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Winter clover pastures for peninsular Florida

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Winter clover pastures for peninsular Florida
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Blaser, R. E.
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Gainesville, Fla.
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University of Florida Agricultural Experiment Station
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Copyright Date:
1940
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English

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Bulletin 351 November, 1940

WINTER CLOVES PASTUPE5


FOP PENIHSULAIP FLO1PIDA

R. E. BLAS.AkAND EkT





EXECUTIVE STAFF
John J. Tigert, M. A., LL.D., President of the University3
Wilmon Newell, D.Sc., Directors Harold Mowry, M. S. A., Asst. Dir., Research
J. Francis Cooper, M.S.A., Editor3 Jefferson Thomas, Assistant Editors Clyde Beale, A.B.J., Assistant Editors Ida Keeling Cresap, Librarian Ruby Newhall, Administrative Manager3 K. H. Graham, Business Manager3 Rachel McQuarrie, Accountant
MAIN STATION, GAINESVILLE
AGRONOMY
W. E. Stokes, M.S., Agronomist' W. A. Leukel, Ph.D., Agronomists Fred. H Hull, Ph.D., Agronomist G. E. Ritchey, M.S., Associate W. A. Carver, PH.D., Associate John P. Camp, M.S., Assistant Roy E. Blaser, M.S., Assistant ANIMAL INDUSTRY
A. L. Shealy, D.V.M., Animal Industrailist
R. B. Becker, Ph.D., Dairy Husbandman' E. L. Fouts, 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'
W. G. Kirk, Ph.D., Asso. An. Husbandman'
R. M. Crown, M.S.A., Asst. An. Husb3 P. T. Dix Arnold, M.S.A., Asst. Dairy
Husbandman3
L. L. Rusoff, Ph. D., Asst. in An.
Nutrition3
0. W. Anderson, M.S., Asst. Poultry
Husbandman3
SOILS
R. V. Allison, Ph.D., Chemist1 Gaylord M. Volk, M.S., Chemist F. B. Smith, Ph.D., Microbiologist3 C. E. Bell, Ph.D., Associate Chemist H. W. Winsor, B.S.A., Assistant Chemist J. Russell Henderson, M.S.A., Associate3 L. H. Rogers, M.S., Asso. Biochemist Richard A. Carrigan, B.S., Asst. Chemist
ECONOMICS, AGRICULTURAL
C. V. Noble, Ph.D., Agricultural
Economist3
Bruce McKinley, A.B., B.S.A., Associate Zach Savage, M.S.A., Associate A. H. Spurlock, M.S.A., Assistant
ECONOMICS, HOME
Ouida D. Abbott, Ph.D., Home Economist'
Ruth Overstreet, R.N., Assistant R. B. French, Ph.D., Asso. Chemist
ENTOMOLOGY
J. R. Watson, A.M., Entomologist A. N. Tissot, Ph.D., Associate H. E. Bratley, M.S.A., Assistant
HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist' A. L. Stahl, Ph.D., Associate F. S. Jamison, Ph. D., Truck Hort.3 R. J. Wilmot, M.S.A., Fumigation Specialist
R. D. Dickey, M.S.A., Asst. Horticulturist J. Carlton Cain, B.S.A., Assistant Horticulturist
Victor F. Nettles, M.S.A., Assistant Horticulturist
F. S. Lagasse, Ph.D., Horticulturist' H. M. Sell, Ph.D., Asso. Horticulturist2
PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologisti 3 George F. Weber, Ph.D., Plant Path.' L. 0. Gratz, Ph.D., Plant Pathologist Erdman West, M.S., Mycologist Lillian E. Arnold, M.S., Asst, Botanist


BOARD OF CONTROL
H. P. Adair, Chairman, Jacksonville W. M. Palmer, Ocala Chas. P. Helfenstein, Live Oak R. H. Gore, Fort Lauderdale N. B. Jordan, Quincy J. T. Diamond, Secretary, Tallahassee
BRANCH STATIONS
NORTH FLORIDA STATION, QUINCY J. D. Warner, M.S., Agron. Acting in Charee
R. R. Kinkaid, Ph.D., Asso. Plant Path, Elliott Whitehurst, B.S.A., Assistant An. Husbandman
Jesse Reeves, Asst. Agron., Tobacco CITRUS STATION, LAKE ALFRED A. F. Camp, Ph.D., Horticulturist in Charge.
John H. Jefferies, Asst. in Cit. Breeding Michael Peech, Ph.D., Soils Chemist L. H. Greathouse, Ph.D., Chemist B. R. Fudge, Ph.D., Associate Chemist W. L. Thompson, B.S., Associate Entomologist
F. F. Cowart, Ph.D., Asso. Horticulturist W. W. Lawless, B. S., Asst. Horticulturist R. K. Voorhees, M.S., Asst. Plant Path.
EVERGLADES STA., BELLE GLADE J. R. Neller, Ph.D., Biochemist in
Charge
J. W. Wilson, Sc.D., Entomologist F. D. Stevens, B.S., Sugarcane Agron. Thomas Bregger, Ph.D., Sugarcane
Physiologist
Frederick Boyd, Ph.D., Asst. Agronomist G. R. Townsend, Ph.D., Plant Pathologist R. W. Kidder, B.S., Asst. An. Husbandman W. T. Forsee, Ph.D., Asso. Chemist B S. Clayton, B.S.C.E., Drainage Engineer'
F. S. Andrews, Ph.D., Asso. Truck Hort.
SUB-TROPICAL STA., HOMESTEAD W. M. Fifield, M.S., Horticulturist Acting in Charge
S. J. Lynch, B.S.A., Asst. Horticulturist Geo. D. Ruehle, Ph.D., Associate Plant
Pathologist
W. CENTRAL FLA. STA.,
BROOKSVILLE
W F. Ward, M.S., Asst. An. Husbandman in Charge'
FIELD STATIONS
Leesburg
M. N. Walker, Ph.D., Plant Pathologist
in Charge
K. W. Loucks, M.S., Assistant Plant Pathologist
Plant City
A. N. Brooks, Ph.D., Plant Pathologist
Cocoa
A. S. Rhoads, Ph.D., Plant Pathologist
Hastings
A. H. Eddins, Ph.D., Plant Pathologist. E. N. McCubbin, Ph.D., Asso. Truck Horticulturist
Monticello
Samuel 0. Hill, B.S., Asst. Entomologist'
Bradenton
Jos. R. Beckenhnch. Ph.D., Truck Horticulturist in Charge David G. Kelbert, Ast. Plant Pathologist
Sanford
R. W. Ruprecht, Ph.D., Chemist in Charge, Celery Investigations W. B. Shippy, Ph.D., Asso. Plant Path.
Lakeland
E. S. Ellison, Meteorologist' B. H. Moore, A.B., Asst. Meteorologist'
'Head of Department 'In cooperation with U.S.D.A. 'Cooperative, other divisions, U. of F.









WINTER CLOVER PASTURES FOR PENINSULAR FLORIDA R. E. Blaser and F. T. Boyd

CONTENTS
PAGE PAGE
Plan of Experiments 5 Fertilizer Requirements on Acid
Fertilization Treatments --- - ---- 5 Flatwoods Sands and Acid Mucks 8 Seedbed Preparation, Planting and Fertilizer Requirementsion Slightly Acid or Alkaline So Is ----------------- -- Iq,
Inoculation ------------ --- - ---------- - ---------- --- Seeding and Management of Clover
Methods of Evaluating Forage Yields 6 Pastures - _ -- - ---- ---- ------------------------ 19
Farmers' Plantings ------- ----- ------------- ------ - 6 Advantages of Clover in Pasture
M ixtures -- - --- ------------- - ----- 23
Experimental Results - ---- - 6 Summary -- ---- -- - - - -- ---- ------------------------ 25
Soils of Peninsular Florida Adapted Practical Pointers for Establishing
to Clover - -- ------------------------------------ ____ 7 and Managing Clover Pastures . 26

INTRODUCTION
Many pasture plants are well adapted to the varying soil and climatic conditions of Florida, but these plants produce most of their growth during the warm summer months. Many of the summer growing plants are suitable for hay which could be fed during the winter months. But heavy dews and rainfall are not conducive to hay making. Thus, under Florida conditions, the economical produ,-tion of milk and beef depends on the availability of an ample supply of cheap and nutritious pasture feed during the entire year.
Recent research has shown that many clover:3 and grasses are suitable for winter grazing in Florida. It has been found that clovers may be grown satisfactorily in con'iunction with perennial summer grasses. With this pasture mixture, winter clovers and summer grasses greatly lengthen the grazing period. Clovers serve also to improve the mineral, protein, and vitamin content of livestock feed, and increase the fertility of the soil.
From the standpoint of feed production for dairy cattle, clovers should be readily used where soils are adapted to them. Clover and grass pastures, supplemented with silage and concentrates, provide economical feed. This feeding program will largely eliminate the purchase of roughages and thereby reduce feeding costs.
While clovers cannot furnish all winter feed for economical beef production they may, however, constitute a sli.bstantial part of the cattle feeding program. The protein requirement for beef cattle during the winter months might profitably be supplied by a small acreage of clover. Valuable breeding animals may






Florida Agricultural Experiment Station


be largely fed on winter clovers. The possibility of marketing an early calf crop is increased by having available a suitable acreage of winter clover pasture. Winter feed, which may be furnished by lovers, will reduce livestock mortality.
Research conducted by the Florida Agricultural Experiment Station demonstrated in 1937 how to grow clovers in this state. Experiments are under way to find better clovers and cheaper fertilizer practices and it is possible that better varieties of clover and more desirable fertilizer practices will be found. As new results develop reports will be made to bring clover research up to date.









xperiments


e and Phosphate Source
ver Variety

�tilizer Combinations








:g. 1.-Location o,- clover variety and ilizer experiments (Those in western 'ida are carried on by the North FlorExperiment Station.)







Winter Clover Pastures bor Peinsular Florida


PLAN OF EXPERIMENTS
Experiments presented in this bulletin were largely cooperative between the Florida Experiment Station and livestock owners. The clover trials were located in several different areas throughout the state to determine the effect of fertilizers and the possibility of growing clover on various soil types, Fig. 1. The soils studied may be grouped into two general classes; namely,
(1) the acid soils of the flatwoods and acid mucks and (2) the slightly acid or alkaline soils with calcareous substrata, consisting of sandy and muck soils.
FERTILIZATION TREATMENTS
For Acid Soils (Sandy Flatwoods and Mucks).-Clover experiments started in the fall of 1937 have been reported in Florida Experiment Station Bulletin 325. These experiments included fertilizer, planting date and variety tests on several soil types. New experiments established in the fall of 1938 and 1939 were designed to compare different sources of lime and phosphate and combinations of these materials with and without nitrogen and potash on clover yields. These experiments were arranged in duplicate in randomized blocks, and seeded with a mixture of clovers. Experimental areas, originally fertilized in 1937 and 1938, were refertilized in 1939 with different rates and combinations to study the need of refertilization on different soil types.
For Lower East Coast Soils Underlain With Calcareous Substrata.-During the fall of 1938 experiments similar to those on
flatwoods soils were established in northern Dade County. These experiments showed that clovers there failed to benefit from lime. Clovers on plots which received superphosphate, potash and nitrogen were generally best. Consequently in 1939 new tests were started with superphosphate, muriate of potash, lime, nitrogen, and minor elements such as copper, manganese and zinc. Various amounts of superphosphate and muriate of potash were used. These experiments were established in December on farms in Dade, Broward and Palm Beach counties. All plots were seeded with a mixture of winter clovers and grasses.
SEEDBED PREPARATION, PLANTING AND INOCULATION
Preparation of the seedbed differed according to soil conditions and type of vegetation present. The experiments located near DeLand and Starke were established on undisturbed soil carrying wiregrass vegetation. The wiregrass was burned prior to the application of fertilizer and seed. Both seed and fertilizer were surface applied during a rain on the DeLand area. On one






Florida Agricultural Experiment Station


replication of the Starke area the seed and fertilizer were surface applied while on the other replication the fertilizer was disked into the ground, after which the plots were seeded and rolled. The remaining flatwoods areas were established on carpet grass sods. In these experiments the fertilizer was incorporated in the surface one- to two-inch soil layer; then the plots were seeded and rolled.
On the Lower East Coast soils the experimental areas were plowed and double-disked before planting, and rolled after the seed was broadcast.
The technique for inoculating clover seed was as follows: the"A" and "B" clover inoculation groups' were inoculated separately, since they require different bacteria cultures. Clover seeds were placed in a tub. Syrup was added (while mixing) until each seed was thinly coated with syrup. The proper bacteria culture was added and thoroughly mixed. The bacteria were supplied at 10 times the rate recommended by the manufacturer. Cottonseed meal or other drying agents were added (while stirring) until the seeds separated and became dry enough to be planted. After the "A" and "B" clover groups were inoculated separately, the seeds were mixed and Wanted immediately.
METHODS OF EVALUATING FORAGE YIELDS
All experimental areas were fenced so that yield and growth data could be obtained before the plots were grazed. All areas were inspected frequently during the rapid growing period of clover. Clippings for yield determinations were made on representative areas within plots.
FARMERS' PLANTINGS
Specific recommendations for starting clovers were made to many county agricultural agents and farmers. Some observations of these plantings are included in the recommendations.
EXPERIMENTAL RESULTS
Experimental results are discussed in the following order:
(1) soils of peninsular Florida adapted to clovers; (2) fertilizer requirements for producing winter clover on acid sandy and acid muck soils; (3) fertilizer requirements for soils with calcareous substrata; (4) seeding and management of clover pastures; and
(5) the value of clover in a pasture mixture. Practical pointers on establishing and managing clover pastures, based on research data, are given.

ISee page 28.






Winter Clover Pastures for Peninsular Florida


SOILS OF PENINSULAR FLORIDA ADAPTED TO CLOVER
Tests conducted by the Florida Agricultural Experiment Station show that clovers require soils with ample moisture during the winter months. Clover plantings made on "high ridge" soils such as Norfolk sand have generally failed because of an inadequate moisture supply, while good growth was obtained on low-lying moist soils. Most of the clover plantings made in 1938 in central Florida (Fig. 1) failed because of the abnormally low rainfall during the fall of that year. Two of the 1938 experiments, one on a low phase of Plummer soil near DeLand and the other on an acid muck near Davenport, produced good clover growth because of the high moisture-holding capacity of those soils.
Rainfall approached normal during the fall of 1939, and only three experiments failed to produce satisfactory clover growth. The clover on the acid muck area near Davenport failed because of excess water caused by inadequate drainage. The clovers on two areas near Arcadia on high phases of Leon sandy soil-one on flatwoods, the other on prairie land-produced unsatisfactory growth primarily because of drought. These latter two soils possessed a shallow surface organic layer which was underlaid with coarse sand, causing them to be dry.
Clover tests made on acid soils such as low-lying phases of Leon, Plummer, Portsmouth, Johnson, Scranton, Bladen fine



















Fig. 2.-Clover-carpet grass pasture furnishing winter feed for bulls. Left, lime, phosphate and potash produced good clover. Right, without fertilizer clover similarly seeded did not grow.






Florida Agricultural Experiment Station


sands and acid mucks have given good growth. Slightly acid or alkaline soils, with calcareous substrata, such as mucks and sandy mucks and low marl hammocks, also have proven satisfactory for clovers.
Moisture requirements for different varieties of clover vary but none of the winter clovers which have been tested in Florida furnish much feed under dry soil conditions. The adaptation of clovers to different soil moisture conditions is given under clover variety tests.
Any soil of sufficient moisture, when properly fertilized, is suitable for clovers. The best criteria for selecting soils for clover pasture are as follows: (1) select soils with a fine textured surface layer, high in organic matter, 6 to 12 inches in depth; (2) the finer the texture of the subsoil the better the moisture-holding capacity of the soil and the clover growth produced; (3) soils with clay subsoils are better than hardpans, and impervious hardpan soils are inferior to pervious hardpan soils; (4) muck soils have produced very good clover growth.

FERTILIZER REQUIREMENTS FOR PRODUCING WINTER CLOVERS
ON ACID FLATWOODS SANDS AND ACID MUCKS
Fertilizer Combinations and Sources of Lime.-The effect of fertilizer mixtures on clover growth is shown in data presented in Table 1 and summarized in Figs. 3 and 4. In Table 1 the average relative yields of clover from nine soil types produced with


no
so Ca-Mg - 1500 ibs. ground limestone and 500 lbs. dolomite.
F - 12 c superphosphate.
70 K - 500 muriate of potash.
- nitrogen (2 sulfate of ammoonia and 2 nitrate
.f soda).
6o
-ates i0 ibs. per dore.
50
S4o
15 30

20
I [ C C a-1.11,- 2000
10 Ca-EIg- 200 Ca-'r- 2000 Ca-'If- 2000 - 600 F - 600
-75 K - 100 F - 600 : - 100 K - 100
No fertilizer 75 N- 75 N- 75 IJ - 75

Fig 3.-Average relative clover yields with different fertilizer mixtures for nine soil types. (See table 1.)








Winter Clover Pastures for Peninsular Florida


a fertilizer mixture consisting of 2,000 pounds lime, 600 pounds 18% superphosphate, 100 pounds 50% muriate of potash, and 75 pounds of an 18% nitrogen fertilizer is represented by 100. When potash was omitted the relative yield was 25; without phosphate


100 9o

* 80 70 60

d
50

40 30

20 10


Ca-hfg- 2000 P - 600 K - 100
N - 75


Ca - 2000 P - 60 K - 100 N- 75


Mg - 2000 P - 6o0 K - 100
- 75


Ca-yg - 4000 r 6o K - 100 i- 75


Ca-Mg - 1000 P - 300 K - 100 N1 - 75


Ca - ground limestone; Ig - dolomite; Ca-Mg - 3/4 ground lime, 1/4
dolomite; P - 18 ' superphosphate, K - 50% muriate of rotash; I - 13>
nitrogen. Rates given in pounds per acre.

Fig. 4.-Average relative clover yields with sources, combinations and rates of lime with other fertilizers.

12; without lime 33; without potash and phosphate 14; and with no fertilizer 3. When twice as much lime was used with the complete fertilizer, the yield was 123. One-half the amount of lime and phosphorus in the mixture reduced the yield to 70. When ground limestone and dolomite were substituted for the lime mixture, the relative yields were 115 and 80, respectively.

The clover plants on plots without phosphate or potassium fertilizers developed phosphate and potassium deficiency symptoms described in Florida Experiment Station Bulletin 325.

The source of lime is important from the standpoint of the residual effect on clover growth in succeeding years. Fig. 5 shows that the average clover growth, during the second year after fertilizing five soil types, was greater when ground






Florida Agricultural Experiment Station


7000 Ca -1 ton ground limestone.
Mg - 1 ton dolomite.
6000 CatMg - 1500 lbs.ground limestone and 500 lbs. dolomite.
P - 600 lbs. 18% superphosphate
5000 -K - 100 lbs. 50% potash
(rates per acre)
S4000

n 3000 S2000

1000 CatMg Ca Mg
a aMg Ca PK PK PK
PK PK pK
Not refertilized in 1939 Refertilized with 2 initial
fertilizer in 1939

Initial fertilizer was applied in October 19,8.
Fig. 5.-The effect of refertilization on subsequent clover yields based on averages of five soil types. (High calcium limestone produced larger yields than dolomite.)

limestone, high in calcium, was used than when dolomite or a mixture of lime and dolomite was used.
Research results indicate that the use of nitrogen fertilizer in conjunction with lime, phosphate and potash for growing clovers depends on such factors as rainfall, soil type, and dates and amounts of the nitrogen application. In establishing clovers the use of 75 pounds per acre of an 18% nitrogen fertilizer was found (Table 2) to be of much benefit on Scranton fine sand and of little or no benefit on a Portsmouth fine sand. On established clover pastures, little benefit was obtained from small applications of nitrogen fertilizers, and less growth occurred with heavy nitrogen applications (300 pounds of 18% nitrogen mixture),
Table 3.
Refertilization of Established Clover Pastures.-The importance of refertilizing established clover pastures with lime, phosphate and potash is shown in Figs. 5-7 and Table 3. Leon fine sandy soil was fertilized in 1937 with a mixture consisting of one ton dolomite, 600 pounds 18% superphosphate, and 100 pounds 50% muriate of potash. Clover yields of 14,130 pounds; 7,020 pounds; and 4,420 pounds per acre were obtained when refertilized with one-half, one-fourth and none of the above mixture, respectively. When clovers on a Bayboro fine sandy soil were refertilized with one-half, one-fourth and none of the fertilizer





TABLE 1.-AVERAGE ACRE YIELDS IN POUNDS OF GREEN CL OVER FROM VARIOUS FERTILIZER TREATMENTS ON NINE VIRGIN SOILS.


Fertilized in October 1938, and 1" of
Fertilizer Applied in September 193


Fertilizer Kissimmee
Applied Ports
Leon mouth
f.s. f.s.
pH2 4.63 pH 4.81
1 1940 1940
(lbs.) I (lbs.)
No fertilizer 0 0
(Ca + Mg) N 560 0
(Ca + Mg) KN 570 0
(Ca + Mg) PN T 4,180 840
PKN - Trace 1,600
(Ca + Mg) PKN 4,250 6,930
CaPKN 6,900 8,990
MgPKN 3,280 2,790
'2(Ca + Mg) I
2PKN 4,950 2,160
2(Ca/,} Mg)PKNI 6.690 11.710 PbsKN 3,410 1 7,840
(Ca+Mr') I I
PbsKN I 5,510 3,550


Penney Farms

Leon Plummer
f.s. f.s.
pH 4.38 pH 4.98


1940 1939 (lbs.) I (lbs.)
0 250
340 2,270 480 2,980 1,120 2,930 Trace 3,180 6,270 5,690 6,130 111,510 4,530 1 9,000

2,160 6,310 4.950 110.190 2,160 I 8,040

3,210 7,160


1940 (lbs.)
0
140 420 490 1,050 1 4,670 1 4,210 1 4,530

2,850 5.220 3,000

2,160


Ti Tr Tr

1
5
5
4

4 10
5
4


lYield index-ht. of vegetation in inches with a 100% stand inwine formula. (%t around cover) X (It clover) X (heiehtofc


Initial Fertilized in October Fertilized in
9 1939 October 1938
Wau- I DavenSamsula chula Orlando Starke port Relative :
Scran- Yields,
Plummer ion Portsmouth Peaty All Soil "
f. s. f. s. I f. s. Muck Types "
pH 4.91 pH 4.98 pH 5.05 pH 5.44 pH 4.12 Q
9391 1940 1940 19401 1 1940 19391e
[.1. (lbs.) (lbs.) Y. I. (lbs.) Y. I. race Trace 0 .01 1,650 .10 1 3
race Trace 1,220 .10 5,670 1 .80 1 14
race Trace 1,780 .13 2,580 1 .30 12
.60 2,790 1,050 1.03 3,707 1.30 25
.40 1 4,600 I 420 .60 5,670 4.00 33
.80 11,570 6,620 4.40 6,980 4.90 100
5.00 7,600 7,250 6.70 9,500 4.90 1 115 .40 7,110 2,680 3.20 9,300 1 3.70 80

.00 1 3,690 6,410 4.80 7,510 1 4.00 1 70 .00 6,340 I 7,180 6.20 9.310 I 5.10 123 , .00 1 7,800 6,410 3.90 7,640 1 3.80 86

.90 8,020 1 8,290 6.30 1 6,560 1 4.00 89

or ground cover. The yield index is computed by the folclover).


2The pH values of the various soils were measured before fertilization. Ca-1 ton ground lime (90% calcium carbonate). Mg-1 ton dolomite (49% and 36% calcium and magnesium carbonates, respectively). Ca -4- v-i1 ton lime (,4 ground lime and '4 dolomite). P-600 lbs. 18% superphosphate. K-100 lbs. 50% muriate of potash. Pbs.-1500 lbs. basic slag per acre (10% - 12%PO,). N.-75 lbs. 18% nitrogen mixture per acre ( sodium nitrate and 12 sulfate of ammonia). Note: Clovers planted in October 1938 and 1939.






Florida Agricultural Experiment Station


Fig. 6.-Refertilizing established clover pastures increases the earliness of feed as well as the total feed. Areas represented above were similarly fertilized with one ton of lime, 600 pounds of superphosphate and 100 pounds of muriate of potash in October 1937. These areas were refertilized in October 1939 and photographed in February 1940.
Upper, early yield of California Bur clover produced when refertilized with one-half of the initial fertilizer treatment. Lower, early growth of California Bur without refertilization.






IWinter Clovcr Pastures for Peninsular Florida


16000 Leon soil, Dinsmore

14000
a
12000

10000 8000
4000


Prer cent of ini ia
2 6000


Bayboro soil, GainesvilLe


Initial fertilizer applied in 1937: 1 ton dolomite, 600 lbs.
13' superphosphate, 100 lbs. 50Y potash. Nitrogen nas aprlied
at uniform rates both years.
Fig. 7.-Effect of soil type and fertility level on the need for frequent fertilizer applications.

mixture previously mentioned, the green yields were 15,490 pounds; 15,580 pounds; and 14,130 pounds (green weight) per acre, respectively. The early season clover yields were greatly affected by the refertilizer treatments on the Leon soil type, Table 3.
Sources of Phosphate.-Clover research with sources of phosphate has been carried on for two years. The use of any source of phosphate is dependent upon soil types and accompanying fertilizers. The results, which follow, concerning the insoluble phosphates such as colloidal and rock phosphate, should be considered as preliminary. Four sources of phosphates with the characteristics given below were used.
Superphosphate-18% available P205.
Rock phosphate-50% through a 200 mesh sieve, 28% total
P205.
Colloidal phosphate-22% total P205.
Basic slag-10% to 12% available P205.
The suitability of superphosphate, when applied with a proper mixture of other fertilizers, has been previously discussed. Basic slag applied at a rate of 750 pounds per acre with one ton of lime and 100 pounds of muriate of potash, or a mixture of 1,500











TABLE 2.-EFFECT OF NITROGEN ON THE YIELD OF CLOVER WHEN GROWN WITH VARIOUS LIME, PHOSPHATE, AND POTASH FERTILIZERS, ON SCRANTON AND PORTSMOUTH FINE SANDS.
Scranton Fine Sand, Wauchula i Portsmouth Fine Sand, Starke
Total Yield Early Yield 3/20/40
Fertilizer Applied -- - - 75 lbs. (18%) 75 lbs. (18%) '
No Nitrogen Nitrogen per Acre No Nitrogen Nitrogen per Acre
Pounds Green Weight per Acre
P K 350 420 680 1,020
Ca P K 5,850 7,250 1,830 1,980 ;
Mg P K 1,790 2,680 1,420 2,330 D.
(CaqMg) PK 3,550 6,620 1,880 1,020
1/2(CaMg)PK 2,090 6,410 1,490 1,770
2(Ca+Mg) P K 2,510 7,180 3,050 2,190
Relative Yields- 1
with and without nitrogen 100 189 100 100

P-600 lbs. 18% superphosphate.
Ca-i ton ground limestone.
Mg-1 ton dolomite.
Ca-Mg-1 ton lime, 1/4 dolomite and 3/4 ground lime.
K-100 lbs. 50% muriate of potash.






Winter Clover Pastures for Peninsular Florida


pounds basic slag and 100 pounds muriate of potash per acre, has generally given good clover growth on most acid soils tested, Table 1.
Fertilizer combinations including rock phosphate and superphosphate, are compared on two soil types (Table 4). A fertilizer mixture of 3,000 pounds of rock phosphate and 100 pounds of muriate of potash produced a green clover yield of 6,460 pounds per acre as compared with 9,500 pounds for the fertilizer consisting of one ton of lime, 600 pounds superphosphate and 100 pounds of muriate of potash per acre on a Portsmouth soil. When one ton of lime was added to rock phosphate and potash, the yield was decreased to 4,440 pounds per acre. One thousand pounds of rock phosphate applied in conjunction with lime and potash produced a yield of 2,557 pounds per acre. The fertilizer mixture of 3,000 pounds rock phosphate, 200 pounds superphosphate, 500 pounds lime and 100 pounds muriate of potash produced a yield of 9,970 pounds of clover and was the highest yielding fertilizer on the Portsmouth soil. On the Scranton soil, 7,250 pounds of green clover was produced by the fertilizer treatment made up of lime, superphosphate and potash, as compared with 1,390 pounds of green clover per acre produced from 3,000 pounds of rock phosphate and 100 pounds of potash per acre. The addition of 2,000 pounds lime to the latter fertilizer increased the clover yield to 5,090 pounds per acre.
Results with colloidal phosphate were similar to those with rock phosphate.
Effect of Different Fertilizers and Soil Types on the C hemical Composition of Clovers.-The chemical composition of clovers is influenced mostly by fertilizer treatments and soil type, though the variety of clover has some effeCt2. The average phosphorus and calcium contents of clovers grown on a Johnson soil were considerably higher than for the same clovers on Leon soil. Conversely, the potassium and magnesium contents were highest in clovers grown on the Leon type. These two soils were fertilized identically.
The elemental composition of clovers on a Leon soil was found to be directly correlated with the kind and amount of fertilizer applied (Table 5). On a series of clover plots, fertilized uniformly in 1937, an experiment was conducted to determine the effect of different refertilization treatments on the chernical


2Unpublished data.





Florida Agricultural Experimnent Station


TABLE 3.-THE EFFECT OF REFERTILIZATION, WITH AND WITHOUT NITROGEN, ON CLOVER YIELD FOR LEON AND BAYBORO FINE SANDY SOILS.
(GREEN YIELD IN POUNDS PER ACRE.)


Fertilizer Applied


Initial 1937 Mg-2000 P-600
K-100 N-75 Mg-2000 P-600
K-100 N-75
Mg-2000 P-600 K-100 N-75 Mg-2000 P-600 K-100 Mg-2000 P-600
K-100 N-300


Refertilized
1939
Ca-1000 P-300 K-50 N-75 Ca-500 P-150 K-25 N-75 N-75


Ca-500 P-150 K-25 Ca-1000 P-300 K-50 N-300


Mg-dolomite. Ca-ground limestone.


Leon Soil Bayboro Soil
Dinsmore Gainesville

Early* Total* Early"* Total"*

9,000 14,130 1,870 15,490


I 7
3,350 7,020 I 1,790 15,580
]


4,420 8,990 6,740


1,670 1,450 1,370


1,830 4,290 2,470


P-18% superphosphate. K-50% muriate of potash.


14,130 14,950 19,250


N-18% nitrogen (1/2 nitrate soda
and 1/2 sulfate of ammonia).
Note: All areas were seeded with 8 lbs. of California Bur, 2 lbs. each of White Dutch, Little Hop, Black Medic and Persian.
*Yield consisted of 55% Calif. Bur, 10% Black Medic, and 25% White
Dutch, 10% other clover.
*-90% White Dutch and 10% others.

composition of resulting forage. One group of plots, which received no additional fertilizer, produced clover with an ash content of 6.56% as compared with 9.12% for clover refertilized
with acre applications of 1,000 pounds limestone, 300 pounds 18% superphosphate and 50 pounds 50% muriate of potash. The calcium content of clovers was increased from 1.03 % to 1.48 %; phosphorus was increased from 0.29% to 0.46%; and the potassium content was increased from 1.33% to 1.84% when the above refertilization treatment was used. When one-half the above rate of fertilizers was used, intermediate results were obtained. The higher refertilizer treatment increased the protein content from 22.6% to 28.2%, but produced no change in magnesium content of clovers.





Winter Clover Pastures for Peninsular Florida


TABLE 4.-INFLUENCE OF DIFFERENT MIXTURES OF LIME, SUPERPHOSPHATE, AND ROcK PHOSPHATE FERTILIZERS ON THE GREEN YIELD
OF CLOVER ON Two SANDY SOIL TYPES.
Portsmouth Soil, * Scranton Soil,
Starke Wauchula
Fertilizer in Pounds per Acre pH 5.44 pH 4.98
(Lbs.) (Lbs.)

P600, K100 5,670 420
Ca2000, P600, K100 9,500 7,250
Pr3000, K100 6,460 1,390
Ca2000, Pr3000, K100 4,440 5,090
Ca2000, PrOOO, K100 2,557 836
Ca500, P200, Pr3000, K100 9,970

Ca-lime; P-18% superphosphate; K-50% muriate of potash; Prrock phosphate.
'75 pounds per acre of 13%c nitrogen mixture was added to the fertilizer mixture used on the Scranton soil.
pH on both soils was measured before fertilization.


FERTILIZER REQUIREMENTS FOR PRODUCING WINTER GRASSES
AND CLOVERS ON SLIGHTLY ACID OR ALKALINE SOILS
(Lower East Coast Soils with Calcareous Substrata)

Since most pasture soils along the lower East Coast of Florida are underlain with a calcareous substratum, the fertilizer requirements for growth of winter pasture grasses and clovers are considerably different from those for acid soils of other sections of the state. Initial fertilizer experiments established in 1938 with various mixtures of fertilizers compared superphosphate with basic slag, raw rock phosphate, and colloidal phosphate. These trials showed the superiority of a fertilizer mixture containing superphosphate and potash, and failed to show a response to either high calcium or dolomitic limestone. Very little growth was obtained when either superphosphate or potash was used alone, but when both were used, highest yields resulted.
Clover experiments established in December of 1939 were designed to show the most profitable amounts of superphosphate and potash to use, as well as to study further the effects of lime. nitrogen and a mixture of copper, maganese and zinc. The results are presented in Table 6 and show that, in general, sandy soils in this region respond to a higher ratio of phosphorus to





Florida Agricultural Experiment Station


Fig. 8.-Louisiana White Dutch clover growing in carpet grass pasture on a low, moist soil (Leon fine sand) in Hardee County. Left, lime, phosphate and potash produce good growth. Right, seeded as at left but lime was not applied. Photographed in February.

potash than do muck soils. Statistical treatment of the original data has shown that on sandy soils represented by the Acme and Waldrep Dairies, treatment 6 produced most economical use of fertilizers. This consisted of an acre application of 200 pounds 20% ammonium sulfate, 160 pounds 44% superposphate, and 240 poun-ds 50% muriate of potash, and a mixture of small quantities of copper, maganese and zinc. On muck soil located at Ives

TABLE 5.-EFFECT OF REFERTILIZATION ON CHEMICAL COMPOSITION OF CLOVERS GROWN ON A LEON SOIL, DINSMORE, FLORIDA* Lbs. per Acre-1939 Chemical Composition in Percent of Dry Matter
180 90 Phs !am- Mg
50% Super- Ground Phos- PotasPotash phos- Lime- Ash phorus sium cium nesium Proteir
phate stone
0 0 0 6.56 0.29 1.33 1.03 0.43 22.6
25 150 500 8.11 0.38 1.62 1.43 0.43 27.6
50 300 1000 9.12 0.46 1.84 1.48 I 0.46 28.2
*In 1937 this area was fertilized with one ton dolomite, 600 pounds 18% superphosphate, and 100 pounds 50% potash. 75 pounds 18% nitrogen per acre has been applied annually.
Note: Mineral fractions given as elements and not as oxides.






Winter Clover Pastures for Peninsular Florida


Dairy the most economical use of fertilizer was obtained from treatment 3, or an acre application of 200 pounds of 20%c ammonium sulfate, 70 pounds of 44% superphosphate, 240 pounds of 50Vo muriate of potash, and a mixture of minor elements consisting of acre applications of 50 pounds 25% copper sulfate, 50 pounds 257o manganese sulfate and 10 pounds 79% zinc sulfate. It is possible that smaller quantities of copper, manganese and zinc could be used to advantage. Large nitrogen responses were obtained
*on the sandy soils and only small responses on the muck soils. No significant increases in yield were obtained by adding two tons per acre of lime to these soils.

TABLE 6.-AVRAGE ACRE YIELDS IN POUNDS OF GREEN PASTURE FORAGE OBTAINED FROM CLOVER PASTURE FERTILITY EXPERIMENTS IN DADE, BRO-WARD, AND PALM-% BEACH COUNTIES (1940).
Pounds per Acre: Bout44~ 50% Ives Acme Waidrep wl Average
Treamens Sper- Muriat Dairy Dairy Dairy Diy___phos- of Sa-ndy Sand & All
phate Potash Muck Loam Sand Muck Soils
1 Check Check 5,808 484 0 484 1,694
2 70 I 120 7,381 9,922 7,623 8,228 8,296
3 70 240 14,036 12,463 8,712 6,050 10,316
4 70 360 14,157 13,189 8,954 20,812 I14,279
5 160 120 8,228 9,317 12,463 11,858 10,421
6 160 240 11,253 17,666 12,826 13,552 13,824
7 I160 360 9,559 15,488 14,762 1 24,442 1 16,063
8 275 120 2,662 10,406 14,883 19,196 19.287
9 275 240 8,833 17,182 14,520 7,744 1 12,070
10 275 360 14,762 15,609 16,335 25,168 117,969
*11 I 275 360 15,246 19,481 11,011 I29,524 1 18.816
**12 I275 360 9,317 115,125 1l,374 I18,634 1 13,612
*Treatment 11 received 2 tons dolomite.
**No minor elements on Treatment 12, all other treatments had 50 pounds CuSO4, 50 pounds MnSO4, and 10 pounds ZnSO, per acre included.
All plots received 200 pounds per acre ammonium sulfate.
Yield data for Ives and Boutwell dairy plots are relative, but incomplete.
Yield differences over 5,000 pounds are significant at the 5% point.

SEEDING AND MANAGEMENT OF CLOVER PASTURES
Seeded Preparation.-Clovers in Florida have been established successfully on unimproved cut-over lands, on grass pastures. and on moist land that has been cultivated, provided that competing vegetation was retarded or destroyed and the soil left in a firm condition. The manner in which the land was prepared for clovers depended upon the type of vegetation present. It was found best on unimproved cut-over lands to disk the soil thorough-






Florida Agricultural Experiment Station


ly well in advance of planting time. By allowing time to elapse between disking and seeding, the soils became packed and soil moisture conditions were improved. On cultivated lands good


Fig. 9-Differences in grazing practices produced the difference in clover growth shown here. Both areas were seeded and fertilized alike. Above, a good stand of clover failed to develop because of dense growth of frosted carpet grass. Below, the carpet grass was grazed close before fall. A good stand of clover developed. Photographed in January.






Winter Clover Pastures for Peninsular Florida


results were obtained when the soil was prepared in much the same manner as for unimproved cut-over lands. On closely grazed improved sods, land fertilized and lightly disked just prior to seeding produced good results. On all of these soils it was found desirable to plant clover seed when the soil was moist, and to roll or pack the soil to cover the seed.
Clovers have been successfully established without intensive seedbed preparations on soils which retain a moist surface. When such soils had native wiregrass vegetation the grass was burned and the area subsequently fertilized and seeded. When the vegetion consisted of carpet or other improved sod grasses, close grazing made possible the successful seeding of clovers. Two experimental areas, one near St. Petersburg and the other near Orlando, failed completely because the grass was not closely grazed. The clovers were unable to grow through the dense so (Fig. 9).
Though good stands of clover were obtained irrespective of rainfall, better results were generally obtained when seed was planted just prior to or during a period of heavy rains.
Planting and Inoculation of Clover Seed.-Tests conducted in 1937 have shown that clovers, for best results, should be sown in October, though good stands have been obtained when plantings were made as late as December 15. October plantings are preferred because:
1. Soil moisture conditions are generally best for the establishment of clovers during that period.
2. Plants require considerable time to grow before grazing is possible.
3. Earlier plantings tend to increase the length of the grazing season.
As is common for all legumes, to obtain most benefit from atmospheric nitrogen it is necessary to inoculate all clovers with the proper legume bacteria before planting. The bacteria form nodules on clover roots and combine nitrogen from the air into compounds which are available to the host plant. Successful nodule formation on clover roots has been obtained by inoculating the clover seed with either proper commercial bacterial cultures or with soils from areas which had previously grown the particular legume.
A Comparison of Clover Varieties for Peninsular Florida Soil and Climatic Conditions.-The planting of adapted clover varieties on moist soil, adequately fertilized, is necessary for the






22 Florida Agricultural Experiment Station

successful establishment of winter pasture. The necessary characteristics of desirable clover varieties are palatability, ability to produce enough seed under Florida conditions to maintain good stands, and ability to withstand close grazing.
Gf the several varieties of clover included in the seed mixture and used in fertility experiments, White Dutch and California Bur were most promising. White Dutch (Louisiana variety) was found especially adapted to low, moist soils, and to tolerate wetter soil conditions than most of the other clovers. White Dutch also tolerated more soil acidity and withstood closer grazing, than California Bur. California Bur clover was found adapted to moist but well drained soils. It seemed to produce higher yields than White Dutch when grown under optimum conditions. Since California Bur clover produced an abundance of growth under low temperature conditions, it provided grazing earlier than White Dutch, but was found to have a shorter growth period. Thus it seems that a mixture of California Bur and White Dutch will provide the most promising clover combination for Florida conditions.
In clover variety trials conducted on two distinct soil types, 18 different varieties were tested (Table 7). Due to difference in the amount of soil moisture present in these two types of soil, the clover varieties responded differently. Johnson loamy fine sandy soil was poorly drained, while Leon fine sandy soil on which these experiments were located was moist but well drained. Louisiana and other White Dutch varieties, Alsike, Persian and Little Hop clovers produced the best average yields on low, wet, poorly drained Johnson soil. California Bur, Hubarn Sweet, Black Medic, and Hop clovers produced the best average yield on the moist but well drained Leon soil.
Data in Table 7 show that varieties of White Dutch cloverdiffer greatly in yielding potentialities. On the poorly drained Johnson soil type the three-year average relative yields of varieties of White Dutch were as follows: Louisiana variety, 100; Ladino, 92; Dixie variety, 83; Oregon variety, 69; and Kent Wild (English White Dutch), 61. One year's test of two New Zealand varieties of White Dutch clover shows that one variety equaled Louisiana White Dutch but the other was inferior. The relationship of yields of varieties of White Dutch clover was similar on the drained Leon soil, except that Ladino White Dutch produced best yields.
Lappa, Trifolium lapaceum, and Louisiana Red were tested for one year on both Leon and Johnson soil types. Louisiana Red pro-







Winter Clover Pastures for Peninsular Florida


TABLE 7.-EFFECT OF A WELL DRAINED LEON SOIL TYPE AND A POORLY DRAINED JOHNSON SOIL TYPE ON THE DRY YIELD OF 18 CLOVER VARIETIES.
Relative Yields of Clover Varieties on Two Soil Types


Clover Variety



White Dutch (La.) T'rijolium repens Little Hop (TriJolium dubium) Hop (Trijolium procumbens) White Dutch (Kent Wild) White Dutch (Oregon) White Dutch (Dixie) White Dutch (New Zealand) White Dutch (New Zealand S100) White Dutch (Ladino) Persian (Trifolium resupinatum) Subterranean (Trifolium subterranean) Cluster (Trifolium glomeraturn) Alsike (Trifoliue hybridum) Crimson (Trifoliun incarnat unt) Carolina (Trifolium carolinianun) Black Medic (Medicago lupulina) Calif. Bur (Medicago hispida) Hubam (llelilotus alba annual)


Leon Fine
Sand, Dinsmore

1940
40 38 65

22 36 35 29 55 54

36

66 116 126


*100-2,174 lbs. dry yield per acre.
"*Yield taken over a period of two years. Soils were fertilized with lime, phosphate 1937 and refertilized in the fall of 1939.


Johnson Loamy Fine Sand, Gainesville 3-Yr, Ave 1940 1938-40
92 i100"
73 72
63 57
61
63 69
42 83


92 89 40** 32* 92 27 70 38** 55 36**


and potash in the fall of


duced satisfactory yields on the Johnson soil, and Lappa was inferior in yielding capacity to other clovers on both soil types.
Since Louisiana White Dutch was found to produce an abundance of seed under Florida conditions, it is recommended over all other varieties of White Dutch clover (Fig.10). Aside from Louisiana White Dutch clover, California Bur, Black Medic, Crimson, Persian, Hop, Little Hop, Red and Sweet clovers are the only promising varieties which have produced sufficient seed for adequate propagation under Florida conditions.


ADVANTAGES OF CLOVER IN PASTURE MIXTURES

Experimental results show that pasture grasses on mineral soils produce greatest increase in yield through the use of nitrogenous fertilizers3. Because of the high cost of commercial nitrogen the probability of increasing the carrying capacity of grass

3Unpublished data.






Florida Agricultural Experiment Station


pastures profitably in Florida is questionable, unless cheaper sources of nitrogen are made available. It has been found that clovers, when well inoculated, greatly stimulate grass growth. Fig. 11 compares the seasonal growth curve of fertilized carpet grass with the growth curve of fertilized carpet grass seeded to clover. The early increases in yield of pasture herbage on the carpet grass-clover plots was due to the presence of clover, while the late seasonal yield increase was primarily carpet grass stimulated by nitrogen which was added to the soil through the clovers. Besides adding to the quantity of pasture herbage, clovers increase greatly the nutritive value of the feed. The average protein content of highly fertilized carpet graSS4 was 11.9% as compared with 28.2 % for fertilized White Dutch clover. The average 4Unpublished data, Florida Agricultural Experiment Stations.

Fig. 10-Seeding habits of three strains of White Dutch clover. Upper, Louisiana White Dutch is both productive and prolific. Lower left, Ladino is productive but a scant seeder in Florida. Lower right, a low-growing and high yielding variety of New Zealand White Dutch that does not produce seeds in Florida. Photographed in February.






Winter Clover Pastures jor Peninsular Florida


phosphorus content of fertilized carpet grass was 0.20% as compared with 0.46% for the clover. The calcium content for carpet grass was 0.65% as compared with 1.48% for clover. It is there6o



Q 45 - . Clover and carpet grass (fertilized)

0
P
30



0 15
PL


Carpet grass (fertilized) .
2/11 2/20 3116 3/21 3/30 4/13 5 2 5 19 5* 1939 Clipping Dates
Fig. 11-Increase in early and total yields due to the presence of White Dutch and other clovers. On the carpet grass-clover growth curve the early growth is clover and the late growth is carpet grass stimulated by soil nitrogen supplied by clover. The fertilized carpet grass growth curve shows that carpet grass makes little growth during the cool season. Both growth curves represent averages of 12 plots fertilized alike with lime, superphosphate and potash.

fore evident that the addition of clover to grass pastures greatly improved the value of feed from the standpoint of livestock production.
SUMMARY
Clovers should be utilized in the Florida pasture program because they furnish winter feed, supply the soil with nitrogen which increases subsequent grass growth, and improve the feeding value of pasture herbage.
To establish clover successfully the soil must be properly fertilized and suitable clover varieties should be planted under adapted ecological conditions in October or November, on closely grazed sods or well packed seedbeds. Seedings should be made during a rainy period.






26 Florida Agricultural Experiment Station

Data on fertilizer combinations and sources of lime and phosphate for different soil types are given.




















Fig. 12-A clover-carpet grass pasture grazed continuously by calves during late winter. The cow droppings form "seed islands" in which the White Dutch clover reseeds. The seed germinate in the fall for the next year's clover crop. Photographed in April.

PRACTICAL POINTERS FOR ESTABLISHING AND
MANAGING CLOVER PASTURES
Clover pastures can be established on those Florida soils which have favorable winter moisture conditions and are adequately fertilized. Unimproved cut-over pine lands, improved grass sods, and cultivated moist to wet soils have grown clovers successfully. To establish and maintain clover pastures, the following practices are necessary:
1. For flatwoods sandy soils and acid mucks, not previously fertilized, apply initial fertilizer at the following rates per acre:
2,000 pounds "high-calcium" limestone or 2,000 pounds dolomite,
600 pounds 16-20% superphosphate, and
100 pounds 50% muriate potash.
75-100 pounds nitrate of soda or its equivalent may be added to encourage earlier growth.
I (Calcium limestone should be used for California Bur, Sweet or black Medic clover.)






Winter Clover Pastures for Peninsular Florida


(600 pounds per acre of an 0-16-8 or 3-16-8 fertilizer and I ton limestone may be used instead of the fertilizers given above.)
2. To maintain clover pastures on acid soils, apply fertilizer at one-fourth to one-half of the above rates every one to two years.
3. For soils with calcareous substrata (lower East Coast soils), apply fertilizers at the following rates per acre:

Muck Soils
150-240 pounds of 501/0 muriate of potash, and
70 pounds of 445 triple superphosphate.
100 pounds 20% ammonium sulfate or other nitrogen equivalent may be added to encourage earlier growth.
(The above is equivalent to 500 pounds of a 4-6-24 mixture.) (A mixture of 50 pounds copper sulfate, 50 pounds of manganese sulfate, and 10 pounds zinc sulfate per acre may be necessary, depending on previous soil treatment.)

Sandy Soils
150-240 pounds 50.,G' muriate of potash and
160 pounds 441/c triple superphosphate.
200 pounds 20 c ammonium sulfate, or its equivalent, appears necessary for initial treatment on most sandy soils in this region.
(The above is equivalent to 1.000 pounds of a 4-6-12 mixture.)
(Copper, manganese and zinc may be necessary in small quantities.)

LOW MARL HAMMOCK SOILS
600 pounds superphosphate and
100 to 150 pounds 5V/, muriate potash.
(75 pounds nitrate soda or its equivalent may be added for early growth.)
600 pounds per acre of fertilizer with the formula 0-16-8 or 3-16-8 may be used instead of the fertilizers given above.
4. Use the following seed mixtures for sandy soils: Low Wet Sandy Acid Soils
3 to 5 pounds Louisiana White Dutch
or
2 to 3 pounds Louisiana White Dutch and






28 Florida Agricultural Experiment Station

I to 3 pounds Persian clover.
3 to 6 pounds Redtop (Agrostis alba) or
5 pounds Italian rye grass may be added to the above mixtures.
Moist to Wet Sandy Acid Soils
2 to 4 pounds Louisiana White Dutch and
5 to 8 pounds California Bur clover.
Moist Drained Sandy Acid Soils
1 to 2 pounds Louisiana White Dutch,
8 pounds Califorina Bur and
3 pounds Black Medic.
or
8 pounds California Bur and
4 pounds Black Medic.
(Avoid purchase of poorly adapted seed.)
5. Use the following seed mixtures on:
Slightly Acid or Alkaline Muck and Sandy Muck Soils
2 to 4 pounds Louisiana White Dutch
5 to 8 pounds California Bur clover and
5 to 7 pounds Italian rye grass.
Acid Muck Soils
3 to 5 pounds Louisiana White Dutch
or
2 to 3 pounds Louisiana White Dutch,
1 to 2 pounds Persian, and
I to 2 pounds Alsike.
(3 to 6 pounds Redtop (Agrostis alba) or 5 to 7 pounds Italian rye grass per acre may be added to the clover mixture given above.)
6. Inoculate clover seed carefully with appropriate bacterial cultures. White Dutch, Persian, Alsike and Hop clovers require commercial bacteria culture "B". California Bur, Black Medic and Sweet clover require bacteria culture "A".
Usually five times the rate of bacteria culture recommended by the manufacturer is necessary for best results in Florida.
(For method of inoculation see page 6).
7. Plant in October or early November when soil moisture conditions are favorable.
8. Prepare a firm seedbed and destroy competing vegetation so that seed can come in contact with moist soil. On established grass sods, close grazing allows seed to contact the soil without further seedbed preparation.






Winter Clover Pashires for Peninsular Florida


9. Distribute the seed and fertilizer uniformly (mechanical spreaders are best adapted). The fertilizer should be applied previous to seeding. It is desirable that clover plantings be made just prior to or during a rain.
10. Delay grazing until clover seedlings are 3 to 5 inches high or until the clover root systems are well established. To allow for re-seeding, graze clover lightly during late spring.
For best results divide clover area into several fields and practice rotational grazing. This practice will insure a more uniform grazing of clovers and a better distribution of cattle droppings.

ACKNOWLEDGMENTS

The writers wish to express their appreciation to W. E. Stokes, head of the Agronomy Department, who offered constructive criticism; to G. E. Ritchey, Division of Forage Crops and Diseases, USDA, for suggestions and for seed used in the strain test; to J. R. Neller for suggestions on fertilizer treatments on alkaline soils; to W. A. Leukel, Agronomist, and Dean Graham, student assistant, for chemical analyses; to J. P. Camp for suggestions on the experimental design for testing legume strains; to G. C. Willson, research assistant of the Soils Department, for help in connection with some of the experiments; to J. R. Henderson of the Soils Department for classifying the soils; to farmers and county agents cooperating in this work; to Jeffery Dawson, student assistant, for computations; and to R. E. Billington for assisting with collecting, drying and weighing clippings.







Full Text

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Bulletin 35 1 Novemb er, 1940 WINTER CLOVER PASTURES FOR PENINSULAR FLORIDA

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EXECUTIVE STAFF John J. Tigert, M. A., LL.D., President of the University3 Wilmon Newell, D.Sc., Director• Harold Mowry, M. S. A. , Asst. Dir . , Research J. Francis Cooper, M.S.A . , Editor 3 Jefferson Thomas, Assistant Editor 3 Clyde Beale, A .B. J . , Assistant Editor• Ida Keelin g Cresap, Librarian Ruby Newhall, Administrative Manager' K. H. Graham, Business Manager3 Rachel McQuarrie, Accountant• MAIN STATION, GAINESVILLE AGRONOMY W. E. Stokes, M.S., Agronomist' W. A. Leukel, Ph . D., Agronomist• Fred. H Hull, Ph . D ., Agronomist G. E. Ritchey, M.S . , Associate• W. A. Carver, PH.D., Associate John P. Camp, M.S., Assistant Roy E. Blaser, M.S., A ssista nt ANIMAL INDUSTRY A. L. Sh ea ly, D.V.M., Animal Industrailist3 R. B. Becker, Ph.D., Dairy Husbandman• E. L. Fouts, 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 Hus bandman• W . G. Kirk, Ph.D., Asso. An. Husband man3 R. M. Crown, M.S.A., Asst. An. Husb• P. T . Dix Arnold, M . S.A . , Asst. Dairy Husbandman 3 L. L. Rusoff, Ph. D., Asst. in An. Nutrition• 0. W. Anderson, M.S., Asst. Poultry Husbandman 3 SOILS R. V. Allison, Ph.D ., Chemist' 3 G ay lord M. Volk, M.S., Chemist F. B. Smith, Ph.D., Microbiologist• C. E. Bell , Ph.D., Associate Chemist H. W. Winsor, B.S.A., Assi sta nt Chemist J . Russell Henderson, M.S.A., Associate• L. H. Ro gers , M.S., Asso. Biochemist Richard A . Carrigan, B.S., Asst. Chemist ECONOMICS, AGRICULTURAL C. V. Noble, Ph.D., Agricultural Economist' 3 Bruce McKinley, A.B., B.S.A., Associate Zach Sava ge , M.S.A . , Associate A. H. Spurlock, M . S.A . , Assistant ECONOMICS, HOME Ouida D. Abbott, Ph.D., Home Econ omist1 Ruth Ov erst reet , R.N., As s i s tant R . B. French, Ph.D., Asso. Chemist ENTOMOLOGY J. R. Watson, A.M., Entom0Jogist 1 A. N. Tis sot, Ph.D . , Associ ate H . E. Bratl ey, M.S . A., Assistant HORTICULTURE G. H. Blackmon, M . S.A., Horticulturist' A. L. Sta hl , Ph.D. , Associate F. S. Jamison, Ph. D., Truck Hort . 3 R. J. Wilmot, M.S.A., Fumigation S pe cialist . . R. D. Dick ey , M.S.A .. Asst. Horticulturist J. Carlton Cain, B.S.A., Assistant Horticulturist Victor F. Nettles, M.S.A., Assistant Horticulturist F. S. Laga sse , Ph.D., Horticulturist' H. M . Sell, Ph.D . , A ss o. Horticulturist' PLANT PATHOLOGY W. B. Tisdale, Ph.D., Plant Pathologist' 3 George F. Weber, Ph.D., Plant Path. 3 L. 0. Gratz, Ph.D ., Plant PathologiSt Erdman West, M.S., Mycologist Lillian E. Arnold , M.S., Asst. Botanist BOARD OF CONTROL H. P. Adair, Chairman, Jacksonvillle W. M. Palmer, Ocala Chas. P. Helfenstein, Live Oak R. H . Gore, Fort Lauderdale N. B. Jordan, Quincy J. T. Diamond, Secretary, Tallahassee BRANCH STATIONS NORTH FLORIDA STATION, QUINCY J. D. Warner, M.S., Agron. Acting in Chan ! e R. R. Kinkaid, Ph.D., Asso. Plant Path. Elliott Whitelrnrst, B.S . A ., Assistant An . Husb a ndman Jesse Reeves, Asst. Agron., Tobacco CITRUS STATION, LAKE ALFRED A. F. Camp, Ph.D., Horticulturist in Charge. John H. Jefferi es , Asst. in Cit. Breeding Micha el Peech, P h.D., Soils Chemist L. H. Greathou se , Ph.D., Chemist B . R. Fudge, Ph.D., Associate Chemist W. L. Thomp s on, B . S. , Associate Entom o logist F. F. Cowart, Ph.D., Asso. Horticulturist W. W. Lawless, B. S., Asst. Horticulturist R. K. Voorhees , M.S., A ss t. Plant Path. EVERGLADES STA., BELLE GLADE J. R. Neller, Ph.D., Biochemist in Charg e J. W. Wilson, Sc.D., Entomologist F. D . St ev ens , B.S., Sugarcane Agron. Thomas Bregger, Ph.D., Sugarcane Physiologist Frederick Boyd, Ph.D., Asst. Agronomist G. R. Townsend, Ph.D., Plant Pathologist R. W. Kidder, B.S . , Asst. An. Husbandman W. T. Forsee, Ph . D., Asso. Chemist B S. Clayton, B.S.C.E., Draina g e En gineer2 F. S. Andrews, Ph . D., Asso. Truck Hort . SUB-TROPICAL STA . , HOMESTEAD W. M. Fifield, M.S., Horticulturist Act ing in Char ge S. J, Lynch, B.S.A., Asst . Horticulturist Geo, D. Ruehle, Ph.D., A ss ociate Plant Pathologist W. CENTRAL FLA. STA., BROOKSVILLE W F. Ward, M.S ., Asst. An. Husband man in Charge 2 FIELD STATIONS Leesburg M. N. Walker, Ph . D., Plant Pathologist in Charge K. W. Loucks , M.S .. Assistant Plant Patholo gi st Plant City A. N. Brooks, P h. D., Pl ant Pathologist Cocoa A. S. Rhoads, Ph.D., Plant Pathologist Hastings A. H . Eddins, Ph.D., Pl a nt Pathologist. E . N. McCubbin , Ph.D., Asso. Truck Horticulturist Monticello Samuel 0. Hill, B.S . , Asst. Entomologist' Bradenton Jos. R. Beckenh.sch. Ph.D .. Truck Horti culturist in Charge David G. Kelbert, .1-1.,st. Plant Pathologist Sanford R. W. Ruprecht, Ph.D., Chemist in Charg e, Celerv Investigations W. B. Shippy, Ph.D., Ass o. Plant Path. Lakeland E. S. Ellison, Meteorologist• B. H. Moore, A.B., Asst. Meteorologist' 1 Head of Department 2 In cooperation with U.S.D.A. •cooperative, other divisions, U . of F.

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WINTER CLOVER PASTURES FOR PENINSULAR FLORIDA R. E. Blaser and F. T. Boyd CONTENTS PAGE PAGE Plan of Experiments 5 F e rtilization Treatments 5 Seedbed Preparation, Plant i n g and 5 Inoculation _ __ _ -------------------:.1ethods of Evaluating Fora ge Yields 6 Farmers' Plantings -----------6 Exp e rimental Results ______ _ _ _ __ _ 6 Soils of Peninsular Florida Adapted to Clover _ -----.. .. ... ... 7 Fertilizer Requir e 111ent H on Acid Flatwoods Sand s and Acid Mucks 8 Fertilizer Requir eme nt s on Slightly Acid or Alkaline Soil s _ __ .... _ .. ----17 Seeding and Management of Clover Pastures .. ............. . ..... ... -...... ..... ___ . 19 Advantages of Clov e r in Pasture Mixtures .. .... .. . __ _ 23 Su1nmary _ ---------------25 Practical Point ers for E s tablishing and Managin g Clo v er Pa s tures 26 INTRODUCTION Many pasture plants are well adapted to the varying soil and climatic conditions of Florida, but these plants produce most of their growth during the warm summer months. Many of the summer growing plants are suitable for hay which could be fed during the winter months . But heavy dews and rainfall are not conducive to hay making. Thus, under Florida conditions, the economical production of milk and beef depends on the avail ability of an ample suppl y of cheap and nutritious pasture feed during the entire year. Recent research has shown that many clover:, and grasses are suitable for winter grazing in Florida. It has been found that clovers may be grown satisfactorily in con j unction with perennial summer grasses. With this pasture mixture, winter clovers and summer grasses greatly lengthen the grazing period. Clovers serve also to improve the mineral, protein, and vitamin content of livestock feed , and increase the fertility of the soil. From the standpoint of feed production for dairy cattle, clovers should be readily used where soils are adapted to them. Clover and grass pastures, supplemented with silage and concen trates, provide economical feed. This feeding program will large ly eliminate the purchase of roughages and thereby reduce feed ing costs. While clovers cannot furnish all winter feed for economical beef production they may, however, constitute a svb!:itantial part of the cattle feeding program . The protein requirement for beef cattle during the winter months might profitably be supplied by a small acreage of clover . Valuable breeding animals may

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4 Florida Agricultural Experiment Station be largely fed on winter clovers. The possibility of marketing an early calf crop is increased by having available a suitable acreage of winter clover pasture. Winter feed, which may be furnished by dovers, will reduce livestock mortality. Research conducted by the Florida Agricultural Experiment Station demonstrated in 1937 how to grow clovers in this state. Experiments are under way to find better clovers and cheaper fertilizer practices and it is possible that better varieties of clover and more desirable fertilizer practices will be found. As new results develop reports will be made to bring clover research up to date. :xperiments b and Phosphate Source ~er Variety tilizer Combinations .g. 1.-Location o.'. clover variety and 'lizer experiments (Those m western ida are carried on by the North Flor Experiment Station.) Q_ G

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Wint , er Clover Pastures for Peninsular Florida 5 PLAN OF EXPERIMENTS Experiments presented in this bulletin were largely coopera tive between the Florida Experiment Station and livestock owners. The clover trials were located in several different areas throughout the state to determine the effect of fertilizers and the possibility of growing clover on various soil types, Fig. 1. The soils studied may be grouped into two general classes; namely, (1) the acid soils of the flatwoods and acid mucks and (2) the slightly acid or alkaline soils with calcareous substrata, consisting of sandy and muck soils. FERTILIZATION TREATMENTS For Acid Soils (Sandy Flatwoods and Mucks).-Clover ex periments started in the fall of 1937 have been reported in Florida Experiment Station Bulletin 325. These experiments included fertilizer, planting date and vari e ty tests on several soil types. New experiments established in the fall of 1938 and 1939 were designed to compare different sources of lime and phosphate and combinations of these materials with and without nitrogen and potash on clover yields. These experiments were arranged in duplicate in randomized blocks, and seeded with a mixture of clovers. Experimental areas, originally fertilized in 1937 and 1938, were refertilized in 1939 with different rates and combina tions to study the need of refertilization on different soil types . For Lower East Coast Soils Underlain With Calcareous Sub strata.-During the fall of 1938 experiments similar to those on flatwoods soils were established in northern Dade County. These experiments showed that clovers there failed to benefit from lime. Clovers on plots which received superphosphate, potash and nitrogen were generally best. Consequently in 1939 new tests were started with superphosphate, muriate of potash, lime, nitrogen , and minor elements such as copper , manganese and zinc. Various amounts of superphosphate and muriate of potash were used. These experiments were established in December on farms in Dade, Broward and Palm Beach counties. All plots were seeded with a mixture of winter clovers and grasses. SEEDBED PREPARATION, PLANTING AND INOCULATION Preparation of the seedbed differed according to soil condi tions and type of vegetation present. The experiments located near DeLand and Starke were established on undisturbed soil carrying wiregrass vegetation. The wiregrass was burned prior to the application of fertilizer and seed. Both seed and fertilizer were surface applied during a rain on the DeLand area. On one

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6 Florida Agricultural Experiment Station replication of the Starke area the seed and fertilizer were surface applied while on the other replication the fertilizer was disked into the ground, after which the plots were seeded and rolled. The remaining flatwoods areas were established on carpet grass sods. In these experiments the fertilizer was incorporated in the surface oneto two-inch soil layer; then the plots were seeded and rolled. On the Lower East Coast soils the experimental areas were plowed and double-disked before planting, and rolled after the seed was broadcast. The technique for inoculating clover seed was as follows: the "A" and "B" clover inoculation groups 1 were inoculated separ ately, since they require different bacteria cultures. Clover seeds were placed in a tub. Syrup was added (while mixing) until each seed was thinly coated with syrup. The proper bacteria culture was added and thoroughly mixed. The bacteria were supplied at 10 times the rate recommended by the manufacturer. Cotton seed meal or other drying agents were added (while stirring) until the seeds separated and became dry enough to be planted . After the "A" and "B" clover groups were inoculated separately , the seeds were mixed and plant e d immediately. METHODS OF EVALUATING FORAGE YIELDS All experimental areas were fenced so that yield and growth data could be obtained before the plots were grazed. All areas were inspected frequently during the rapid growing period of clover. Clippings for yield det e rminations were made on repre sentative areas within plots. FARMERS' PLANTINGS Specific recommendations for starting clovers were made to many county agricultural agents and farmers. Some observa tions of these plantings are included in the recommendations. EXPERIMENTAL RESULTS Experimental results are discussed in the following order: (1) soils of peninsular Florida adapted to clovers; (2) fertilizer requirements for producing winter clover on acid sandy and acid muck soils; (3) fertilizer requirements for soils with calcareous substrata; (4) seeding and management of clover pastures; and (5) the value of clover in a pasture mixture. Practical pointers on establishing and managing clover pastures, based on research data, are given. lSee page 28 .

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Wint er Clover Pastures for Peninsular Florida 7 SOILS OF PENINSULAR FLORIDA ADAPTED TO CLOVER Tests conducted by the Florida Agricultural Experiment Station show that clovers require soils with ample moisture during the winter months. Clover plantings made on "high ridge" soils such as Norfolk sand have generally failed because of an inadequate moisture supply , while good growth was obtained on low-lying moist soils. Most of the clover plantings made in 1938 in central Florida (Fig. 1) failed because of the abnormally low rainfall during the fall of that year. Two of the 1938 experiments, one on a low phase of Plummer soil near DeLand and the other on an acid muck near Davenport , produced good clover growth because of the high moisture -h olding capacity of those s o ils . Rainfall approached normal during the fall of 1939, and only three experiments failed to produce satisfactory clover growth. The clover on the acid muck area near Da venport failed because of excess water caused by inadequate drainage. The clovers on two areas near Arcadia on high phases of Leon sandy soil-one on flatwoods, the other on prairie land-produced unsatisfactory growth primaril y because of drought. These latter two soils possessed a shallow surface organic layer which was u n derlaid with coarse sand , causing them to be dr y . Clover tests made on acid soils such as low-lying phases of Leon , Plummer , Portsmouth , Johnson , Scranton , Bladen fine Fig. 2.-Clover-carpet grass pasture furnishing winter feed for bulls . Left, lime, phosphate and potash produced good clov e r . Right , without fertilizer clover similarly seeded did not grow.

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8 Florida Agricultural Experiment Station sands and acid mucks have given good growth . Slightly acid or alkaline soils, with calcareous substrata, such as mucks and sandy mucks and low marl hammocks, also have proven satisfactory for clovers. Moisture requirements for different varieties of clover vary but none of the winter clovers which have been tested in Florida furnish much feed under dry soil conditions. The adaptation of clovers to different soil moisture conditions is given under clover variety tests. Any soil of sufficient moisture, when properly fertilized, is suitable for clovers. The best criteria for selecting soils for clover pasture are as follows: (1) select soils with a fine textured sur face layer, high in organic matter, 6 to 12 inches in depth; (2) the finer the texture of the subsoil the better the moisture-holding capacity of the soil and the clover growth produced; (3) soils with clay subsoils .are better than hardpans, and impervious hardpan soils are inferior to pervious hardpan soils; (4) muck soils have produced very good clover growth. FERTILIZER REQUIREMENTS FOR PRODUCING WINTER CLOVERS ON ACID FLATWOODS SANDS AND ACID MUCKS Fertilizer Combinations and Sources of Lime.-The effect of fertilizer mixtures on clover growth is shown in data presented in Table 1 and summarized in Figs. 3 and 4. In Table 1 the aver age relative yields of clover from nine soil types produced with 100 _ 90 80 _ 70 ._ 6 0 f. Ca-Mg, 1500 lb s . rro 1 md lim c o tone and JOO l bs . dolo mite . F 18 ~; s uperp hosphat e. K 50% m uria te of pot ash. H 18 ~; nit r ogen ( sulfate of ammon i a un d n i tr ate o f sod e. } . Ea t es in lbf:: . per ta.ere .:i:; 20 110 I ~u M,; 2 00 0 I Cu t l r, 2 0 00 1------< i , 75 K 100 No fertilizer I H 75 Co.-rJ ~ 2 000 F 600 N 75 P Goo t 100 l! 75 Cu J, !r2000 P 600 K 100 II 75 Fig 3.-Average relative clov e r yields with different fertili z er mix tures for nine soil types. (See table 1.)

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Wint e r Clover Pastures for Peninsular Florida 9 a fertilizer mixture consisting of 2,000 pounds lime, 600 pounds 18% superphosphate, 100 pounds 50% muriate of potash, and 75 pounds of an 18 % nitrogen fertilizer is represented by 100. When potash was omitted the relative yield was 25; without phosphate 120 110 1 00 90 80 'O .... ... 70 :,.. " 60 ... ..., .. .... 50 ix: 40 30 20 10 '.... ._ Ca-Mg2000 Ca 2000 l -.-! g 2000 Ca Mg 4000 Ca-h: g 1 000 P 600 p 600 p 600 P 600 F 300 K 100 K 100 ;; 100 ;; 100 K 100 N 75 N 75 N 75 N 75 N 75 ._ ,Ca g ro u nd limestone; 1,!g do l omite ; Ca -? 1t; 3/4 grounC. lime, 1/L. dolomite i P 18 ::'. superphos;:,hate, K 50% muriate of ,:, otash; N 1 3 1, nitrogen. Rates given in pounds per acre, Fig. 4.-Average relative clover yi e lds with sources, combinations and rates of lime w ith other fertilizers. 12; without lime 33; without potash and phosphate 14; and with no fertilizer 3. When twice as much lime was used with the complete fertilizer , the yield was 123. One-half the amount of lime and phosphorus in the mixture reduced the yield to 70 . When ground limeston e and dolomite were substituted for the lime mix ture, the relative yields were 115 and 80, respectively . The clover plants on plots without phosphate or potasE:ium fertilizers developed phosphate and potassium deficiency symp toms described in Florida Experiment Station Bulletin 325. The source of lime is important from the standpoint of the residual effect on clover growth in succeeding years. Fig. 5 shows that the average clover growth, during the second year after fertilizing five soil t y pes , was greater when ground

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"' ,0 ...:I s:: ..... 'd ...., Q) ..... >< ID bl) al ,._ I 7000 6000 500 0 4000 3000 2000 1000 Florida Agricultural E x periment Station ._Ca -1 ton ground lime stone . Mg 1 ton do lomite. C u -r11g 1500 lbs.ground lime >stone and 500 lbs. dolomi,te. P 600 lbs. 15 % superphosphate >-K 100 lbs. 50 1 s potash >PK ( rat e s per acre) Ca PK Mg PK No t r e fert1l1zed 1n 1939 ca.Mg PK Ca. PK Mg PK Refert1.hzed with 2 untia.l fertilizer in 1939 Initia.l fertilizer was a.pplied in October 1 9;8 . Fig. 5.-The effect of refertilization on subsequent clover yields based on averages of five soil types. (High calcium limestone produced larger yields than dolomite.) limestone, high in calcium, was used than when dolomite or a mixture of lime and dolomite was used. Research results indicate that the use of nitrogen fertilizer in conjunction with lime, phosphate and potash for growing clovers depends on such factors as rainfall, soil type, and dates and amounts of the nitrogen application. In establishing clovers the use of 75 pounds per acre of an 18 % nitrogen fertilizer was found (Table 2) to be of much benefit on Scranton fine sand and of little or no benefit on a Portsmouth fine sand. On established clover pastures, little benefit was obtained from small applica tions of nitrogen fertilizers, and less growth occurred with heavy nitrogen applications (300 pounds of 18 % nitrogen mixture) , Table 3 . Refertilization of Established Clover Pastures.-The import ance of refertilizing established clover pastures with lime, phos phate and potash is shown in Figs. 5-7 and Table 3. Leon fine sandy soil was fertilized in 1937 with a mixture consisting of one ton dolomite, 600 pounds 18 % superphosphate, and 100 pounds 50% muriate of potash. Clover yields of 14,130 pounds; 7,020 pounds; and 4,420 pounds per acre were obtained when referti lized with one-half, one-fourth and none of the above mixture , respectively. When clovers on a Bayboro fine sandy soil were refertilized with one-half , one-fourth and none of the fertilizer

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TABLE 1. AVERAGE ACRE YIELDS IN PO U NDS OF GREEN CL OVER FROM VARIO US FERTILIZER TREATMENT S ON NINE VIRGIN SOIL S. --------F e rtilized in O ct o ber 1938, a nd % of In i t ia 1 Fertiliz e r Applied in S e pt e mber 1939 F e rt ilized in O c t obe r 1939 F e rtilized in Oct o b e r 1938 Fertiliz er Appli P d Ki s sim me e P o rtsLeon m o uth f. s. f. s. ---pH2 4 . 6 3 pH 4.81 I 1940 I 1940 -1 (lbs.) I (lbs.) No fertili zer
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12 Florida Agricultural Experiment Station Fig. 6.-Refertilizing established clover pastures increases the earli ness of feed as well as the total feed. Areas represented above were similarly fertilized with one ton of lime, 600 pounds of superphosphate and 100 pounds of muriate of potash in October 1937. These areas were refertilized in October 1939 and photographed in February 1940. Upper, early yield of California Bur clover produced when refer tilized with one-half of the initial fertilizer treatment. Lower, early growth of California Bur without refertilization.

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1 6 000 14000 Q) ... 0 < 1 2000 .., " P< 10000 .,; ,0 ,..i 8000 '1 ..... -0 6 000 ..... (I) ..... ;,-. '1 4000 Q) <> ... <.'.> 2000 Wint e r C loi ,e r Pastur es j or P e nin s ular Florida 13 L eon so il Dins ,n o re " ' B av bo r o soil, Gai ne s v ille Fer c ein t o f ini ial fe r t i iz e re-a pp li id in 0 ct c ber 1 9 3 9 50 % 25 1, 0 50 % 25 % C I n itial fertiliz e r applied iri 1 93 7: 1 t on dolomite, 6 0 0 lbs, 1 s ;; superpho s pn a t e, 100 lbs. 5 0% p otas h . N i tro ,;e n VIas ap nli e d a t u n ifo nn r a t e s bo th yea r s , Fig. 7.-Effect of soil type and fertility level on the need for fre quent fertili ze r application s. mixture previously mentioned , the green yields were 1!5,490 pounds; 15,580 pounds; and 14,130 pounds (green weight) per acre, respectively. The early season clover yields were greatly affected by the refertilizer treatments on the Leon soil type, Table 3. Sources of Phosphate.-Clover research with sources of phos phate has been carried on for two years. The use of any source of phosphate is dependent upon soil types and accompanying fertilizers. The results, which follow , concerning the insoluble phosphates such as colloidal and rock phosphate, should be con sidered as preliminary. Four sources of phosphates with the characteristics given below were used. Superphosphate-18 % available P 2 0 5 Rock phosphate-50 % through a 200 m e sh sieve , 28 % total P205 . Colloidal phosphate-22% total P 2 0 5 B a sic slag-10 % to 12 % available P 2 0 5 . The suitability of superphosphate, when applied with a prop er mixtur e of other fertilizers, has been previously discussed . Basic slag applied at a rate of 750 pounds per acre with one ton of lime and 100 pounds of muriate of potash , or a mixture of 1,500

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TABLE 2.-EFFECT OF N ITROGEN ON THE YIELD OF CLOVER WHEN GROWN WITH VARIOUS LIME, PHOSPHATE, AND POT ASH FERTILIZERS, ON SCRANTON AND PORTSMOUTH FINE SANDS. Fertilizer Applied PK Ca PK Mg PK (Ca+Mg) PK (Ca+Mg)PK 2(Ca+Mg) PK Relative Yieldswith and without nitrogen P-600 lbs . 18 % superphosphate . Ca-1 ton ground limeston e. Mg-1 ton dolomite. Scranton Fine Sand, Wauchula I Portsmouth Fine Sand, Starke 1 ______ T_o _ ta _ l_Y _ i_eld Early Yield 3/20 / 40 \ 75 lbs. (18%) j 75 lbs. (18%) No Nitrogen Nitrogen per Acre No Nitrogen Nitrogen per Acr e 350 5,850 1,790 3,550 2,090 2,510 100 Pounds Green Weight per Acre 420 680 7,250 1,830 2,680 1,420 6,620 1,880 6,410 1,490 7 , 180 3,050 189 100 1 , 020 1,980 2 , 330 1,020 1,770 2 , 190 100 Ca+Mg-1 ton lime, 1 / 4 dolomite and 3 / 4 ground lime . K-100 lbs. 50 % muriate of potash.

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Wint.er Clover Pastures for Peninsular Florida pounds basic slag and 100 pounds muriate of potash per acre, has generally given good clover growth on most acid soils tested, Table 1. Fertilizer combinations including rock phosphate and super phosphate, are compared on two soil types (Table 4). A fertilizer mixture of 3,000 pounds of rock phosphate and 100 pounds of muriate of potash produced a green clover yield of 6,460 pounds per acre as compared with 9,500 pounds for the fertilizer con sisting of one ton of lime, 600 pounds superphosphate and 100 pounds of muriate of potash per acre on a Portsmouth soil. When one ton of lime was added to rock phosphate and potash, the yield was decreased to 4,440 pounds per acre. One thousand pounds of rock phosphate applied in conjunction with lime and potash produced a yield of 2 , 557 pounds per acre. The fertilizer mixture of 3 , 000 pounds rock phosphate, 200 pounds superphos phate, 500 pounds lime and 100 pounds muriate of potash pro duced a yield of 9,970 pounds of clover and was the highest yield ing fertilizer on the Portsmouth soil. On the Scranton soil, 7,250 pounds of green clover wa s produced by the fertilizer treatment made up of lime , superpho s phate and potash, as compared with 1 , 390 pounds of green clover p e r acre produced from 3,000 pounds of rock phosphate and 100 pounds of potash per acre. The addi tion of 2,000 pounds lim e to the latter fertilizer increased th e clover y ield to 5 , 090 pounds per acre . Results with colloidal phosphate were similar to thos , 2 with rock phosphate . Effect of Different Fertilizers and Soil Types on the Chemi cal Composition of Clovers.-The ch e mical composition of clovers is influenced mostl y b y f e rtiliz e r treatments and soil type , though th e variet y of clover has some effect 2 The average phos phorus and calcium contents of clovers grown on a Johnson soil were considerably higher than for the same clov e rs on Leon soil. Conv e rsel y, the potassium and magnesium contents were hi g he s t in cl ov ers grown on the Leon t y pe . These two soils were f e rtilized id e nticall y . The elem e ntal comp o sition of clovers on a Leon soil was found to b e directly corr e lat e d with the kind and amount of fer tili z er appli e d (Table 5). On a series of clover plots , fertilized un i formly in 1937 , an experiment was conducted to determine the effect of different refertilization treatments on the chemical 2Unpublish e d da t a.

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16 Florida Agricultural Experiment Station TABLE 3.-THE EFFECT OF REFERTILIZATION, WITH AND WITHOUT NITROGEN, ON CLOVER YIELD FOR LEON AND BAYBORO FINE SANDY SOILS. (GREEN YIELD IN POUNDS PER ACRE.) Fertilizer Applied Leon Soil I Bayboro Soil Dinsmore Gainesville Initial Refertilized j j j 1937 1939 Early* Total* Early*'' Total** Mg-2000 Ca-1000 \ \ I P-600 P-300 9,000 I 14,130 I 1,870 II 15,490 K-100 K-50 N-75 N-75 Mg-2000 Ca-500 I I I P-600 P-150 3,350 I 7,020 I 1,790 I 15,580 K-100 K-25 II ,I N-75 N-75 Mg-2000 N-75 I I I k--1ii 1,830 Ill 4,420 II 1,670 Iii 14,130 N-75 Mg-2000 Ca-500 I I K-100 K-25 i 1,450 I 14,950 P-600 P-150 4,290 1 1 8,990 1 1 -M=-=-g--2~oc-.co-=-o--l---:cC:-a---c-lc--cOc-;:0-;:-0-1 --------+-I ----l---~I ---K-100 K-50 P-600 P-300 2,470 I 6,740 II 1,370 / N -300 N -300 j Mg-dolomite. P-18% superphosphate. Ca-ground limestone. K-50% muriate of potash. N-18 % nitrogen ( nitrate soda and sulfate of ammonia). 19,250 Note: All areas were seeded with 8 lbs. of California Bur, 2 lbs. each of White Dutch, Little Hop, Black Medic and Persian. *Yield consisted of 55% Calif. Bur, 10% Black Medic, and 25% White Dutch, 10% other clover. ,,,:,go% White Dutch and 10% others. composition of resulting forage. One group of plots, which re ceived no additional fertilizer, produced clover with an ash con tent of 6.56% as compared with 9.12% for clover refertilized with acre applications of 1,000 pounds limestone, 300 pounds 18 % superphosphate and 50 pounds 50 % muriate of potash. The cal cium content of clovers was increased from 1.03 % to 1.48 % ; phos phorus was increased from 0.29 % to 0.46 % ; and the potassium content was increased from 1.33% to 1.84% when the above re fertilization treatment was used. When one-half the above rate of fertilizers was used, intermediate results were obtained. The higher refertilizer treatment increased the protein content from 22.6 % to 28.2 % , but produced no change in magnesium content of clovers.

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Wint,er Clov e r Pastures fo r Peninsular Florida 17 TABLE 4.-INFLUENCE OF DIFFERENT MIXTURES OF Lnrn, SuPER PHOSPHATE, AND RocK PHOSPHATE FERTILIZERS ON THE GREEN YIELD OF CLOVER ON Two SANDY SorL TYP ES. Fertilizer in Pounds p e r Acre P600, KlOO Ca2000, P600, KlOO Pr 30 00, KlOO Ca2000 , Pr3000, KlOO Ca2000, PrlOOO, KIOO Ca500, P200, Pr3000, KlOO Portsmouth Soil, 1 *Scranton Soil , Starke Wauchula pH 5.44 pH 4.98 (Lbs . ) (Lbs.) 5,670 420 9,500 7,250 6,460 1, 39 0 4 , 440 5 , 090 2 , 557 836 9,970 Ca-lim e ; P-18 % superphosphate; K-50 % muriate o f potash; Pr rock phosphate. ,:, 75 pounds per acre of 1 8'7c nitro ge n mixture w as added t o th e f e tili ze r mixture used on th e Scranton soil. pH on bot h s oi ls wa s measured befor e f er tilization . FERTILIZER REQUIREMENTS FOR PRODUCING WINTER GRASSES AND CLOVERS ON SLIGHTLY ACID OR ALKALINE SOILS (Lower East Coast Soils with Calcareous Substi-ata) Since most pasture soils along the lower East Coast of Florida a re underlain with a calcareous substratum, the fertilizer require ments for growth of winter pasture grasses and clover s are con siderably different from those for acid solls of other sections o f the st a te. Initial fertilizer experiments established in 19 38 with various mixtures of fertiliz e rs c ompa r e d superphosphate with basic slag , raw rock phosphate , and colloidal phospha t e. The s e trials showed the superiority of a fertilizer mixture containing superphosphate and potash, and failed to show a r es ponse to either high calcium or dolomitic lim e ston e . Ve ry little grow th was obtained wh e n either sup er phosph a te or potash was us ed a lone, but w hen both were used , high es t y i e ld s r e sulted. Clover experiments established in Decemb e r of 1939 were d esign e d to show the most profitable amounts of superphosphate a nd potash to use , as well as to st ud y furth e r t he effects of lim e. nitrogen and a mixture of copper , maganese and zinc . The re sults are presented in Table 6 and show that , in general , sandy soils in this region respond to a higher ratio of phosphorus to

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18 Florida Agricultural Experiment Station Fig. 8.-Louisiana White Dutch clover growing in carpet grass pas ture on a low, moist soil (Leon fine sand) in Hardee County. Left, lime , phosphate and potash produce good growth. Right, seeded as at left but lim e was not applied . Photographed in February . potash than do muck soils. Statistical treatment of the original data has shown that on sandy soils represented by the Acme and Waldrep Dairies, treatment 6 produced most economical use of fertilizers . This consisted of an acre application of' 200 pounds 20 % ammonium sulfate, 160 pounds 44 o su~hate, and 240 pou~ ~J2Q.!_ as , and a mixture of small quan tities of coppE;r _ maganese and zinc. On muck soil located at Ives ---TABLE 5 . EFFECT oF REFERTILIZATION oN CHEMICAL CoMPOSI. TION OF CLOVERS GROWN ON A LEON SOIL, DINSMORE, FLORIDA* Lbs. per Acre-1939 Ch e mical Composition in Percent of Dry Matter 50 % Potash 0 25 50 18 % Superphosphat e 0 150 300 90 % Ground LimeAsh stone o I 6.56 500 8.11 1000 9.12 ' I I Phosphorus I 0.29 0.38 0.46 Potassium 1.33 1.62 1.84 Calcium 1.03 1.43 1.48 Mag[ nesium Protein 0.43 0.43 0.46 I 22 . 6 27.6 I 28.2 ''In 1937 this area was fertilized with one ton dolomite, 600 pounds 18 % superphosphate, and 100 pounds 50 % potash . 75 pounds 18 % ni trogen per acre has been applied annually. Note: Mineral fractions given as elements and not as oxides.

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W i nt ,e r Clo ve r Pastur es for P e ninsular Florida 19 Dairy the most economical use of fertilizer was obtained from treatment 3 , or an acre application of 200 pounds of 20 % ammon ium sulfate, 70 pounds of 44% superphosphate, 240 pounds of 50 % muriate of potash, and a mixture of minor elements consisting of acre applications of 50 pounds 25 % copper sulfate, 50 pounds 25 % manganese sulfate and 10 pounds 79 % zinc sulfate. It is pos sible that smaller quantities of copper , manganese and zinc could be used to advantag e. L arge nitrogen responses were obtained on the sandy soils and only small responses on the muck soils . No significant increases in yield were obtained by adding two tons per acre of lime to these soils. TABLE 6.-Av E RAG E AcRE YIELDS IK PouNDS OF GREEN PAST URE FORAGE OBTAINED FROM CLOVER PASTURE FERTILITY EXPERIMENTS IN DADE, BROWARD, AND PABI BEA CH COUNTIES ( 1940). / Pounds per Acre : Bout44 % I 50 % i Iv es Acme \ waldr e p well Averag e Trea tments SuperMuriate 0 , Dairy Dairy Dairy Dairy I phosof I Sandy j Sand & All phate Pot as h : Muck Loam Sand Muck Soils 1 Ch e ck Check 5,808 4 8 4 0 484 1,694 2 70 120 7,381 9 , 922 7,623 8,228 8,296 3 70 240 14,036 12,463 8,712 6 , 050 10 ,3 16 4 70 360 14,157 13,189 8,954 20,812 14,279 5 160 120 8,228 9,317 12,463 11,858 10,421 6 160 240 11,253 17,666 12,826 13,552 13,824 7 160 360 9,559 15 , 488 14 , 762 24,442 16 , 063 8 275 120 2,662 10,406 14 , 883 9,196 9.287 9 275 240 8,833 17,182 14,520 7,744 12 , 070 10 275 360 14 , 762 15 , 609 16 , 335 25,168 17 ,9 69 *11 275 360 15,246 19,481 11,011 29,524 18.816 * * 12 I 275 360 9,317 15,125 11,374 18,634 13,612 *Treatment 11 receiv e d 2 tons dolomite. **No minor elements on Treatment 12, all other treatments had 50 pounds CuSO -1 , 50 pounds MnSO 4 , and 10 pounds ZnSO ~ p e r acre in cluded. All plots r e ceiv e d 200 pounds per a cre ammonium sulfate. Yield data for Ives and Boutwell dairy plots are r e lativ e , but in co mpl e te. Yield diff e r e nces over 5,000 pounds ar e significant at the 5 % p o int . SEEDING AND MANAGEMENT OF CLOVER PASTURES Seedbed Preparation.-Clovers in Florida have been estab lished successfully on unimproved cut-over lands , on grass pas tures , and on moist land that has been cultivated, provided that competing ve g etation was retarded or destroyed and the soil left in a firm condition . The manner in which the land was prepared for clovers depended upon the typ e of vegetation present. It was found best on unimproved cut-over lands to disk the soil thorough

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20 Florida Agricultural Experiment Station ly well in advance of planting time. By allowing time to elapse between disking and seeding , the soils became packed and soil moisture conditions were improved . On cultivated lands good Fig . 9.-Differences in grazing practices produced the difference in clover growth shown here. Both areas were seeded and fertilized alike. Above , a good stand of clov e r failed to develop because of dense growth of frost e d carpet grass. Below , the carpet grass was grazed close before fall. A good stand of clover developed. Photographed in January.

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Wint,er Clover Pastures for Peninsular Florida 21 results were obtained when the soil was prepared in much the same manner as for unimproved cut-over lands. On closely grazed improved sods , land fertilized and lightly disked just prior to seeding produced good results. On all of these soils it was found desirable to plant clover seed when the soil was moist, and to roll or pack the soil to cover the seed. Clovers have been successfully established without intensive seedbed preparations on soils which retain a moist surface. When such soils had native wiregrass vegetation the grass was burned and the area subsequently fertilized and seeded. When the vege tion consisted of carpet or other improved sod grasses, close grazing made possible the successful seeding of clovers. Two experimental areas, one near St. Petersburg and th e other near Orlando, failed completely because the grass was not closely grazed. The clovers were unable to grow through the dense sod (Fig. 9) . Though good stands of clover were obtained irrespective of rainfall , better results wer e generally obtained when seed was planted just prior to or during a period of heavy rains. Planting and Inoculation of Clover Seed.-Tests conducted in 1937 have shown that clovers, for best results, should be sown in October, though good stands have been obtained when plant ings were made as late as December 15. October plantings are preferred because: 1. Soil moisture conditions are generally best for the estab lishment of clovers during that period. 2. Plants require considerable time to grow before grazing is possible. 3. Earlier plantings tend to increase the l e ngth of the graz ing season . As is common for all legumes , to obtain most benefit from atmospheric nitrogen it is necessary to inoculate all clovers with the proper legume bacteria before planting . The bacteria form nodules on clover roots and combine nitrogen from the air into compounds which are available to the host plant. Successful nodule formation on clover roots has been obtained b y inoculat ing the clover seed with either proper commercial bacterial cul tures or with soils from areas which had previously grown the particular legume. A Comparison of Clover Varieties for Peninsular Florid"i Soil and Climatic Conditions.-The planting of adapted clover varieties on moist soil , adequately fertilized, is necessary for the

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22 Florida Agricultural Experiment Station successful establishment of winter pasture. The necessary char acteristics of desirable clover varieties are palatability, ability to produce enough seed under Florida conditions to maintain good stands, and ability to withstand close grazing. Of the several varieties of clover included in the seed mixture and used in fertility experiments, White Dutch and California Bur were most promising. White Dutch (Louisiana variety) was found especially adapted to low, moist soils, and to tolerate wet ter soil conditions than most of the other clovers. White Dutch also tolerated more soil acidity and withstood closer grazing than California Bur. California Bur clover was found adapted to moist but well drained soils. It seemed to produce higher yields than White Dutch when grown under optimum conditions. Since California Bur clover produced an abundance of growth under low temperature conditions, it provided grazing earlier than White Dutch, but was found to have a shorter growth period . Thus it se e ms that a mixture of California Bur and White Dutch will provide the most promising clover combination for Florida conditions. In clover variety trials conducted on two distinct s oil types, 18 different varieties were tested (Table 7). Due to difference in the amount of soil moisture pres e nt in these two types of soil, the clover varieties responded differently. Johnson loamy fine sandy soil was poorly drained, while Leon fine sandy soil on which these experiments were located was moist but well drained. Louisiana and other White Dutch varieties, Alsike, Persian and Little Hop clovers produced the best average yields on low , wet, poorly drained Johnson soil. California Bur , Hubam Sweet, Black Medic, and Hop clovers produced the best average y ield on the moist but well drained Leon soil. Data in Table 7 show that varieties of White Dutch clover differ greatly in yielding potentialities. On the poorly drained Johnson soil type the three-year average relative yields of varie ties of White Dutch were as follows: Louisiana variety, 100 ; Ladino, 92; Dixie variety, 83; Oregon variety, 69; and Kent Wild (English White Dutch) , 61. One year's test of two New Zealand varieties of White Dutch clover shows that one variety equaled Louisiana White Dutch but the other was inferior. The relation ship of yields of varieties of White Dutch clover was similar on the drained Leon soil. except that Ladino White Dutch produced best yields. Lappa, Trijolium lapa ce um, and Louisiana Red were tested for one year on both Leon and Johnson soil types. Louisiana Red pro

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Wint , er Clover Pastures jor Peninsular Florida 23 TABLE 7.-EFFECT OF A WELL DRAINED LEON SorL TYPE AND A PooRLY DRAINED JOHNSON SOIL TYPE ON THE DRY YIELD OF 18 CLOVER VARIETIES. / Relative Yields of Clover Varieties on -~~~ T _ w _ o Soil Ty _ p _ e _ s _ _ Leon Fine Sand, Dinsmore Clover Variety Johnson Loamy Fine Sand , Gainesville _ _ ____ _ _ _ [ _ _ 1940 ~ -1 _ 9 _ 4 _ 0~ White Dutch (La.) Tr i jolium r e peu s I 40 92 Little Hop (Trifoli111n dubium) 38 73 Hop (Trif o limn pr oc 11mbens ) 65 63 White Dutch (Kent Wildl White Dutch (Oregon) 22 63 White Dut c h (Dixie ) 36 42 White Dutch (N ew Zealand ) 35 78 White Dutch (l'iew Ze a land S1001 29 92 White Dutch (Ladino ) 55 99 P e r s ian (Trifoli11m re s up i natum) 54 82 Subterranean ( Trijolium subterranean) Clu s ter (Trifoli111n gl o meratmn) Al s ikc (Trifolimn hybr i dum) 36 Crimson (Trifol i 11n1 iucarna t um) Carolina (Trifoliu.m caroli11ia11111n) Bl a ck M e dic (M c dicag o !11p11lina) 66 Calif. Bur (Jfedicago hispida ) 116 Hubam (Melilotu s alba an1111a ) 126 *100-2,174 lbs. dry yield per acr e . ' ''*Yield taken over a period of two years. 70 59 3-Yr, Ave 1938-40 100* 72 57 61 69 83 92 89 40** 32** 92 27 70 38" 55 36** Soils were fertilized with lime, phosphate and potash in the fall of 1937 and refertilized in the fall of 1939. duced satisfactory yields on the Johnson soil, and Lappa was in ferior in yielding capacity to other clovers on both soil types. Since Louisiana White Dutch was found to produce an abund ance of seed under Florida conditions , it is recommended over all other varieties of White Dutch clover (Fig.10). Aside from Louisiana White Dutch clover, California Bur, Black Medic, Crimson, Persian, Hop, Little Hop, Red and Sweet clovers are the only promising varieties which have produced sufficient seed for adequate propagation under Florida conditions. ADVANTAGES OF CLOVER IN PASTURE MIXTURES Experimental results show that pasture grasses on mineral soils produce greatest increase in yield through the use of nitro genous fertilizers 3 . Because of the high cost of commercial nitro gen the probability of increasing the carrying capacity of grass 3Unpublished data.

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24 Florida Agricultural Experim en t Station pastures profitably in Florida is questionable, unless cheaper sources of nitrogen are made available . It has been found that clovers, when well inoculated, greatly stimulate grass growth . Fig. 11 compares the seasonal growth curve of fertilized carpet grass with the growth curve of fertilized carpet grass seeded to clover. The early increases in yield of pasture herbage on the carpet grass-clover plots was due to the presence of clover, while the late seasonal yield increase was primarily carpet grass stimu lated by nitrogen which was added to the soil through the clovers. Besides adding to the quantity of pasture herbage , clovers in crease greatly the nutritive value of the feed. The average pro tein content of highly fertilized carpet grass 4 was 11.9 % as com pared with 28.2 % for fertilized White Du~ch clover. The average 4Unpublished data , Florida Agricultural Experiment Stations . Ci:/ J; l1/. I } II , ' I . : ; / III / / I /lJ Fig. 10 . -Seeding habits of three strains of White Dutch clover. Upper, Louisiana White Dutch is both productive and prolific. Lower le ft, Ladino is productive but a scant seeder in Florida. Lower right, a low-growing and high yielding variety of New Zealand White Dutch that does not produce s ee ds in Florida . Photographed in February.

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Wint,er Clover Pastures jor Peninsular Florida 25 phosphorus content of fertilized carpet grass was 0.20% as com pared with 0.46 % for the clover. The calcium content for carpet grass was 0.65 % as compared with 1.48 % for clover. It is there60 .. 8. 45 .. " p. 'd .... " ,,., >< I'.' A i 0 15 Clover and carpet grass (fertili~ed) 2 11 2 20 19 3 9 Clipping Dates Fig. IL-Increas e in early and total yi e lds due to the presence of White Dutch and other clovers. On the carpet grass-clover growth curve the early growth is clover and the late growth is carpet grass stimulated by soil nitrogen supplied by cl o ver . Th e fertiliz e d carpet grass growth curve s hows that carp e t grass makes littl e growth during th e cool season. Both growth curves represent averages of 12 plots fertilized alike with lime, superphosphate and potash. fore evident that the addition of clover to grass pastures greatly improved the value of feed from the standpoint of livestock pro duction. SUMMARY Clovers should be utilized in the Florida pasture program be cause they furnish winter feed , supply the soil with nitrogen which increases subsequent grass growth, and improve the feed ing value of pasture herbage. To establish clover successfully the soil must be properly fertilized and suitable clover varieties should be planted under adapted ecological conditions in October or November, on close ly grazed sods or well packed seedbeds. Seedings should be made during a rain y period . '

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26 Florida Agricultural Experim e nt Station Data on fertilizer combinations and sources of lime and phosphate for different soil types are given. Fig. 12.-A clover-carpet g r ass pasture g ra ze d continuously by calves during lat e winter . Th e cow droppings form "seed i s lands " in which the White Dutch clover r esee d s. Th e s ee d germinate in th e fall for the next y ea r's clover crop. Photo gra phed in April. PRACTICAL POINTERS FOR ESTABLISHING AND MANAGING CLOVER PASTURES Clover pastures can be established on those Florida soils which have favorable wint er moisture conditions and are ade quately fertilized. Unimproved cut-over pine lands, improved grass sods , and cultivat e d moist to wet soils have grown clovers successfull y . To establish and maintain clover pastures , the fol lowing practices are necessary: 1. For flatwoods sandy soils and acid mucks, not previously fertilized , apply initial fertili ze r at the following rates per acre : 2,000 pounds "high-calcium" limestone or 2 , 000 pounds dolo mite , 600 pounds 16-20 % superphosphate, and 100 pounds 50 % muriate potash. 75-100 pounds nitrate of soda or its eq uivalent may be added to encourage earlier growth. (Calcium limestone should be used for California Bur , Sweet or Black Medic clover.)

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Wint , er Clover Pastures jor Peninsular Florida 27 (600 pounds per acre of an 0-16-8 or 3-16-8 fertilizer and 1 ton limestone may be used instead of the fertilizers given above . ) 2. To maintain clover pastures on acid soils, apply fertilizer at one-fourth to one-half of the above rat e s ever y one to two years. 3. For soils with calcareous substrata (lower East Coast soils), appl y fertilizers at the following rates per acre: Muck Soils 150-240 pounds of 50 % muriate of potash, and 70 pounds of 44 % triple superphosphate. 100 pounds 20 % ammouium sulfate or other nitrogen equiv alent may be added to encourage earlier growth. (The above is equivalent to 500 pounds of a 4-6-24 mixture.) (A mixture of 50 pounds copper sulfate, 50 pounds of man ganese sulfate, and 10 pounds zinc sulfate per acre may be neces sary, depending on previous soil treatment.) Sandy Soils 150-240 pounds 50 % muriate of potash and 160 pounds 44 % triple superphosphate. 200 pounds 20 % ammonium sulfate, or its equivalent, ap pears necessary for initial treatment on most sandy soils in this region . (Th e above i s equival e nt to LOOO pounds of a 4-6-12 mix ture.) (Copper, manganese and zinc ma y b e necessar~ in small quantities . ) LOW MARL HAMMOCK SOILS 600 pounds superphosphate and 100 to 150 pounds 50 % muriate potash. (75 pounds nitrate soda or its e quivalent may be added for early growth.) 600 pounds per acre of fertilizer with the formula 0-16-8 or 3-16-8 may be used instead of the fertilizers given above. 4 . Us e the following seed mixtures for sand? soils: Low Wet Sandy Acid Soils 3 to 5 pounds Louisiana White Dutch or 2 to 3 pounds Louisian a White Dutch and

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28 Florida Agricultural Experiment Station 1 to 3 pounds Persian clover. 3 to 6 pounds Red top ( Agrostis alba) or 5 pounds Italian rye grass may be added to the above mix tures. Moist to Wet Sandy Acid Soils 2 to 4 pounds Louisiana White Dutch and 5 to 8 pounds California Bur clover. Moist Drained Sandy Acid Soils 1 to 2 pounds Louisiana White Dutch, 8 pounds Califorina Bur and 3 pounds Black Medic. or 8 pounds California Bur and 4 pounds Black Medic. (Avoid purchase of poorly adapted seed . ) 5. Use the following seed mixtures on: Slightly Acid or Alkaline Muck and Sandy Muck Soils 2 to 4 pounds Louisiana White Dutch 5 to 8 pounds California Bur clover and 5 to 7 pounds Italian rye grass. Acid Muck Soils 3 to 5 pounds Louisiana White Dutch or 2 to 3 pounds Louisiana White Dutch, 1 to 2 pounds Persian, and 1 to 2 pounds Alsike. (3 to 6 pounds Redtop ( Agrostis alba) or 5 to 7 pounds Italian rye grass per acre may be added to the clover mixture given above.) 6. Inoculate clover seed carefully with appropriate bacter ial cultures. White Dutch, Persian, Alsike and Hop clovers require commercial bacteria culture "B". California Bur, Black Medic and Sweet clover require bacteria culture "A". Usually five times the rate of bacteria culture recommended by the manufacturer is necessary for best results in Florida. (For method of inoculation see page 6). 7. Plant in October or early November when soil moisture conditions are favorable. 8. Prepare a firm seedbed and destroy competing veg etation so that seed can come in contact with moist soil. On established grass sods, close grazing allows seed to contact the soil without further seedbed preparation.

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Wint , er Clover Pastures jor Peninsular Florida 29 9. Distribute the seed and fertilizer uniformly (mechanical spreaders are best adapted). The fertilizer should be applied pre vious to seeding. It is desirable that clover plantings be made just prior to or during a rain. 10. Delay grazing until clover seedlings are 3 to 5 inches high or until the clover root systems are well established. To allow for re-seeding, graze clover lightly during late spring. For best results divide clover area into several fields and practice rotational grazing. This practice will insure a more uni form grazing of clovers and a better distribution of cattle drop pings. ACKNOWLEDGMENTS The writers wish to express their appreciation to W , E. Stokes, head of the Agronomy Department, who offered constructive criticism; to G. E. Ritchey, Division of Forage Crops and Diseases , USDA, for suggestions and for seed used in the strain test; to J. R. Neller for suggestions on fertilizer treatments on alkaline soils; to W. A. Leukel, Agronomist, and Dean Graham, student assistant , for chemical analyses; to J. P. Camp for suggestions on the experimental design for testing legume strains; to G. C. Willson , research assistant of the Soils Department , for help in connection with some of the experiments; to J. R. Henderson of the Soils Department for classifying the soils; to farmers and county agents cooperating in this work; to Jeffery Dawson, student assistant, fpr com putations; and to R. E. Billington for assisting with collecting, drying and weighing clippings.