Bulletin 453 December, 1948
UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
HAROLD MOWRY, Director
Carpet Grass and Legume
Pastures in Florida
Their Growth, Composition and Contribution to Beef
R. E. BLASER, R. S. GLASSCOCK, G. B. KILLINGER
and W. E. STOKES
Fig. 1.-Applications of fertilizer when the grass was grazed closely
increased the total and early season clover growth. Left fertilized with
400 pounds 0-10-10 in October and right in February. Photograph taken
in January, 1945.
Single copies free to Florida residents upon request to
AGRICULTURAL EXPERIMENT STATION
BOARD OF CONTROL ECONOMICS, AGRICULTURAL
. Th Gurney.hairman, Orlando C. V. Noble, Ph.D., Agri. Economist s
N. B. Jordan, Quincy Zach Savage, M.S.A., Associate
Those. W. Bryant, LakelandA. H. Spurlock, M.S.A., Associate
Thos.W. Bryan, LakeD. E. Alleger, M.S., Associate
J. Henson Markham, Jacksonville. M.. As ate
Holli Rie, M i D. L. Brooke, M.S.A., Associate
ois Rinehart, Miami IR. E. L. Greene, Ph.D., Agri. Economist
W. F. Powers, Secretary, Tallahassee H. W. L ile, .S., Assist
H. W. Little, M.S., Assistant
EXECUTIVE STAFF Orlando, Florida (Cooperative USDA)
J. Hillis Miller, Ph.D., President of the G. Norman Rose, B.S., Asso. Agr. Economist
University3 J. C. Townsend, Jr., B.S.A., Agr. Statisticians
H. Harold Hume, D.Sc., Provost for Agr.8 J. B. Owens, B.S.A., Agr. Statisticians
Harold Mowry, M.S.A., Director J. F. Steffens, Jr., B.S.A., Agr. Statisticians
L. O. Gratz, Ph.D., Asst. Dir., Research
W. M. Fifield, M.S., Asst. Dir., Admin. ECONOMICS, HOME
J. Francis Cooper, M.S.A., Editors
Ouida D. Abbott, Ph.D., Home Econ.1
Clyde Beale, A.B.J., Associate Editors uda Abbott, Ph.D., Home Econ.'
ydeeals A As iate E B. French, Ph.D., Biochemist
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Managers ENTOMOLOGY
Geo. F. Baughman, M.A., Business Manager3
Claranelle Alderman, Accountants A. N. Tissot, Ph.D., Entomologistx
L. C. Kuitert, Ph.D., Assistant
H. E. Bratley, M.S.A., Assistant
MAIN STATION, GAINESVILLE
AGRICULTURAL ENGINEERING HORTICULTURE
Frazier Rogers, M.S.A., Agr. Engineer3 G. H. Blackmon, M.S.A., Horticulturist'
J. M. Johnson, B.S.A.E., Asso. Agr. Engineer F. S. Jamison, Ph.D., Horticulturists
J. M. Myers, B.S., Asso. Agr. Engineer H. M. Reed, B.S., Chem., Veg. Processing
R. E. Choate, B.S.A.E., Asst. Agr. Engineer3 Byron E. Janes, Ph.D., Asso. Hort.
A. M. Pettis, B.S.A.E., Asst. Agr. Engineer R. A. D'ennison, Ph.D., Asso. Hort.
R. K. Showalter, M.S., Asso. Hort.
Albert P. Lorz, Ph.D., Asso. Hort.
AGRONOMY R. H. Sharpe, M.S., Asso. Hort.
Fred H. Hull, Ph.D., Agronomist' R. J. Wilmot, M.S.A., Asst. Hort.
G. E. Ritchey, M.S., Agronomist2 R. D. Dickey, M.S.A., Asst. Hort.
G. B. Killinger, Ph.D., Agronomists Victor F. Nettles, M.S.A., Asst. Hort.'
H. C. Harris, Ph.D., Agronomist3 F. S. Lagasse, Ph.D., Asso. Hort.2
R. W. Bledsoe, Ph.D., Agronomist L. H. Halsey, B.S.A., Asst. Hort.
M. E. Paddick, Ph.D., Associate Forrest E. Myers, B.S.A., Asst. Hort.
S. C. Litzenberger, Ph.D., Associate
W. A. Carver, Ph.D., Associate PLANT PATHOLOGY
Fred A. Clark, B.S., Assistant W. B. Tisdale, Ph.D., Plant Pathologist'
Phares Decker, Ph.D., Asso. Plant Path.
ANIMAL INDUSTRY Erdman West, M.S., Mycologist and Botanist
A. L. Shealy, D.V.M., An. Industrialist' Howard N. Miller, Ph.D., Asso. Plant Path.
R. B. Becker, Ph.D., Dairy Husbandman3 Lillian E. Arnold, M.S., Asst. Botanist
E. L. Fouts, Ph.D., Dairy Technologist3
D. A. Sanders, D.V.M., Veterinarian SOILS
M. W. Emmel, I.V.M. Veterinarian3 F. B. Smith, Ph.D., Microbiologist'
L. E. Swanson, D.V.M., Parasitologist Gaylord M. Volk, Ph.D., Chemist
N. R. Mehrhof, M.Agr., Poultry Husb.3 J. R. Henderson, M.S.A., Soil Technologists
G. K. Davis, Ph.D., Animal Nutritionist3 atR.anNealer, Ph r.D .DSSoi Chemist
Nathan Gammon, Jr., Ph.D., Soils Chemist
R. S. Glasscock, Ph.D., An. Husbandman3 C. E. Bell, Ph.D., Associate Chemist
P. T. Dix Arnold, M.S.A., Asst. Dairy Hush.3 R. A. Carrigan, Ph.D., Asso. Biochemists
C. L. C Ph., As. B H. W. Winsor, B.S.A., Assistant Chemist
C. L. Comar, Ph.D., Asso. Biochemist Geo. D. Thornton, Ph.D., Asso. Microbiologists
L. E. Mull, M.S., Asst. in Dairy Tech. R. E. Caldwell, M.S.A., Asst. Chemists
Katherine Boney, B.S., Asst. Chem. J. B. Cromartie, B.S.A., Soil Surveyor
J. C. Driggers, B.S.A., Asst. Poultry Husb.3 Ralph G. Leighty, B.S., Asso. Soil Surveyor
V. W. Cyzycki, B.S., Asst. Soil Surveyor
Glenn Van Ness, D.V.M., Asso. Poultry R. B. Forbes, M.S., Asst. Soils Chemist
Pathologist W. L. Pritchett, M.S., Asst. Chemist
S. John Folks, B.S.A., Asst. An. Hush.3 Jean Beem, B.S.A., Asst. Soil Surveyor
W A. Krienke, M.S., Asso. in Dairy Mfs.
S P Marshall, Ph.D., Asso. Dairy Hus. Head of Department.U.
2 In cooperation with U. S.
U. F. Simpson, IY.V.M., Asso. Veterinarian 3 Cooperative, other divisions, U. of F.
C. '. Winchester, Ph.D., Asso. Biochemist3 4 On leave.
BRANCH STATIONS C. B. Savage, M.S.A., Asst. Horticulturist
D. L. Stoddard, Ph.D., Asso. Plant Path.
NORTH FLORIDA STATION, QUINCY
J. D. Warner, M.S., Vice-Director in Charge SUB-TROPICAL STATION, HOMESTEAD
R. R. Kincaid, Ph.D., Plant Pathologist
W. H. Chapman, M.S., Asso. Agron. Geo. D. Ruehle, Ph.D., Vice-Dir. in Charge
R. C. Bond, M.S.A., Asso. Agronomist Dl. O. Wolfenbarger, Ph.D., Entomologist
L. G. Thompson, Ph.D., Soils Chemist Francis B. Lincoln, Ph.D., Horticulturist
Frank S. Baker, Jr., B.S., Asst. An. Husb. Robt. A. Conover, Ph.D., Asso. Plant Path.
R. W. Harkness, Ph.D., Asst. Chemist
Mobile Unit, Monticello Milton Cobin, B.S., Asso. Horticulturist
R. W. Wallace, B.S., Associate Agronomist
W. CENT. FLA. STATION, BROOKSVILLE
Mobile Unit, Marianna William Jackson, B.S.A., Animal Husband-
R. W. Lipscomb, M.S., Associate Agronomist man in Charge2
Mobile Unit, Wewahitchka RANGE CATTLE STATION, ONA
J. B. White, B.S.A., Associate Agronomist W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Associate Agronomist
Mobile Unit, DeFuniak Springs D. W. Jones, B.S., Asst. Soil Technologist
H. J. Fulford, B.S.A. Asst. Animal Hush.
R. L. Smith, M.S., Associate Agronomist
CENTRAL FLORIDA STATION, SANFORD
CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Vice-Director in Charge R W. Ruprecht, Ph.D., Vice-Dir. in Charge
W. L. Thompson, B.S., Entomologist J. W. Wilson, Sc.D., Entomologist
J. T. Griffiths, Ph.D., Asso. Entomologist Ben F. Whitner, Jr., B.S.A., Asst. Hort.
R. F. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, M.S., Plant Pathologist WEST FLORIDA STATION, MILTON
R. K. Voorhees. Ph.D., Asso. Horticulturist H. W. Lundy, B.S.A., Associate Agronomist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
A. F. Mathias, B.S.A., Asst. Chemist
T. W. Young, Ph.D., Asso. Horticulturist FIELD STATIONS
J. W. Sites, M.S.A., Horticulturist
H. 0. Sterling, B.S., Asst. Horticulturist Leesburg
J. A. Granger, B.S.A., Asst. Horticulturist G. K. Parris, Ph.D., Plant Path. in Charge
H. J. Reitz, M.S., Asso. Horticulturist
Francine Fisher, M.S., Asst. Plant Path. Plant City
I. W. Wander, Ph.D., Soils Chemist A. N. Brooks, Ph.D., Plant Pathologist
A. E. Willson, B.S.A., Asso. Biochemist
J. W. Kesterson, M.S., Asso. Chemist
R. N. Hendrickson, B.S., Asst. Chemist Hastings
E. H. Bitcover, M.A., Soils Chemist A. H. Eddins, Ph.D., Plant Path. in Charge
L. C. Knorr, Ph.D., Asso. Histologist E. N. McCubbin, Ph.D., Horticulturist
Joe P. Barnett, B.S.A., Asst. Horticulturist
J. C. Bowers, B.S., Asst. Chemist Monticello
D. S. Prosser, Jr., B.S., Asst. Horticulturist A. M. Phillips, B.S., Asso. Entomologist2
R. W. Olsen, B.S., Biochemist
F. W. Wenzel, Jr., Ph.D., Supervisory Chem. radento
J. R. Beckenbach, Ph.D., Hort. in Charge
EVERGLADES STATION, BELLE GLADE
EVERGLADES STATION, BELLE GLADE E. G. Kelsheimer, Ph.D., Entomologist
R. V. Allison, Ph.D'., Vice-Director in Charge David G. Kelbert, Asso. Horticulturist
F. D. Stevens, B.S., Sugarcane Agronomist E. L. Spencer, Ph.D., Soils Chemist
Thomas Bregger, Ph.D., Sugarcane Robert O. Magie, Ph.D., Gladioli Hort.
Physiologist J. M. Walter, Ph.D., Plant Pathologist
J. W. Randolph, M.S., Agricultural Engineer Donald S. Burgis, M.S.A., Asst. Hort.
W. T. Forsee, Jr., Ph.D., Chemist
R. W. Kidder, M.S., Asso. Animal Husb.
T. C. Erwin, Assistant Chemist Lakeland
Roy A. Bair, Ph.D., Agronomist Warren O. Johnson, B.S., Meteorologist2
C. C. Seale, Asso. Agronomist
N. C. Hayslip, B.S.A., Asso. Entomologist 1 Head of Department.
E. H. Wolf, Ph.D., Asst. Horticulturist 2In cooperation with U. S.
W. H. Thames, M.S., Asst. Entomologist 3 Cooperative, other divisions, U. of F.
J. C. Hoffman, M.S.. Asso. Horticulturist 4 On leave.
INTRODUCTION ............- ................................... ........... ......... 5
PLAN OF EXPERIMENTS -...............-.. .. --...... ..... .... ...- ............ 5
SOIL REACTION ............. .............---.......-- 11
BOTANICAL COMPOSITION AND YIELD OF HERBAGE .....................--.......--....... 12
CHEMICAL COMPOSITION .----- --..... ...................... -- .................... 21
GRAZING RESULTS --........... ------.--....---------------................... 24
BLOOD STUDIES ....... ..---- ............-------------...............--. ....... ..... ....... 26
CARCASS GRADES .. ........ ...............------- -............... 26
QUALITY OF HERBAGE ..........-- ...................------ ....... ...... .............. ... 27
SUMMARY- CONCLUSION ..................--..-----. ..............-..................... 34
LITERATURE CITED ----.----. -------..................------ -----.................. .. 36
This research stresses the importance of pasture im-
provement and management. By using recommended
fertilizer practices and legume-grass mixtures, the
beef production (for a four-year period) was eight
times as high as for unfertilized pastures. This high
beef production was dependent upon both quality and
quantity of herbage. When legumes are used, the
quality and amount of herbage can be improved simul-
taneously. The best feeding value of herbage is pro-
duced by active new leaf growth. Rapid new leaf
growth of grasses can be stimulated by fertilization,
particularly nitrogen fertilizers. Because leguminous
plants fix nitrogen for their growth as well as im-
prove the soil nitrogen, rapid new leaf development
can be obtained in grass-legume mixtures without ap-
plying nitrogen fertilizers. It may be concluded that
the isolation of adapted legumes for the various soil en-
vironments of Florida is of paramount importance in
improving the quality of herbage and thus the pro-
ductivity and quality of livestock.
Carpet Grass and Legume Pastures
Their Growth, Composition and Contribution to Beef
By R. E. BLASER, R. S. GLASSCOCK, G. B. KILLINGER
and W. E. STOKES
Many Florida soils are low or deficient in one or more mineral
nutrients which are essential for vigorous and rapid plant
growth. After needed nutrients are supplied, it is possible to
grow certain improved pasture grasses and legumes (2).1 With
proper fertilization and grazing management, the mineral com-
position of plants as well as the yield can be increased (1, 2, 3, 9).
Native and improved pasture herbage grown under low fer-
tility environments is usually low in yield and nutritive value.
The protein content of the herbage grown under such low fer-
tility conditions is usually low. This low protein status of the
herbage is associated with low soluble nitrogen and the absence
of a leguminous associate. Native or other forage produced
under low fertility conditions is often so low in feeding value
that cattle consuming the herbage become malnourished (4, 5).
Since it is known that legumes are relatively higher in protein
and certain minerals, particularly calcium, and that fertilization
improves the mineral composition of grasses, an experiment to
study the grazing value of fertilized and unfertilized grasses
and of legume grass mixtures was initiated.
Plan of Experiments
Twenty acres of carpet grass pasture, sown in 1934 without
fertilization, were divided into eight lots of 21/2 acres each in
1940 and 1942. The following mixtures and treatments with
NOTE: Blaser is former associate agronomist at the Main Station;
Stokes (deceased) was agronomist and head of the department; Glasscock
is animal husbandman, Killinger agronomist at the Main Station. Dr.
W. G. Kirk helped plan and conduct the experiments during 1941. J. R.
Henderson classified the soil types and divided the pastures into lots so
that soil environments were equalized as nearly as possible. Suggestions
on some statistical procedure were made by Dr. F. H. Hull.
SItalic figures in parentheses refer to Literature Cited in the back of
TABLE 1.-FERTILIZER TREATMENTS, SEEDINGS AND LOT NUMBERS FOR TEST PASTURES.
Date Legumes Seeded *
Pastures Lot Nos. Started Fertilizer Treatments in Pounds per Acre Pounds per Acre
Grass and 1 and 3 1940 La. White Dutch 3 lbs., Per-
clover Oct. 1940-1 ton ground limestone and 600 lbs. 0-16-8 sian 1 lb., Little Hop 1 lb.,
Oct. 1941--% ton ground limestone and 300 lbs. 0-16-8 Cal. Bur 4 lbs., La. Red 2 lbs.,
Oct. and Nov. annually thereafter 400 lbs. 0-10-10 Annual Sweet 2 Ibs., Crimson
2 lbs., Black Medic 2 lbs.
Grass and 6 and 8 1942 Mar. 1942-1 ton ground limestone and 350 Ibs. 0-16-8 Kobe lespedeza, 10 lbs.
lespedeza Mar. annually thereafter 300 lbs. 0-10-10 Common lespedeza, 10 Ibs.
Fertilized 2 and 4 1941 Mar. 1941-400 pounds 8-8-5
grass Mar. 1942-1 ton ground lime and 400 lbs. 8-8-5
Mar. 1943 and 1944-500 Ibs. 6-6-6
Mar. 1945-30 lbs. nitrogen (as nitrate of soda) NONE
Grass not 5 and 7 1942 No fertilizer NONE
*The fertilizer, lime and seed were broadcast on the surface of closely grazed carpet grass.
Ground lime, 99% calcium carbonate.
Commercial fertilizers were used which supplied some magnesium (dolomite was used as a filler)..
Carpet Grass and Legume Pastures in Florida 7
two lots for each system were used: (1) grass alone without
fertilization; (2) lime and complete fertilizer on grass (no
legume); (3) lime, superphosphate and potash and seeded with
a mixture of eight winter annual, perennial or biennial legumes ;2
and (4) lime, superphosphate and potash and seeded with a
mixture of Kobe and common lespedeza, Table 1.
After fencing, pastures to be used for grass-legume mixtures
were grazed closely to improve the environment for seedlings.
Soil for clover pastures received a surface broadcast application
of lime and fertilizer in the fall of 1940, after which a mixture
of thoroughly inoculated pasture legume seeds was also surface
broadcast. Inoculated soil was broadcast over these pastures
again in December, as it was assumed that the inoculum was
injured by dry weather in October and November. A mixture
of many legumes was included (Table 1) because the adaptation
of legume species was not well established at the time this ex-
periment was started. The grass-clover pastures were fertilized
annually in October or November, except for a small plot in each
where fertilization was delayed until spring.
The two lespedeza-grass pastures received a surface applica-
tion of lime and fertilizer in January 1942 and were sown with
a mixture of inoculated Kobe and common lespedeza seed in
February. The seed was surface broadcast.
The fertilized grass pastures without legume sowings received
complete fertilizer annually in March, except in 1945 when only
nitrogen fertilizer was used. One ton of lime was applied in
1942 (Table 1).
These fertilizer and lime rates, seeding mixtures and estab-
lishment methods for the grass and grass-legume mixtures were
used because good growth responses were received from previous
tests (1, 2, 3, 9).
Grazing at the beginning of the season was started on each
pasture when the vegetation reached good grazing stage. Graz-
ing on the clover pastures was initiated when the clover was
3 to 6 inches high. The carpet grass was generally ready for
grazing before the lespedeza, thus the grazing on the carpet
grass and carpet grass-lespedeza pastures was initiated when
the grass was 2 to 3 inches in height. The carpet grass-legume
pastures were grazed alternately throughout the test. The
2The eight legumes (Louisiana White, Persian, Little Hop, California
Bur, Black Medic, Louisiana Red, Crimson and Annual Sweet clovers) were
included to study their adaptation under grazing. After the first year
more than 95 percent of the leguminous growth was Louisiana White clover.
8 Florida Agricultural Experiment Stations
fertilized and unfertilized grass pastures were grazed continu-
ously, except in 1941 when the fertilized carpet grass pastures
were grazed rotationally. It was not possible to graze the carpet
grass pastures alternately during the remainder of the experi-
ment because mineral supplements were introduced as an addi-
tional variable in 1942.
During the early season on the grass-clover pastures, when
most of the growth was clover, grazing was generally not closer
than 2 inches. The grazing conditions of the pastures just
before withdrawal of the steers and the accumulated growth
of clover on the alternate pasture is shown in Figure 2.
An endeavor was made to avoid over- or under-grazing, the
objective being to obtain maximum production of active leaf
growth (vegetative growth stage). The number of cattle placed
in one pasture lot varied and was based on growth and amount
of herbage. In this way it was possible to avoid a feed shortage
as well as an excess of unpalatable herbage growth.
Grade yearling steers purchased from Florida cattlemen were
used as test animals. The grade of most animals used was
rather low, but an effort was made to divide them uniformly
into the various groups according to age, type, weight and
quality before making assignments to the experimental pas-
tures. All steers were treated with phenothiazene to reduce
infestation of some intestinal parasites in case of their presence.
Herbage samples were obtained for yields and chemical com-
position. Four to eight cages (10 x 5 ft. made of wood frame-
work and woven wire) were placed in each pasture to protect
herbage from being grazed. In 1941 and 1945 the "difference
method" of taking yields was used (7). With this method the
cages were placed on a grazed area and at the next sampling
date yields of vegetation inside and outside the cages were taken.
The differences served as an estimate of the herbage consumed.
In 1942 and 1943 the direct "harvesting method" was used (6).
With this method the cages were placed over a clipped area and
the yields did not include the ungrazed portion of the vegetation.
In 1944 the cages were placed over grazed areas as for the
difference method but through error no samples were taken
from grazed areas to measure herbage consumption by differ-
ence. Herbage samples were taken at the time of animal with-
drawal from the pastures grazed alternately, and at 10- to 21-day
intervals from the pastures which were continuously grazed.
One or two cages were assigned to each quarter and moved at
random within the quarter after each herbage harvest.
Fig. 2.-Louisiana White clover was the predominating clover, as shown
by growth in 1942. Alterate grazing was practiced. The vegetation was
grazed to an average height of two inches (above), after which the steers
were moved to the alternate pasture where growth accumulated (below).
". 23 ,
10 Florida Agricultural Experiment Stations
Herbage samples for chemical analysis were saved from the
vegetation grown in the cages during 1941 through 1944. In
1945, samples of vegetation were hand plucked while the pas-
tures were grazed, as it was assumed that these samples would
more nearly typify the herbage consumed by the animals. The
herbage samples, irrespective of sampling technique, were com-
posited into early-, mid- and late-season samples for making
chemical analyses. The samples for the duplicate pasture lots
were not composite.
A botanical analysis of the vegetation of various pastures was
made in the beginning of the experiments and in 1944 and 1945.
At the beginning of the test the percentage ground cover of
carpet grass, centipede grass, other grasses, weeds and legumes
was estimated for the entire pasture, as the vegetation was
rather uniform. In 1944 and 1945 the botanical composition of
vegetation was estimated for blocks approximately 24 x 48 ft.
in size. The fence posts spaced 12 feet apart were used as
markers for these areas. Strings were stretched across the
fields at 48-foot intervals in one direction and 24-foot intervals
in the opposite direction. This method made it possible to re-
locate any of the 24 x 48-foot areas for making botanical com-
position estimates in subsequent years. With this technique it
was possible to associate botanical composition changes for
specific areas within the pastures.
The soil types on this experimental area varied widely. Thus
the lots were laid out in a manner to equalize, as much as pos-
sible, the soil variation for any grazing test. The predominating
soil types on the clover-grass pastures were Portsmouth and
Plummer fine sand, with a lesser amount of Kanapaha; on the
carpet-lespedeza pastures, primarily Plummer and Kanapaha fine
sands, with some Portsmouth. The soil types on the fertilized
carpet grass were primarily Kanapaha and Plummer fine sand
and some Portsmouth, and primarily Portsmouth and Plummer
on field 4. On field 5, unfertilized grass, the soil type was pri-
marily Kanapaha fine sand and on field 7 Plummer, Kanapaha
and Portsmouth fine sands. The native vegetation on the
Kanapaha soil was hammock, such as live oaks and laurel, sweet
gum, ironwood, hickory, magnolia, other deciduous trees and
loblolly pines. On the Portsmouth the predominating vegeta-
tion consisted of black gum, sweet gum and bay.
Carpet Grass and Legume Pastures in Florida 11
TABLE 2.-SOIL REACTION (PH) OF TEST PASTURES.
Soil Reaction (pH)
S8-14 Inches in
Pasture 0-3 Inches in Depth Depth **
1942 1945 1942
Grass not fertilized .... 5.48 5.22 5.78
Grass fertilized .......... 5.25t 6.02 4.92
fertilized .................. 4.96t 5.87 I 5.12
Grass-clover fertilized 5.76 5.80 4.97
Based on a mean of eight samples, each representing one-fourth of each of the
"** Based on a mean of two samples, one from each pasture.
t Sampled before lime was applied.
Soil samples were taken to measure the acidity (pH) in 1942
and 1945. Each pasture was quartered and a composite sample,
0-3 inches in depth, was taken for each quarter. The mean soil
pH for the unfertilized grass pastures was 5.48 in 1942 and
5.22 in 1945 (Table 2). The pH for the grass pastures before
lime was applied in 1942 was 5.25, as compared with 6.02 in
1945. This increase is attributed to a ton of ground limestone
per acre applied in 1942. Soil pH of the lespedeza-grass pas-
tures was 4.96 before liming and 5.87 after liming. The soil
pH of the grass-clover lots after one ton of lime was applied
averaged 5.76 in 1942 and 5.80 in 1945.
Although the grass-clover pastures received 11/2 tons of lime
per acre, the pH of the soil was lower than of the soil for the
grass-lespedeza or fertilized grass pastures which received only
one ton of lime per acre. This may be attributed to the higher
average organic matter content of the grass-clover pasture lots,
which increases the base exchange and buffer capacity, thus
requiring more lime to change the reaction than for soils that
are lower in organic matter content.
Soil samples of the sub-soil, 8-14 inches in depth, were also
taken in 1942. The pH of the sub-soil of the unfertilized pas-
tures was 5.78 as compared with a range of 4.92 to 5.12 for the
other pasture lots. The higher pH of the sub-soil of the un-
fertilized pastures may be attributed to strip application of lime
several years before establishment of the experiments and pos-
12 Florida Agricultural Experiment Stations
sibly to a low base exchange capacity, since one of these two lots
(No. 5) was lower in organic matter than remaining pastures.
Botanical Composition and Yield of Herbage
Botanical composition and yield of herbage should be asso-
ciated with fertilization and management practices as well as
with the seeding mixtures. Botanical composition with respect
to grasses and legumes on the grass-clover pastures showed
abrupt changes with season. A vivid presentation of the change
of dominant species is shown in Figure 3. In early season
(January to April) the growth was primarily Louisiana White
clover and in August it was largely grass. It was estimated that
clover made up more than 90 percent of the grazable herbage
in early season and less than 5 percent in August, Table 3 and
Figure 4. Surviving perennial White clover plants showed im-
proved growth in late September and October, but grasses were
predominant until late fall, or frost, at which time the legume
population increased rapidly.
Detailed estimates on botanical composition were taken dur-
ing September, 1944 and 1945. This was a critical time to
evaluate the survival of White clover, as the population in
September is very low. Detailed data on the percentage of
various species are given in Table 3 and the more significant
changes in species are given in Figure 4. On the grass-clover
pastures, an average of 79% of the ground cover was made up
of carpet grass in 1940 before clover was sown, as compared
with 70 and 58 percent in 1944 and 1945, respectively. Centipede
grass, which occurred as a contaminant, averaged 0.8 percent
in 1940, 1.9 in 1944 and 3.7 percent in 1945. At the time the
experiment was established there was only a trace of Bermuda
grass (0.1 percent), but in 1944 the percentage ground cover
increased to 12.5 and by 1945 there was an additional increase
to 23.5 percent. This increase in Bermuda grass may be at-
tributed to the increased fertility level of the soil as a result
of nitrogen fixation by the Louisiana White clover.
For the grass-lespedeza pastures, the carpet grass averaged
74.5 percent ground cover in 1942 when the experiment was
Fig. 3.-The vegetation in clover-grass pastures changed with season.
Top: During January to April the growth was largely White clover; in
September the growth was primarily grass; center and below: The grass
was grazed closely and fertilized in October or November to stimulate
new clover growth for the subsequent season.
14 Florida Agricultural Experiment Stations
1 g g
1942 1944 1945
Unfertilized Grass Pastures
0 d d H a
t to io i p i
1940 1944 1945
Fertilized Grass Pastures
4 -1 ii
1940 1944 1945
Fertilized Grass P astures
i a a s i
SI ID -
1942 1944 1945
Fertilized Grass-Leepedeza Pastures
F Grs Pastre
Fig. 4.-Changes in botanical composition of pastures as related to
fertilization and seeding mixtures.
Carpet Grass and Legume Pastures in Florida 15
initiated and decreased to 45.3 percent in 1945. Centipede grass
averaged 8 percent in 1942 and increased to 20.4 and 34.5 percent,
respectively, in 1944 and 1945. There was a trace of lespedeza
before sowing in 1942, and after sowing lespedeza the botanical
composition showed 6.8 and 3.6 percent, respectively, in 1944
and 1945. The low percentage composition of lespedeza in 1945
may be attributed to the prolonged dry period in March and
April of 1945 and competition from White clover which made
up a large portion of the vegetation on these pastures during
early season.3 Lespedeza made up a higher percentage of the
herbage in July and August than in September.
On the fertilized grass pastures the percentage ground cover
of carpet grass averaged 79 in 1940, 61.6 in 1944 and 41.7 in
1945. The centipede grass averaged 2.8 percent in 1940, 28.1
percent in 1944, and 44.3 percent in 1945. Leguminous species
increased from a trace in 1940 to 1.5 percent in 1945.
On the unfertilized grass pastures the percentage carpet grass
decreased from an average ground cover of 75.5 percent in 1942
to 34.4 percent in 1945. Conversely, there was an increase in
centipede grass from 7.0 percent in 1942 to 48.3 percent in 1945.
Lespedeza also showed slight increase, in percentage ground
cover, a trace in 1942 and 2.4 percent in 1945.
These data show that Bermuda grass came in naturally only
where White clover was present. This may be associated with
the higher fertility level, particularly nitrogen, as a result of
fixation by the clover. Other data also show that Bermuda
grass requires a higher fertility level than carpet grass (2).
Centipede grass increased in all pastures, particularly those
with lower fertility levels. Centipede grass made up less of the
ground-cover on grass-lespedeza and grass-clover pastures than
on fertilized grass pastures. Percentage of centipede grass was
particularly low on grass-clover pastures where the fertility
level as based on productivity was highest.
Centipede is an undesirable pasture species because it forms
a dense and thick sod and causes the more desirable grasses to
be crowded out. It is difficult to grow leguminous plants in
association with it.
Natural spreading of White clover is associated with fertility
level. This is made evident by the natural spread of White
clover into the limed and fertilized grass and grass-lespedeza
3 White clover spread naturally in the lespedeza-grass pastures. This
may be attributed to the adequate fertility level.
TABLE 3.-BOTANICAL COMPOSITION OF TEST PASTURES.1
}o_ Ground Cover Occupied by Plants in Pastures (Percent) Total
Pasture Lot Year I I Other I Ground
No. Clover2 Lespedeza | Carpet 2 Centipede Bermuda I Grasses" I Weeds 2 Cover,
SI Mean S.D. Mean I S.D. Mean I S.D.I Mean | S.D.I Mean S.D.I Mean S.D.I Mean I S.D. Percent
Grass- 1 1940 0 0 0 80.0 1.0 T 1.0 5.0 87.0 0
clover 1944 1.4 .1 0 73.4 2.4 0.6 .2 12.2 2.4 .8 .15 6.6 .9 95.
1945 3.4 .04 0 56.0 11.5 1.9 .1 27.7 11.6 1.3 .10 .5 .01 90.8
1940 0 0 78.0 0.5 T 1.0 8.0 87.5
3 1944 1.6 .1 0 65.9 3.1 3.1 .8 12.7 2.7 1.1 .9 9.4 .9 93.8
1945 5. .3 59.6 3.1 i 5.5 1.1 19.2 3.1 2.2 .4 4.9 .3 96.4
Grass- 1942 T T 75. i 7.0 3. 2.0 87.
lespedeza 6 1944 .3 .1 6.9 .7 59.5 2.1 17.2 2.8 3.6 .6 2.7 .30 90.2
1945 6.2 .6 43.7 2.1 31.5 2.5 7.8 .8 4.5 3 93.7
1942 0 T 74. 9.0 4. 2. 89.
8 1944 1.2 .2 6.6 .5 59.1 2.3 23.5 2.6 1.8 .2 1.2 1.1 93.4
1945 .03 46.9 5.6 37.5 6.2 2. .6 4.7 .03 94.5
fertilized 2 1944 .6* .14 41.6 2.3 47.1 2.5 .1 .01 3.1 92.5
1945 .2* .04 21.7 1.8 64.8 1.8 1.4 .3 3.8 91.9
1940 0 82. 0.5 1. 5. 88.5
4 1944 .3* .01 81.6 1.7 9.0 .03 .3 .1 3.4 .01 94.6
1945 2.8* .02 61.7 4.3 23.8 3.6 1.3 .7 4.9 .2 94.8
Grass not 1942 74. ] 8.0 | 1. 2.1 85.
fertilized 5 1944 .1 .04 27.1 1.901 59.7 2.2 .4 .01 2.9 .8 90.2
_1945 .1 .06 12.5 .91 69.2 1.5 1.9 .3 5.6 .5 89.3
1942 77.0 | 6.0 1. 3. 87.
7 1944 5.7 .3 59.2 2.8 I 27.1 3.1 1.2 .07 .8 .2 94.
1945 4.4 .4 56.2 2.6 1 27.3 2.7 1.6 .2 5.2 .2 94.7
1 The estimates on botanical composition were taken during September when the leguminous population is low.
"2 S. D.-Standard error.
Lespedeza and clover mixed.
3 Other grasses-Paspalum and Panicum spp.
Carpet Grass and Legume Pastures in Florida 17
lots, as shown by photographs taken in early spring, Figure 5.
The invasion of White clover into these pastures was evident
in 1944 and was pronounced in the spring months of 1945, when
it made up as much as 25 percent of the vegetation in the fertil-
ized grass lots and 30 to 50 percent of the vegetation in the
grass-lespedeza pastures. Its occurrence in these pastures may
Fig. 5.-Louisiana White clover invaded pastures which were limed and
fertilized. Above: Clover growth in 1945 on a fertilized grass pasture.
Below: Louisiana White clover on a grass-lespedeza pasture and its ab-
sence on an adjacent unfertilized pasture.
18 Florida Agricultural Experiment Stations
be attributed to spreading of seed through animal droppings and
to clover seed washed or blown in from adjacent pastures.
The productivity of the four experimental grazing systems
differed materially, as shown by the large differences in yield,
Table 4.4 The average dry weight of herbage during the four-
year period, 1942-1945, was 2,328 pounds per acre for the un-
fertilized grass pastures, 4,230 pounds for fertilized grass, 4,167
pounds for the fertilized grass-lespedeza mixture and 8,840
pounds for the grass-clover mixture.
The high yield of the grass-clover mixture may be attributed
to early season growth of clover and productive grass growth
later in the season. An apparent high soil nitrogen condition
of the grass-clover pastures was made evident by the rapid
growth of grasses, the dark green color and high nitrogen con-
tent of the herbage which will be discussed later.
The grazing and fertilizer management were planned to favor
productive clover growth. During October and early November
the vegetation, which was generally more than 95 percent grass,
was grazed very closely, as shown in Figure 3. The pastures
were fertilized annually in October or November. In early
November, when grasses generally become dormant or grow
slowly, cattle were removed and grazing was withheld for a
63- to 91-day period. In case of a continual warm period in
November and December the grasses made considerable growth.
Since this occurred in 1942, a herd of cattle was introduced for
TABLE 4.-DRY YIELDS OF HERBAGE OF TEST PASTURES, BASED ON SAMPLES
TAKEN FROM PROTECTED AREAS WITHIN CAGES.
Dry Herbage in Pounds per Acre Mean
Pasture (Mean for Two 5-Acre Pastures) _
19411 1942 1943 1944 1945 1942-45
Grass not fertilized .... ........ 3,230 1,621 2,611 1,851 2,328
Grass fertilized .......... 3,325 3,390 3,280 7,398 2,850 4,230
Grass and lespedeza
fertilized ---.......-.......-....... 3,104 3,845 6,745 2,972* 4,167
Grass and clover
fertilized .....-...-........ 6,898 8,260 7,797 12,224 7,079 8,840
One early season sampling of herbage was not obtained.
The method for taking yields was not consistent for all years, but was
alike for all pastures during any one growing season. The mean yields
may thus serve as indices of productivity.
Carpet Grass and Legume Pastures in Florida 19
TABLE 5.-CHEMICAL COMPOSITION OF HERBAGE FROM FERTILIZED AND UN-
FERTILIZED GRASS PASTURES AND OF GRASS-LEGUMINOUS MIXTURES.1
Pasture Season of Constituents in Percentage of Dry Matter
Herbage Sampling Cal- Mag- Phos- Potas- I Crude
cium nesium phorus sium IProtein
Grass and I
clover Aug. to Oct. .70 .17 3.17 1.28 9.48
fertilized Aug. to Oct. .44 .23 2.51 1.01 7.61
Grass and | May & June .88 .23 .38 1.50 14.73
clover July & Aug. .63 .25 .34 1.23 8.61
I Sept. & Oct. .66 .28 .38 1.41 10.61
Grass and May & June .77 .23 .32 .97 11.86
lespedeza July & Aug. .50 .21 .26 1.11 8.24
Sept. & Oct. .62 .22 .31 1.21 9.92
Grass May & June .53 .19 .40 .96 8.99
fertilized July & Aug. .50 .28 .37 .96 6.36
Sept. & Oct. .55 .21 .39 1.11 8.74
Grass not May & June .57 .24 .26 .62 7.74
fertilized July & Aug. .50 .23 .26 .74 6.80
Sept. & Oct. .58 .22 .28 .81 8.17
interactions H* H* H* H**
significant H x S**
Grass and February 1.92 .32 .55 1.52 19.28
clover March 2.07 .44 .51 1.15 23.84
April 1.67 .37 .43 1.27 22.65
May & June 1.40 .43 .51 1.71 20.03
July & Aug. .68 .31 .39 1.45 14.91
Sept. to Nov. .77 .24 .40 1.26 13.29
Grass and May & June .92 .18 .31 1.28 12.48
lespedeza July & Aug. .69 .22 .29 1.21 11.17
Sept. to Nov. .68 .17 .30 .95 10.17
Grass May & June .64 .22 .30 1.09 9.55
fertilized July & Aug. .45 .27 .30 1.15 7.99
Sept. to Nov. .54 .19 .28 .82 8.30
Grass not May & June .59 .22 .28 .79 9.17
fertilized July & Aug. .44 .23 .27 .86 8.49
_Sept. to Nov. .63 .25 .26 .57 5.62
interactions 2 H* H** S**
significant S* H** H** H x S**
1 Samples of herbage for each pasture were composite to measure seasonal changes.
The analyses are means of duplicate pastures. Herbage samples through May, 1944, were
taken from cages. During 1945 the samples were clipped from representative grazed areas
to obtain herbage more like that actually grazed.
2 Mean differences are significant (*) and highly significant (**). H-herbage samples
for different pastures. S-herbage samples from different seasons. H x S shows the inter-
action or the failure of herbage samples from different pastures to show similar trends
in composition with season.
20 Florida Agricultural Experiment Stations
TABLE 5.-CHEMICAL COMPOSITION OF HERBAGE FROM FERTILIZED AND UN-
FERTILIZED GRASS PASTURES AND OF GRASS-LEGUMINOUS MIXTURES.
Pasture Season of Constituents in Percentage of Dry Matter
Herbage Sampling Cal- Mag- Phos- Potas- Crude
cium nesium phorus sium Protein
Grass and January 1.67 .39 .52 1.49 27.39
clover March 1.55 .35 .49 1.39 26.52
April & May 1.69 .27 .45 1.36 21.15
June-Aug. .67 .29 .34 1.50 12.36
Sept. & Nov. .59 .30 .35 1.54 10.36
Grass and April & May 1.32 .23 .29 .85 14.04
lespedeza June-Aug. .71 .22 .27 1.32 10.11
_Sept. & Nov. .57 .21 .26 1.19 8.30
Grass April & May 1.11 .15 .31 .71 10.55
fertilized June-Aug. .53 .19 .27 1.25 8.42
Sept. & Nov. .5 .19 .24 .95 6.68
Grass not April & May .50 .24 .25 .38 9.42
fertilized June-Aug. .48 .25 .24 .97 8.55
Sept. & Nov. .43 .27 .21 .69 6.80
interactions H** S** S* H* H* H** S**
significant H x S* S* S** HxS**
April & May 1.32 .31 .45 1.53 18.60
Grass and June-Aug. .67 .29 .35 1.39 11.98
clover I Sept. & Nov. .67 .27 .37 1.40 11.42
Grass and April & May 1 1.06 .21 .30 1.06 13.04
lespedeza June-Aug. .65 .21 .47 1.21 9.86
I Sept. & Nov. .64 .20 .29 1.29 9.48
Grass IApril & May .76 .34 .34 .92 9.67
fertilized June-Aug: .49 .32 .32 1.12 7.61
1Sept. & Nov. .53 .31 .31 .96 7.92
Grass not April & May .74 .26 .26 .60 8.80
fertilized June-Aug. .47 .26 .26 .86 7.80
1Sept. & Nov. .48 .25 .25 .69 6.86
Factors or H** S** H* S* H** H** S**
interactions 2 H x S** H x S* [ H x S**
1 Samples of herbage for each pasture were composite to measure seasonal changes.
The analyses are means of duplicate pastures. Herbage samples through May, 1944, were
taken from cages. During 1945 the samples were clipped from representative grazed areas
to obtain herbage more like that actually grazed.
S Mean differences are significant (*) and highly significant (**). H-herbage samples
for different pastures. S-herbage samples from different seasons. H x S shows the inter-
action or the failure of herbage samples from different pastures to show similar trends in
composition with season.
several days to graze the vegetation to reduce grass competition.
With these combinations of grazing and fertilization practices,
the Louisiana White clover made sufficient growth to be grazed
in late January. White clover growth in January, 1945, when
the pastures were grazed closely and fertilized in the fall of
1944, as compared with growth from February fertilization, is
Carpet Grass and Legume Pastures in Florida 21
shown in Figure 1 (front cover). Similar results were obtained
in January, 1944, when the clover yields in late January were
2,021 pounds per acre after fall fertilization, as compared with
762 pounds when fertilization was delayed until February.
Close grazing during the fall also seemed to favor lespedeza
growth during the subsequent spring.
The calcium, phosphorus, magnesium, potassium and crude
protein contents of herbage taken during different seasons for
four years is given in Table 5 and a summary of the four years'
data appears in Table 6.
The mineral and crude protein contents of the herbage for the
different pastures differed greatly. The mean percentage cal-
cium content of herbage for the various pastures for all seasons
and years was as follows: grass herbage not fertilized 0.53,
grass herbage fertilized 0.59, grass-lespedeza pasture herbage
0.80, and grass-clover pasture herbage 1.11 percent. The per-
centage phosphorus content was 0.26, 0.32, 0.31 and 0.42 for
the herbage in the order given above. Protein is possibly one
of the most important elements necessary for growth or pro-
ductivity of animals in Florida. The mean percentage of crude
protein of the herbage for the four-year period was as follows:
7.9 for unfertilized grass, 8.4 for fertilized grass, 10.7 for grass-
lespedeza and 14.5 for grass-White clover pastures.
The magnesium content of herbage from the grass-clover pas-
tures averaged 0.31 percent, as compared with 0.21 to 0.24 per-
cent for the other pastures. Potassium content for the herbage
from clover pastures averaged 1.42 percent, grass-lespedeza 1.10,
fertilized grass 1.00 and unfertilized grass pastures 0.71 percent.
Annual data for herbage composition during the four-year
period showed similar trends in mineral and protein composition
(Table 5). Herbage samples taken from the different pastures
showed significant differences annually in calcium, phosphorus,
potassium and protein contents (Table 5). Differences in mag-
nesium content of herbage samples from the various pastures
were significant only in 1944, grass-clover herbage being higher
in magnesium content than herbage from the other pastures.
Mean calcium and protein contents of the herbage from all
pastures was generally higher in early season than in summer
or fall. In the grass-clover pastures there was also a- decrease
in phosphorus content of the herbage as the season advanced.
22 Florida Agricultural Experiment Stations
TABLE 6.-MEAN CHEMICAL COMPOSITION OF HERBAGE HARVESTED FROM
TEST PASTURES FROM 1942-1945 (SEE TABLE 5 FOR ANNUAL DATA).
Constituents-Percentage of Dry Matter
Season I Mag- Phos- Potas- Crude
Calcium nesium phorus sium Protein
Grass alone, not fertilized
Spring .............. 0.60 0.23 0.26 0.60 8.8
Summer .......... 0.47 0.24 0.26 0.86 7.9
Fall .................. 0.53 0.25 0.25 0.69 6.9
Mean ............... 0.53 0.24 0.26 0.71 7.9
Grass alone, lime and complete fertilizer
Spring ............. 0.76 0.19 0.34 0.92 9.7
Summer .......... 0.49 0.25 0.32 1.12 7.6
Fall ................. 0.53 0.20 0.31 0.96 7.9
Mean .............. 0.59 0.21 0.32 1.00 8.4
Grass-lespedeza, lime and fertilizer
Spring .............. 1.02 0.21 0.31 1.04 12.8
Summer .......... 0.64 0.22 0.32 1.21 9.8
Fall .................. 0.63 0.20 0.29 1.16 9.5
Mean ................ 0.80 0.21 0.31 1.14 10.7
Grass-clover, lime and fertilizer
Spring ...... 1.78 0.37 0.50 1.36 23.9
Spring .............. 1.32 0.31 0.45 1.53 18.6
Summer ......... 0.66 0.29 0.36 1.39 12.0
Fall ...--............ 0.67 0.27 0.35 1.40 11.4
Mean ................ 1.11 0.31 0.42 1.42 14.5
Based on two years' data (see Table 5).
These decreases in mineral and crude protein content with ad-
vance of season may be attributed to changes in botanical com-
position as exemplified by a calcium content of 1.78 percent for
samples taken during the period of January to April, when the
vegetation was largely clover, as compared with 0.67 percent
for samples taken in September to November, when the vegeta-
tion was largely grass. For these same grass-clover pastures
the early season vegetation averaged 0.50 and 23.9 percent phos-
phorus and protein, respectively, as compared with 0.35 and
11.4 percent for the September to November season.
The -protein and calcium contents of the herbage from the
grass pastures were highest during the spring period. This
Carpet Grass and Legume Pastures in Florida 23
reduction in calcium and protein contents of the vegetation from
the grass pastures with advance of season may be attributed to
vegetative growth condition (leafiness) of grass and also leach-
ing of fertilizer nutrients, especially nitrogen. Carpet grass
reverts to a seeding stage readily during the summer months,
hence it is difficult to maintain a leafy growth stage where
minerals and proteins are higher than in the seeding stage.
Pure carpet grass herbage samples were also hand plucked
from all eight pastures to study the effect of fertilization and
association with leguminous plants on its protein composition.
All portions of pasture lots were carefully sampled at eight
different dates during the 1945 season (Table 7).
TABLE 7.-CRUDE PROTEIN CONTENT OF CARPET GRASS AS AFFECTED BY
FERTILIZATION AND ASSOCIATED LEGUME.
Sampling Dates During 1945 Sea-
Pastures May June 1 June | July ( Aug. Aug. I Sept. Oct.-1 son
3 9 20 5 1 5 29 31 INov. Mean
fertilized ........ 7.2 9.3 7.5 9.3 7.6 8.4 8.7 7.8 8.2
Grass fertilized 9.8 7.8 10.0 14.6 10.3 8.5 9.2 10.0 10.0
fertilized ........ 13.4 15.2 11.2 15.1 10.4 11.7 9.9 11.7 12.3
fertilized ........ 20.4 18.2 13.9 19.6 14.2 14.1 10.7 15.4 15.8
Least significant difference for mean difference for any date
odds 99:1- 1.63; odds 19:1 = 0.98.
Least significant difference for mean for all dates
odds 99:1=0.58; odds 19:1=0.35.
The protein content of herbage differed from the various pastures, as
indicated by the significant date x treatment interaction.
Unfertilized pure carpet grass averaged 8.2 percent protein
for the entire season, as compared with 10.0 when limed and
fertilized with a complete, fertilizer. When carpet grass was
grown in association with lespedeza the average protein content
was 12.3, when grown with Louisiana White clover 15.8 percent.
The protein content of the grass samples taken from the
grass-clover pasture in the early season gave values somewhat
higher than for samples taken in mid or late season. The samples
24 Florida Agricultural Experiment Stations
from the other pastures showed less variation in protein con-
tent with season than the clover-grass pastures.
Grazing Season.-The clover on the grass-clover pastures
made sufficient growth to begin grazing in January after the
year it was established. The earliest grazing date was January
8, 1942, and latest January 30, 1945. The other pastures were
ready for grazing from the latter part of March to May 16.
There was more herbage on the fertilized grass pastures than
on the unfertilized fields in early season, but grazing was started
at the same time except in 1942. The unfertilized grass pastures
were stocked lighter with grazing animals than the fertilized
grass pastures. The steers were removed from the pastures
in late October or early November, as the vegetation on all pas-
tures made little growth after that date.
TABLE 8.-GRAZING PERIOD AND CARRYING CAPACITY OF TEST PASTURES.
1 1 Carrying
Time of I Date of Length of Capacity
Pasture Year First Steer Grazing Mean Number
Spring Removal Season of Steers
Grazing (Days) per Acre
Grass not 1942 April 18 Nov. 9 205 0.8
fertilized 1943 April 2 Nov. 6 202 0.8
1944 Mar. 30 Nov. 6 205 0.8
1945 April. 30 Oct. 29 182 0.8
Mean 199 0.8
Grass 1942 April 2 Nov. 9 221 0.9
fertilized 1943 April 2 Nov. 6 202 0.9
1944 Mar. 30 Nov. 1 200 1.0
1945 April 30 Oct. 29 182 1.0
Mean 201 .95
Grass-lespedeza 1942 April 2 Nov. 9 221 0.9
fertilized 1943 May 16 Nov. 9 177 1.1
1944 Mar. 30 Nov. 6 205 1.0
1945 Mar. 29 Oct. 23 208 1.6
Mean 203 1.1
Grass-clover 1942 1 Jan. 8 1 Nov. 2 298 2.5
fertilized 1943 Jan. 11 Nov. 9 302 2.5
1944 Jan. 26 Oct. 30 277 2.4
1945 Jan. 30 Oct. 30 273 2.8
Mean 288 2.6
Carpet Grass and Legume Pastures in Florida 25
The average length of the grazing season per year was 199
days for unfertilized grass pastures, 201 days for fertilized grass
pastures, 203 days for the grass-lespedeza pastures, and 288
days for the grass-clover pastures, Table 8.
The average number of steers per acre per day (carrying
capacity) for the grazing season was 0.8 for unfertilized grass,
0.95 for fertilized grass, 1.1 for grass-lespedeza mixture, and
2.6 for the grass-clover fields. These data show that the grass-
clover combination gave more than twice the carrying capacity
of the other pastures.
The annual weight gains of steers ranged from 46 to 88
pounds, with an average of 75 pounds per acre when grazing
the unfertilized grass pastures, Table 9. For the fertilized pas-
tures not sown with leguminous plants the average weight gain
of the steers for the four-year period was 148 pounds per acre.
Annual production varied from 111 to 164 pounds. For the
grass-clover pastures the weight gains per acre ranged from
556 to 732 pounds per acre, with an average production of 619
pounds per acre for the four-year period. The grass-lespedeza
pastures produced an average weight gain of 209 pounds per
acre, ranging from 179 to 324 pounds.
The average daily gain for steers consuming unfertilized her-
TABLE 9.-GRAZING RESULTS OF FERTILIZED AND UNFERTILIZED CARPET
GRASS AND OF CARPET GRASS SEEDED WITH LEGUMES.
and Average Daily GainI
Treat- per Steer, Pounds Mean Gain per Acre, Pounds Mean
ment I I_
| 1942 1943 19441 1945 1 | 1942 11943 1944 1 1945 1
fertilized 0.48 0.57 0.41 0.32 0.45 88 93 72 46 75
fertilized 0.89 0.69 0.62 0.88 0.77 177 111 141 164 148
Lespedeza 0.90 0.96 0.99 0.97 0.96 179 171 200* 324 219
White 0.75 1.10 1.13 0.75 0.93 556 605 732** 581 619
60 cow days-additional grazing. ** 310 cow days-additional grazing.
26 Florida Agricultural Experiment Stations
bage was 0.45, with a variation of 0.32 to 0.57 pound, Table 9.
On fertilized pastures daily gains varied from 0.62 to 0.88 pound,
with an average of 0.77. For grass-lespedeza pastures average
daily gain was 0.96, with a range of 0.90 to 0.99 pound. On
the grass-clover pastures, daily gain averaged 0.93 pound and
annual variation ranged from 0.75 to 1.13 pounds per day.
All experimental animals, except those on one unfertilized
and one fertilized grass pasture, received a complete mineral
mixture consisting of 100 pounds of common salt, 25 pounds
of red oxide of iron, 2 pounds of copper sulfate and 1 ounce of
cobalt chloride. This mixture was available in one compartment
of the box, common salt was in another section and the third
section contained steamed bone meal. On the two remaining
areas, consisting of fertilized and unfertilized grass, the steers
had access only to common salt. The average mineral consump-
tion per steer, per season, for the complete mineral group was
8.75 pounds of red oxide of iron, 6.5 pounds of bone meal and
12.5 pounds of salt. The groups of steers receiving salt con-
sumed 9.75 pounds each per season.
Blood samples were analyzed over a three-year period in an
effort to determine the value of mineral supplements, Table 10.
In addition, blood plasma was analyzed for inorganic phosphorus
and calcium. For the three-year period the cattle receiving the
complete mineral mixture averaged 6.08 mg. of inorganic phos-
phate per 100 cc. of serum and 12.58 mg. of calcium, as compared
with 6.30 mg. and 12.98 mg. for the cattle receiving salt alone.
Statistical analysis of the data failed to give significant dif-
ferences in hemoglobin 'regeneration, weight gains, or the in-
organic phosphorus and calcium levels in the blood between the
two groups of animals. The average individual weight gains
for steers receiving the complete mineral mixture was 123 pounds
for the grazing season, as compared with 114 pounds for the
steers receiving common salt. Average hemoglobin gain for steers
receiving complete mineral was 0.81 grams per 100 cc. of blood.
The data on carcass grades are somewhat misleading because
of seasonal variation in quality of herbage. In order to get
complete data for the grazing season it was necessary to carry
steers on the areas until approximately November 1. By this
Carpet Grass and Legume Pastures in Florida 27
time the quantity and quality of available feed was far below
that produced earlier in the season. As a result, gains made by
the cattle in late season were primarily due to growth and at
the expense of finish. All cattle would have graded higher
during mid-summer, and under a practical management program
they should have been sold and replaced by thinner cattle at
that time. Such a system of management no doubt would have
resulted in larger returns. Animals were carried throughout
the grazing season so that results obtained from the various
types of pasture would be comparable. It may be assumed that
the reduction in quality of carcasses was in accordance with the
plane of nutrition in the various pastures, and that comparison
of the various groups is justified.
Cattle slaughtered from the fertilized grass pastures produced
carcasses that graded 75 percent Commercial and 25 percent
Utility, as compared with 33 percent Commercial and 67 percent
Utility from unfertilized carpet grass. The carpet-clover pas-
ture produced 20 percent Good, 70 percent Commercial and 10
percent Utility carcasses. Carcass grades were not obtained
for steers that grazed the lespedeza-grass pastures.
Quality of Herbage
The quality of herbage produced is often more important than
the amount produced, as shown in Figure 6. Average daily
gains of steers may be taken as a rather reliable index of quality
of herbage. Table 9 indicates that average daily gains of steers
consuming unfertilized herbage was 0.45 pound for the four-
year period, with a range of 0.32 to 0.57 pound per steer per
day. On fertilized pastures daily gains ranged from 0.62 to 0.77
pound, with an average of 0.77 pound for the four-year period.
When legumes were included with grasses the quality of
herbage was improved, as shown by the increased daily gains
of steers. For the grass-lespedeza pastures average daily gains
were 0.96 pound, with a range of 0.90 to 0.99 pound during
the period of 1942-45. On the grass-clover pastures, the daily
gains averaged 0.93 pound and ranged from 0.75 to 1.13 pounds.
Daily gains of steers consuming the grass-clover herbage are
lower than would be expected. It should be pointed out that
the grass-clover pastures furnished grazing for about a three
months longer season than the other pastures. Steers grazing
on these pastures showed high daily gains (1.5 to 2.5 pounds)
for the early season, when the vegetation consumed was made
TABLE 10.-BLOOD COMPOSITION OF STEERS WHEN GRAZING FERTILIZED AND UNFERTILIZED GRASS WITH AND WITHOUT
COMPLETE MINERAL SUPPLEMENTS (1943-45).
Fertilized No Fertilizer
_(Gms. per 100 cc. Blood) (Gms. per 100 cc. Blood)
COMPLETE MINERAL I
Initial hemoglobin ..-.......... ...... 10.9 12.0 9.3 10.8 10.8 8.9 10.9 9.7 11.2 10.3 7.8 10.0 o
Final hemoglobin ..................... 13.0 12.4 9.5 10.4 14.0 12.8 10.1 10.4 8.9 9.8 9.1 11.9 .
Difference ...................- ...... ............ 2.1 0.4 0.2 -0.4 3.2 3.9 -0.8 0.7 -2.3 -0.5 1.3 1.9
Average initial hb. (complete mineral) 10.22
Average final hb. (complete mineral) 11.03
Difference hb. (complete mineral) 0.81
Initial hemoglobin ...---......------. 10.0 9.7 10.1 9.6 10.2 9.5 9.7 10.0 10.1 9.7 7.4 9.5
Final hemoglobin ..-.-................--.. 10.5 11.1 13.0 13.1 9.1 10.3 13.0 12.5 11.0 8.4 9.8 10.7
Difference ..- .......-.... -.. ....... .... 0.5 1.4 2.9 3.5 -1.1 0.8 3.3 2.5 0.9 -1.3 2.4 1.2
Average initial hb. (salt only) 9.63
Average final hb. (salt only) 11.04
Difference (salt only) 1.41
Average weight gain per steer for season (complete mineral) 123 pounds
Average weight gain per steer for season (salt only) 114 pounds
Average weight gain per steer for season (fertilized areas) 148 pounds
Average weight gain per steer for season (unfertilized areas) 88 pounds
Carpet Grass and Legume Pastures in Florida 29
up largely of clover. Daily gains decreased as the period of
grazing on the grass-clover pastures increased. Gains were
particularly low in August and September, when the steers were
in good condition and the herbage was largely grass.
Fig. 6.-The quality of cattle produced depended upon the quantity and
quality of pasture herbage. A, steers on unfertilized grass pasture; B,
fertilized grass pasture; C, grass-lespedeza; D, grass-clover; E, individual
steer from unfertilized grass pasture; F, individual steer from grass-clover
pasture. Pictures were taken in September.
_ ___ As
30 Florida Agricultural Experiment Stations
The quality of herbage may be roughly determined by esti-
mating the herbage consumption for maintenance and a pound
of gain (Table 11). The dry yield of herbage consumed by the
steers was estimated in pounds per acre by using cages. The
best estimates on production of herbage were obtained in 1945
when eight cages were used in each pasture. The data show
that it required 40 pounds of dry herbage from the unfertilized
pastures for maintenance and production of one pound of gain,
as compared with 17 pounds for the fertilized grass, nine pounds
for lespedeza-grass and 12 pounds for clover-grass herbage.
Since Louisiana White clover occurred as a contaminant in
the carpet-lespedeza and fertilized carpet pastures in 1945, the
mean herbage consumption per pound of gain for 1942, 1943
and 1945 should serve as a more accurate estimate to evaluate
herbage quality, as there was little clover contamination in 1942
and 1943. The 1944 herbage yields were omitted from the mean
estimate as the herbage yields that year included the ungrazed
residue. The mean herbage consumption for maintenance and
a pound of gain for the three years was 31 pounds for the un-
fertilized herbage, 21 pounds for fertilized grass herbage, 16
pounds for the grass-lespedeza herbage and 13 pounds for the
grass-clover herbage. Obviously, the variances of such figures
are large, but the data do show a consistent trend.
There is an interesting relationship between the herbage con-
sumption per pound of gain and maintenance and the average
daily gain (Figure 7). As herbage consumption per pound of
gain and maintenance increased, average daily gains decreased.
TABLE 11.-ESTIMATED CONSUMPTION OF DRY HERBAGE PER POUND OF
LIVE WEIGHT GAIN AND MAINTENANCE.
Dry Herbage Consumed
Pasture per Pound Live Weight Mean
__1941 1942 1943 1945 1942-45
Grass not fertilized ...--.....--. ...... .... 37 17 40 31
Grass fertilized ..--.....................-- ..... 28 20 25 17 21
Grass and lespedeza fertilized ...... 17 23 9* 16
Grass and Louisiana White clover
fertilized ...--.........-...........-- ....-- ..... 21 15 11 12 13
Grazing was initiated several days before the cages were set up, hence the indicated
consumption is less than actual consumption.
Carpet Grass and Legume Pastures in Florida 31
This relationship may indicate the inability of an animal to
consume sufficient quantities of low grade feeds to maintain
itself and produce at maximum rates.
An attempt was made to evaluate herbage quality as char-
acterized by various chemical constituents. To do this the
regression of various chemical constituents on average daily
gain was measured. Since daily gains are considered as indices of
herbage quality, the mean annual chemical composition of herb-
age from the four grazing treatments was correlated with the
respective average daily gains.
Regression Coefficient ..01
11.3 23.4 35.5 47.6
Herbage Consumption per pound of
live weight gain.
Fig. 7.-With an increase in herbage consumption per pound of live weight
gain, there was a decrease in daily gain.
32 Florida Agricultural Experiment Stations
As the phosphorus, calcium, protein or potassium content of
the herbage increased the average daily gain increased. This
relationship was significant for all four constituents (Figure 8).
The specific effect of any one or all of these four constituents
on daily gains cannot be measured, but the relationship is inter-
esting. Magnesium content of herbage was not associated with
the magnitude of daily gains.
1.09 A. 1.09
0 .78 0 o.78
R / gre.sin Coefficient Regressen Coefficient
a / 0.063 a 2.7
3.6 7.0 10.4 13.8 17.2 0.168 0.240 0.314 0.387 0.460
Crude Protein Content of Herbage Phosphorus Centent of Herbage
S0.78 V o.78
0.46 Regre.sion Coefficient 0.96 0.6 Rreesion Coefficient 0.547
0.22 0.4 0.70 0.94 1.18 0.32 0.69 1.06 1.43 1.80
Calcium Content of Herbage Ptassium Content of erbage
Fig. 8.-Relationship of Crude protein, calcium, phosphorus and potassium
content of herbage to daily gains of steers (lbs.).
Potassium is essential for animals, but it occurs in abundance
in feeds and forage. For all mineral constituents given in Table
5, an increase of potassium content of herbage was found to be
associated with an increase in crude protein as shown by the
significant regression in Figure 9. This association may be
attributed to higher protein content of legumes than grasses
and the concurrent higher potassium content of the former.
Carpet Grass and Legume Pastures in Florida 33
An increase in calcium and magnesium contents of herbage also
was associated with an increase in protein content. The per-
centage phosphorus content of herbage displayed no significant
relationship to the crude protein content.
Samples of herbage that were hand plucked from all eight
of the pastures and composite into three seasonal periods in
1945 were analyzed for crude fiber and crude protein. An increase
in crude protein content was accompanied by a decrease in fiber
(Figure 10). This relationship is expected.
Although data on total digestible nutrients are not available,
interesting speculations may be made. Referring to Table 7,
it is evident that the crude protein content of carpet grass was
increased by fertilization. When clover or lespedeza was grown
with the grass, the crude protein content of carpet grass dis-
played additional increases. The data infer that nitrogen,
whether from fertilizer or fixed by legumes, improved the feed-
ing value of grass. Largest increases in content of protein in
carpet grass occurred when leguminous associates were used.
Potassium Content of Herbage
Fig. 9.-Increase in potassium content was accompanied by increase in
34 Florida Agricultural Experiment Stations
Four types of pastures with duplicate lots were established
to measure the productivity, chemical and botanical composition,
and grazing value of pasture herbage.
The pastures were designed to compare fertilized and un-
fertilized grass in the absence of legumes, a fertilized grass-
lespedeza mixture, and a fertilized grass-winter clover mixture.
The winter clover after the first year was Louisiana White clover.
Yearling steers were used as test animals. Production of the
pastures differed materially, as shown by the following average
weight gains per acre during a four-year period: unfertilized
grass 75 pounds per acre; fertilized grass 148; grass-lespedeza
mixture 219; and grass-clover mixture 619 pounds per acre.
g.4 Regression Coefficient -0.46
17.2 19.7 22.2 -24. 27.3 29.8
Fiber Content in Percent
Fig. 10.-Relationship of fiber and crude protein contents of
pasture harbage (1945).
The feeding value of the herbage as indicated by the daily
weight gains of steers showed large differences. Average daily
weight gains for a four-year period were as follows: unfertilized
Carpet Grass and Legume Pastures in Florida 35
grass 0.45; fertilized grass 0.77; grass-lespedeza 0.96; and the
grass-clover mixture 0.93 pound.
The herbage production of pastures was estimated by protect-
ing areas from grazing to estimate feed consumption of the
steers. The estimated oven-dry feed consumption per pound
of weight gain and maintenance for a period of three years
was 31 pounds for unfertilized grass, 21 pounds for fertilized
grass, 16 pounds for the grass-lespedeza mixture and 13 pounds
for the grass-clover mixture.
Increased consumption of herbage from any pasture for main-
tenance and a pound of gain was associated with a decrease in
daily gains. This indicates that poor quality herbage could not
be consumed in large enough quantities or that consumption was
too low for efficient production because of palatability.
The mineral and protein composition of the pasture herbage
differed with season of harvest (decreasing with season ad-
vance). Fertilization improved the calcium, phosphorus, potas-
sium and protein contents of the grasses.
When legumes were used with the grass mixtures, the crude
protein, phosphorus, potassium and calcium contents of herbage
were much higher than for the grass pastures. Magnesium
content of herbage from the different pastures showed only
small differences. According to chemical analyses and weight
gains of steers, the best quality of herbage was produced on
the grass-White clover pastures.
An attempt was made to associate different chemical con-
stituents with daily gains of steers. Increase in potassium, cal-
cium, crude protein, and phosphorus content of herbage was
associated with increased daily gains. The relative significance
of these constituents cannot be measured, but the data point
out that these interesting relationships exist and are character-
istic of high quality feed. Increases in potassium, calcium and
magnesium content of herbage were associated with increases
in crude protein content.
Blood studies over a three-year period, comparing common
salt with a complex mineral mixture containing sodium chloride,
ferric oxide, copper sulfate and cobalt chloride, failed to give
significant differences in hemoglobin regeneration or in the
phosphorus and calcium ratio in the blood plasma.
There was no significant difference in weight gains of steers
receiving a complex mineral mixture and those receiving salt.
Carcasses of cattle slaughtered from fertilized carpet grass
36 Florida Agricultural Experiment Stations
areas graded 75 percent Commercial and 25 percent Utility, as
compared with 33 and 67 percent, respectively, for carcasses
from unfertilized carpet grass. The carpet-clover pastures pro-
duced 20 percent Good, 70 percent Commercial and 10 percent
Pure samples of carpet grass herbage were hand-plucked from
all pastures for making chemical analyses. Fertilization in-
creased the protein content of the grass from 8.2 to 10 percent.
When carpet grass was grown in association with clover, the
crude protein content averaged 15.8 percent. An increase in
crude fiber content was associated with decrease in crude protein.
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