Title Page
 Table of Contents

Group Title: Bulletin - University of Florida Agricultural Experiment Station ; no. 325
Title: Preliminary pasture clover studies
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00027034/00001
 Material Information
Title: Preliminary pasture clover studies
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 24 p. : ill. ; 23 cm.
Language: English
Creator: Blaser, R. E ( Roy Emil ), 1912-
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1938
Subject: Clover -- Field experiments   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
Statement of Responsibility: by Roy E. Blaser.
General Note: Cover title.
Funding: Bulletin (University of Florida. Agricultural Experiment Station) ;
 Record Information
Bibliographic ID: UF00027034
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000924551
oclc - 18214081
notis - AEN5178

Table of Contents
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Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida

4 -^, ..

Bulletin 325 September, 1938

WILMON NEWELL, Director State Collee

f Washingtor




Fig. 1.-Cows grazing on an established pasture of White Dutch clover and carpet
grass in Florida. Carpet grass grows during the summer, and clover furnishes most of
the grazing during winter months.

Bulletins will be sent free to Florida residents upon request to


John J. Tigert, M.A., LL.D., President of
the University
Wilmon Newell, D.Sc., Director
H. Harold Hume, D.Sc., Asst. Dir., Research
Harold Mowry, M.S.A., Asst. Dir., Adm.
J. Francis Cooper, M.S.A., Editor
Jefferson Thomas, Assistant Editor
Clyde Beale, A.B.J., Assistant Editor
Ida Keeling Cresap, Librarian
Ruby Newhall, Administrative Manager
K. H. Graham, Business Manager
Rachel McQuarrie, Accountant

W. E. Stokes, M.S., Agronomist**
W. A. Leukel, Ph.D., Agronomist
G. E. Ritchey, M.S., Associate*
Fred H. Hull, Ph.D., Associate
W. A. Carver, Ph.D., Associate
John P. Camp, M.S., Assistant
Roy E. Blaser, M.S., Assistant
A. L. Shealy, D.V.M., Animal Husbandman**
R. B. Becker, Ph.D., Dairy Husbandman
L. M. Thurston, Ph.D., Dairy Technologist
W. M. Neal. Ph.D., Asso. in An. Nutrition
D. A. Sanders, D.V.M., Veterinarian
M. W. Emmel, D.V.M., Veterinarian
N. R. Mehrhof, M.Agr., Poultry Husbandman
O. W. Anderson, M.S., Asst. Poultry Husb.
W. G. Kirk, Ph.D., Asst. An. Husbandman
R. M. Crown, B.S.A., Asst. An. Husbandman
P. T. Dix Arnold, M.S.A., Assistant Dairy
L. L. Rusoff, M.S., Asst. in An. Nutrition

R. V. Allison, Ph.D., Chemist**
R. M. Barnette, Ph.D., Chemist
F. B. Smith, Ph.D., Soils Chemist
C. E. Bell, Ph.D., Associate
R. B. French, Ph.D., Associate
H. W. Winsor, B.S.A., Assistant
J. Russell Henderson, M.S.A., Assistant
L. W. Gaddum, Ph.D., Biochemist
L. H. Rogers, M.A., Spectroscopic Analyst
Richard A. Carrigan, B.S., Asst. Chemist

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

Ouida Davis Abbott, Ph.D., Specialist**
Ruth Overstreet, R.N., Assistant

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

G. H. Blackmon, M.S.A., Horticulturist**
A. L. Stahl, Ph.D., Associate
F. S. Jamison, Ph.D., Truck Horticulturist
R. J. Wilmot, M.S.A., Spec., Fumigation Res.
R. D. Dickey, B.S.A., Assistant Horticulturist
J. Carlton Cain, B.S.A., Asst. Horticulturist
Victor F. Nettles, B.S.A., Asst. Hort.

W. B. Tisdale, Ph.D., Plant Pathologist**
George F. Weber, Ph.D., Plant Pathologist
R. K. Voorhees, M.S., Assistant
Erdman West, M.S., Mycologist
Lillian E. Arnold. M.S.. Assistant Botanist


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


L. 0. Gratz, Ph.D., Plant Path. in Charge
R. R. Kincaid, Ph.D., Asso. Plant Pathologist
J. D. Warner, M.S., Agronomist
Jesse Reeves, Farm Superintendent
A. F. Camp, Ph.D., Horticulturist in Charge
John H. Jefferies, Superintendent
Michael Peech, Ph.D., Soils Chemist
B. R. Fudge, Ph.D.. Associate Chemist
W. L. Thompson, B.S., Asst. Entomologist
W. W. Lawless, B. S., Asst. Horticulturist

J. R. Neller, Ph.D., Biochemist in Charge
J. W. Wilson, Sc.D., Associate Entomologist
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane
Jos. R. Beckenbach, Ph.D., Asso. Horticul.
Frederick Boyd, Ph.D., Asst. Agronomist
G. R. Townsend, Ph.D., Asst. Plant Path.
R. W. Kidder, B.S., Asst. Animal Husbandman
W. T. Foresee, Ph.D., Asst. Chemist
B. S. Clayton, B.S.C.E., Drainage Engineer*

H. S. Wolfe, Ph.D., Horticulturist in Charge
W. M. Fifield, M.S., Asst. Horticulturist
Geo. D. Ruehle, Ph.D., Asso. Plant Pathologist

W. F. Ward, M.S., Asst. An. Husbandman
in Charge*


M. N. Walker, Ph.D., Plant Pathologist in
K. W. Loucks, M.S., Asst. Plant Pathologist
C. C. Goff, M.S., Assistant Entomologist

Plant City
A. N. Brooks, Ph.D., Plant Pathologist
R. N. Lobdell. M.S., Entomologist

A. S. Rhoads, Ph.D., Plant Pathologist

A. H. Eddins, Ph.D., Plant Pathologist

Sam O. Hill, B.S., Asst. Entomologist*

David G. Kelbert, Asst. Plant Pathologist

R. W. Ruprecht, Ph.D., Chemist, Celery Inv
W. B. Shippy, Ph.D., Asso. Plant Pathologist

E. S. Ellison, Meteorologist*
B. H. Moore, A.B., Asst. Meteorologist*
*In cooperation with U.S.D.A.
** Head of Department.




INTRODUCTION ........... .....---- --- ----- .......-- 3
PLAN OF E XPERIMENTS ............................. .... .... ................ ... 4
Fertilizer, Inoculation and Planting Date Tests .......... ..... ..... 4
Strain and Variety Test of Pasture Legumes...................... ........... 6
1937-1938 RESULTS WITH EXPERIMENTAL CLOVER PLANTINGS .......................... 7
Soils A adapted to Clovers ................................ ................. .. ...... .... .... 7
Lime and Fertilizer Requirements for Growing Pasture Legumes ........ 8
Inoculation and Planting Technique ........ ............... ........ ...... .... 12
Time and Rates of Planting Clovers ................. .. ....--- --. -- .- .. 15
Pasture Legumes Adapted to Florida .......................................... ....... 15
Tentative Methods for Establishing and Grazing Clovers ...................... 17
Clovers as Related to Quality and Quantity of Pasture Herbage .......... 21
SU M M ARY ....................-------. ------- ............................ .................... ... 23
A CK N OW LEDGM EN TS ........... -. .................... ........... ........ ...... .... ....... ......... 24


The economical production of livestock and livestock com-
modities in Florida is directly dependent upon ample quantities
of cheap and nutritious pasture feed during the entire year.
Most pasture plants utilized at present furnish feed primarily
during the summer months. The desirability of growing winter
legumes for pasture in this state has long been recognized.
White Dutch clover and other pasture legumes are desirable
in the Florida pasture program because:
1. Clovers will furnish feed during the winter and early spring
when there is generally a shortage of feed.
2. Florida soils are low in nitrogen and legumes may be used
to build up the nitrogen content of the soil to augment
grass growth.
3. The admixture of clovers and grasses will increase the
mineral and protein composition of pasture herbage as
well as the quantity of feed produced.
Research work on this winter feed problem has been in pro-
gress for some time and results, while very encouraging, have
not yet been sufficiently substantiated to warrant a detailed
report of experiments. The demand, however, for suggested
solutions to these winter feed problems seems to warrant this
preliminary report on winter pasture clovers and other legumes
for grazing purposes.

Florida Agricultural Experiment Station

The experimental methods used in these investigations are
given in detail. Since these studies have been under observa-
tion a short time, a detailed report of the experimental results
is not included.
Kinds and amounts of fertilizer and kinds of inoculation
materials used are shown in Table 1. Experiments using com-
binations of lime, phosphate, potash, nitrogen, manure and
minor elements were designed to determine the necessity of
supplying different nutrient materials for normal clover growth.
The purpose is to find whether pasture legumes can be grown
on Florida soils under different environmental conditions when
supplemented with various standard fertilizer materials.
Inoculation experiments include studies of (1) commercial
bacterial culture, (2) soil (200-500 pounds of soil per acre)
that has previously grown the legume, and (3) a combination
of the two materials. Since Medicago and Trifolium legume
species are not commonly grown in this state, a treatment
without inoculation was not included.
The fertilizer and inoculation treatments were laid out on
small plots (7 x 25 feet) which were replicated three to four
times in randomized blocks. The experiments were established
in various parts of the state to study plant responses to several
soil types and other ecological factors. Two or three plant-
ings with the replicated fertilizer treatments were made on
all the soil types to determine the best planting dates.
Fertilizer was weighed separately for each plot. All lime
and fertilizer materials were surface broadcast by hand. After
the fertilizers were applied the seedings were made. The seed
on one-half of each plot was covered by a light disking and
subsequent rolling.
These legume plantings were made with different methods
of soil preparation. Seedings on the two Portsmouth and
Alachua soil types were made on established carpet grass sod,
those on Leon, Leon-Plummer, Leon-Bladen, Norfolk and John-
son soil types on disked soil varying from well to poorly pre-
pared seedbeds; two, on Bladen and Bayboro soils, respectively,
were seeded without soil preparation. Vegetation on the Bladen
soil planting was wiregrass sod and plants on the Bayboro area



Rates of fertilizer and
Number Dolomitic Superphosphate Muriate of
limestone (18% POs) potash
(lbs.) (Ibs.) (lbs.)

1 500 150 30
2 300 60
3 500 300 60
4 2,000 300 60
5 0 600
6 0 600 100
7 500 600 100
8 2,000 600 100
9 2,000 600 200
10 2,000 600 100
11 2,000 600 100
12 4,000 600 100
13 2,000 0 100
14 2,000 1,000 200
15 2,000 600 100
16 2,000 600 100
17 2,000 600 100
18 2,000 600 100
19* 2,000 600 100
20 2,000* ; 600 100
21 No Treatments
*Received all secondary nutrient elements. Zinc sulphate 15 lbs.,
sulphate 50 lbs., copper sulphate 30 lbs., per acre, respectively.
**Ground limestone (calcium).

Carpet 12
Kentucky Blue 2
Canada Blue 2
Brome 2

Dallis 2
Orchard 2
Italian Rye 4
Redtop 2

Slime per acre
50/50 mixture
nitrate of soda
and sulphate of
ammonia (lbs.)







Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil
Commercial & soil

borax 5 lbs., magnesium sulphate 100 lbs., manganese sulphate 50 lbs., iron


White Dutch Clover 4
California Bur 2
Yellow H-op 2
Crimson 2

Black Medic 2
Alsike 2
Persian 2

The treatments in this table were made on Leon line sand on the Johnson Dairy, Dinsmore, Fla.; Portsmouth line sand and Leon-Plummer
fine sand at Penney Farms, Fla.; Bayboro fine sand at Camp Ranch, Gainesville, Fla.; Johnson loamy fine sand, Alachua fine sand, Norfolk fine Cn
sand, Experiment Station Farm, Gainesville, Fla.; and Fellowship fine sand at Chinsegut Hill Sanctuary, Brooksville, Fla.
In addition to the above experiments, three demonstrational setups including larger plots with various lime and fertilizer treatments were
made on Bladen fine sand at the Carlton Dairy, Dinsmore, Fla.; Portsmouth fine sand at Nolan Dairy, Jacksonville, Fla.; and Leon-Bladen soil
at Welkener Dairy, Jacksonville, Ila. These three demonstrational areas were established in cooperation with the Dixie Lime Products Company.

Florida Agricultural Experiment Station

included Paspalum species, giant carpet grass. Digitaria species,
maiden cane, sedges, dogfennel, thistles and other species.
Yield data were obtained with a power mower fitted with a
grass catching apparatus (Fig. 2). A 25-inch cut for yields
and chemical analysis was made lengthwise through the center
of each plot to eliminate border effects from lateral fertilizer
movements. The remaining vegetation on each plot was cut
after yield samples were taken. The entire sample was oven-
dried and weighed. Frequency of cutting was dependent upon
growth conditions. Clovers were cut in the early blooming
stage. The cutting methods used would resemble a rotational
grazing system. Plots of clover and grass were cut one-half
inch from the ground to resemble close grazing by cattle.

Flg. 2.-Power mower used for obtaining yield records. White Dutch clover will
endure close grazing if grazing is rotated. This plot has been clipped three times. The
vegetation consists of White Dutch clover, Italian Rye grass, and Redtop grass. This
planting was made on tilled land at the Experiment Station, Gainesville, on November
25, 1937. Photographed April, 1938.


A clover strain test was established on Johnson loamy fine
sand at Gainesville and on Leon fine sand at Dinsmore. Sixteen
varieties and strains of winter pasture legumes were included.
All of the legumes were tested with three lime and fertilizer

Pasture Clover Studies

levels consisting of a combination of 3,000 pounds per acre of
dolomitic limestone, 800 pounds of superphosphate, and 200
pounds of muriate of potash; and rates one-half and one-fourth
of this combination. The lime and fertilizer rates with the
various legumes were replicated twice in randomized blocks.
Legumes were seeded at heavy rates to assure good stands.
All legumes in this strain test were inoculated with soil and
commercial cultures, and additional inoculated soil at the rate
of 5,000 pounds per acre was broadcast to aid nodulation and
rapid growth. The inoculated seed and soil were raked in and
rolled immediately after planting. All the plots including checks
were seeded with Italian rye, Redtop, orchard, carpet and Dallis
grasses. The plantings on both areas were made in November
1937. Yields were taken with the power mower heretofore

Experimental results obtained during the 1937-1938 season
will be discussed in the following order: (1) good distribution
of moisture and selection of moist soil types; (2) proper com-
binations of lime and fertilizer materials; (3) careful and proper
technique of inoculation and planting; (4) planting of clovers
at the right time of the year with proper rates per acre; (5)
planting of the high yielding varieties of pasture legumes;
(6) tentative methods for establishing and grazing clovers;
and (7) the relation of clover to quality and quantity of pas-
ture herbage.
Those soil types which are moist to wet during fall, winter
and early spring when clovers make most of their growth are
best suited for growing White Dutch clover and other pasture
legumes. Experimental pasture legume plantings were success-
ful on the flatwoods soils (Leon, Bladen, Johnson, Plummer and
Portsmouth soil types) and low lying Fellowship, Alachua and
Bayboro soil types. Low soils, where water accumulates for
several weeks but being fairly well drained during the remain-
ing season, also are adapted. Three trial plantings were made
on Norfolk fine sand but all the plants died in the early seedling
stage due to dry conditions.

Florida Agricultural Experiment Station


Since clovers are higher than grasses in minerals (Table 2),
it is evident that soils in Florida must be treated with certain
minerals before clovers can be successfully grown. Yield and
growth records clearly demonstrate that a combination of lime-
stone, superphosphate, and potash is generally required to grow
clovers successfully. Ground limestone at rates of 2,000 to 4,000

Fig. 3.-Need of lime and phosphate is clearly shown here. Two adjacent plots on
Leon soil were seeded alike but fertilized differently. Plot on left received 2,000 pounds of
lime, 600 pounds superphosphate, 100 pounds muriate of potash, and 75 pounds nitrate of
soda and sulphate of ammonia per acre. Plot on right received potash and nitrogen.
Vegetation previous to seeding consisted primarily of wiregrass and saw palmetto.
The soil was disked several weeks in advance of planting to allow it to pack by rains.
Lime and fertilizer materials were broadcast just previous to seeding with clovers and
grasses on November 16, 1937. Seed mixture on both plots, harrowed in and lightly rolled,
consisted of a mixture of clovers, winter grasses and carpet grass.
When photographed March 4, 1938, 21 days following last mowing, vegetation was
6 inches high on left plot. Most of the growth was made up of White Dutch clover,
Italian rye and redtop grasses.

pounds per acre gave good results in the 1937-38 season. The
degree of soil acidity should determine the rate to be used.
Good clover growth was obtained with soil acidity varying from
pH 4.9 to pH 6.0 and above. Either ground calcium (agricul-
tural) limestone or dolomitic limestone may be used*.

*Ordinary ground or calcium limestone furnishes calcium while dolomitic
limestone furnishes calcium and magnesium.

Pasture Clover Studies

Superphosphate was applied at acre rates of 150 to 1,000
pounds on experimental plantings on all soil types studied. Rates
of 600 pounds per acre proved most satisfactory during the 1937-
38 season. Potash fertilizer studies indicate that 100 pounds of
muriate of potash per acre is ample for normal clover growth.

Fig. 4.-White Dutch clover needs potash and phosphorus, as well as lime. Upper left,
normal clover growth followed applications of a ton of lime, 600 pounds superphosphate
and 100 pounds muriate of potash per acre. Upper right, potash deficiency is shown on
the plot receiving lime and phosphorus but no potash. Lower, omission of superphosphate
from the fertilizer greatly reduced the clover growth.
Potash deficiency causes a leaf spot, the leaves eventually turn yellowish-brown and
the plants die. The trouble is apt to be more pronounced if heavy applications of lime
and phosphorus are made and moisture is abundant. Lack of phosphorus causes extremely
dwarfed growth. The plants, dark green in color, eventually turn purple and suscumb.
Insert (lower) shows normal leaf and phosphate-deficient plant.
Photographed March 25, 1938, on Leon fine sandy soil.

Florida Agricultural Experiment Station

Five tons of manure per acre may be supplied in addition
to the lime, phosphate and potash with greatly improved results.
Nitrate of soda at the rate of 75 pounds per acre may be some-
what beneficial, but the practicability of supplying nitrogenous
fertilizers to legumes which, when properly inoculated, furnish
their own nitrogen needs is questionable.
Records indicate that 75 pounds of nitrate of soda (when
applied with a combination of lime, superphosphate and potash)
increased the yield of clover slightly. However, 300 pounds of
nitrate of soda per acre returned lower yields than 75 pounds.

Left: Mostly wiregrass, with stunted
clover plants, grew on the plot receiving
2,000 pounds of lime per acre, but no phos-
phate and potash.

R.Vhl : Ch..-r greiv rapidll. crowded
e,repr&..; C., plo rceierng 2.olll pounds
Jime. r.qs.) po,unm ..pcror-pphste ar. lea
F.Or.*Pr rr.tiarE of polamC. pir acre.

Fig. 5.-Growth of clover planted on wiregrass sod, Bladen fine sand, the wiregrass
grazed heavily after the clover was seeded until seedlings began to appear. Planted Novem-
ber 3. 1937, without soil preparation. Photographed March 14. 1938.

The nutrient combination of 2,000 pounds of lime, 600 pounds
of superphosphate and 100 pounds of muriate of potash per acre
was a desirable one for clovers. Manure may be added for im-
proved results. The growth of clover as related to various
combinations of lime, superphosphate and muriate of potash is

Pasture Clover Studies 11

shown in Figs. 3, 4, 5, and 6. Phosphate awd potassium defi-
ciency symptoms occurring when these nutrient materials are
present in insufficient quantities in the soil are identified in
Fig. 4.

Fig. 6.-Without phosphate, clover plants die. Upper foreground and lower left show
luxuriant growth of clover, redtop and Italian rye grasses on Leon-Plummer flatwoods
soil properly fertilized with 2,000 pounds lime, 600 pounds superphosphate and 100 pounds
muriate of potash per acre. Lower right shows what happened when phosphate was
Clover and grass mixture seeded October 20, 1937, on wiregrass land which had been
double-disked and fertilized. Phographed April 16, 1938.

Florida Agricultural Experiment Station

It is not yet known how frequently lime, superphosphate and
potash must be applied, but indications are that lime and super-
phosphate should be applied every four or five years. Potash
leaches out of the soil more rapidly and may need to be applied
every year.
Inoculation of legume seeds is the process of supplying the
proper nitrogen-fixing bacteria for nodule formation on the roots
of legume seedlings. These bacteria form numerous small wart-
like masses known as nodules on the roots of legumes and fix
elemental atmospheric nitrogen into available nitrogen com-
pounds for the legume plant*.
Three methods of inoculation were successfully used in these
experiments: (1) inoculation with commercial cultures, (2) use
of soil that has previously grown the legume which is well sup-
plied with the proper bacteria, (3) a combination of the two
methods. The seed may be thoroughly mixed with soil supplied
with the necessary bacteria so that 200 to 500 pounds or more
of soil is scattered on each acre of land, or equivalent amounts
of seed and soil may be thoroughly mixed with the commercial
inoculants and the remaining quantity of soil spread separately.
If the soil supplying the bacteria is dry it is advisable to add
water and sugar or syrup to make it stick to the seed. If the
mixture of seed and soil is too wet to broadcast it may be dried
in the shade. Directions for using the commercial bacteria
cultures accompany the material. In this work three times the
recommended amount of commercial culture was used. Whether
or not such heavy applications are essential has not been
determined. The seed should be sown soon after inoculation
to prevent severe drying or development of molds on the moist
The inoculated seed and soil should be disked, harrowed, or
rolled into the soil immediately after broadcasting to prevent
direct sunlight from contacting and devitalizing the bacteria.
If the bacteria are allowed to remain on the soil surface they may
*Some of this fixed nitrogen is exuded from the nodules and utilized
by the grasses growing in association with legumes.
tInoculated soil may be obtained from an area previously established
with a legume possessing the bacteria needed for inoculation. Hop, White
Dutch, Ladino, Persian, Alsike, and other clovers belong to a certain group
of legumes (Trifoliwm) requiring identical strains of bacteria. Black
Medic, Sweet and California Bur clovers belong to the Medicago-Melilotus
group, requiring bacteria different from the Trifolium group. The proper
strains of bacteria must be used to get legume roots well nodulated.

Pasture Clover Studies

dry out and die. If the seeding is made on unprepared soil,
a disk must be used to assure seed coverage. The disk should
be set nearly straight to avoid covering the seed too deeply.
Immediate rolling to pack the soil around the seeds promotes
rapid germination by increasing the moisture content of the
surface layer of soil.
Seedings made just previous to or during a heavy rain favor
nodulation probably because the bacteria will be washed into
the soil and protected from sunlight and drought. It may be
considered a good practice to seed late in the afternoon and
disk the seed in early the following morning. Preliminary re-
sults suggest that in event of a heavy rain following seeding,
covering the seed would not be necessary.
The importance of exercising the utmost care in the inocula-
tion of clover seed is verified in Figures 7 and 8.

Left: Good growth followed when inoc-
ulated seeds were lightly harrowed into
the soil and packed with a roller.

Right: Poor stand and growth resulted
from leaving inoculated seed broadcast on
the surface, without covering.

Fig. 7.-Inoculation practices affect clover growth. Two plots were fertilized with
2,000 pounds lime, 600 pounds superphosphate and 100 pounds muriate of potash per acre.
Inoculated clover seeds were broadcast over both, rolled in on one. Sunlight and dry
weather devitalized the bacteria not covered; plants with poor nodulation yellowed, indi-
cating nitrogen starvation.

14 Florida Agricultural Experiment Station

Pasture Clover Studies


Proper planting dates for all pasture legumes for different
sections of the state have not yet been determined. The 1937-38
experimental clover plantings seeded during the period of Octo-
ber 15 to December were most successful in the northern section
of the state. August and September plantings were inferior to
October plantings. Good stands of Hop clover were obtained
from January seedings, but the herbage for grazing was much
later than that from earlier plantings. January seedings of
White Dutch, Alsike, Sweet, Persian and California Bur clovers
produced poor growth and seed germinated poorly. That White
Dutch clover growth was influenced by time of planting is
shown in Fig. 8.
White Dutch, Hop, Alsike and Persian clovers seeded at rates
of 2 to 6 pounds per acre gave good stands in the 1937-38
season. Black Medic, California Bur, Sweet clover and Augusta
vetch should be seeded at rates of 6, 8, 10 and 40 pounds per
acre, respectively.
A well packed seedbed is imperative. If the soil is loose and
clumpy the small clover seeds will be covered too deeply and
poor stands will result.


White Dutch and Ladino clovers were the highest yielding
clovers for the season of 1937-38*. Yield records also indicate
that these two varieties of clovers furnish earlier grazing and
establish themselves more rapidly than other legumes, if they
are planted on moist soil types. These two clover varieties
also tend to be perennials and seed prolifically to reestablish
themselves for subsequent years.

*Louisiana White clover, Ladino, Oregon White, and Wild White clover
are strains or varieties of White Dutch clover. White Dutch and Louisiana
clovers are generally considered synonymous.

Fig. 8. (Opposite page)-Planting time and technique affect clover growth. Best
period for planting (1937-38) was October-December. Earlier seedings produced earlier
grazing. Light covering of the seeds proved efficacious.
Plots shown above were established in carpet grass sod on Portsmouth fine sand, a
flatwoods soil type. Portions disked were run over several times with the disk set shallow
to keep down sod injury. Packing the sod with a roller after disking also reduced injury.
Upper: Good growth from clover seeded October 8, 1937. Right, clover seed lightly
disked and rolled into soil; left, seed surface broadcast, followed almost immediately by
rainfall which washed bacteria into soil.
Center: Clover planted December 1, 1937. Disked in, left: surface broadcast, right.
Vegetation on right is composed primarily of carpet grass, the clovers died of nitrogen
starvation due to poor nodulation.
Lower: Very little clover growth on plot planted January 1, 1988. Seed disked in, left:
surface broadcast, right.

Florida Agricultural Experiment Station

Alsike clover produced fair yields for the first season but
this strain is not a prolific seeder and may need to be re-seeded
annually. Persian clover produced later and lower yields than
White Dutch. Hop, Little Hop, Black Medic, Sweet and Cali-

I. I

Fig. 9.-Clovers are frost-tolerant. A mixture of clovers and winter grasses was
seeded diskedd lightly twice and rolled) November 13, 1937, on Bayboro fine sand. Vegeta-
tion previous to seeding consisted of lowland grasses and weeds.
Resulting clover growth was mostly White Dutch. Upper picture taken February 12,
1938, after several heavy frosts, indicates that White Dutch is frost-tolerant. Lower
photograph is of same plot on March 16, 1938, when native vegetation in background
was dormant.

I i 'f

Pasture Clover Studies

fornia Bur clovers furnish most of their herbage for feed dur-
ing early spring, while White Dutch is ready for grazing con-
siderably earlier and also furnishes feed for a longer time, as
shown in Fig. 9.
Oregon White, Cluster, Subterranean, Crimson and Wild
White clovers were inferior to the legumes previously mentioned.
The adaptation of winter pasture legumes is not yet definitely
known, but tentative summary remarks will be made. White
Dutch, Ladino, Alsike and Persian clovers have made good
growth on moist and wet soils. California Bur and Black Medic
clovers made good growth on soils that are well drained, but
will not tolerate very dry or very wet soils. Hop and Sweet
clover seem to be widely adapted, but apparently will not tolerate
dry soil conditions.
Nutritive requirements for the legumes studied are similar.
In general, good results can be anticipated with acre rates of
lime ranging from 1,500 to 3,000 pounds, superphosphate 400
to 800 pounds and muriate of potash 75 to 200 pounds for
White Dutch clover. Hop clover will tolerate a somewhat lower
nutrient level than White Dutch. California Bur, Black Medic
and Sweet clovers require heavier applications of lime per acre
than White Dutch. The phosphate and potash requirements
appear to be the same as for the other legumes.
Since White Dutch and Ladino clovers generally have proved
to be most satisfactory it seems advisable to plant either of
these alone or a mixture of clovers consisting primarily of one
of these varieties. A good general trial mixture of clovers would
be 4 pounds of White Dutch and 2 pounds of Hop clover per
acre. Any one of several other adapted clovers may be added
to the mixture at a rate of 2 to 4 pounds per acre. Soil moisture
conditions on the area to be planted should determine the vari-
eties of clovers to be added.
Experimental clover plantings during the 1937-38 season were
established on native grass sods (wiregrass and other growths)
with and without soil preparation and on carpet grass sod.
Good stands and growths of clovers were obtained on all plant-
ings made on moist to wet soil types properly supplemented
with minerals if the clovers were well nodulated.

Florida Agricultural Experiment Station

Clover plantings made on closely grazed improved permanent
pasture grass sods, such as carpet grass, seem most desirable.
Established grass sods appear favorable for clover plantings
because a vegetative cover reduces soil temperatures and im-
proves moisture relationships during the period when clovers
are getting established. The 1937-38 results also show that
the grass protection increases the length of growing period of
clover (Fig. 12). It is also desirable to make clover seedings
on grass sods because the clovers greatly increase grass yields
by supplying quantities of nitrogen for grasses (Figs. 11 and
12). This nitrogen supplied to the soil is utilized if previously
established grasses are present to consume it. Clover seedings
made on carpet grass should be disked or harrowed and rolled
to aid in getting clover roots nodulated. Heavy disking should
not be practiced since it covers the seed too deeply. Packing
the soil around the carpet grass roots with a roller or culti-
packer after disking will reduce injury to the grass and improve
clover germination.
If clover plantings are to be made on native grass sods either
of two procedures may be pursued: (1) Cattle may be concen-
trated on the area immediately after the clovers have been
seeded. Cattle tramp clover seeds and the inoculation material
into the ground which aids in getting legume roots nodulated
and also diminishes the height and density of wiregrass to re-
duce its competition with clover seedlings. Cattle should be
removed after the clover seedlings appear above the ground.
If the native grass growth becomes dense, mowing is helpful.
(2) Legume seedings may be made on closely grazed or mowed
native grass growths or burned-over areas, followed with im-
mediate disking and rolling. The disking should be light to
prevent the seeds and inoculation material from being covered
too deeply. Packing with a roller immediately after disking
is beneficial as it improves surface moisture content which is
important for getting seedlings started. Good results may be
obtained also by seeding clovers on disked land and rolling it
to cover the seeds. If heavy diskings are practiced it is prefer-
able to disk several weeks in advance of seeding to allow the
soil to become packed before seeding. These clover establish-
ing procedures gave good results for the 1937-38 season.
The fertilizer materials may be broadcast directly in advance
of seeding or the lime and phosphate may be broadcast in the
spring or summer followed with the other fertilizer materials
and the legume seedings in the fall.

Pasture Clover Studies

Clover seedlings on a newly established area make very slow
growth for the first five weeks. Considerable time is required
to build up a high bacterial concentration in the soil to initiate
abundant nodule formation on legume roots. After the root
system is well established and nodulated the clovers grow very
rapidly if soil moisture and plant nutrients are amply supplied.
Grazing should be prohibited during this 'period when clovers
are getting established. If a poor stand is obtained from the
first planting, a second seeding may be made.

Fig. 10.-White Dutch clover grazed or cut when 4 to 6 inches high, just previous to
blooming, develops rapid new growth and furnishes feed for a longer period than that
infrequently cut or grazed, which matures seed and discontinues growth. Left, clover
clipped with mower 22 days before being photographed. Right, not mowed.

Grazing should commence after the clovers reach a height of
4.to 6 inches or just previous to the blooming period (Fig. 10).
Grazing at this time reverts the plants to a vegetative growth
stage and they will again grow rapidly if cattle are removed
for several weeks. It is evident that this system of grazing
management requires several fields so that animals may be
rotated from one field to another. Continuous grazing may be
practiced, but with less satisfactory results.
Since most of the clovers are annuals, stands in subsequent
years are dependent upon volunteer seedings. It is advisable

Florida Agricultural Experiment Station

Fig. 11.-Clovers add nitrogen to the soil and stimulate grass growth. White Dutch
clover and redtop and Italian rye grasses shown above were fertilized with 2,000 pounds
lime, 400 pounds superphosphate and 100 pounds muriate of potash per acre. Planted
November 27, 1937; photographed March 25, 1938. Yielded 1,359 pounds dry weight per
acre in three cuttings. The grass below yielded 377 pounds dry weight per acre in three
cuttings from a plot fertilized in the same manner.

Pasture Clover Studies

to discontinue close grazing during late April or early May to
permit the clovers to reseed. Seeds which mature in spring
germinate in the fall of the year.
It would be advisable to locate soils with various moisture
conditions for making several trial clover plantings (an acre
or more in each planting seeded with a mixture of clovers and
grasses). These trial plantings will determine which soils are
satisfactory for clovers and which clovers are adapted to the
soils. Plantings more extensive than the initial ones could be
made in subsequent years.
The classes of plants known as "legumes" are commonly con-
sidered to be soil-building crops because, when properly inocu-
lated, in addition to supplying their own nitrogen needs they
add abundant quantities of nitrogen to the soil. This nitrogen
is utilized by the grasses, which are unable to supply their
nitrogen needs. Since practically all soil types in Florida are
low in plant nutrients and extremely low in available nitrogen,
the desirability of fertilizing with lime, phosphate and potash
so that legumes will grow to furnish winter feed and simul-
taneously add nitrogen to the soil for subsequent growth of
the co-existent grasses is manifest. The supplying of nitrogen
to the soil by the legumes and this influence on grass growth
is shown by the photographs in Figs. 11 and 12. These two
photographs were taken just previous to the third cutting. The
oven-dry yield of grass alone was 377 pounds while White Dutch
clover and a grass mixture yielded 1,359 pounds per acre. The
grasses in these photographs are redtop and Italian rye. Clover
has a similar influence on carpet grass (Figs. 11 and 12).
The increase in quantity of pasture herbage should be accom-
panied by increased feeding value, which will influence growth
or production and value of animals or animal products. The
quantities of calcium, phosphorus, other minerals and proteins
are particularly important for animal growth and maintenance.
Table 2 shows that the percentages of these important constitu-
ents are considerably lower in grasses than in clovers. The
combined averages of calcium (CaO), phosphorus (P205), and
protein for carpet, centipede, and Bahia grasses are 0.685%,
0.637% and 10.54%, respectively. The average percentages in
a mixture of clovers and grasses consisting primarily of White

Florida Agricultural Experiment Station

Fig. 12.-Clover growing with carpet grass adds nitrogen to the soil and helps the
grass to grow; the grass also helps the clover, reducing soil temperature and increasing
length of clover growing cycle. Above, carpet grass and White Dutch clover photographed
July 1, 1938. The sod had been established for many years, and was grazed closely in
the fall before the clover was seeded. Below, carpet grass without clover is yellowed and
dwarfed for lack of nitrogen. Both plots were fertilized with 2,000 pounds lime, 600
pounds superphosphate and 100 pounds muriate of potash per acre.

Pasture Clover Studies

Dutch clover are 1.843%c for calcium (CaO), 1.111% for phos-
phorus (P205) and 22.7% for crude protein. These results
show that clover increases both the quality and the quantity
of pasture herbages.

Phos- Mag-
phorus Calcium nesium Crude
Grass or Clover (P2Os) (CaO) (MgO) Protein
Percent Percent Percent Percent

Average of Bahia, Carpet
and Centipede grasses .......... 0.637 0.685 0.633 10.54

Primarily White Dutch clover
with some Redtop and
Carpet grass (Average of
growth from 5 soil types).... 1.111 1.843 0.887 22.7

*Chemical composition on dry weight basis.
Grasses were fertilized with nitrate of soda; analysis from Fla. Agri. Exp. Sta. Bul. 269.
Clovers were fertilized with 2,000 lbs. dolomite, 600 lbs. superphosphate and 100 lbs. muriate
of potash per acre. Chemical analysis of clovers made by G. B. Fehmerling in the Agronomy

Clovers have a place in the Florida pasture program because
they furnish winter feed, supply the soil with large quantities
of nitrogen to augment grass growth, and greatly improve the
nutrient value of pasture herbage.

Success in establishing clover is dependent upon three pri-
mary factors. (1) The soil must be supplied with lime, phos-
phorus, potash and perhaps in some cases other nutrient ma-
terials. The nutrients to be added are dependent upon soil types
and previous soil treatment. The formula 2,000 pounds of lime,
600 pounds of superphosphate, and 100 pounds of muriate of
potash per acre has given good results during the 1937-38 sea-
son. Manure may be added for superior results and light appli-
cations of nitrogen appear slightly beneficial. (2) Inoculation
in such manner that the roots of legumes become thoroughly
nodulated is imperative. Growth of clovers is directly dependent
upon degree of nodulation if plant nutrients and moisture are
amply supplied. (3) Choice of soil types with good winter
moisture is essential. Clover plantings made on dry soil types
such as Norfolk fine sand were complete failures.

Florida Agricultural Experiment Station

Winter pasture clovers best adapted to Florida, their nutri-
tive requirements, some mineral deficiency symptoms, methods
of establishing, and grazing management are discussed.
The writer wishes to express his appreciation to W. E. Stokes, Head
of the Agronomy Department, Florida Agricultural Experiment Station,
who offered constructive criticism during the progress of these investiga-
tions; to G. E. Ritchey, Division of Forage Crops and Diseases, USDA,
for suggestions, for the cover photograph, and for furnishing some seed
material used in the strain test; and to J. P. Camp for suggestions on the
experimental design for testing legume strains; to J. R. Henderson of the
Soils Department for classifying the soils; to members of the Department
of Agronomy and to G. W. Burton of the Division of Forage Crops and
Diseases, USDA, for reading the manuscript; to farmers cooperating in
this work; and to R. E. Billington for collecting, drying and weighing

1888 -1938





Florida Agricultural

Experiment Station


50 Years of Service


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