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Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 740
Title: Production response and economic returns from five pasture programs in north central Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027091/00001
 Material Information
Title: Production response and economic returns from five pasture programs in north central Florida
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 45 p. : ; 23 cm.
Language: English
Creator: Koger, Marvin, 1915-
Publisher: Agricultural Experiment Stations, Institute of Food and Agricultural Sciences, University of Florida
Place of Publication: Gainesville Fla
Publication Date: 1970
 Subjects
Subject: Pastures -- Florida   ( lcsh )
Pastures -- Economic aspects -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 45.
Statement of Responsibility: M. Koger ... et al..
General Note: Cover title.
General Note: "Beef Research Unit Experimental Phase No. 2"--T.p.
 Record Information
Bibliographic ID: UF00027091
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000929601
oclc - 18422694
notis - AEP0392

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Full Text
SBulletin 740 (tehnial
070 Bulletin 740 (technical)


July 1970


Production Response and

Economic Returns from

Five Pasture Programs in

North Central Florida


Beef Research Unit
Experimental Phase No. 2




M. Koger, W. G. Blue, G. B. Killinger,
R. E. L. Greene, J. M. Myers, N. Gammon, Jr.,
A. C. Warnick, and J. R. Crockett





Ot/ 8




Agricultural Experiment Stations
Institute of Food and Agricultural Sciences
J. W. Sites, Dean for Research
University of Florida, Gainesville










CONTENTS


Page

Introduction .......................- --- --- .....- -- ..- 3

Experimental Plan -....................................-- 4

Soils Studies .................................----- -..- 5
Methods 5... ... ------------- --- 5
Results ............-- ----------- 7
Summary ........ .........--.-- ----- -.. .--.--- 11

Agronomic Studies ......................--------..- -----12
Methods ............- ----------- --- --12
Results -..... ................--------. -- 14
Summary .............. --.---------. 19

Irrigation Studies ..................--.- -. --.. .------- -- --- -- 22
M methods ... .... ..-- .- ...-------.. --.- ---......-- 22
R results ... .. ..----- --- --- -- -- --..... -- --. 23
Summary ...................................--.. .- 24

Animal Response -....... ....- ... .........--.-...- ----. --- --------- 24
M methods ............ ...---- -- .....-- ---- .- .. ..--- 24
Results .................... ............. ------- --- .27
Sum m ary .......0..- .... ...-- --- .. --.- ..- --- -. ---- 30

Economic Analysis .. .... .. ... 30
Methods -...-..-..-................... -----30
Results ..............- -- ... .....----. --- -- 35
Summary ............ .. -----.. ........------- ---38

General Discussion of Results ...... ..... ...... ..--.--.-.-- ------. 39

General Summary of Experimental Results .............. ................... 43

Acknowledgments .. ... .................---.. ------------ 45

Literature Cited ......................- -.-. -- .- ------45







Production Response and Economic Returns

From Five Pasture Programs in

North Central Florida

M. Koger, W. G. Blue, G. B. Killinger, R. E. L. Greene,
J. M. Myers, N. Gammon, Jr., A. C. Warnick,
and J. R. Crockett'

INTRODUCTION
The Beef Research Unit was established near Gainesville in
1952 with the objective of pursuing a comprehensive study of
pasture programs and systems of breeding cattle for beef pro-
duction on flatwoods soils of north central Florida. Such a
study was deemed imperative in view of the continuing increase
in demand for beef and the presence of some 15 million acres of
flatwoods in Florida, much of which would be potentially avail-
able for pasture development if economical production practices
were developed.
To achieve this objective, the unit was organized with the
departments of Soils, Agronomy, Agricultural Engineering,
Animal Science, and Agricultural Economics cooperating in
designing a coordinated approach in experimental investigation.
The results of Phase 1 of the study covering a five-year
period were reported previously by Koger et al. (7) .2 Utilizing
a total of eight pasture programs grazed by cows and calves,
it was found that clover-grass programs produced beef at ap-
proximately 60% of the cost for all-grass programs. The ad-
vantages for clover-grass pastures included a higher weaning
percent (83% vs. 64%), slightly heavier calves, and a lower
total cost per cow ($56 vs. $79). Increased fertilization rates
1Koger: Professor (Animal Geneticist), Animal Science Department.
Blue: Professor (Biochemist), Soils Department.
Killinger: Professor (Agronomist), Agronomy Department.
Greene: Professor (Agricultural Economist), Agricultural Economics
Department.
Myers: Professor (Agricultural Engineer), Agricultural Engineering
Department.
Gammon: Professor (Soil Chemist), Soils Department.
Warnick: Professor (Animal Physiologist), Animal Science Depart-
ment.
Crockett: Associate Professor (Associate Animal Geneticist), Ever-
glades Experiment Station.
2 Numbers in parentheses refer to literature citation.







on all-grass pastures improved carrying capacity, but the costs
of production were increased more than returns for prevailing
prices. Clover-grass pastures fertilized at the lowest rate of
600 pounds of 0-12-12 per acre produced beef at the same rate
as pastures fertilized at higher rates. Total soil phosphate and
soil organic matter increased significantly with years in all
programs.
An encouraging result from the first phase of this study was
that clover-grass pastures fertilized at a moderate rate produced
beef at a profit, demonstrating that flatwoods pastures provide
a valuable potential for increasing beef production in Florida.
Two results that were somewhat surprising were the low repro-
ductive efficiency of cows grazing all-grass pastures, and the
failure of higher fertilization rates on clover-grass pastures to
increase production above that of a moderate fertilization rate
of 600 pounds of 0-12-12 per acre annually.
The purpose of this bulletin is to report the results from
Phase 2 of the study covering the period from 1958 through
1964. Five pasture programs were included and were designed
to supplement the information gained from the preceding phase.

EXPERIMENTAL PLAN
Experimental Area.-The study was conducted at the Beef
Research Unit which is located anlplxiniuiately 15 miles north-
east of Gainesville on flat pine land commonly called "flat-
woods." The area was originally cleared and pastures were
established in 1952. The soils in the experimental area vary
from moderately well drained to very poorly drained. The major
soil type is Leon fine sand and the topography is level to gently
sloping, typical of large areas found thrll-.i.u~lho Florida. A
more detailed desk rilption of the area and of establishment of
pastures was reported previously (7).
Experimental Design.-This study was d1ienLd to evaluate
five different pasture programs in terms of forage production,
soil nutrient balance, animal response, and economy of beef
production. The study was designed also to compare the effec-
tiveness of different systems of breeding for improving beef
production. The cattle breeding systems are being evaluated
and will be reported elsewhere.
Five pasture programs were included. The type-; of forage
and fertilization rates are shown in Table 1. The grziu program
was included to continue the comparison of all-grass pastures







TABLE 1. PASTURE PROGRAMS
Program Forage Total Annual Fertilization
Numbers Plants Acres 0-10-20 Nitrogen
(lbs/A) (Ibs/A)
1 Grass 32 450 180 t
2 Clover-grass 40 300 0
3 Clover-grass 32 500 60
4 Clover-grass 32 700 120 $
5 Irrigated 24 900 180 1
clover-grass
t 120 pounds of nitrogen applied in 1962, 63, and 64.
$ No nitrogen applied after 1960.

with clover-grass pastures. The four clover-grass pastures were
concerned with varying rates of fertilization and the value of
irrigation. The clover in all pastures was White Clover (Tri-
folium repens L.) of the giant Louisiana type, either Louisiana
S-1 or Nolin's Improved variety. Grasses for all programs con-
sisted of one-third Pensacola bahiagrass (Paspalum notatum
Fligge), one-third pangolagrass (Digitaria decumbens Stent.),
and one-third Coastal bermudagrass (Cynodon dactylon (L.)
pers.). Each program had two replications, and except for
Program 1 all were divided into six equal areas to allow for
controlled grazing, timed fertilization, and separation of grass
or forage species. Each replicate of Program 1 was divided
into three areas.
Experimental cows were assigned to a specific pasture pro-
gram and remained on that program until removed from the
experiment. All replacement heifers came from their respective
breeding programs.

SOIL STUDIES
Methods
Sampling Procedure.-Soil samples were collected in a man-
ner similar to that used in Phase 1 of this experiment (7);
however, a modification was used to insure more uniform samples
from this extremely variable soil area. Two permanent posts
were randomly placed in each sub-pasture to serve as markers
so that repeated samples could be collected from the same loca-
tion. Soil samples consisted of composites of 10 cores from the
surface 6 inches, taken within a 30-foot radius of each post.
Twelve samples were taken annually from the grass program
and 24 from each of the clover-grass programs. In addition,
selected profile samples were taken to a depth of 21 inches.




















TABLE 2. THE EFFECT OF FORAGE SEQUENCE AND TIME ON SOIL ORGANIC MATTER, NITROGEN, AND CARBON-NITROGEN RATIOS
Forages Organic Matter Nitrogen C/N
1952-57 1958-64 1958 1964 1958 1964 1958 1964

% o ppm ppm


Grass
Grass
Clover-grass


Grass
Clover-grass
Clover-grass


620
752
682


769 t
939 t
934 t


? Probability that value for 1964 exceeds that for 1958 = 0.05.







Soil Analysis.-Soil analytical procedures were the same as
those described previously (7).

Results
Nitrogen and Organic Matter.-Soil organic matter levels
for 1958 and 1964 from 96 sampling locations in the programs
which included white clover-grass forage species were compared
statistically. The average organic matter content was 2.92% in
1958 and 3.82% in 1964. This 31% increase was highly sig-
nificant. Direct comparisons of individual pastures for years
prior to 1958 were not possible because of inadequate identifi-
cation of sampling locations, but a similar trend was indicated.
Organic matter content of numerous samples averaged 2.25%,
2.32%, 2.60%, and 3.07% for 1951, 1953, 1955, and 1957,
respectively. Fifty-three samples were included in the 1951
average from virgin soil and 90 samples in the average for
subsequent years.
Three soil sample groups were selected to determine the ef-
fects of forage species on soil organic matter and nitrogen (N).
The forage species were continuous grass from 1952 through
1964, grass from 1952 through 1957 followed by clover-grass
from 1958 through 1964, and continuous clover-grass. These
measurements and the carbon:nitrogen (C:N) ratios for 1958
and 1964 samples are shown in Table 2. Soil organic matter
increased by 29% under continuous grass and by 27% under
continuous white clover-grass. Differences in organic matter at
the two sampling dates approached significance for both forage
comparisons. There was no difference in organic matter concen-
tration where clover-grass followed grass. Increases in soil N
were significant for the three programs. The continuous clover-
grass program had the highest percentage N increase. The C:N
rations were variable at the beginning of the experiment, but
by, 1964 there was a trend toward narrower ratios when the
legume was present.
It was observed that adequately limed and fertilized clover-
grass pastures on these soils showed continued improvement.
The increase in soil organic matter and accompanying increase
in water holding and nutrient retention capacities were the
probable factors contributing to this improvement. The in-
crease in soil N, particularly for clover-grass pastures, suggests
the possibility that periodic renovation and/or cropping to non-
legumes such as corn or temporary grazing crops might permit
utilization of immobilized N (4).








The recovery of fertilizer N by grass forages, after equi-
librium conditions with respect to plant root and crown develop-
ment are reached, has been no more than 40% to 60% (1,10).
It has been assumed that most of the N not recovered from
sandy soils was lost by leaching and volatilization. The present
data indicate that significant quantities of fertilizer N applied
to grass pastures may be immobilized in soil organic matter.
In the grass program, the average annual soil N increase was
approximately 50 pounds per acre. The annual N application
was 180 pounds per acre through 1961 and 120 pounds per acre
thereafter. Assuming no other N supply, approximately 33%
of the fertilizer N was immobilized in the soil.
Even larger soil organic matter and N increases have been
shown by supplementary small-plot experiments involving white
clover-grass at the Beef Research Unit (3). From 1953 through
1963, organic matter was essentially doubled in the surface soil
from approximately 2% to 4% for both limed and unlimed treat-
ments, as shown in Table 3. The effect of time was very highly
significant. There was no other significant effect in spite of the
difference in lime treatments which caused sufficient variation
in soil pH to bring about differences in forage species. The
unlimed treatment was essentially devoid of white clover. Since
much of the N used by the grass was supplied by clover, forage

TABLE 3. THE EFFECT OF WHITE CLOVER-PENSACOLA BAHIAGRASS
PASTURE ON SOIL ORGANIC MATTER AND NITROGEN
Organic Matter Nitrogen
Treatment t 1953 1963 1953 1963
% % ppm ppm

Unlimed 2.05 3.85 829 909
Limed 2.12 4.03 756 1170

"F" Ratios from Statistical Analyses

Source d.f. O.M. N

Total 79
Years 1 257.50** 251.75**
Treatments 9 0.32 1.19
Unlimed vs. limed 1 0.39 5.48*
Blocks 3 2.21 7.01**
Years x treatments 9 0.75 2.19*
Years x blocks 3 0.25 1.09
Error 54
t Unlimed values are averages of four plots while limed values are averages of 36' plots.
P 0.05
** P = 0.005








production from the unlimed treatment was only slightly more
than 33 % that of the limed treatments. All forage was removed;
therefore, the increased soil organic matter must have come
primarily from the decomposition of plant roots and crowns.
There were no significant changes in organic matter at depths
between 6 and 24 inches.
Surface soil N also was significantly increased during the
experiment. A comparison of lime treatments showed that un-
limed soil contained significantly less N than soil from the limed
treatment. The treatment x year interaction was also signifi-
cant. There was an indication that the magnitude of organic
matter increase was inversely related to the initial level.
Soil pH and Ammonium Acetate (pH 4.8) Extractable Nu-
trients.-Soil pH and extractable nutrients are shown in Table
4. During the first phase of this study, grass pastures were
limed with 3 tons of high calcic limestone per acre and the


TABLE 4. SOIL pH AND AMMONIUM ACETATE
Ca, K1O, and PsOs


(pH 4.8) EXTRACTABLE


Programs 1958


1959 1960 1961 1962 1964


5.8 5.9
5.5 5.5
5.5 5.3
5.7 5.0
5.6 5.2

Ca (Lb/A)
970 900
1230 1030
1160 960
1250 1100
1060 920

KO (Lb/A)
27 52
37 50
59 58
53 78
61 55

P2O, (Lb/A)
8 37
32 47
21 56
40 53
33 68


1130
1410
1280,
1480
1260


48
61
84
70
67


6.0
5.7
5.8
6.0
6.0


1640
1840
1850
2150
1700


65
52
82
85
77


32
21
41
37
43


5.9
5.8
5.8
6.0
6.1


1500
2020
1930
2240
1680


83
83
111
133
111



19
22
33
37
44


6.0
5.9
6.0
6.3
6.3


1690
1940
1990
2270
2020


110
76
95
118
108


32
35
54
75
103







clover-grass pastures with 4 tons. The last application of 1 ton
per acre was made during the late summer of 1957. The initial
ton of lime for grass pasture and 2 tons for clover-grass pas-
tures were disked into the surface 6 inches of soil. Subsequent
applications were surface applied. By 1960 the pH had de-
creased to an average of 5.3, which probably resulted in reduced
forage production (2,5). Calcium (Ca) also had declined. The
magnesium (Mg) level averaged about 35 pounds per acre
compared with 66 pounds per acre in 1951, and supplementary
experiments had indicated possible response to Mg under simi-
lar conditions. In the spring of 1961 1 ton of high calcic lime
per acre was applied to Program 1 with grass only and 1 ton
each of dolomitic and high calcic lime per acre was applied to
all other programs. Soil samples taken during October 1961
showed marked increases in pH, Ca, and Mg. Extractable Mg
was 86 pounds per acre from clover-grass programs and 37
pounds per acre from the grass program. Potash (K20) values
increased slightly from 1960 through 1964, demonstrating the
conservation effect of pH and Ca on potassium (K).
The data for phosphorus (P) are not conclusive, but with
the 1960 depression in soil pH there appeared to be an increase
in extractable phosphate (P205) and a decrease in total P205.
Apparently the pH had reached a critical point where P, which
had accumulated in aluminum and calcium forms, was solubil-
ized and leached from the soil. After lime was applied in 1961,
total soil P205 increased, the rate of increase being dependent
upon the amount of P20, applied on the program.
Lower forage yields from clipping plots were obtained from
Program 2 than from Programs 3, 4, and 5 (Table 7). There
is the possibility that a slight deficiency of P or K existed, since
the annual fertilizer application for Program 2 was only 300
Il.i.l,,1- of 0-10-2,-' per acre. However, the residual levels of
K20 increased in 1962 and 1964. These residual levels with 60
pounds annual K20 application should essentially supply the
needs of the clover and grass under grazing conditions (2).
Residual extractable soil P205 also was in the range reported
.,d-.iou.te for fr,-..1 (8).
Nutrient Distribution in Soil Profile.-Soil profile samples
were taken to depths of 21 inches in January 1961 from selected
locations to determine the effect of treatments on pH, organic
matter, and nutrient concentrations. In Pr.yL-riiui 1, N was ap-
plied three times during the summer of 1960, and P205 and
K2O in April 1960. Phosphate and K20 were applied in October








TABLE 5. pH, ORGANIC MATTER, AND AMMONIUM ACETATE (pH 4.8)
EXTRACTABLE NUTRIENTS IN SELECTED SOIL PROFILES
Profile Organic Extractable Nutrients
Sample Depth pH Matter K20 P20O Ca

Inches % ppm ppm ppm
1 0-1O- 5.8 5.4 188 24 840
1-1 5.9 3.9 94 16 780
1-3 5.8 3.7 99 3 680
3-6 5.4 2.8 9 1 320
6-9 5.0 9 0 30
9-14 5.1 7 1 0
14-21 5.3 5 1 0
5 F 0-1/' 5.4 15.5 398 227 2080
-1 5.5 8.1 301 165 1360
1-3 5.8 2.6 154 69 740
3-6 5.3 1.7 87 19 370
6-9 5.0 38 13 250
9-14 4.9 24 7 100
14-21 5.0 57 7 40
5a$ 0-/2 5.4 5.7 256 54 1040
1/2-1 5.2 5.2 156 63 740
1-3 5.0 4.4 138 30 620
3-6 4.8 3.6 92 17 480
6-9 4.2 24 5 130
9-14 4.5 7 3 20
14-21 4.6 7 0 0
t Samples l.and 5 were from pastures established in 1952.
$ Sample 5a was from a pasture established in 1958.

1960 for Program 5. Samples 5 and 5a were taken from Pro-
gram 5, but sample 5 represented an area that had been in
pasture for nine years while sample 5a had been in pasture for
only three years. Data are reported in Table 5. After nine years
of surface liming and fertilization there was little measurable
effect on the soil below the 6-inch depth. An estimate of the
total profile contents of Ca, P, and K showed substantially
smaller quantities of these elements present than had been ap-
plied. They were aipii:Ir.-iltly removed by leaching with very
little retention below 6 inches in the profile. The high concen-
trations of P205 and Ca in the top inch of soil suggest that pas-
ture renovation may be advantageous from the standpoint of
distributing nutrients through the plant rooting zone.

Summary
Organic matter in the top 6 inches of soil under undisturbed
clover-grass sods increased from 2.r2'. in 1958 to 3.2',. in
1964. This change was highly significant. The average level in
1951 at the initiation of the pasture programs was 2.25%. Soil







N in the surface 6 inches also increased significantly under both
grass and clover-grass sods. There were no changes below the
6-inch depth.
The soils gradually became more acid, and by 1960 the pH
had declined to 5.3 or lower. This was below the critical point
for P retention and resulted in some leaching loss of P which
had accumulated from fertilization during the previous several
years. One ton of high calcic lime per acre was applied to Pro-
gram 1, and 1 ton each of dolomitic and high calcic lime was
applied to the clover-grass programs in 1961. Soil analysis
indicated a level of 35 pounds of Mg per acre, and supplementary
small plot experiments had shown possible clover-grass yield
response from Mg under these conditions.
Although forage yield from Program 2 as determined by
harvesting forage from caged areas was less than from the
other clover-grass programs, previous work and current KO2
and P205 analyses indicate that these two nutrients were prob-
ably in adequate supply, particularly after reliming in 1961.

AGRONOMIC STUDIES
Methods
Agronomic data collected during the period of October 1,
1957, through September 30, 1964, were primarily green and
oven-dry yields of forage for each year with chemical analyses
for the years 1960, 1961, 1962, and 1964. The botanical com-
position was determined for the 1958 and 1964 seasons.
Forage.-Forage yields were determined from mowed sam-
ples taken from caged areas within each pasture at approxi-
mately 30-day intervals during the growing season. Two cages,
5 x 10 feet, were located in each pasture within a 30-foot radius
of permanently marked posts. These markers made it possible
to collect forage and soil samples from the same area and made
possible the determination of correlations between herbage
yields, forage composition, and soils data. Mower strips 3.33
by 10 feet were cut through each caged area for the forage
samples. From 5 to 7 samplings of forage were made each
season. Sub-samples of 2 to 3 pounds each were taken from the
fresh cut material and dried in a heated forced air drier at
135 F. Oven-dry weights were determined, and the samples
were then ground in a Wiley Mill for chemical analyses. The
botanical composition of each program and pasture area was
determined in 1958 at the beginning of this phase and again in








1964 at the conclusion of the experiment. Ground cover, per cent
of the original planted grass present, other grasses, weeds, and
per cent clover stand were noted.
Fertilization.-Program numbers, total acres per program,
pounds of 0-10-20 fertilizer mixture per acre, and pounds N per
acre are shown in Table 1.
The 0-10-20 fertilizer was applied in a single application
annually during the fall for Programs 2 through 5, since these
were grass-clover programs. Program 1, which was exclusively
grass, received the mixed fertilizer in the spring. Nitrogen was
applied in the spring and summer. During the 1959 season only
half of the pastures in Programs 3, 4, and 5 received N and
then only at a rate of 60 pounds per acre. From 1960 through
1964 N was not applied to any of the clover-grass programs.
At the end of the 1960 season it was decided to eliminate N
fertilization of Programs 3, 4, and 5, since for two years no
beneficial results were noted.
Dolomitic and high calcic limestone was applied to all pas-
tures as results of soil tests and plant composition indicated a
need.
Botanical Composition.-Visual quadratic sampling of forage
grass species was made in early November, 1958 and 1964, and
for clover in April, 1958 and 1964. Ground cover, percentage
of several grass species, and per cent clover stand were esti-
mated for each pasture.
Climatic Records.-Rainfall and temperature recordings were
made at the Beef Research Unit headquarters during the 1957-
64 period.
Precipitation for 1961-63 was somewhat low, which may have
adversely affected the total quantity of forage but at the same

TABLE 6. AVERAGE ANNUAL RAINFALL AND MINIMUM
TEMPERATURES DURING STUDY
Annual
Period t Rainfall Minimum Temperature

Inches Month "F
1957-58 54.06 Dec. 16
1958-59 63.48 Jan. 20
1959-60 50.73 Jan. 18
1960-61 53.67 Dec. 22
1961-62 39.75 Dec. 16
1962-63 47.48 Dec. 11
1963-64 64.00 Jan. 20
t October 1 through September 30.







time allowed for slightly better quality. Clover survival and
growth were also hindered by this rather extended dry period.
Temperatures were generally favorable for forage produc-
tion during the trial. There were no unusually high tempera-
tures; however, on several occasions low temperatures delayed
winter clover growth. The 1962-63 season was the coldest, with
December, January, February, and March having temperatures
below 30 F. Clover growth was late during this season. Low
temperatures coupled with low rainfall during April and early
May resulted in low yields of clover, which also affected the
subsequent grass growth. Average annual rainfall and mini-
mum temperatures are shown in Table 6.

Results
Oven-dry forage yields for each program are shown in Table
7. Forage yields from Programs 2, 3, 4, and 5 were somewhat
below average for the 1962-63 season because of severe and
extended cold periods with temperatures below freezing. Yields
from the all-grass Program 1, however, were above average,
probably because N application and rainfall were adequate for
grass, but not for clover. Clipping plots from Program 2 con-
sistently produced less weight of forage than plots from the
other programs. The cause may have been that the 300 pounds
per acre of 0-10-20 fertilizer applied annually was insufficient
to support maximum forage production. Carrying capacity and
performance of cattle on this program under the procedures of
this trial, however, were comparable to that of other programs.
Nitrogen applied to clover-grass pastures during the 1958
and 1959 seasons appeared to have no effect on forage yields.
Only 60 pounds of N per acre were applied to half the clover-
grass pastures during the 1959-60 season, and all N was with-
held during the 1961 through 1964 seasons.
The all-grass pastures in Program 1 produced total annual
forage yields equal to the best clover-grass pastures. The rate
of N was reduced from 180 to 120 pounds per acre in Program
1 for the 1962, 1963, and 1964 seasons with no apparent reduc-
tion in forage yield. Because of the reduction in stand of pan-
golagrass and Coastal bermudagrass, bahiagrass predominated
by 1962. Certain other varieties would have been expected to
respond to the higher level of N.
Per cent of crude protein in oven-dry forage from all pro-
grams is shown in Table 8. Because the extended cold weather








TABLE 7. OVEN-DRY FORAGE YIELDS
Program
No. 1958 1959 1960 1961 1962 1963 1964 Avg.

Lb./A/Yr.

1 7344 7207 6951 8877 7781 8247 7786 7742
2 6279 8618 5317 6622 5288 4907 5254 6041
3 8048 10939 6544 8532 6513 6398 6959 7705
4 7932 9198 7068 8504 7007 6505 7582 7685
5 7788 11375 7155 8428 7475 6128 6864 7888




TABLE 8. PER CENT PROTEIN CONTENT OF OVEN-DRY FORAGE
Sample Dates
Year: 1959 1960 1961 1962 1964 Season Avg.
Program
No. Date: 4-7 8-3 5-5 7-12 9-20 5-11 6-28 10-3 6-13 7-10 9-24 4-29 6-30 9-28 Early Mid Late

1 11.2 10.0 17.1 8.9 8.9 17.0 8.8 9.2 16.0 10.1 9.7 18.0 7.2 11.1 15.9 8.8 9.8
2 25.8 10.1 21.1 12.2 9.9 19.6 13.4 10.1 15.1 10.2 8.8 21.8 8.8 9.8 20.7 11.2 9.7
3 26.1 11.6 15.6 11.2 9.6 19.6 12.8 9.7 16.9 11.0 8.9, 22.8 10.9 9.9 20.3 11.5 9.9
4 22.8 10.3 17.9 12.0 9.8 21.1 13.6 9.0 15.0 10.7 8.8 22.6 10.0 11.2 19.9 11.6 9.8
5 24.7 11.6 14.9 12.5 10.1 19.9 13.0 9.5 14.2 10.5 9.2 22.4 11.7 9.2 19.2 11.9 9.9







in late 1962 and early 1963 resulted in little early spring growth,
forage samples were not analyzed for the 1963 season. Forage
samples were collected in April or May, in June or July, and in
September or October for chemical analyses. These were termed
early-, mid-, and late-season forage samples. Only early- and
mid-season samples were analyzed in 1959. Early-season samples
consisted largely of clover and had a crude protein concentration
of 18.0% to 22.8%; mid-season samples contained less clover
and averaged from 7.2% to 11.7%, while late-season forage
averaged from 9.8% to 9.9%. Program 1 had no clover, and the
forage protein content was dependent upon stage of growth and
time lapse following N fertilization. Early and mid-season pro-
tein was less in forage from the N-fertilized Program 1 than it
was in the clover-grass programs.
The average crude protein of forage samples for each year is
shown in Table 9. Since only two sample dates were used for
protein analyses in 1959, the average protein composition for
the entire period covers only 1960 through 1964. Forage from
the all-grass Program 1 averaged 11.8% crude protein for this
period, while forages from Programs 2 through 5 (clover-grass)
averaged 13.1% to 13.5% crude protein. Thus, the rate and
distribution of N applied in Program 1 did not result in forage
with protein equivalent to that from Programs 2, 3, 4, and 5,
which received no N, but did have clover.
Composition of forage in terms of feed constituents is shown
in Tables 10 and 11 for forage harvested in 1964. Table 11
shows the effect of season on quality of forage in terms of crude
fiber, ether extract, N free extract, ash, and crude protein con-
tent. The all-grass pastures (Program 1) produced forage higher

TABLE 9. ANNUAL AVERAGE CRUDE PROTEIN CONTENT
OF OVEN-DRY FORAGE t
Program
No. 1959 1960 1961 1962 1964 Average
% % % % % %
1 10.6 11.6 11.7 11.9 12.1 11.8
2 17.9 14.4 14.4 11.4 13.5 13.4
3 18.9 12.1 14.1 12.3 14.5 13.2
4 15.6 13.2 14.6 11.5 14.6 13.5
5 18.2 12.5 14.1 11.3 14.4 13.1
t These values represent arithmetic averages and are not weighted for quantity of
forage produced.
$ Samples for 1959 included only two harvest dates and were not included in 1960-64
average.







TABLE 10. PROXIMATE FEED ANALYSIS OF 1964 FORAGE f
Program
Constituent 1 2 3 4 5
% % % % %
Crude fiber 32.4 30.5 30.5 30.9 30.2
Ether extract 1.8 1.8 1.9 1.8 1.9
Nitrogen F. E. 48.4 49.0 47.5 46.0 46.2
Ash 5.3 5.4 6.6 6.8 7.2
Crude protein 12.1 13.5 14.5 14.6 14.4
t Values shown are unweighted arithmetical average for all clipping dates.

in crude fiber during early and mid-season growth periods than
the programs with grass and clover in combination. The ash
content of the forage was highest in the heavily fertilized clover-
grass Program 5.
The P, K, Ca, Mg, and sodium (Na) content of the forage
is shown in Table 12. The P, Ca, Mg, and Na contents of forage
from Program 1 were lower than those from any other pro-
gram. A fall application of dolomitic limestone in 1960 was
followed by an increase in Ca and Mg in the forage in 1961 and
subsequent years. The K content of the forage was in direct
relation to the applied K. All minerals were present in the
forage in sufficient quantities for normal plant development and
for cattle feed.
The botanical composition was determined at the start of
Phase 2 of the experiment in 1958 and at its conclusion in 1964
(Table 13). Areas planted to pangolagrass in 1952 had less
than a 50 % stand in 1958, and little if any pangolagrass sur-
vived until October 1964. Pensacola bahiagrass pastures main-
tained a near perfect stand during the experimental period.
Bermudagrass pastures established in 1955 were largely invaded
by other grasses. Coastal bermudagrass pastures planted in
1957-58 are still largely bermudagrass. Pensacola bahiagrass
has increased in all pangola and bermuda pastures. Carpetgrass
(Axonopus affinis Chase) and vaseygrass (Paspalum urvillei
Steud.) increased during some seasons but did not appear to be
a problem. Weeds were not a serious problem except at certain
seasons of the year. Smutgrass (Sporobolus poiretil Roem and
Schult.) and water sedge (Cyperus spp.) along with dog fennel
(Eupatorium spp.) were the most serious weeds. The herbicide
2-4D was applied several times to Program 1 pastures to elimi-
nate volunteer clover.























Constituent

Crude fiber
Ether extract
Nitrogen F. E.
Ash
Crude protein


TABLE 11. SEASONAL COMPOSITION OF 1964 FORAGE

Per Cent Composition by Program and Season
1 2 3 4 5
4-29 6-30 9-28 4-29 6-30 9-28 4-29 6-30 9-28 4-29 6-30 9-28 4-29 6-30 9-28

28.4 35.6 33.2 24.4 33.5 33.6 24.2 33.2 34.0 24.6 34.0 34.0 24.0 33.2 33.5
2.3 1.7 1.5 2.2 1.7 1.5 2.3 1.9 1.5 2.3 1.7 1.5 2.6 1.8 1.4
44.6 51.0 49.6 43.8 51.9 51.3 41.1 48.4 50.0 40.7 48.7 48.5 39.8 47.4 51.3
6.7 4.5 4.7 7.8 4.1 4.4 9.5 5.7 4.7 9.8 5.5 5.0 11.1 5.9 4.6
18.0 7.2 11.1 21.8 8.8 9.8 22.8 10.9 9.9 22.6 10.0 11.2 22.4 11.7 9.2








TABLE 12. MINERAL CONTENT OF FORAGE ON OVEN-DRY SAND-FREE BASIS t


Mineral
and Year


Phosphorus
1960
1961
1962
1964
Ave.
Potassium
1960
1961
1962
1964
Ave.
Calcium
1960
1961
1962
1964
Ave.
Magnesium
1960
1961
1962
1964
Ave.


Program
1 2 3

% %0 %
0.29 0.35 0.32
0.26 0.30 0.30
0.28 0.31 0.34
0.28 0.29 0.34
0.28 0.31 0.32


Sodium
1960 -
1961 0.07 0.14 0.13 0.12
1962 0.05 0.07 0.06 0.04
1964 0.05 0.06 0.06 0.06
Ave. 0.06 0.09 0.08 0.07
t Values shown are unweighted avera-es of three clippings per year.


Summary
The application of 500 pounds per acre of 0-10-20 fertilizer
annually on clover-grass pastures resulted in forage yields from
clipping plots nearly as high as larger amounts and a higher
yield than from applying 300 pounds.
Supplemental N did not influence yield or chemical compo-
sition of the forage from clover-grass programs, suggesting
that N fixation by clover was adequate to support near-maximum
forage production.
Mixed fertilizer including N applied to grass pastures in
Program 1 resulted in the protein content of the forage being
at a favorable level, and forage yields were satisfactory. Little
difference was noted between 180 and 120 pounds in N in terms
of forage yield.







TABLE 13. BOTANICAL COMPOSITION OF PASTURES
1958 AND 1964t


Pasture Total
No. Plant Species Ground Cover


11A
11B
11C
12A
12B
12C
21A
21B
21C
21D
21E
21F
22A
o 22B
22C
22D
22E
22F


Bahia
Bermuda
Pangola
Bermuda
Bahia
Pangola
Pangola
Bahia
Bermuda
Bermuda
Bahia
Pangola
Bahia
Bermuda
Pangola
Bahia
Bermuda
Pangola
Bahia
Pangola
Bermuda
Bahia
Bermuda
Pangola
Bahia
Pangola
Bermuda
Bahia
Bermuda
Pangola


100-100
100-100
100-100
100-100
100-100
100-100
100-100
100-100
100-100
95-90
100-100
100-100
100-100
100-100
100-100
100-100
100-100
100-100
100-100
100-100
100-100
100-100
95-100
95-100
100-100
100-100
100-100
100-100
100-100
95-90


Cover by Plant
Bahia Bermuda Pangola Other Weeds Clover


98-95
98-95
40-85
40-80
98-98
30-55
65-80
100-100
25-40
20-4
100-100
35-87
90-37
15-55
40-60
90-85
20-45
35-38
90-87
75-87
65-55
90-85
90-98
70-75
85-78
80-83
50-50
70-65
50-55
40-37


55-15

15-25
5-10

55-35
80-41


75-25


65-15
5-30


15-35
5-15
5-0


2-5
40-30
2-8
20-13


10-10


45-10
25-0


30-0

30-0





11-3

10-5


20-25


5-5

7-10
20-25

10-30
15-22

15-0
10-0
5-0
3-0
10-12
10-17
2-2
2-10
25-20
15-22
25-30


SFirst value shown is for 1958; the second for 1964. Grass, weed and ground cover were determined on November 4;


2-5
2-5
-5
5-5
-2
10-10
5-10
T-T
T-T
T-17
T-T
5-8
10-13
3-10
10-15
10-15
5-10
15-10
10-13
10-13
10-10

-2
9-10
5-5
6-5
8-10
3-7
15-10
23-15
clover density


2-5
0-5
4-10
1-6
0-1
2-9
75-77
80-70
70-39
60-65
70-65
92-95
75-80
80-73
75-77
90-90
85-85
90-93
70-65
-73
-75
-87
-90
75-73
80-87
70-70
70-75
70-75
80-85
98-98
on April 15.












Total
Ground Cover


100-100
95-90
90-95
100-100
80-95
85-100
95-100
95-90
100-100
95-90
95-100
100-100
100-100
98-100
99-100
100-100
100-100
90-85
90-75
95-100
100-100
95-100
100-100
95-100


TABLE 13. Continued
Cover by Plant
Bahia Bermuda Pangola Other


95-94
35-50
55-70
95-95
40-85
50-77
35-50
20-45
95-95
60-85
50-90
100-100
35-55
15-33
100-100
10-20
85-75
30-40
50-65
95-90
15-25
5-3
90-80
35-43


45-30


35-7

55-45


5-5
40-10

60-40
75-60

80-70
10-10
10-10
10-10

70-60
90-87

5-0


25-10


15-0

40-15

20-0


3-3
10-5
10-5
5-5
10-3
20-10
5-0
20-5
5-5
10-5
5-0


41A
41B
41C
41D
41E
41F
42A
42B
42C
42D
42E
42F
51A
51B
51C
51D
51E
51F
52A
52B
52C
52D
52E
52F


Weeds Clover


2-3
10-15
10-15

15-5
15-13
5-5
20-35

5-5
5-0


Bahia
Bermuda
Pangola
Bahia
Bermuda
Pangola
Bermuda
Pangola
Bahia
Pangola
Bermuda
Bahia
Pangola
Bermuda
Bahia
Bermuda
Bahia
Pangola
Pangola
Bahia
Bermuda
Bermuda
Bahia
Pangola


85-83
85-77
92-70
90-70
95-87
85-77
80-78
90-93
92-99
90-85
85-83
90-78
80-75
87-73
95-95
91-90
95-92
95-98
95-95
92-90
80-75
90-87
95-93
-83


Pasture
No.


Plant Species


5-15
20-25
10-18
5-10
10-12
5-10
10-20
20-35


10-10

20-20
9-5

5-3


25-17






Clover in combination with grass resulted in a more uniform
distribution of forages than grass alone.
Dolomitic limestone applied in the fall resulted in increased
Ca and Mg content of the forage during the following season.
White clover was successfully maintained without reseeding in
all species of grass pastures during this experiment.

IRRIGATION STUDIES
Methods
Program 5, consisting of two replications of clover-grass
pasture, was irrigated. A medium pressure, portable pipe
sprinkler irrigation system was used to distribute water over
the pastures. Approximately three days of operating time was
required for each irrigation of the 24 acres in Program 5. Irri-
gation was obtained from both shallow and deep wells.
The irrigation management procedure for determining the
time to begin a cycle and the frequency of subsequent cycles
was based on soil moisture content and estimated evapotranspi-
ration. An irrigation cycle was begun when the soil moisture
content reached a level where the average soil moisture defi-
ciency below field capacity in the top 18-inch layer of soil was
equivalent to a depth of 1 inch of water. Subsequent cycles were
started when the soil moisture deficiency was computed to be 1
inch of water. Computations were based on evapotranspiration

TABLE 14. ESTIMATED AVERAGE DAILY EVAPOTRANSPIRATION BY MONTHS

Gainesville Estimated Daily
Month Mean Temperature Water Use t
SF Inches
January 58.05 .11
February 59.15 .12
March 64.20 .13
April 69.35 .15
May 75.50 .17
June 79.80 .18
July 80.75 .19
August 81.00 .19
September 79.10 .17
October 72.15 .15
November 63.45 .13
December 58.25 .11
Computation based on McCloud's Evapotranspiration Formula, KWT-32 where K =: 0.07,
W = 1.02 and T = monthly mean temperature.







rates as shown in Table 14. Cycles were continued until inter-
rupted by a significant amount of rainfall.
To measure the moisture content of the soil in the pastures,
six cores of soil extending from the surface to a depth of 18
inches were removed from random locations and analyzed for
moisture content by the oven-drying method. Frequency of
sampling was based on judgements derived primarily from the
physical appearance of the soil and pasture plants.

Results
Average values of physical properties of the soil which relate
to irrigation management were as follows: bulk density, 1.50
g/cc; total pore space, 42.29% ; non-capillary pore space, 30.00% ;
moisture content, 50 cm water tension, 8.24% (moisture equiv-
alent) ; moisture content, 100 cm water tension, 4.85%; and
moisture content, 15 atm tension, 2.68% (wilting percentage).
The average moisture content of the top 18-inch layer of soil
was estimated to be 4.46% when the soil moisture deficiency
below field capacity was equivalent to 1 inch of water.
From one to five applications of water were required per
year to supplement rainfall. Most of the applications were made
in May and June, with occasional applications being made in
April, September, and October. Table 15 shows the annual rain-
fall and the number of irrigation applications for each year
of the study. The data for yield and composition of forage are
summarized in Tables 7 and 11. Animal response data are shown
in Table 16. These data show that forage production and growth
rate of calves on the irrigated pastures (Program 5) were
slightly superior to that of the other clover programs, but not

TABLE 15. RAINFALL AND IRRIGATION BY YEARS

Irrigation
Year t Rainfall Applications I
Inches Number
1957-58 54.06 4
1958-59 63.48 2
1959-60 50.73 1
1960-61 53.67 1
1961-62 39.75 5
1962-63 47.48 2
1963-64 64.00 3
t October 1 to September 30.
$ Based on an estimated application efficiency of 80%, a net of 1.00 inch of water was
applied at each application.







enough to pay for the added costs of irrigation (Table 21).
These results confirm those from Phase 1 of the study (7).

Summary
It appears, from the results of two trials on this area where
moisture conditions are naturally favorable for clover produc-
tion, that irrigation of flatwoods pastures with a portable pipe
sprinkler irrigation system contributes little in increased pro-
duction and is uneconomical. More frequent irrigations possibly
would result in higher forage yields, but probably would not
improve the economic feasibility of this method of irrigation
on flatwoods pastures. In this type of situation, high irrigation
costs are inevitable with a portable-type sprinkler system be-
cause of the frequent water applications and, consequently,
frequent pipe moves that are required to maintain a high level
of soil moisture in flatwoods soils during extended drought
periods. Also, high irrigation costs are not usually justified for
relatively low value crops such as a pasture that is used for
producing beef with a cow-calf production system. For irriga-
tion of beef cattle pastures to be economically feasible, less
costly methods of irrigation must be used.

ANIMAL RESPONSE
Methods
As in the preceding phase of the project, pasture programs
were evaluated by grazing with cows and calves (7). Produc-
tivity of pastures was measured by carrying capacity, weaning
rate, weight, and market value of the calves produced on the
program. The cattle were utilized also in a breeding study which
was incomplete at the end of Phase 2, and will be reported later.
Approximately equal numbers of animals from each of six
breeding groups were grazed on each pasture program. The
data reported in this bulletin were the least squares averages
for the six breeding groups.
Stocking Rates.-Arriving at appropriate stocking rates for
evaluating pastures by grazing with animals is frequently a
problem, as was the case in this trial. Facilities were not ade-
quate for testing various stocking rates. Thus, the appropriate
procedure appeared to be that of stocking the different programs
at rates which would result in the forage produced being grazed
at approximately the same intensity with the restriction that
all of the grazable forage be utilized.






The method chosen for this study was to stock each of the
programs at the beginning of the grazing season (February 15
to March 1) with the number of cows estimated to be required
for grazing off all of the forage produced by approximately
December 10. From that date until new grazing became avail-
able the animals were given supplemental feed outside the graz-
ing area. This balance between the lengths of the grazing and
winter feeding periods was estimated to result in maximum net
returns, assuming prevailing cost and production data. Further,
the system provided for utilizing all of the grazable forage by
animals. The additional feed required to support the cattle was
charged against the costs of the program.
The criteria used in estimating the number of animals needed
per program included carrying capacities of different programs
observed during Phase 1 of the study, stocking rate and time re-
quired to graze off forage during the preceding year, yields from
clipping plots, and visual appraisal of the pastures and cattle.
Based on the uniformity of dates at which different programs
were depleted of grazable forage and the small number of ad-
justments in numbers required to achieve uniform grazing, it
appeared that experimental error in stocking rates was no larger
than that from other sources of error such as sampling errors
in pasture site, allotment of cattle, reproduction rate, and death
loss in calves.
.11,,nr,ement Procedures.-The objective was to manage the
pastures and cattle in accordance with the best practices in use
on successful private enterprises, insofar as this objective could
be obtained under experimental conditions. The cattle were
grazed on permanent pastures from March 1 until approximate-
ly December 10, when all of the utilizable roughage had been
grazed off. From this date until the end of the winter period,
all cows were fed silage and 1.0 to 1.5 pounds per head daily of
41% or 60% protein supplement. During the winter of 1960-61
it was necessary to feed a small amount of hay and concentrate
to extend the supply of silage. No supplement was fed on the
clover-grass pastures after February 28. On the all-grass pro-
gram, however, it was necessary to supply supplemental feed
until grass growth was adequate to support the cattle. This date
varied with years from March 31 to May 27, depending on grow-
ing conditions. Other than the supplemental feeding described
above, the cows obtained all of their feed by grazing the experi-
mental pastures.
During periods of short supply of pasture forage (early












TABLE 16. FIVE-YEAR AVERAGE FOR PRODUCTION ITEMS BY PASTURE PROGRAM, 1960-1964

Item Program
1 2 3 4 5
Area in program, acres 32 40 32 32 32
Fertilizer per acre, Ibs.
Nitrogen 120 0 0 0 0
0-10-20 450 300 500 700 900
Stocking rate, acres per cow 1.40 1,33 1.45 1.45 1.33
September cow weight, lbs. 1010 1000 1017 999 1072
Weaning data
Birth rate, % 91.3 96.9 94.2 95.5 98.6
Survival rate, % 97.5 98.0 94.5 96.7 91.3
Weaning rate, % 89.0 95.0 89.0 92.3 90.0
Age at weaning, days 265 267 265 264 262
Market grade, score f 11.3 11.8 11.6 11.6 12.1
Market weight, lbs. 523 539 527 530 542
Calf production per cow, lbs. 1 465 512 469 488 489
Calf production per acre, lbs. ft 332 385 323 336 368

t Score of 11 is equivalent to federal market grade of high good, 12 to low choice.
: Sale weight x weaning rate.
ft Production per cow acres per cow.






spring and winter), the cattle were allowed to graze all of the
allotted area continuously. During periods of more rapid growth,
the cows were confined to approximately one-half of the area
and rotated periodically as judged advisable from visual eval-
uation of the cattle and pastures. There were no indications of
parasitism in the cattle, and other than the rotation described,
no parasite control was practiced; that is, anthelmentics were
not administered.
The cows were exposed to fertile bulls during a 90-day
breeding season extending from March 1 to May 29. All cows
palpated non-pregnant at weaning time were culled and replaced
with pregnant heifers, as were cows which produced calves
with unsatisfactory weaning weights. Calves were weighed and
graded in late August in accordance with previous procedures.
These data were used in computing 205-day weights. The calves
were then turned back with cows until approximately September
30. Market weights on that date were the data used in evaluat-
ing the pasture programs.

Results
Carrying Capacity of Pastures.-The realized carrying ca-
pacities of the five different programs did not differ greatly,
varying from 1.33 to 1.45 acres per cow (Table 16). These acre-
ages do not include approximately 0.13 acres required for pro-
ducing the silage fed during the winter season. The capacities
of certain programs were identical because of the acreages in-
volved and necessity of adding or removing a whole cow at a
time.
These results are in general agreement with those from the
first phase of the study (7), where all clover-grass pastures and
the all-grass program fertilized at the same rate as Program 1
of the present study, all had approximately equal carrying ca-
pacities. Forage yields from clipping plots in the present study
(Table 7) are likewise in general agreement with carrying
capacities except for Program 2, where yields from clipping
plots were low as compared with carrying capacity. Whether
this discrepancy is explained on the basis of experimental error,
or by factors such as distribution of growth or differences in
composition, is not known. It is noted, however, that the carry-
ing capacity of Program 2 has continued into Phase 3 of the
program presently underway.
Production Performance.-The production performance real-













TABLE 17. LEAST SQUARES ANALYSES OF VARIANCE FOR PRODUCTION TRAITS
Mean Squares
Degrees of Birth Sur. Age at Mkt. Gr. Calf Wean Wt. of
Item Freedom Rate Rate Weaning Weight Cow
% % Days Score lbs. Ibs.
Main Effects
Year (Y) 4 13.34 1.59 662 26.48** 55,619** 91,638**
Program (P) 4 9.76 7.39 358 7.99** 6,123* 80,944**
Breed (B) 5 4.17 4.83 1575** 13.68** 82,136** 210,438**
^ Sex on calf (S) 2t 3.50 346 1.74 54,046** 19,801
o00
Interactions
Y x P 16 3.35 2.25 233 1.72 1,295 10,641
Y x B 20 6.69 1.38 265 4.66** 3,022* 7,611
P x B 20 3.67 4.26 409 2.44* 2,010 20,598**
Regression on 1 3.46 0.01 250 65.55** 206,693** 698,817**
Age of dam
Error $ 279 7.13 4.61 397 1.13 2,378 8,955
Degrees of freedom for sex was "2" for all analyses other than birth rate where sex could not be included.
SDegrees of freedom for error was "279" in all analyses except for birth rate and survival rate where they were 557 and 303, respectively.
P 0.05
P = 0.01







ized in the different experimental programs is summarized in
Table 16. The various traits contributing to production per-
formance were analyzed statistically, utilizing the least squares
method outlined by Harvey (6). The variance analyses for the
different production traits are shown in Table 17. Although not
used in evaluating the different pasture programs, weight of
cow is included as a matter of interest in Tables 16 and 17.
Pasture program had a highly significant effect on market
grade of calf and a significant effect on weight of calf, with
Program 1 (all-grass) being low and Program 5 (irrigation)
being high for both traits. These differences are apparently ex-
plained by the quality of forage produced. The apparent low
quality of roughage in all-grass pastures confirms the findings
reported from the first phase of this study (7).
Birth rate in the different pasture programs tended to
parallel weight and grade of calves, although differences in birth
rate for the different programs were not statistically signifi-
cant. The difference in survival rate of calves approached sig-
nificance. Program 5 (irrigation) had the lowest survival rate,
91.3%. This observation confirms results of the first phase of
the study. The increased death loss in the irrigated program
during both phases was the result of more calves dying from
"white muscle" disease. Weaning per cent varied from a low
of 89% in Programs 1 and 3 to a high of 95% in Program 2,
with differences being statistically non-significant.
Production per acre of calf weight was used to evaluate the
productivity of pasture programs. It was determined by carry-
ing capacity of the program, weaning rate, and weight of calves.
This item along with the market grade of calf determined the
gross economic return. Production per acre from Programs 1
through 5 was 350, 385, 353, 367, and 368 pounds, respectively.
The low production per acre for Program 1 was brought
about by both a low weaning rate (89%) and low weaning
weight (523 pounds). These are good production levels but were
less than those of the clover-grass programs. The lower produc-
tion level occurred even though more fertilizer was used and
much more supplemental feed was supplied on this program than
on the higher producing clover-grass programs.
In the clover-grass programs, rate of fertilization did not
significantly influence beef production rate. The program re-
ceiving 300 pounds of 0-10-20 per acre annually produced beef
at a slightly higher rate than those receiving 500, 700, or 900
pounds.







These results were not in complete agreement with forage
yields from clipping plots. Forage yields for Program 2 were
lower than from other clover-grass programs; while in Program
1 where beef production was low, forage yields were high. The
discrepancy involving Program 1 may be explained on the basis
of seasonal distribution of production and quality of feed as
shown by chemical analyses (Tables 8-12). The reason for the
high level of beef production occurring in Program 2 where
caged-area forage yields were low was not apparent from this
study.
Irrigation (Program 5) resulted in a slight increase in birth
rate, market grade, and weaning weight of calves. Survival
rate of calves was low, however, because there was a high inci-
dence of white muscle disease and production per acre was less
than that for Program 2. The experimental site is well adapted
to growth of clover under natural moisture conditions; thus it
is not surprising that beef production was not influenced greatly
by irrigation.

Summary
Beef production did not vary greatly between programs,
although differences were significant statistically. Production
was high on all programs, varying from 350 pounds per acre
for the all-grass program to 385 pounds per acre for the clover-
grass program fertilized at the rate of 300 pounds of 0-10-20
per acre annually. Heavy supplemental feeding on the all-grass
program from approximately December 1 to late April was
necessary to maintain a satisfactory level of production. Vary-
ing levels of fertilization on clover-grass programs did not sig-
nificantly influence beef production, although forage yield from
caged areas was lower for Program 2, fertilized with 300 pounds
of 0-10-20 annually, than for the other clover programs. Irri-
gation by sprinkler system during dry weather resulted in a
slight increase in weight and grade of calves, but this was offset
by a non-significant increase in death loss of calves.

ECONOMIC ANALYSIS
Methods
Costs and returns were calculated for each program. The
experimental data were supplemented with data from other
studies to show approximate costs and returns for the various
programs on commercial operations if the level of experimental








practices were used and similar weaning percentages and calf
weights obtained.
Investment per Acre in Pastures.-In the experiment, the
level of practices followed annually appeared sufficient to main-
tain or improve the pastures. Therefore, in calculating annual
costs, the original costs of establishing the pastures were not
depreciated over a stated number of years. An investment
charge was made to cover the cost of capital invested in estab-
lishing the improved pasture programs. The calculated invest-
ment was $90 per acre for the all-grass pastures and $107
per acre for clover-grass pastures. These amounts were based
on the costs of establishing the pastures in the first phase of the
program as shown in Table 18. A value of $100 per acre was
added to the establishment cost to cover the value of the land
and cost of fencing. It was assumed that pastures on a ranch
would be fenced with barbed wire. A value of $160 per acre
was used as the needed investment in a well and equipment to
irrigate Program 5, which was irrigated by sprinkler irriga-
tion. This was the value used in the first phase of the experi-
ment and was based on the estimated costs of a sprinkler irri-
gation system to irrigate 40 acres.
Method Used in Computing Costs and Returns.-Calculations
were made of the annual costs of maintaining pastures in each
program based on the level of experimental practices used. An
investment charge was included to cover costs of capital invested
in establishing the pastures and the value of land and fences.
Charges were included to cover costs of supplemental feeds and
minerals, depreciation, breeding fees, and other costs of main-
taining the cattle. Prices for items purchased were an average
of those paid by the Experiment Station during the period
1960-1961 to 1963-1964 for items used at the Beef Research
Unit. The value of beef produced was based on the state average

TABLE 18. INVESTMENT PER ACRE IN PASTURES
Program
1 2 3 4 5

Cost of establishing t $ 90 $107 $107 $107 $107
Value of land and fences 100 100 100 100 100
Investment in irrigation
facilities 160
TOTAL $190 $207 $207 $207 $367
t Based on cost of establishing pastures in Phase 1 (6).







price of slaughter calves of various slaughter grades for August
1961, 1962, 1963, and 1964.
Costs, rates, and prices used in calculating costs and returns
are shown in Table 19. Physical quantities of selected inputs
and supplemental feeds and minerals are shown in Table 20.
Cost of Fertilizer and Limestone.--The charge to each pro-
gram for fertilizer and lime was based on the amount applied
and the average price paid for these items (Table 21). Program
1 received 1 ton of high calcic limestone per acre in 1961, and
the clover-grass programs received 1 ton of high calcic limestone
and 1 ton of dolomite per acre. Cost per ton for lime included
spreading and was prorated on a yearly basis.
Pasture Maintenance.-Cost of spreading fertilizer was
charged on a per ton basis. Mowing was charged on a per hour
basis. In each case the rate used was based on the normal time
of commercial operators. The rate charged was assumed to cover
cost of labor, power, and use of equipment. Only those areas
that needed mowing were mowed each year. The per acre charge
for mowing was based on an average of the annual costs ob-
tained by dividing the cost of mowing for each program by the
number of acres in the program.
Cost of Irrigation.-Cost of irrigation was charged on the
basis of the estimated cost of installing and operating equipment
to irrigate 40 acres. From unpublished data of the experiment
station, it was estimated that the fixed cost of maintaining a
sprinkler system was 12% of the investment cost. Cost of opera-
tion depends on the amount of water applied. For a system of
the size assumed, it would require about 11/2 hours to apply an
acre inch of water.
Investment Charge.-The investment charge was based on
6% of the estimated cost of establishing pastures including the
value of land and fences.
Supplemental Feeds and Minerals.-A record was kept of
supplemental feeds and amount of minerals consumed by cows
on each program. As indicated previously, items purchased were
charged at average prices paid by the Experiment Station during
the period 1960-61 to 1963-63. Silage harvested on reserve areas
and fed cows was charged at its equivalent value in terms of
the estimated cost to purchase hay.
The kinds of supplemental feeds fed varied over the period
of the experiment (Table 20). Amounts fed in various years
were multiplied by the prices of feed in Table 19 to calculate








TABLE 19. COST RATES AND PRICES USED IN CALCULATING
ANNUAL COSTS AND RETURNS

Item Unit Cost Unit
Cost Rates
Fertilizer, top dressing, and lime
0-10-20 fertilizer ton $34.32
Ammonium nitrate ton 78.23
Lime t
High calcic limestone ton 5.45
Dolomite limestone ton 8.36
Maintenance operations
Spreading fertilizer ton 5.00
Spreading top dressing ton 10.00
Mowing hour 3.00
Irrigation
Annual cost of maintaining equipment acre 19.20
Cost of operating equipment acre-inch 1.50
Labor acre-inch .75
Feed and minerals
41% cottonseed meal ton 78.22
41% cottonseed meal pellets ton 76.50
Ground snap corn ton 46.17
Dried citrus pulp ton 48.14
60% protein concentrate ton 96.59
Aureomycin crumbles cwt 22.90
Vita-Flak A-10 (10 M units per gm) cwt 56.00
Mineral mix ton 94.60
Alyce cloves hay ton 35.00
Pangola hay ton 40.00
Silage ton 7.50
Miscellaneous costs
Breeding fee per cow 6.00
Labor per cow 3.00
Vet., med., ins., taxes, etc. per cow 2.00
Depreciation per cow 9.00
Interest per cow 9.00
Other per cow 3.00
Prices
State average for slaughter calves in August
Good cwt 22.34
Standard cwt 20.42
Price per program based on mkt. gr. of calves
Program 1 cwt 22.84
Program 2 cwt 23.27
Program 3 cwt 23.28
Program 4 cwt 23.33
Program 5 cwt 23.74
t Includes cost of spreading.

yearly cost per cow. The yearly costs per cow per program
for various classes of feed were averaged and totaled to obtain
the annual cost for supplemental feeds.
Miscellaneous Charges for Cattle.-In the experiment, heifers
for herd replacements were not raised on the experimental pas-








TABLE 20. PHYSICAL QUANTITIES OF SELECTED INPUTS
Program
Item Unit 1 2 3 4 5

Mowing Per acre t hr. .34 .12 .20 .34 .25
Irrigation Per Acre t acre-in. 2.58
Supplemental feeds and
minerals per cow:
1960-61
41% cottonseed meal lb. 254 89 89 89 138
Ground snap corn lb. 563 156 156 156 156
Silage lb. 1715 1715 1715 1715 1715
Alyce clover hay lb. 624 195 173 233
Minerals lb. 42 36 55 43 38
1961-62
41% cottonseed meal lb. 241 75 75 75 75
S 41% cottonseed meal pellets lb. 14 -
Ground snap corn lb. 691 -
Silage lb. 2625 2625 2625 2625 2625
Pangola hay Ib. 410 -
Minerals lb. 42 36 55 43 38
1962-63
41% cottonseed meal lb. 38 74 74 74 74
BRU wintering ration No. 1 lb. 969 -
Silage lb. 2870 2870 2870 2870 2870
Pangola hay lb. 437 -
Minerals lb. 56 48 52 42 68
1963-64
41% cottonseed meal lb. 29 29 29 29 29
60% protein concentrate lb. 90 90 100 100 100
BRU wintering ration No. 8 lb. 171 -
Silage lb. 3010 3010 3010 3010 3010
Minerals Ib. 49 45 43 59 60
t Average for the period 1960-61 to 1963-64.







tures. To obtain cost estimates that approximate a commercial
operation, charges were made on a per cow basis to cover esti-
mated costs of breeding, labor on cattle, veterinary services,
medicines, insurance, taxes, depreciation, interest on investment
in cows, and other costs. The charge for these items was based
on data obtained in a study in Central Florida with the rates
adjusted for increases in costs since 1958 and the better quality
of cows used in the experiment (9). Cows were valued at $150
per head. The interest charge was calculated at 6%.
Production of Beef.-The amount of beef produced on each
program was based on the per cent calf drop that was weaned
and the average market weight of calves at weaning. The calf
crop weaned was 89% for Programs 1 and 3, 95% for Program
2, 92% for Program 4, and 90% for Program 5.
Gross calf weights were reduced by 4% to adjust for normal
shrinkage in marketing. The estimated production of beef per
cow varied from 465 pounds for Program 1 to 512 pounds for
Program 2 (Table 16). The production of beef per acre ranged
from 350 pounds for Program 1 to 385 pounds for Program 2.
Production of beef per acre was not adjusted for supplemental
feeds fed during the winter period, since such feeds were in-
cluded as a cost for the program.

Results
Estimated Financial Returns.-In making a comparison of
financial returns, calculations were made in terms of the require-
ments to carry 100 cows on each of the five programs. Based on
the per cent calf crop weaned and market calf weights, produc-
tion of beef per 100 cows varied from 46,547 pounds for Pro-
gram 1 to 51,205 pounds for Program 2 (Table 21). The value
of beef produced was $10,631 for Program 1 and $11,915 for
Program 2.
The total operating costs per 100 cows for the different pro-
grams were $12,866, $7,606, $8,605, $9,204, and $12,750, respec-
tively, for Programs 1 through 5. Net returns per 100 cows
were -$2,235, $4,309, $2,314, $2,172, and -$1,170, respectively.
Items causing the largest differences in costs between Pro-
grams 1 and 2 were fertilizer, lime, and supplemental feeds
(Table 21). The cost of fertilizer and lime in Program 1 was
a little more than three times that for Program 2. The cost
of supplemental feeds for Program 1 was more than double that
of Program 2, or any of the clover-grass programs. The cost of









TABLE 21. ESTIMATED INCOME AND EXPENSES FOR 100 COW HERDS FOLLOWING PASTURE PROGRAM
SIMILAR TO THOSE AT BEEF RESEARCH UNIT

Program Number
Item 1 2 3 4 5

Number of acres 140 133 145 145 133
Number of calves weaned 89 95 89 92 90
Market weight of calves, etc. 523 539 527 530 542
Pounds of beef produced 46,547 51,205 46,903 48,760 48,780
Price per hundredweight $22.84 $23.27 $23.28 $23.33 $23.74
Income:
Value of beef produced $10,631 $11,915 $10,919 $11,376 $11,580
o Expenses:
Cost of pasture maintenance:
0-10-20 fertilizer $ 1,081 $ 685 $ 1,244 $ 1,741 $ 2,054
Ammonium nitrate 1,993
Lime f 255 306 334 334 306
Total $ 3,329 $ 991 $ 1,578 $ 2,075 $ 2,360
Maintenance Operations:
Spreading 0-10-20 158 100 181 254 299
Spreading ammonium nitrate 255
Mowing 141 50 88 ,148 98
Irrigation:
Fixed cost of equipment 2,554
Operating and labor costs 766
Total direct cost $ 3,883 $ 1,141 $ 1,847 $ 2,477 $ 6,077
Investment charge 1,596 1,652 1,801 1,801 1,652
Total cost of maintaining
pastures $ 5,479 $ 2,793 $ 3,648 $ 4,278 $ 7,729














TABLE 21. CONTINUED

Program Number
Item 1 2 3 4 5

Supplemental feeds and
minerals:
Grain and protein feeds $ 2,309 $ 460 $ 472 $ 472 $ 520
Silage 958 958 958 958 958
l Hay 696 85 75 102
S Minerals 224 195 242 221 241
Totals $ 4,187 $ 1,613 $ 1,757 $ 1,726 $ 1,821
Other costs:
Breeding fees 600 600 600 600 600
Labor on cattle 300 300 300 300 300
Vet., med., ins., taxes, etc. 200 200 200 200 200
Depreciation on cows 900 900 900 900 900
Interest on investment in cattle 900 900 900 900 900
Other costs 300 300 300 300 300
Total costs $12,866 $ 7,606 $ 8,605 $ 9,204 $12,750
Net returns -$ 2,235 $ 4,309 $ 2,314 $ 2,172 -$ 1,170

t Cost for lime is prorated on a yearly basis.







fertilizer for Program 5 was more than twice that of Program 2.
It was estimated that the maintenance and operation of a sprink-
ler irrigation system added $3,320 per 100 cows annually to the
cost of Program 5. Under the experimental conditions of this
trial, irrigation did not result in a significant increase in beef
production. Therefore, it added to the costs but did not add to
returns.
In Table 22 estimated income and expenses for the various
programs were expressed on the basis of amounts per acre, per
cow, per calf weaned, and per pound of beef produced. The value
of beef produced per acre varied from $75.94 for Program 1 to
$89.59 for Program 2. The estimated cost per acre was $91.90
for Program 1 and $57.19 for Program 2. The net return per
acre for Program 3 and 4 was approximately two-thirds that
of Program 2. To irrigate Program 5 with sprinklers cost
$24.96 per acre. The net return for this program was -$8.79
per acre.
Cost per cow varied from $76.06 for Program 2 to $128.66
for Program 1. The value of beef per cow was $106.31 on Pro-
gram 1 but $115.80 on Program 5 because of the higher per cent
calf crop weaned. Net returns per cow were -$22.35 on Program
1 and -$11.70 on Program 5.
The price per hundredweight for beef was calculated at
$22.84 for Program 1, $23.27 for Program 2, $23.28 for Pro-
gram 3, $23.33 for Program 4, and $23.74 for Program 5. Dif-
ferences in price were due to variations in grade of calves. Gross
cost per pound of beef varied from 14.85 cents for Program 2
to 27.64 cents for Program 1. The net returns per pound were
-4.80 cents for Program 1, 8.42 cents for Program 2, 4.94 cents
for Program 3, 4.46 cents for Program 4, and -2.40 cents for
Program 5.

Summary
The experimental data were supplemented with data from
other studies to show the approximate costs and returns for the
various l' -t.ir- programs in commercial operations. Investment
costs included $190 per acre for grass pastures or $207 per acre
for clover pastures. Cows were valued at $150 per head. The
interest rate charged was 6%.
Net return per cow for the non-irrigated clover-grass pro-
grams was $43 for Program 2, $23 for Program 3, and $22 for
Program 4, fertilized annually with 0-10-20 at the rate of 300,







500, and 700 pounds, respectively. The irrigated clover-grass
program had a net loss of $12 per cow because of the high cost
of sprinkler irrigation. The all-grass program had a net loss
of $22 per cow because of a slightly lower production level, high
cost of N fertilizer, and an excessive wintering cost as compared
with the clover-grass programs. Total costs per cow varied from
$76 in Program 2 to $129 for Program 1. These costs emphasize
the necessity of a high level of production for profitable produc-
tion of beef on improved pastures.

GENERAL DISCUSSION OF RESULTS
The last year of the present study concluded 12 years results
from the Beef Research Unit. The first trial, reported previ-
ously (7), included the years 1953 through 1957. This study
included the years 1958 through 1961. The first two years were
transitional, however, and some of the data reported include the
period from 1960 through 1964.
Eight pasture programs were studied during the previous
trial (7). Two of these eight programs (numbers 3 and 5) were
repeated during the present trial as check programs (numbers
1 and 3). Thus, a total of 11 different pasture programs had
been evaluated through 1964.
The two most important conclusions drawn from the first
trial were: 1) that clover-grass pastures fertilized at a moder-
ate rate (600 pounds of 0-12-12 per acre annually) showed a
superiority in economy of beef production over more heavily
fertilized clover-grass programs and a marked superiority over
all-grass programs; and 2) that all-grass programs resulted in
a much lower weaning rate than clover-grass pastures (64% vs.
84%). The present trial was designed to obtain more informa-
tion on production performance on an all-grass program (num-
ber 1) and to extend information on levels of fertilization on
clover-grass programs (numbers 2, 3, and 4). Program 5, a
clover-grass program also, was included to gain additional in-
formation on the effects of sprinkler irrigation.
Results from Program 1, in agreement with the results from
the previous trial, showed that the production of beef on all-
grass pastures was uneconomical. This was due to high costs
for fertilization and supplemental feed, along with a slightly
reduced income as compared with clover-grass pastures. The re-
sults from this and the previous trial suggest that beef produc-
tion on improved all-grass pastures on flatwoods soil in this area













TABLE 22. ESTIMATED INCOME AND EXPENSES PER ACRE, PER COW, PER CALF, AND PER CWT OF BEEF FOR A COMMERCIAL OPERATION
FOLLOWING THE VARIOUS EXPERIMENTAL PASTURE PROGRAMS
Program Number Program Number
Item 1 2 3 4 5 1 2 3 4
per Acre per Calf

beef $75.94 $89.59 $75.30 $78.45 $87.07 $119.45 $125.42 $122.68 $123.65


Expenses:
Fertilizer, top dressing
and lime:
0-10-20 fertilizer
Ammonium nitrate
Lime
Total
Maintenance operations
Cost of irrigation
Investment charge
Total pasture cost
Supplemental feeds and
minerals
Misc. livestock costs
Total costs, $
Net returns, $


7.72
14.24
1.82
23.78
3.95

11.40
39.13

29.91
22.86
91.90
-15.96


5.15

2.30
7.45
1.13

12.42
21.00

12.13
24.06
57.19
32.40


8.58

2.30
10.88
1.86

12.42
25.16

12.11
22.07
59.34
15.96


12.01

2.30
14.31
2.77

12.42
29.50

11.90
22.07
63.47
14.98


15.44
J0-
2.30
17.74
2.99
24.96
12.42
58.11

13.69
24.06
95.86
-8.79


12.15
22.39
2.86
37.40
6.23

17.93
61.56

47.04
35.96
144.56
-25.11


7.21

3.22
10.43
1.58

17.39
29.40

16.98
33.68
80.06
45.36


13.98

3.75
17.73
3.02

20.24
40.99

19.74
35.95
96.68
26.00


18.92 22.82

3.63 3.40
22.55 26.22
4.37 4.41
36.89
19.58 18.36
46.50 85.88

18.76 20.23
34.78 35.55
100.04 141.66
23.61 -13.00


Income:
Value of


5


$128.66













TABLE 22. CONTINUED
Program Number


Item


Income:
Value of beef
Expenses:
Fertilizer, top dressing
and lime:
0-10-20 fertilizer
Ammonium nitrate
Lime
Total
Maintenance operations
Cost of irrigation
Investment charge
Total pasture costs
Supplemental feeds and
minerals
Misc. livestock costs
Total costs, $
Net returns, $


per Cow

$106.31 $119.15 $109.19 $113.76 $115.80 $ 22.84


10.81
19.93
2.55
33.29
5.54

15.96
54.79

41.87
32.00
128.66
-22.35


6.85

3.06
9.91
1.50

16.52
27.93

16.13
32.00
76.06


12.44

3.34
15.78
2.69

18.01
36.48

17.57
32.00
86.05


17.41

3.34
20.75
4.02

18.01
42.78

17.26
32.00
92.04


20.54

3.06
23.60
3.97
33.20
16.52
77.29

18.21
32.00
127.50


43.09 23.14 21.72 -11.70


2.32
4.28
.55
7.15
1.19

3.43
11.77

9.00
6.87
27.64
- 4.80


Program Number
2 3 4 5
per Cwt of Beef Produced

$ 23.27 $ 23.28 $ 23.33 $ 23.74


1.34

.60
1.94
.29

3.22
5.45

3.15
6.25
14.85


2.65

.71
3.36
.57

3.84
7.77

3.75
6.82
18.34


3.57

.69
4.26
.82

3.69
8.77

3.54
6.56
18.87


4.21

.63
4.84
.81
6.81
3.39
15.85

3.73
6.56
26.14


4.46 2.40







will not prove to be economical with present methods of winter-
ing the cow herd and current cost of N fertilizer. Economical
wintering programs to support high levels of production in this
area need serious study. The outlook for cheaper N appears
good. Favorable developments in these two areas would improve
the outlook for economical production on grass pastures.
The results from Programs 2, 3, and 4 confirm the results
from the preceding trial, where clover-grass pastures produced
beef at a profit. Likewise, results confirmed the finding that
fertilization of clover-grass pastures at more than a moderate
rate of 500 pounds of 0-10-20 per acre per year did not increase
production and merely added to costs. Program 2, which was
fertilized at what was considered to be a low rate of 300 pounds
of 0-10-20 per acre annually, produced more beef per acre at
a lower cost than programs fertilized at higher rates. Forage
yields estimated from caged areas, however, showed that Pro-
gram 2 produced less total forage per acre than pastures ferti-
lized at higher rates. This discrepancy possibly may be explained
by experimental error, seasonal distribution of forage pro-
duction, or other factors. Visual observation indicated earlier
growth of clover in the low fertilization program and less com-
petition from weeds, particularly during February and March.
Thus, the results from this trial indicate that once pastures are
well established, from 300-400 pounds per acre of 0-10-20 will
maintain optimum fertility for clover-grass pastures. Since
clipping plots indicated some reduction in total forage produc-
tion at the low level of fertilization, and soils studies showed the
P205 and K20 levels did not increase at this fertilization level,
it is probable that less than 300 pounds of 0-10-20 per acre per
year would not support optimum production, although this is
a point that needs further experimental verification. It is
emphasized that optimum fertilization rates would vary from
location to location because of differences in soil characteristics
rainfall and drainage which in turn would effect retention and
leaching of soil nutrients.
An important feature of this study is the information ob-
tained on the changes in soil nutrients, species composition of
pasture plants, and carrying capacity of permanent pastures
over a period of 12 years. Average values for soil organic mat-
ter, N, P205 and K20 increased during both the first and present
trials. The levels of extractable P205 and K20 remained approx-
imately constant in Program 2 during the present trial, with
increases occurring in other programs. Forage yields, estimated







from clipping plots, fluctuated from year to year depending on
growing conditions. This makes it difficult to establish any trend.
The average production for the last year of the present trial
(1964) was slightly less than that of comparable programs from
1953 through 1957. These data along with stocking rate, sup-
plemental feed required, and production performance lead to
the conclusion that even though there has been some deteriora-
tion in forage species composition, grazable forage production
has remained nearly constant over a period of 11 years.
The deterioration in composition which occurred was due
mainly to the encroachment of "native" species and smutgrass
in areas originally planted to pangolagrass and to bermudagrass
with some encroachment of smutgrass into areas planted to
bahiagrass. Encroachment of the more hardy and less palatable
species into improved pastures is to be anticipated. Periodic
renovation to improve species composition eventually becomes
one of the costs of pasture maintenance. Had there been no
deterioration in the plant population, it is possible that forage
production would have improved with the increase in soil nu-
trients which occurred.
Another significant outcome from the trial was to demon-
strate conclusively that a high level of beef production can be
obtained from flatwoods pastures. The average weaning rate
was 91% and weaning weight was 532 pounds in this trial. Each
was a significant increase over that of the preceding trial and
would be considered excellent in any environment. Gross income
per cow was $112.30 for an income per acre of $84.44.
A study of the data shown in this bulletin demonstrates the
necessity of having a high rate of production and quality of
cattle to command a good selling price if a profit is to be realized
from grazing improved pastures. The procedures used in achiev-
ing the genetic potential in cattle necessary for the production
levels observed will be the subject of a later publication for the
reason that the breeding study is incomplete and some of the
breeding groups have not stabilized.

GENERAL SUMMARY OF EXPERIMENTAL RESULTS
Five pasture programs were evaluated over a 5-year period
in terms of soil nutrients, forage production, animal response,
and economy of beef production with a cow-calf operation.
Pasture programs included all-grass pasture (Program 1) fer-
tilized with 450 pounds of 0-10-20 and 120 or 180 pounds of N







per acre p r year; three non-irrigated clover-grass pastures
(Programs 2, 3, and 4) fertilized, respectively, at the rates of
300, 500, aid 700 pounds of 0-10-20 per acre per year; and an
irrigated cloer-grass iai-tui' (number 5) fertilized at the rate
of 900 pondl of 0-10-20 per acre per year.3 Calf weight pro-
duced per co was 465, 512, 469, 488, and 489 pounds, respec-
tively, for the five programs. Net returns per cow, in dollars,
were -22, 43,. 23, 22, and -12, respectively. The negative eco-
nomic return for Program 1 was due to high costs of fertilizer
and supplemental feed relative to the quantity of beef produced.
The negative return for Program 5 resulted from a high cost
for sprinkler irrigation and no response to increased fertiliza-
tion rate. The favorable return for Program 2 resulted from a
high rate of beef production and a low fertilizer cost. Soil levels
of organic matter, N, P20s, and K20 were maintained or in-
creased during the trial in all programs. There was a gradual
encroachment of smutgrass into the pastures, although forage
production and carrying capacity remained approximately con-
stant.
3 During the first two years of the study, the four clover-grass programs
were treated respectively with 0, 60, 120, and 180 pounds of N. No bene-
ficial response to N on the clover-grass programs was observed, and the
higher levels of N resulted in encroachment of weeds. After 2 years, N
application on the clover-grass programs was deleted. The animal response
data and economic evaluation of the programs include only the last 5 years
of the study, after deletion of N application on the clover-grass pastures.







ACKNOWLEDGMENTS
Personnel in addition to the authors who were closely associated with
the project included Dr. T. J. Cunha, then Head, Department of Animal
Science (now Chairman); Dr. F. H. Hull, then Head, Department of
Agronomy; Dr. F. B. Smith, then Head, Soils Department; Dr. D. T.
Kinard, then Head, Department of Agricultural Engineering (now Pro-
fessor and Agricultural Engineer); Dr. H. G. Hamilton, then Head,
Department of Agricultural Economics; Dr. J. R. Beckenbach, then Direc-
tor, Agricultural Experiment Stations; Dr. J. W. Sites, then Associate
Director (now Dean for Research); Dr. H. H. Wilkowske, then Assistant
Director (now Assistant Dean); and G. R. Freeman, Assistant Director.
These personnel and the authors composed the coordinating committee
for the Beef Research Unit. The committee met monthly and was presided
over by the Chairman of the Department of Animal Science. The Project
Leader from Animal Science served as the executive representative of the
committee and supervised operation of the project.
Special acknowledgment is made to R. W. Rainey and F. L. Burgess,
Herdsmen. To them goes much of the credit for operating the Beef Re-
search Unit in a successful manner.


LITERATURE CITED

1. Blue, W. G., N. Gammon, Jr., and H. W. Lundy. 1961. Late summer
fertilization for winter forage in north Florida. Soil and Crop Sci.
Soc. Fla. Proc. 21:56-62.
2. Blue, W. G., and N. Gammon, Jr. 1963. Differences in nutrient re-
quirements of experimental pasture plots managed by grazing and
clipping techniques. Soil and Crop Sci. Soc. Fla. Proc. 23:152-161.
3. Blue, W. G., N. Gammon, Jr., and H. W. Winsor. 1964. Accumulation
of organic matter and nitrogen in flatwoods soils planted to white
clover-grass pastures. Soil and Crop Sci. Soc. Fla. Proc. 24:20-26.
4. Blue, W. G., C. F. Eno, N. Gammon, Jr., and D. F. Rothwell. 1964.
Timing liming applications to obtain maximum beneficial effects in
clover-grass pasture establishment on virgin flatwoods soils. Soil and
Crop Sci. Soc. Fla. Proc. 24:162-166.
5. Gammon, Jr., N. and W. G. Blue. 1968. Rates of calcium loss and
production of clover-grass herbage at four lime levels on Leon fine sand.
Soil Sci. 106:369-373.
6. Harvey, W. R. 1960. Least squares analysis of data with unequal
subclass numbers. ARS-20-8. USDA Agr. Res. Ser.
7. Koger, M., W. G. Blue, G. B. Killinger, R. E. L. Greene, H. C. Harris,
J. M. Myers, A. C. Warnick, and N. Gammon, Jr. 1961. Beef produc-
tion, soil and forage analyses, and economic returns from eight pasture
programs in north central Florida. Fla. Agr. Exp. Sta. Bul. 631.
8. Neller, J. R., H. W. Lundy, and D. W. Jones. 1965. Relation between
soluble phosphorus in fertilized soils and growth response of pasture
forage. Fla. Agr. Exp. Sta. Bul. 558.
9. Reuss, L. A. 1958. Cost of clearing and establishing pastures in
Central Florida. Fla. Agr. Exp. Sta. Bul. 600.
10. Volk, G. M. 1961. Gaseous loss of ammonia from surface applied
nitrogenous fertilizers. Agr. and Food Chem. 9:280-283.




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