
72 144 50 A in May, % in Sept. 1,960 2,670 2,800 2,480
36 144 50 1,700 2,300 3,020 2,340
72 144 50 _1,790 2,600 3,890 2,760
N (actual nitrogen) a 50/50 mixture of Nitrate of Soda and Sulfate of Ammonia (18% N) applied annually in March or as indicated. P2Os-
Superphosphate (18% P2Os), 800 pounds per acre in March 1937. KaO-Muriate of Potash (50% KaO). 100 pounds per acre in March 1937.
** The "F" test of the mean differences of yields from all treatments for all years on all soil types are significant at the 1% level of significance
(P < .01). Check plots were omitted in computing "F" test by analysis of variance method.
t Mean 1938-40; no yields taken in July during 1987 because of excess moisture on Bladen soil.
Early season yields-yields from April to June 15.






10 Florida Agricultural Experiment Station

A comparison of the carpet grass yields obtained from a
superphosphate-potash fertilizer mixture with those of unfer-
tilized carpet grass shows that this mixture, without nitrogen,
did not increase the early season growth appreciably on any of
the 4 soil types. Carpet grass treated with a superphosphate-
potash mixture produced significantly higher total mean yields
during the 4-year period than unfertilized grass on the Leon
and Bladen soil types; but yields were similar on the other 2
soil types.
Nitrogen applications with and without a superphosphate-
potash mixture were made as early as March and as late as
November to ascertain what differences in growth might be
obtained (Table 1).
Nitrogen2 alone, when applied at 18, 36 or 72 pounds per
acre in March, augmented early season and total yields on all
4 soils significantly when compared with untreated carpet grass.
Early season carpet grass yields were higher following each
higher rate of nitrogen application.
Following a complete fertilizer total and early season mean
yields were significantly higher than those where like quantities
of nitrogen fertilizer were used in the absence of phosphorus
and potash. The efficiency of nitrogen fertilizer as indicated
by increased growth was improved when applied with a super-
phosphate-potash mixture, particularly after the first year. This
suggests that these soils were also low in minerals other than
nitrogen.
Combined with superphosphate and potash, 72 pounds of nitro-
gen applied in March may be compared with the following split
applications of nitrogen; 36 pounds nitrogen in March and again
in June; 36 pounds of nitrogen in March and August; 18 pounds
of nitrogen in March and May and 36 pounds in September; and
36 pounds of nitrogen in March and November. Total mean
yields also show that the March nitrogen applications produced
higher yields of grass than late-season nitrogen applications.
Mean grass yields from nitrogen applications in combination
with superphosphate and potash were similar on the Bladen fine
sand, except that the March-June and March-August split nitro-
gen treatments produced yields that did not differ appreciably
from yields where all the nitrogen was applied in March.
The most desirable growth curve resulted when all the nitro-

S Nitrogen given as actual nitrogen (N); 100 pounds of nitrate of soda
is equivalent to 16 pounds of nitrogen.







Effect of Fertilizer on Carpet and Other Grasses 11

gen was applied in March. August applications of nitrogen in-
creased growth' during August and September; but results indi-
cate that these late-season applications of nitrogen were not
generally used efficiently. September and November applica-
tions of nitrogen did not increase the late-season carpet grass
growth appreciably; however, the grass remained greener dur-
ing the winter months following late-season nitrogen applica-
tions.
GROWTH RESPONSE TO COMBINATIONS OF FERTILIZERS
This phase of the work was a study of the growth response
of carpet grass on several soil types to different lime and fer-
tilizer mixtures and to lime from different sources. The carpet
grass on 4 soils was top-dressed with a total of 2,000 pounds of
calcic lime, 144 pounds of P2053 and 100 pounds of K204 per acre
applied as superphosphate and muriate of potash, respectively,
during a 4-year period. In 3 additional treatments each indi-
vidual nutrient material (lime, superphosphate, and potash) was
omitted from the lime and complete fertilizer mixture. Nitro-
gen was applied annually at the rate of 72 pounds of N per
acre with all of these treatments.
When either the lime, superphosphate, or muriate of potash
was omitted both early season and total yields were significantly
less than for grass treated with lime and complete fertilizer on
the Bladen, Leon, and Fellowship soil types. The omission of
superphosphate or potash limited growth more than lime. Nitro-
gen stimulated growth more than the other fertilizer elements
(Table 2).
On the Plummer fine sand the 4-year mean yields of carpet
grass fertilized with calcic lime and complete fertilizer did not
differ significantly from the grass yields when either lime, super-
phosphate or potash was omitted. However, the yields from
the plots treated with lime and complete fertilizer were signifi-
cantly higher than those from grass plots treated with nitrogen
alone. This area of Plummer fine sand, once farmed and prob-
ably fertilized, apparently was high in residual fertilizer nu-
trients.

'144 pounds POs is equivalent to 800 pounds of superphosphate
(18% PA.O).
*100 pounds KzO is equivalent to 200 pounds of muriate of potash
(50% KI0).
72 pounds of N is equivalent to 400 pounds of a 50/50 mixture of
nitrate of soda and sulfate of ammonia (18% N).









TABLE 2.-CARPET GRASS GROWTH (POUNDS DRY WEIGHT PER ACRE) AS RELATED TO COMBINATIONS OF FERTILIZER ELEMENTS
ON 4 SOIL TYPES.
Fertilizers and Lime- Fertilizer Ap- I
Pounds per Acre* plied in 1939 Early Season Yields** TOTAL YIELDS**
N I P20, K2O I Lime I PO I KIO I 1937 ( 1938 | 1939 I 1940 I Mean [I 1937t( 1938 1939 [ 19401 Mean
"**Bladen Fine Sand, Duval County
S 0 0 0 301 238 337 136 253 1,200 1,840 1,790 1,680 1,770
72 0 0 0 403 583 630 405 505 1,620 3,130 2,670 2,480 2,760
72 144 100 2,000 447 837 923 787 749 1,600 3,810 3,470 3,050 3,440
72 144 100 0 72 50 507 884 798 745 734 1,900 3,520 3,050 3,160 3,240
72 144 200 0 458 960 900 711 757 1,750 4,030 3,330 3,070 3,480
72 144 0 2,000 72 0 526 821 850 638 709 1,830 3,870 3,280 2,880 3,340
72 0 100 2,000 411 727 798 625 640 1,600 3,700 2,990 2,750 3,150
72 144 0 0 72 0 567 850 845 680 736 2,030 3,610 3,210 2,820 3,210
72 0 100 0 72 0 452 779 795 693 680 1,700 3,700 3,280 2,880 3,290
72 144 200 2,000 72 100 604 1,433 845 795 919 2,110 4,890 3,680 3,200 3,920
(Dolomite)
72 144 50 2,000 390 978 873 934 794 1,750 4,320 3,690 3,380 3,800
**Leon Fine Sand, Alachua County
0 0 0 0 395 1 233 152 243 256 1,450 1,100 1,550 1,650 1,440
72 0 0 0 458 594 492 633 544 2,000 2,320 2,810 2,620 2,440
72 144 100 2,000 594 813 654 792 713 2,300 2,970 3,320 3,280 2,970
72 144 100 0 72 50 539 751 638 468 599 2,190 2,780 2,750 2,580 2,580
72 144 200 0 513 722 612 612 615 2,410 2,720 2,890 2,470 2,620
72 144 0 2,000 72 0 518 698 581 730 632 2,150 2,800 3,200 2,980 2,780
72 0 100 2,000 505 575 418 667 541 2,080 2,300 2,750 2,880 2,500
72 144 0 0 72 0 523 709 583 641 614 2,190 2,680 2,820 2,710 2,600
72 0 100 0 507 625 531 570 558 1,950 2,440 2,730 2,570 2,420
72 144 200 2,000 72 100 575 771 581 860 697 2,290 2,760 2,980 3,080 2,780
(Dolomite)
72 144 50 2,000 599 811 654 934 750 2,320 2,880 3,210 3,410 2,960





TABLE 2.-CARPET GRASS GROWTH (POUNDS DRY WEIGHT PER ACRE) AS RELATED TO COMBINATIONS OF FERTILIZER ELEMENTS
ON 4 SOIL TYPES-Concluded.
Fertilizers and Lime--- Fertilizer Ap- I
Pounds per Acre* plied in 1939 Early Season Yields** TOTAL YIELDS**
N I PIO, I K0O I Lime ( P20 I K20 I 1937 I 1938 | 1939 1940 ( Mean 1937t1 1938 ( 1939 I 1940 I Mean
"**Plummer Fine Sand, Alachua County
0 0 0 0 217 209 207 183 204 1,390 1,240 1,620 1,610 1,470 h
72 0 0 0 557 656 601 601 604 2,740 2,720 3,070 2,780 2,830 i
72 144 100 2,000 455 667 599 658 595 2,550 2,770 3,140 2,940 2,850 a
72 144 100 0 72 50 447 659 596 580 571 2,410 2,630 2,920 2,670 2,600 S
72 144 200 0 400 669 583 465 529 2,330 2,550 3,100 2,450 2,610
72 144 0 2,000 72 0 565 560 533 604 566 2,570 2,320 2,910 2,830 2,660 '
72 0 100 2,000 502 578 523 583 547 2,490 2,310 2,800 2,790 2,600
72 144 0 0 72 0 421 599 615 588 556 2,280 2,580 2,860 2,640 2,590 .
72 0 100 0 520 656 510 565 563 2,530 2,580 2,800 2,800 2,680-
72 144 200 2,000 72 100 479 599 607 641 582 2,420 2,530 2,890 2,820 2,670
(Dolomite) O
72 144 50 2,000 434 586 586 683 572 2,460 2,540 2,920 2,930 2,710
"**Fellowship Fine Sand, Hernando County 1
0 0 0 0 415 403 711 510 1,370 1,970 2,210 1,850
72 0 0 0 499 552 1,090 714 1,560 2,600 2,820 2,330
72 144 100 2,000 651 646 1,220 839 2,080 3,020 3,240 2,780
72 144 100 0 72 50 484 554 1,090 709 1,510 2,760 3,030 2,430
72 144 200 0 547 641 1,200 796 1,900 3,040 3,210 2,720 -
0
72 144 0 2,000 72 0 458 575 1,080 704 1,510 2,360 3,010 2,290
72 0 100 2,000 450 573 1,030 684 1,380 2,390 2,780 2,180
72 144 0 0 72 0 630 703 1,450 928 1,890 2,950 3,440 2,760
72 0 100 0 463 594 1,050 702 1,550 2,630 2,860 2,350
72 144 200 2,000 72 100 588 722 1,330 880 1,750 3,010 3,270 2,680
(Dolomite) o
72 144 50 2,000 497 565 1,010 691 1,530 2,420 2,740 2,230
*N from 18% nitrogen (50/50 mixture of nitrate of soda and sulfate of ammonia) applied annually, 1/ in March and % in August. PzOs from
superphosphate (18% P.0s) and KaO from muriate of potash (50% KIO) applied in 1937 or as indicated. Lime-ground calcic limestone (93% Ca COs).
Dolomite (36% Mg COB).
** In separate analyses of variance in annual and 4-year mean yields (both early season and total) from Leon, Plummer and Bladen soil types,
the variance between treatments in each case was highly significant (P < .01). Unfertilized plots were omitted in making the analyses. The "F"
test of the mean yields was not significant on the Fellowship soil.
t Mean 1938-40; no yields taken in July during 1937 because of excess moisture on Bladen soil.
Early season yields-yields from April to June 15.







14 Florida Agricultural Experiment Station

An abnormal growth response was exhibited by carpet grass
on the Bladen fine sand when superphosphate or muriate of
potash was omitted from the calcic lime and complete fertilizer
treatment. When phosphorus was omitted from the lime and
fertilizer mixture, the grass was dwarfed and the blades were
dull dark green to purplish green in color (Figure 1). This
purplish coloration occurred on the apex first and later developed
toward the basal portion of the blades. These phosphorus defi-
ciency symptoms occurred on all of the replicated plots treated
with lime, potash and nitrogen and were absent on all plots
where superphosphate was supplied.
Without fertilization, carpet grass blades were yellowish in
color with a purplish tint (Figure 1). The grass treated with
superphosphate and potash was yellowish due to insufficient
nitrogen, but the purplish coloration was absent. It is thus
evident that the presence or absence of certain nutrients in-
fluences the characteristics of phosphorus deficiency.
























Fig. 1.-Phosphorus Deficiency of Carpet Grass. Large leaves, given
complete fertilizer, are normal; 4 blades on right, from no-phosphorus plots,
vary in color from dark green to purple; 2 blades on left, from nitrogen
and phosphorus-deficient plots, show a yellowish and purplish discoloration.






Effect of Fertilizer on Carpet and Other Grasses 15

When carpet grass was top-dressed with calcic lime, super-
phosphate and nitrogen on the Bladen fine sand, blades were
"burned" or brownish at the apex and yellowish discolorations
frequently developed along the midrib. During incipient potas-
sium deficiency the blade tips were yellowish; such affected
parts subsequently died, resulting in the burned appearance as
shown in Figure 2. These symptoms occurred on all of the repli-
cated plots where muriate of potash was omitted from the fer-
tilizer treatment. Plant analyses substantiated both the potas-
sium and phosphorus deficiency symptoms (Table 7).





















Fig. 2.-Potassium Deficiency of Carpet Grass. The 2 normal blades
of carpet grass treated with lime and complete fertilizer are shown on the
left. Right, abnormal growth (potassium deficiency) of carpet grass oc-
curred when potassium was omitted from the lime and fertilizer mixture.

The grass treated with nitrogen alone also exhibited the
abnormal dull dark green color which is characteristic of phos-
phorus deficiency. It is evident that phosphorus became a limit-
ing growth factor before potassium on this soil type.
Dolomitic and calcic ground limestones were applied in 1937
with a complete fertilizer mixture to compare these two lime
sources. Although more potassium was supplied with the dolo-
mitic limestone treatment, the yields of carpet grass were higher
for grass treated with calcic limestone on the Leon, Plummer






16 Florida Agricultural Experiment Station

and Fellowship soil types. On the Bladen soil the grass yields
"were higher for plots treated with dolomitic limestone. The
differences in yields as influenced by those two kinds of lime
were not large (Table 2).
GROWTH RESPONSE TO HEAVY INFREQUENT AND LIGHT
FREQUENT APPLICATIONS OF LIME, SUPER-
PHOSPHATE AND POTASH
The lime and fertilizer treatments in this experiment were
designed to measure growth of carpet grass as affected by in-
frequent heavy applications of lime, superphosphate and potash
with frequent light applications of these nutrient materials dur-
ing a 4-year period (Table 3). Thirty-six pounds of nitrogen
were applied annually in March and again in August with all
of the lime and fertilizer mixtures.
One ton of calcic lime, 144 pounds P205 and 100 pounds of
K20 applied in March 1937 may be considered the basic treat-
ment and compared with 1/ and 1/ the rate of these minerals
the same year. The fertilizer rates of 14 the basic treatment
were applied annually for 4 years, and the treatments which
received 1/ the basic rate were reapplied every 2 years. Thus
equal quantities of lime, P205 and K20 were applied to all plots
during the 4-year period.
The carpet grass fertilized with the basic treatment of 1 ton
of calcic lime, 144 pounds of P205 and 100 pounds of K20 per
acre and nitrogen did not produce higher yields during 1937 than
grass fertilized with 1/ or 1/4 of the basic fertilizer rate on the
Leon, Plummer and Fellowship fine sands. On the Bladen fine
sand the grass fertilized with 1/4 the basic rate of lime, P205
and K20 during 1937 produced higher yields than the grass
treated with the basic or 2 the basic rate (Table 3).
Total mean yields of carpet grass, from these 3 treatments
for the 4-year period did not differ significantly on the Leon,
Plummer and Fellowship fine sands. Annual light applications
of lime, P205 and K20 produced higher yields of carpet grass
than heavy applications of these nutrients made every 2 or 4
years on the Bladen soil.
Carpet grass was also treated with the following quantities
of lime, superphosphate and potash during a 4-year period: the
basic rate in 1937; 1/2 the basic rate in 1937; and 1/4 the basic
rate in 1937 and 1939 (Table 3). The total mean carpet grass
yields during the 4-year period did not differ appreciably on
the 4 soils for these 3 treatments.







Effect of Fertilizer on Carpet and Other Grasses 17

TABLE 3.-CARPET GRASS YIELDS AS RELATED TO HEAVY INFREQUENT AND
LIGHT FREQUENT APPLICATIONS OF LIME, SUPERPHOSPHATE AND POTASH.

Fertilizer and Lime* Time of Applying P,20 Total Pounds per Acre
(Lbs. per Acre) K20 and Lime
N IP20, K2O Limel 19371 19381 19391 1940 Mean

Bladen Fine Sand, Duval County

72 144 100 2,000 All in 1937 1,600 3,810 3,470 3,050 2,980
72 144 100 2,000 % in 1937, % in 1939 1,680 3,690 3,390 2,820 2,900
72 144 100 2,000 % in 1937, '38, '39 & '40 2,220 4,630 3,960 3,520 3,580
72 72 50 1,000 All in 1937 1,750 3,910 3,650 2,950 3,070
72 72 50 1,000 % in 1937, % in 1939 1,900 4,070 3,750 3,070 3,200

Value of P for F test of between Not Not
treatment variance xx Sig. Sig. xx x

Leon Fine Sand, Alachua County

72 144 100 2,000 All in 1937 2,300 2,970 3,320 3,280 2,970
72 144 100 2,000 % in 1937, % in 1939 2,350 2,930 3,150 3,480 2,980
72 144 100 2,000 4 in 1937, '38, '39 & '40 2,080 2,790 2,940 3,310 2,780
72 72 50 1,000 All in 1937 2,020 2,640 3,020 3,090 2,690
72 72 50 1,000 % in 1937, % in 1939 2,240 2,690 3,150 3,240 2,830

Value of P for F test of between Not Not Not Not
treatment variance Sig. Sig. Sig. xx Sig.

Plummer Fine Sand, Alachua County

72 144 100 2,000 All in 1937 2,550 2,770 3,140 2,940 2,850
72 144 100 2,000 % in 1937, in 1939 2,240 2,570 3,140 3,010 2,740
72 144 100 2,000 %4 in 1937, '38, '39 & '40 2,540 3,200 3,060 2,770 2,890
72 72 50 1,000 All in 1937 2,470 2,600 2,960 2,950 2,750
72 72 50 1,000 % in 1937, % in 1939 2,330 2,930 3,300 2,930 2,870

Value of P for F test of between Not Not Not Not
treatment variance Sig. xx Sig. Sig. Sig.
Fellowship Fine Sand, Hernando County

72 144 100 2,000 All in 1937 2,080 3,020 3,240 2,780
72 144 100 2,000 % in 1937, % in 1939 1,770 3,040 3,350 2,720
72 144 100 2,000 1 in 1937, '38, '39 & '40 1,530 2,670 3,160 2,450
72 72 50 1,000 All in 1937 1,600 2,750 3,080 2,480
72 72 50 1,000 % in 1937, % in 1939 1,810 3,130 3,470 2,800

Value of P for F test of between Not Not Not Not
treatment variance Sig. Sig. Sig. Sig.
N applied in March and % in August. N, P0Os, KxO and lime source as for Table 2.
x-P < .05. xx-P < .01.







18 Florida Agricultural Experiment Station

It is thus apparent that light applications of lime, super-
phosphate and potash are as effective as heavy applications of
these nutrient materials for stimulating growth of carpet grass.
GROWTH RESPONSE TO TRACE ELEMENTS
A complete fertilizer mixture consisting of N 72 pounds,
P205 144 pounds, and K20 50 pounds per acre was applied with-
out trace elements and with zinc sulfate, borax, copper sulfate,
manganese sulfate, magnesium sulfate, iron sulfate added singly,
and finally all 6 in combination (Table 4).
TABLE 4.-TOTAL YIELDS OF CARPET GRASS (POUNDS DRY WEIGHT PER
ACRE) AS AFFECTED BY 6 TRACE ELEMENTS ON 4 SOIL TYPES, 1937-40.
Soil Types
Plum- Fellow-
Fertilizer Treatment-Pounds per Acre Bladen Leon mer ship
Fine Fine Fine Fine
N ]I'P20 IKOI K2 Sand Sand Sand Sand
72 144 50 2,870 2,400 2,630 2,550
72 144 50 20 lbs. zinc sulfate 2,590 2,360 2,340 2,360
72 144 50 10 lbs. borax 2,610 2,500 2,510 2,460
72 144 50 20 Ibs. copper sulfate 2,610 2,250 2,520 2,320
72 144 50 75 Ibs. manganese sulfate 2,710 2,510 2,550 2,380
72 144 50 100 Ibs. magnesium sulfate 2,760 2,390 2,690 2,250
72 144 50 75 lbs. iron sulfate 2,700 2,420 2,690 2,450
72 144 50 six minor elements at
above rates 2,840 2,360 2,390 2,170
Not Not Not Not
"F" Test Sig. Sig. Sig. Sig.
N 72 pounds applied annually % in March and % in August.
P.0 144 pounds and KO0 50 pounds applied in 1937.
The 4-year mean carpet grass yields as affected by the trace
elements during a 4-year period did not differ significantly on
any of the 4 soil types tested. The effect of these treatments
on chemical composition was not determined. However, in recent
tests the growth of grass on virgin soils was greatly stimulated
when treated with certain minor elements (3). The lack of a
response to trace elements on these soils may be attributed to
the previous treatment, soil type and location of these soils.
CHEMICAL COMPOSITION AS AFFECTED BY LIME AND
FERTILIZER MIXTURES
1937 and 1939 Analyses.-The chemical composition of carpet
grass on Bladen fine sand, as altered by liming and fertilization,
during the 1937 and 1939 seasons is given in Table 5. The carpet
grass which was treated with 2,000 pounds of calcic lime, 72






TABLE 5.-CHEMICAL COMPOSITION OF CARPET GRASS AS INFLUENCED BY FERTILIZATION AND SEASON ON A BLADEN FINE SAND
IN DUVAL COUNTY DURING 1937 AND 1939.
Fertilizer and Lime* (Pounds per Acre)
and Time Applied Grass Chemical Constituents (Percent Dry Basis)
Sample Calcium Phosphorus Magnesium Potassium Nitrogen
N P.05 K,0 Lime 1937 1939 1937 1939 1937 1939 1937 1939 1937 1939 0j
0 0 0 0 Spring 0.320 0.355 0.156 0.159 0.193 0.160 0.757 0.652 1.477 1.787
Summer 0.204 0.281 0.156 0.139 0.123 0.195 0.958 0.880 1.030 1.526
Fall 0.472 0.267 0.195 0.175 0.142 0.167 0.427 0.956 1.098 1.455
Mean 0.332 0.301 0.169 0.158 0.153 0.174 0.714 0.829 1.202 1.589
72j 0 0 0 Spring 0.288 0.291 0.149 0.153 0.175 0.218 0.642 0.526 1.416 2.207
Summer 0.230 0.241 0.152 0.126 0.145 0.175 0.914 1.144 1.875
Annually % in March and in August Fall 0.186 0.129 0.170 0.747 2.217
for all treatments Mean 0.259 0.239 0.151 0.136 0.160 0.188 0.778 0.637 1.280 2.100
72 108 75 1,500 Spring 0.287 0.587 0.172 0.236 0.164 0.173 0.793 0.858 1.480 2.235 ^
Summer 0.304 0.474 0.174 0.209 0.119 0.273 0.917 0.884 0.973 1.835
% of P20s, KsO and lime in 1937, Fall 0.457 0.535 0.239 0.120 0.268 0.639 0.926 1.048 1.780
1938 and 1939 Mean 0.349 0.532 0.173 0.228 0.134 0.238 0.783 0.889 1.167 1.950
72 144 100 2,000 Spring 0.237 0.539 0.186 0.233 0.150 0.229 1.164 0.651 1.440 2.265 a
Summer 0.384 0.456 0.231 0.216 0.142 0.293 1.266 0.883 1.072 1.936
All in 1937 Fall 0.487 0.417 0.166 0.156 0.122 0.207 0.680 0.966 1.238 1.685
_Mean 0.369 0.471 0.194 0.202 0.138 0.243 1.037 0.833 1.250 1.962
72 0 100 2,000 Spring 0.327 0.288 0.157 0.155 0.112 0.141 0.961 1.089 1.392 1.624
Summer 0.244 0.229 0.177 0.130 0.112 0.187 1.252 1.209 1.082 1.906
All in 1937 Fall 0.213 0.154 0.151 1.157 1.460 0
Mean 0.286 0.243 0.167 0.146 0.112 0.160 1.107 1.152 1.237 1.663
72 144 0 2,000 Spring 0.441 0.493 0.221 0.238 0.188 0.270 0.593 0.465 1.512 2.230 2
Summer 0.318 0.493 0.241 0.194 0.150 0.293 0.838 0.604 1.096 2.021
All in 1937 Fall 0.320 0.239 0.239 0.694 1.560
Mean 0.380 0.435 0.231 0.224 0.169 0.267 0.716 0.588 1.304 1.937 9
72 144 200 2,000** Spring 10.393 0.376 0.203 0.207 0.282 0.219 1.041 1.222 1.530 2.093 ^
Summer 0.262 0.231 0.189 0.107 0.127 0.204 1.330 0.810 1.000 1.821
PA20 and K,O in 1937 and 1939 Fall 0.307 0.204 0.252 1.200 1.747
Dolomite in 1937 Mean 0.328 0.305 0.196 0.173 0.205 0.225 1.186 1.077 1.265 1.887
Fertilizer and lime sources as given in Table 2.
"** Dolomitic limestone (36% Mg COs). Spring sample, April to July; Summer, July and August; and Fall after August. e
t Nitrogen applications were alike for all treatments which received nitrogen.







20 Florida Agricultural Experiment Station

pounds N, 144 pounds P20s and 100 pounds K20 in 1937 was
higher in calcium, phosphorus and potassium than untreated
grass. The lime and fertilizer did not alter the magnesium and
nitrogen content of the grass appreciably. When the P205 or
K20 was omitted from the lime and complete fertilizer applica-
tions the phosphorus or potassium content of grass was dimin-
ished accordingly.
A light application of a lime and fertilizer mixture consisting
of 72 pounds nitrogen, 36 pounds P205, 25 pounds K20 and 500
pounds of calcic lime in 1937 also produced carpet grass that
was higher in calcium, phosphorus and potassium content than
unfertilized grass during that year. Additional P205, K20 and
lime applied during the 1938 and 1939 growing seasons resulted
in additional increases of the calcium, phosphorus and potassium
content.
Carpet grass fertilized with 72 pounds of nitrogen per acre
annually was lower in calcium, phosphorus and potassium content
than unfertilized grass during both 1937 and 1939.
The nitrogen content of carpet grass on the Bladen fine sand
was not altered significantly during the 1937 season by fertiliza-
tion. However, during the 1939 season, the carpet grass which
was treated with nitrogenous fertilizer was significantly higher
in nitrogen content than that of unfertilized grass.
The substitution of dolomitic for calcic limestone on the Bla-
den fine sand did not alter the magnesium content of carpet grass
consistently during either 1937 or 1939.
There was also considerable fluctuation in the chemical com-
position of carpet grass as affected by seasonal conditions. Car-
pet grass was generally higher in minerals and nitrogen during
the spring than in the summer or fall.
The 1937 seasonal chemical analyses of carpet grass top-
dressed with certain lime and fertilizer mixtures on a Leon fine
sand are given in Table 6. The unfertilized carpet grass on the
Leon fine sand was higher in phosphorus and potassium content
than unfertilized carpet grass on the Bladen soil type. Carpet
grass treated with nitrogen alone was also higher in phosphorus
and potassium content on the Leon than on the Bladen soil type.
However, the mineral content of carpet grass was altered appre-
ciably by fertilization on the Leon fine sand. When lime or
phosphorus was omitted the calcium or phosphorus content of
carpet grass was appreciably less than for carpet grass treated
with lime and complete fertilizer.







Effect of Fertilizer on Carpet and Other Grasses 21

TABLE 6.-CHEMICAL COMPOSITION OF CARPET GRASS AS INFLUENCED BY
FERTILIZATION AND SEASON ON A LEON FINE SAND IN ALACHUA COUNTY
DURING 1937.


Fertilizer and Lime* Composition on Percent Dry Basis
Applied in 1937 Grass Cal- Phos- Mag- Potas- Nitro-
I Sampled cium chorus nesium sium gen
N P20O KO20 Lime C__ % % % % %
0 0 0 0 Spring 0.287 1.766 1.582
Summer 0.270 1.568 1.243
Fall 0.287 0.833 1.686
Mean 0.281 1.389 1.504
72 0 0 0 Spring 0.318 1.642 1.772
% applied in March and Summer 0.264 1.506 1.344
% in August for all Fall 0.281 1.227 1.581
treatments Mean 0.288 1.458 1.566
72 36 25 500 Spring 0.423 0.281 0.217 1.612 1.721
Summer 0.290 0.262 0.198 1.435 1.447
Fall 0.338 0.286 0.196 1.308 1.824
Mean 0.350 0.276 0.204 1.452 1.664
72 72 50 1,000 Spring 0.463 0.322 0.215 1.735 1.686
Summer 0.313 0.292 0.210 1.530 1.394
Fall 0.383 0.299 0.188 1.169 1.752
Mean 0.386 0.304 0.204 1.478 1.611
72 144 100 2,000 Spring 0.483 0.350 0.153 1.607 1.765
Summer 0.368 0.305 0.154 1.726 1.458
Fall 0.472 0.330 0.142 1.499 1.835
Mean 0.441 0.328 0.149 1.611 1.686
72 0 100 2,000 Spring 0.357 0.297 0.244 1.506 1.733
Summer 0.270 0.278 0.237 1.501 1.429
Fall 0.322 0.295 0.238 1.308 1.787
_Mean 0.316 0.290 0.240 1.438 1.650
72 144 100 0 Spring 0.458 0.534 0.210 1.524 1.769
Summer 0.262 0.394 0.200 1.644 1.405
Fall 0.299 0.388 0.135 1.199 1.788
Mean 0.340 0.439 0.182 1.456 1.654
72 72 100 2,000** Spring 0.433 0.418 0.215 1.619 1.726
Summer 0.286 0.344 0.210 1.716 1.459
Fall 0.303 0.352 0.219 1.272 1.759
Mean 0.341 0.371 0.215 1.536 1.648
Spring 0.436 0.351 0.209 1.626 1.719
Mean all treatments Summer 0.298 0.301 0.202 1.578 1.397
_Fall 0.353 0.315 0.186 1.227 1.752
Fertilizer and lime sources as given in Table 2. The nutrient materials were applied
in March or as indicated.
** Dolomitic limestone (36% Mg COa). Spring sample, April to July; Summer, July
through September; and Fall after September.

Dolomitic and calcic limestones were used at the rate of 1 ton
per acre in addition to a complete fertilizer. A comparison of
these 2 treatments shows that the magnesium content of carpet
grass was higher when top-dressed with dolomitic limestone.
However, the large variance in magnesium content of carpet
grass as shown by other treatment comparisons indicates that
it may vary considerably without affecting growth.





TABLE 7.-CHEMICAL COMPOSITION AND DRY YIELD OF CARPET GRASS ON 3 SOIL TYPES AS INFLUENCED BY FERTILIZER MIXTURES.
Dry
Fertilizers and Lime* Chemical Constituents Grass**
(Lbs. per Acre) Time of Applying PzOs, KO2 and Lime (% Dry Basis**) in Lbs.
________________ Cal- IPhos- Mag- Potas- Nitro- Iper
N | P20, I KO Lime [ cium phorus nesium sium gen Acre
Bladen Fine Sand, Duval County
0 0 0 0 0.355 0.134 0.161 0.640 1.869 136
72 0 0 0 0.294. 0.100 0.193 0.366 1.893 408
72 144 100 2,000 %1 of each in 1937, 1938, 1939 and 1940 0.573 0.234 0.182 0.794 1.909 1,058
72 144 100 2,000 All in 1937 0.544 0.169 0.257 0.429 1.945 785
72 144 100 0 of each in 1937 and 1939 0.395 0.161 0.183 0.667 1.918 743
72 0 100 2,000 All in 1937 0.254 0.107 0.150 0.874 1.915 628
72 144 0 2,000 All in 1937 0.395 0.174 0.210 0.401 1.910 638
72 144 200 2,000t % P.Os and K5O in 1937 and 1939 0.392 0.157 0.241 0.934 1.843 794
Dolomite in 1937
Value of P for F test of between Not
treatment variance 0.01 0.01 0.01 0.01 Sig. 0.01
Leon Fine Sand, Alachua County
0 0 0 0 0.481 0.183 0.159 1.399 1.872 240
72 0 0 0 0.428 0.168 0.148 0.929 1.863 637
72 144 100 2,000 1/ of each in 1937, 1938, 1939 and 1940 0.689 0.260 0.130 1.325 1.886 1,365
72 144 100 2,000 All in 1937 0.659 0.225 0.147 0.928 1.828 888
72 144 100 0 of each in 1937 and 1939 0.511 0.182 0.178 1.198 1.854 564
72 0 100 2,000 All in 1937 0.511 0.170 0.120 1.229 1.853 752
72 144 0 2,000 All in 1937 0.670 0.176 0.184 0.846 1.815 732
72 144 200 2,000 % P0Os and KO in 1937 and 1939 0.475 0.197 0.197 1.318 1.858 857
S____Dolomite in 1937
"Value of P for F test of between Not Not
treatment variance 0.01 0.01 Sig. 0.01 Sig. 0.01
Plummer Fine Sand, Alachua County
0 0 0 0 0.502 0.198 0.156 1.382 1.846 183
72 0 0 0 0.496 0.194 0.159 1.398 1.832 601
72 144 100 2,000 %4 of each in 1937, 1938, 1939 and 1940 0.624 0.208 0.100 1.556 1.837 658
72 144 100 2,000 All in 1937 0.568 0.234 0.103 1.415 1.841 640
72 144 100 0 of each in 1937 and 1939 0.461 0.219 0.135 1.370 1.835 580
72 0 100 2,000 All in 1937 0.580 0.206 0.115 1.368 1.843 583
72 144 0 2,000 All in 1937 0.581 0.192 0.139 1.128 1.822 604
72 144 200 2,000t % P0a5 and K,O in 1937 and 1939 0.468 0.223 0.166 1.412 1.798 641
Dolomite in 1937
Value of P for F test of between I Not I Not Not Not
treatment variance 0.01 Sig. Sig. Sig. Sig. 0.01
*N applied annually (% in March and % in August) PeOs, KzO and lime sources as in Table 2.
"** Dry yields are totals for three clipping dates, chemical analysis were made from grass clippings taken at the second date.
tDolomitic limestone (6% Mg COa).
--.- 1a A







Effect of Fertilizer on Carpet and Other Grasses 23

1940 Analyses.-The chemical analyses of variously fertilized
carpet grass on Bladen, Leon and Plummer fine sands for 1940
are given in Table 7.
Carpet grass on the Bladen fine sand which was treated with
144 pounds of P205, 100 pounds of K20 and 2,000 pounds of
calcic lime in 1937 and 72 pounds of nitrogen annually was
significantly higher in calcium, phosphorus, and potassium con-
tent than unfertilized grass. The omission of either lime, phos-
phorus or potassium from the lime and fertilizer mixture resulted
in a decrease of calcium, phosphorus or potassium content, re-
spectively. When the phosphorus or potassium was omitted
from the lime and fertilizer mixture the grass displayed ab-
normal growth which was found to be characteristic of a defi-
ciency of phosphorus or potassium (Figures 1 and 2). Carpet
grass treated with nitrogen fertilizer in the absence of other
fertilizer nutrients was lower in calcium, phosphorus, and potas-
sium than unfertilized carpet grass. Grass which was very low
in phosphorus content was usually also low in calcium, even
though lime was applied.
The chemical composition of carpet grass which was treated
with 1 ton of calcic lime, 144 pounds of P205 and 100 pounds of
K20 per acre in 1937 may be compared with the composition
of grass treated with 1/4 of the lime and fertilizer rates annually
for 4 years. The nitrogen of these 2 treatments was applied
annually at the rate of 72 pounds per acre. The grass fertilized
with the annual light applications of lime, P205 and K20 was
significantly higher in calcium, phosphorus and potassium in
1940 than the grass which received the heavy rate of nutrient
materials in 1937. Differences in phosphorus and potassium
content in favor of the frequent application were pronounced
(Table 7).
A comparison of carpet grass treated with dolomitic and calcic
limestone shows that the grass did not differ significantly in
magnesium content on the Bladen fine sand during 1940. It thus
appears that growth was not limited by magnesium on this soil
type.
The effect of fertilization on the chemical composition of carpet
grass during 1940 on the Leon fine sand is given in Table 7. The
calcium and phosphorus content of unfertilized grass was signifi-
cantly lower than that of grass treated with lime, P205, and K20.
The omission of lime, P205 or K20 from the lime and fertilizer
mixture resulted in significant reductions of calcium, phosphorus






24 Florida Agricultural Experiment Station

or potassium content, respectively. Grass treated with nitrogen,
without other nutrient materials, was also lower in minerals
than unfertilized grass. The calcium, phosphorus and potassium
content of carpet grass treated with 1 ton of calcic lime, 144
pounds P205 and 100 pounds of K20 per acre was lower than
that of grass treated with 1/ of the rate of lime, P205 and K20
annually for 4 years.
Carpet grass was treated with 1 ton of calcic limestone and
1 ton of dolomite per acre on the Leon soil. The lime sources
received like quantities of P205 and nitrogen but the plots which
were treated with dolomitic lime received 200 pounds of K20
and the calcic limestone plots received 50 pounds of K20 per
acre. The magnesium content of carpet grass receiving the
dolomitic limestone was somewhat higher than that of carpet
grass treated with calcic limestone. However, these differences
in magnesium content were not significant, because of the large
variance in magnesium content of grass in the replicated plots
of any one treatment.
The chemical analyses of carpet grass from the experiment
on the Plummer fine sand, which was once farmed, are given in
Table 7. The residual fertility of this soil was rather high, as
demonstrated by the high mineral content of the grass when
compared with the grass grown on the Leon and Bladen fine
sands. Calcium was the only mineral that was increased by
fertilization.
The data on mineral constituents of carpet grass on these 3
soils indicate that the residual fertility of these soils differs
greatly. The large differences in mineral content of grass grown
on these soils may be explained partially on the basis of previous
soil treatment rather than entirely on the basis of soil type.
A comparison of yields and mineral constituents of carpet
grass on these 3 soils shows that the mineral content of grass
may vary greatly without seriously retarding growth. The cal-
cium, phosphorus and potassium content was altered greatly
by fertilization. The effects of fertilization on the phosphorus,
potassium and calcium content of carpet grass were reasonably
consistent for the replicated plots. However, the magnesium
content of carpet grass was altered slightly due to treatment,
but the quantitative variance in this mineral in the plants for
the replicated plots was large. The magnesium content of carpet
grass treated with dolomitic limestone was not altered appre-
ciably when compared with grass treated with calcic limestone.







Effect of Fertilizer on Carpet and Other Grasses 25

TABLE 8.-EFFECT OF FERTILIZERS ON THE COMPOSITION OF CARPET AND
DALLIS GRASS ON VARIOUS SOIL TYPES AND OF DIFFERENT LOCATIONS,
JUNE 1940.*


Chemical Constituents,
Fertilizer Treatments** Percent Dry Basis
Potas- Phos-I Cal- Mag- Nitro-
_sium phorus cium nesium gen

Portsmouth Fine Sand, Osceola County (Carpet Grass)
No fertilizer ......................................... 0.794 0.145 0.391 0.211 1.889
Lime 2,000, 600 lbs. 0-16-8 .................. 0.915 0.236 0.491 0.289 1.875
Pr 3,000, K20 50 ...................... ....-.-- 0.991 0.283 0.437 0.333 1.878
Pc 3,000, K1 O 50 ............................... .... 0.950 0.259 0.424 0.256 1.885
Pbs 1,500, K20 50 ................................... 1.090 0.242 0.451 0.266 1.879

Leon Fine Sand, Osceola County (Carpet Grass)
No fertilizer .............................---......... -0.856 0.181 0.358 0.252 1.887
Lime 2,000, 600 lbs. 0-16-8 .................... 1.332 0.302 0.473 0.261 1.884
Pr 3,000, K20 50 --.....................------ .... 1.480 0.370 0.404 0.275 1.890
Pc 3,000, K 0O 50 .................................... 1.211 0.320 0.342 0.239 1.875

Leon Fine Sand (Prairie Phase), DeSoto County (Carpet Grass)
No fertilizer ...................................... 0.754 0.124 0.362 0.279 1.878
Pr 3,000, K O 50 ...................................... 0.992 0.245 0.453 0.229 1.873

Acid Peaty Muck, Polk County (Carpet Grass)
Fertilized 1930 ........................................------------------- 0.593 0.186 I 0.681 0.214 1.874
Lime 2,000, 600 Ibs. 0-16-8 ................... 0.839 0.221 0.778 0.281 1.888

Plummer Fine Sand, Hardee County (Carpet Grass)

Virgin-no fertilizer .............-- ..... 0.610 0.166 0.305 0.185 1.181
Lime 2,000, 600 lbs. 0-16-8 in 1939 .. 0.77 0.239 0.528 0.189 1.673
Pr 3,000, K,0 50 in 1939 ..............----. 0.93 0.241 0.361 0.188 1.573
Pc 3,000, K20 50 in 1939 ........................ 0.76 0.278 0.344 0.218 1.411

Plummer Fine Sand, Volusia County (Dallis Grass)
Lime 4,000, 600 lbs. 0-16-8 .................... 1.380 0.264 0.860 0.321 1.887
Lime 2,000, Pbs 1,500, K20 50 ............ 2.361 0.283 0.617 0.175 1.893
Lime 2,000, 600 lbs. 0-16-8 ............. 1.50 0.246 0.682 0.220 1.878
Lime 2,000, Pbs 750, KO0 50 ................ 2.008 0.254 0.620 0.244 1.889


Average Dallis grass ............................ 1.812 0.262 0.695 0.240 1.887
Average carpet grass-not fertilized 0.754 0.154 0.354 0.232 1.709
Average carpet grass-fertilized ........ 1.038 0.274 0.428 0.249 1.791
Percent increase over
unfertilized carpet grass ............. 38 78 21 7 5

Grass samples taken from experimental plots. The fertilizers were weighed for each
plot and applied in 1938. Grasses were sampled during the vegetative growth period.
"**Lime-ground limestone (93% Ca COs). Pr-rock phosphate (32.27% PaOs).
Pc-colloidal phosphate (20.4% P.Os). K.O-muriate of potash (50% KaO).
Pbs-basic slag.







26 Florida Agricultural Experiment Station

The calcium content of grass treated with calcic limestone was
higher on all 3 soils than of grass treated with dolomitic lime-
stone. The grass treated with complete fertilizer and lime was
slightly higher in phosphorus content than grass which received
complete fertilizer without lime.

CHEMICAL COMPOSITION OF VARIOUS GRASSES TREATED WITH
PHOSPHORUS FROM DIFFERENT SOURCES AND LIME
WITH FERTILIZER MIXTURES
In these experiments soils of several types were treated with
phosphorus from different sources (superphosphate, rock phos-
phate, colloidal phosphate and basic slag) and mixtures of lime
and fertilizers. The treatments were designed primarily to grow
clover. However, since carpet grass was well established on some
of the soils, samples were plucked from. plots which were vari-
ously fertilized for making chemical analyses. The mineral con-
tent of carpet grass when treated with various lime and fertilizer
mixtures and phosphorus from different sources on several soil
types is given in Table 8.
Fertilization increased the phosphorus, potassium and calcium
content of carpet grass on all 5 soil types as given in Table 8.
A comparison of treated and untreated carpet grass for the 5
soils shows mean increases of 78 percent in phosphorus, 21 per-
cent in calcium, 38 percent in potassium, 7 percent in magnesium,
and 5 percent in nitrogen over unfertilized grass.
The phosphorus from different sources was used in mixtures as
follows: superphosphate with 1 ton of calcic lime and 600 pounds
of 0-16-8; 1,500 pounds of basic slag and 50 pounds of K20;
and rock and colloidal phosphates at rates of 3,000 pounds and
50 pounds of K20. The phosphorus from all 4 sources increased
the phosphorus content greatly over that of unfertilized grass.
The calcium content of carpet grass was also increased by all
of the phosphates from different sources on all 5 soils, with the
exception of the colloidal phosphate treatment on 1 soil. Carpet
grass was slightly higher in calcium when treated with rock
phosphate than with colloidal phosphate. The grass which was
treated with lime was higher in calcium than grass treated with
basic slag, colloidal or rock phosphate in the absence of lime.
In 1941 carpet grass samples were plucked from pastures on
8 soil types on widely separated areas which received rock phos-
phate or other fertilizers and from untreated pastures (Table 9).








Effect of Fertilizer on Carpet and Other Grasses 27

TABLE 9.-CoMPOSITION OF CARPET GRASS FROM SEVERAL PASTURES AS
INFLUENCED BY FERTILIZATION, JULY 1941.

Chemical Constituents-
Treatment in Pounds per Acre Percent Dry Basis
Cal- Phos- IMag- I Potas- Nitro-
cium phorus nesium sium gen
Leon Fine Sand, Osceola County**
Virgin-no fertilizer .............................. 0.403 0.241 1.251
Pr 3,600 lbs. in 1938 .............................. 0.427 0.278 1.380
Pr 1,800 lbs. in 1940 .............................. 0.346 0.257 1.481
Once farmed and fertilized* ................ 0.296 0.185 1.231
Virgin-no fertilizer .............................. 0.264 0.155 1.141
Increased by fertilization (percent) .-| 16 | 35 1 20
Portsmouth Fine Sand (Prairie Phase), Osceola County**
Virgin-no fertilizer .............................. 0.320 0.185 - 1.386
Virgin-no fertilizer ............... ............ 0.321 0.118 -- 1.326
Pr 1,800 lbs. in 1939 .............................. 0.264 0.239 1.183
Pr 1,800 lbs. in 1940 .......-..................... 0.457 0.252 1.486
Pr 1,800 lbs. in 1939 .............................. 0.698 0.324 1.486
Pr 1.800 lbs. in 1939 and 1940 ............ 0.428 0.264 -1.482
Increased by fertilization (percent) ..1 44 1 78 ___4
Acid Peaty Muck, Polk County
No fertilizer .................................-- .... 0.574 0.164 0.190 0.68 1.890
1 ton 0-16-16 in 1928; Pr 1,800 lbs.
in 1940 ........................... 1.299 0.317 0.260 0.61 1.299
Increased by fertilization (percent) ..1 126 | 93 37 -10 | -31
Leon Fine Sand (Prairie Phase), Highlands County**
Virgin-no fertilizer ............................. 0.164 0.180 0.140 0.830 1.492
Pr 1,800 lbs. in 1939 ............................ 0.479 0.277 0.099 0.930 1.397
Pr 1,800 lbs. in 1939 .............................. 0.392 0.305 0.149 0.920 1.915
Increased by fertilization (percent) ..- 166 [ 62 -11 11 11
Leon Fine Sand, DeSoto County
No fertilizer ...-----......--... ---..............------ 0.327 0.133 0.182 0.600 1.165
Pr 1,000 lbs. in 1940 ............................. 0.452 0.286 0.189 0.850 1.372
Increased by fertilization (percent) ..- 38 | 116 4 4 42 | 18
Orlando Fine Sand, DeSoto County
No fertilizer ....--.................................... 0.334 0.180 0.160 0.960 1.143
1% to 1 ton Pr in 1940 ........................... 0.393 0.239 0.168 1.320 1.307
Lime 2,000 lbs., 0-16-8 600 Ibs. in 1940 0.354 0.246 0.166 1.590 1.590
Increased by fertilization (percent) ..- 12 | 35 | 4 52 | 27
Bladen Fine Sand, Duval County
No fertilizer ....--.................................... 0.342 0.153 0.192 1.338 1.215
Lime and complete fertilizer ................ 0.495 0.350 0.259 1.321 1.798
Increased by fertilization (percent) ..) 45 [ 129 1 35 -13 48
Plummer Fine Sand, Clay County**
No fertilizer ........................................ 0.413 0.095 0.288 0.476 1.166
No fertilizer ........................................... 0.279 0.099 0.355 0.535 1.048
Lime and complete fertilizer .............. 0.567 0.156 0.348 0.556 1.246
Increased by fertilization (percent) .. 63 | 61 81 10 13
Average unfertilized grass (all soils) 0.340 0.155 0.215 0.774 1.293
Average fertilized grass (all soils) .... 0.504 0.271 0.205 1.012 1.459
Increase (percent) .................................. 48 | 75 | -5 31 13
Pr-rock phosphate (32% total P2Os). Lime-calcium carbonate (93% Ca COa).
Not used in average percentage computations.
** Grass samples taken from several different pastures.








28 Florida Agricultural Experiment Station

Treated carpet grass was higher by 48 percent in calcium, 75
percent in phosphorus, 31 percent in potassium and 13 percent
in nitrogen than unfertilized grass. The mean magnesium con-
tent was 5 percent less for the fertilized grass.
Chemical composition of St. Lucie grass (Cynodon dactylon
(L.) Pers., Para grass (Panicum purpurascens Raddi), 2 com-
mon pasture grasses in South Florida, and Centella repanda
(Pers.) Small, a common pasture weed, as affected by fertiliza-
tion are given in Table 10. The phosphorus content of all 3
plants was greatly increased by supplying phosphorus, and the
calcium content of the grasses was increased also.

TABLE 10.-COMPOSITION OF PLANTS FROM SEVERAL PASTURES AS
INFLUENCED BY FERTILIZATION, JULY 1941.

Chemical Constituents-
Soil Treatment Percent Dry Basis
Cal- Phos- Mag- Potas- Nitro-
cium phorus nesium sium gen
St. Lucie Grass from Leon Fine Sand (Prairie Phase), Highlands County
Lime and 20 lbs. bluestone .................. 0.280 0.322 0.207 1.280 1.900
8-8-0 400 lbs. and 20 lbs. bluestone .... 0.385 0.387 0.193 1.03 2.297
Para Grass from Muck, Highlands County
20 lbs. bluestone .................................... 0.353 0.367 0.217 2.53
Pr 1,800 lbs. in 1937 ............................ 0.365 0.498 0.216 1.55
Centella* from Acid Muck, Polk County
Virgin-no fertilizer ............................ 1.52 0.115 0.303 1.540 1.891
Pr 3,000 lbs. in 1938 .............................. 1.10 0.349 0.378 0.670 2.032
Pr-rock phosphate (32% PZOs).
Centella repanda--a common pasture weed.

A comparison of mineral analyses of carpet, Dallis (Paspalum
dilatatum Poir), St. Lucie and Para grasses may be made by ob-
serving data of Tables 8 and 10. The mineral content of these
grasses differed appreciably.
The data given in Tables 8, 9 and 10 show that fertilized
grass is higher in minerals than unfertilized grass. This, no
doubt, explains cattle preference for fertilized grass which has
been frequently observed. Observations on these experiments
and pastures show that phosphorus stimulated sodding more
than other fertilizer nutrients on sandy soils of Peninsular
Florida. After phosphorus is supplied, other nutritive elements
also stimulate growth.






Effect of Fertilizer on Carpet and Other Grasses 29

SUMMARY AND CONCLUSIONS
Effects of lime from 2 sources and various lime and fertilizer
mixtures and trace elements on growth and chemical composi-
tion of carpet grass on Leon, Plummer, Bladen and Fellowship
fine sands were tested. Effect of phosphorus from 4 sources
(superphosphate, basic slag, colloidal and rock phosphate) on
the chemical composition of carpet and other grasses grown on
several sandy soil types also was studied.
Growth of established carpet grass was stimulated primarily
by nitrogen fertilizer. Lime, phosphorus and potash increased
the efficiency of the nitrogen fertilizer greatly on 3 of the soil
types. March applications of nitrogen increased the early sea-
son growth greatly, but September and other late-season applica-
tions of nitrogen did not augment the late-season growth of
carpet grass appreciably. The most desirable yield curve oc-
curred when all of the nitrogen was applied in March or March
and June. Smaller yields and less early feed resulted with late-
season nitrogen applications.
Omission of either lime, superphosphate or potash from a
lime and fertilizer mixture generally retarded growth and pro-
duced grass low in the mineral content of the nutrient material
omitted. The omission of phosphorus or potassium from the
lime and fertilizer mixture on the Bladen fine sand caused phos-
phorus or potassium deficiency symptoms of carpet grass.
Yield of carpet grass when treated with 500 pounds of calcic
lime, 36 pounds of P20 and 25 pounds of K20 did not differ
significantly when compared with grass treated with 4 times
this quantity of minerals on the Leon, Plummer and Fellowship
fine sand. On the Bladen fine sand the grass was somewhat
more productive where light application of lime and minerals
was made, but where the quantity of nitrogen was constant.
Other treatments also show that carpet grass does not respond
to heavy applications of lime, superphosphate and potash.
Yields of carpet grass when treated with infrequent heavy
applications of fertilizer did not differ significantly from yields
of grass treated with frequent light applications of fertilizers
on the Leon, Plummer and Fellowship fine sands. The latter
treatment was more productive on the Bladen fine sand. The
phosphorus, calcium and potassium content of grass treated with
frequent light applications of minerals was significantly higher
than that of grass treated with infrequent heavy applications of
minerals on the Leon and Bladen soils.






30 Florida Agricultural Experiment Station

The calcium, phosphorus and potassium content of grass
treated with lime and complete fertilizer was significantly higher
than that of unfertilized grass on the Leon and Bladen fine sands.
Grass treated with nitrogen alone was lower in calcium, phos-
phorus and potassium than unfertilized grass on all soils.
The calcium content of grass growing on Plummer fine sand,
which was once farmed, was altered significantly by soil amend-
ments, but the phosphorus and potassium content was not
changed appreciably by fertilization.
The trace element treatments on these soils did not alter
growth of carpet grass appreciably. The effect of trace ele-
ments on composition was not determined.
Carpet grass treated with dolomitic and calcic limestone did
not show significant differences in yield on the 4 soils. The
calcium content of carpet grass was higher when treated with
calcic limestone than with dolomitic limestone, and the mag-
nesium content for these 2 treatments did not generally differ
significantly.
Plucked carpet grass samples taken in 1940 from 5 experi-
ments on different soil types showed that the phosphorus, cal-
cium and potassium content of carpet grass was increased 78
percent, 21 percent, and 38 percent, respectively, when compared
with unfertilized grass. Phosphorus from 4 sources (super-
phosphate, basic slag, rock and colloidal phosphate) increased
the phosphorus content of carpet grass greatly.
Carpet grass samples taken from numerous pastures on
ranches during 1941 showed the following increases in minerals
over unfertilized grass: calcium 48 percent, phosphorus 75 per-
cent, potassium 31 percent, and nitrogen 13 percent. The mag-
nesium content was reduced 5 percent.
The phosphorus and calcium content of St. Lucie grass, Para
grass and Centella (a common pasture weed) was also aug-
mented by fertilization.
Test plots located on various virgin soils in peninsular Florida
show that a low phosphorus supply is the primary factor limit-
ing growth and development of grass sods. After phosphorus
is supplied insufficient amounts of other elements, potassium,
nitrogen, calcium and minor elements, limit growth.







Effect of Fertilizer on Carpet and Other Grasses 31

LITERATURE CITED

1. BROWN, B. A., and A. E. HOLLOWELL. The Chemical Composition of
Some Pasture and Hay Plants as Affected by Soils and Fertilizers.
Proc. Soil Sci. Soc. of America 5: 131-139. 1940.
2. COOPER, H. P., J. H. MITCHELL, E. D. KYZER and T. M. CLYBURN.
Chemical Composition of Clippings of Carpet Grass from Pasture
Plats Receiving Various Fertilizer Treatments. S. C. Agr. Exp. Sta.
Tech. Contr. 56.
3. KILLINGER, G. B., R. E. BLASER, E. M. HODGES and W. E. STOKES.
Minor Elements Stimulate Pasture Plants. Fla. Agr. Exp. Sta.
Bul. 384. 1943.
4. LEUKEL, W. A., J. P. CAMP and J. M. COLEMAN. Effect of Frequent
Cutting and Nitrate Fertilization on the Growth Behavior and Rela-
tive Composition of Pasture Grasses. Fla. Agr. Exp. Sta. Bul. 269.
1934.
.5. PIETERS, A. J. Effect of Maturity on Chemical Composition of Legum-
inous Forage Plants. Jour. Amer. Soc. of Agron. 29: 436-440. 1937.
6. PIERRE, W. H., and R. R. ROBINSON. The Calcium and Phosphorus
Content of Pasture Herbage and of Various Pasture Species as
Affected by Fertilization and Liming. Jour. Amer. Soc. of Agron.
29: 477-497. 1937.
"7. VANDECAVEYE, S. C. Effects of Soil Type and Fertilizer Treatments
on the Chemical Composition of Certain Forage and Small Grain
Crops. Proc. Soil Sci. Soc. of America 5: 107-119. 1940.





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