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 Introduction
 Experimental procedures
 Results
 Discussion
 Summary, acknowledgements, and...
 Table 2. The effects of potash...
 Historic note






Group Title: Mimeo report - Indian River Field Laboratory (University of Florida) ; 62-1
Title: Yields and quality of pangolagrass resulting from different fall dates of fertilization with ammonium nitrate and muriate of potash
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Permanent Link: http://ufdc.ufl.edu/UF00056010/00001
 Material Information
Title: Yields and quality of pangolagrass resulting from different fall dates of fertilization with ammonium nitrate and muriate of potash
Series Title: Indian River Field Laboratory mimeo report
Physical Description: 7 leaves : ; 28 cm.
Language: English
Creator: Kretschmer, Albert E ( Albert Emil ), 1925-
Ray, Howard E ( Howard Eugene ), 1926-
Hortenstine, Charles C ( Charles Carpenter ), 1919-
Indian River Field Laboratory
Publisher: Indian River Field Laboratory
Place of Publication: Fort Pierce Fla
Publication Date: 1962]
 Subjects
Subject: Pangolagrass -- Field experiments -- Florida   ( lcsh )
Pangolagrass -- Fertilizers -- Florida   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographical references (leaf 5).
Statement of Responsibility: Albert E. Kretschmer, Jr., Howard E. Ray, and Charles C. Hortenstine.
General Note: Caption title.
General Note: "February 1962."
 Record Information
Bibliographic ID: UF00056010
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 69244039

Table of Contents
    Introduction
        Page 1
    Experimental procedures
        Page 1
    Results
        Page 2
    Discussion
        Page 3
        Page 4
    Summary, acknowledgements, and literature cited
        Page 5
    Table 2. The effects of potash fertilization on pangolagrass dry weight yields, dry matter and protein contents, crude protein removed and utilization of the nitrogen applied
        Page 6
        Page 7
    Historic note
        Page 8
Full Text


I O. 6'2 -I ...

Indian River Field Laboratory Mimeo Report 62-1 February 1962

YIELDS AND QUALITY OF PANGOLAGRASS RESULTING FROM DIFFERENT FALL DATES
OF FERTILIZATION WITH AMMONIUM NITRATE AND MURIATE OF POTASH

Albert E. Kretschmer, Jr., Howard E. Ray and Charles C. Hortenstine 1/2


INTRODUCTION

Cattlemen and dairymen are interested in knowing the amount of production
that may be expected from fertilization of grasses in the fall months, in order
that they may determine, under conditions of pasture stress, if additional forage
can be economically obtained from fall fertilization. To determine the effects
of different dates of fall fertilization on the growth and quality of pangola-
grass, four separate experiments were conducted on Immokalee fine sand.


EXPERIMENTAL PROCEDURES

One experiment was completed in 1956, two in 1957, and one in 1960. Plot
sizes ranged from 10 by 10, to 12- by 20 feet, and either a randomized block or
split-plot design was used.

Nitrogen, phosphorus, and potassium were supplied in all instances as
ammonium nitrate, 20C5 superphosphate, and muriate of potash, respectively.
In some of the tests phosphorus was omitted because soil tests and the previous
fertilization history indicated that sufficient phosphorus was present in the
soil. In other tests phosphorus was applied uniformly at a rate of 60 pounds
of P205 per acre. Sixty pounds of nitrogen per acre was used in three trials,
and 75 pounds per acre were used in the remaining (1957) experiment. In three
of the four experiments the effect of additions of potash was determined by
applying 60 pounds of potash per acre to one half of all of the plots ferti-
lized with nitrogen and leaving the other half without potash fertilizer. In
the fourth instance the 60 pounds of potash per acre was applied to all plots.

In the 1956 experiment, plots were fertilized in August, September,
October, November and December. The whole area was mowed originally on July
19, 1956. Plots fertilized in September and succeeding months were harvested
just before fertilization. The August fertilized plots were harvested one
month after fertilization. All plots were harvested again on January 7.

In the other three tests all plots were mowed just prior to the beginning
of the test and then harvested at the end of the test.

Plots were harvested with a conventional 30-inch sickle-bar mower. A
clipping height of about 2- inches was used.

1/ Associate Agronomist, Indian River Field Laboratory, former distantt Soils
Chemist and Assistant Soils Chemist, Everglades Experiment tion, res-
pectively. AAF 2 6 2 i

2/ This was presented before the annual meeting of the Soil a Fop Sciencej
Society of Florida in November, 1961, and will be published n e Pro- /
ceedings, Volume 21. L






I O. 6'2 -I ...

Indian River Field Laboratory Mimeo Report 62-1 February 1962

YIELDS AND QUALITY OF PANGOLAGRASS RESULTING FROM DIFFERENT FALL DATES
OF FERTILIZATION WITH AMMONIUM NITRATE AND MURIATE OF POTASH

Albert E. Kretschmer, Jr., Howard E. Ray and Charles C. Hortenstine 1/2


INTRODUCTION

Cattlemen and dairymen are interested in knowing the amount of production
that may be expected from fertilization of grasses in the fall months, in order
that they may determine, under conditions of pasture stress, if additional forage
can be economically obtained from fall fertilization. To determine the effects
of different dates of fall fertilization on the growth and quality of pangola-
grass, four separate experiments were conducted on Immokalee fine sand.


EXPERIMENTAL PROCEDURES

One experiment was completed in 1956, two in 1957, and one in 1960. Plot
sizes ranged from 10 by 10, to 12- by 20 feet, and either a randomized block or
split-plot design was used.

Nitrogen, phosphorus, and potassium were supplied in all instances as
ammonium nitrate, 20C5 superphosphate, and muriate of potash, respectively.
In some of the tests phosphorus was omitted because soil tests and the previous
fertilization history indicated that sufficient phosphorus was present in the
soil. In other tests phosphorus was applied uniformly at a rate of 60 pounds
of P205 per acre. Sixty pounds of nitrogen per acre was used in three trials,
and 75 pounds per acre were used in the remaining (1957) experiment. In three
of the four experiments the effect of additions of potash was determined by
applying 60 pounds of potash per acre to one half of all of the plots ferti-
lized with nitrogen and leaving the other half without potash fertilizer. In
the fourth instance the 60 pounds of potash per acre was applied to all plots.

In the 1956 experiment, plots were fertilized in August, September,
October, November and December. The whole area was mowed originally on July
19, 1956. Plots fertilized in September and succeeding months were harvested
just before fertilization. The August fertilized plots were harvested one
month after fertilization. All plots were harvested again on January 7.

In the other three tests all plots were mowed just prior to the beginning
of the test and then harvested at the end of the test.

Plots were harvested with a conventional 30-inch sickle-bar mower. A
clipping height of about 2- inches was used.

1/ Associate Agronomist, Indian River Field Laboratory, former distantt Soils
Chemist and Assistant Soils Chemist, Everglades Experiment tion, res-
pectively. AAF 2 6 2 i

2/ This was presented before the annual meeting of the Soil a Fop Sciencej
Society of Florida in November, 1961, and will be published n e Pro- /
ceedings, Volume 21. L







Representative samples of grass were dried at 70 to 750 in a forced-draft
oven. Yields, dry matter contents and protein contents were obtained from these
samples. The AOAC Method (1) was used to determine nitrogen in the grasses,
and the crude protein values were obtained by multiplying the nitrogen contents
by 6.25. Statistical techniques outlined by Patterson were used (2).

"Nitrogen utilization" as used in the text means the amount of protein
(or nitrogen) in that portion of the grass that was harvested. The "percent
nitrogen utilization" was calculated by dividing the pounds of nitrogen re-
moved by harvesting by the amount of nitrogen applied and multiplying by 100.

RESULTS

Yields, Dry Matter and Protein Dry weight yields are presented in Table 1.
In order that the interpretation of results will not be misleading special note
should be made of the 1956 data. Data not included in parentheses represent
that obtained prior to fertilization except for the August fertilization data,
where grass was harvested one month after fertilization on September 4. Data
parenthesized refers to that obtained between the dates of fertilization and
the January 7 harvest, except for the August fertilized plots which had already
been harvested once, on September 4, after fertilization. A truer comparison
between 1956 and the other years may be obtained by adding the yield data within
and without the parenthesis for 1956.

Yields were lower when fertilization was delayed. The production of ferti-
lized pangolagrass was greatest through the month of September in some trials,
and through the month of October in others. Yields were not always progress-
ively reduced from the early to the later fertilization dates, because of the
influence of rainfall. A typical example was in the year 1960 when a reduc-
tion of about 1000 pounds dry matter occurred between the August 29 and Sept-
ember 19 dates. There was a total of about 12 inches of precipitation during
this period, and more than 9 inches between September 22 and 26. Yields of
the October 11 fertilized plots returned to about 5000 pounds. Pangolagrass
fertilized with 60 to 75 pounds of nitrogen per acre after August 1 and before
November 1 produced 3000 to 5500 pounds of dry matter per acre.

Dry matter contents decreased when yields decreased. Pangolagrass ferti-
lized in August or early September and harvested in December or January con-
tained about 40% dry matter. When fertilized approximately a month to six
weeks before harvest, dry matter contents were as low as 18.9%. These data
are presented in Table 1.

Crude protein contents, shown in Table 1, were higher when dry matter and
yields were lower. Grass fertilized in August and early September with 60 to
75 pounds of nitrogen contained 2 to 3% crude protein. These protein levels
increased to 11 to 13% when fertilization was delayed until November, which
was a month to six weeks before harvest.

When grass was not cut just prior to fertilization at each date, the
nitrogen utilization increased as fertilization was progressively delayed.
This phenomenum may be noted in Table 1 for the experiments in 1957 and 1960.








In 1960 the difference in protein between plots fertilized in August and Sept-
ember as compared with those fertilized in November was very large. Grass
fertilized in August and September contained 140 pounds, while that fertilized
in November contained 250 to 300 pounds of protein per acre.

WJhen plots were mowed and clippings removed just prior to each date of
fertilization a different phenomenum occurred. This can be seen by noting the
data for the 1956 experiment in Table 1. Except for the August fertilization
there was little difference between fertilization dates in their effect on
nitrogen utilization by the nangolagrass. However, fertilizing in August and
harvesting one month later resulted in the largest percent nitrogen utilization.

Percent nitrogen utilization is recorded in Table 1, and varied from 20.8
to 79.2'. Generally, 50 or more of the nitrogen was utilized only when the
grass was fertilized later than the first of October. A pre-treatment appli-
cation of 45 pounds of nitrogen per acre about three weeks prior to the ini-
tiation of one of the experiments in 1957 resulted in an average increase from
a utilization of 43, compared to 37% for the non ore-treated grass. The reason
for this relatively small increase evidently was associated with the increased
yields resulting from ore-treatment fertilization and consequently diluted
protein in the tops.

Response to Potash Fertilization In Table 2 the results of three years
experiments are given dealing with the response of pangolagrass to applications
of potash when soil notash levels were initially low. A yield increase oc-
curred only for the 1960 experiment, and the dry matter and crude protein
contents were significantly lowered when notash was applied. In the 1956
experiment, even though there was no yield response, grass receiving potash
contained less protein.

DISCUSSION

There is a distinct problem in fertilizing pangolagrass or other grass in
the fall if one aoolication of fertilizer is used. It is difficult, because
of rainfall and temperature differences every year, to pick the dpte of ferti-
lization where maximum economic yields and satisfactory protein contents may
be obtained for a particular harvest or grazing date. Furthermore, the time
when the grass is needed most also depends upon climatic conditions. Certain
years a heavy frost early in the fall might make it necessary to utilize the
reserve pasture earlier than in other years when frosts occur later or do not
occur at all. According to our results, a cattleman interested in obtaining
maximum grass growth without regard for quality, should fertilize early in
September and no later than the first of October. A rancher who is interested
in obtaining a good quality grass and will accept less tonnage should ferti-
lize about the middle of October and not later than the first of iNovember.
Areas north and west of the Indian River Field Laboratory normally have more
severe winters ond these dates of fertilization should be changed accordingly.
Probably fertilizing about two weeks earlier than the above suggested dates
would result in satisfactory yields and protein levels.








A generally approved fertilization program for most grasses is to alternate
a complete 1-1-1 ratio fertilizer with application of straight nitrogen. Ranchers
who normally fertilize their grass pastures and particularly pangolagrass pastures
twice a year, (once in the fall and once in the spring), should probably apply
the potash in the spring because there is less chance of leaching during this time
of year.

There may be certain advantages to fertilizing twice in the fall. Enough
nitrogen could be used in the early fall to assure good grass growth and then
another application could be applied a few weeks prior to grazing or cutting
for hay or other purposes, to increase the protein levels and palatibility.

The reason that better utilization of nitrogen was obtained from grass
fertilized late in the fall compared to grass fertilized early in the fall is
not known. This better utilization may have been due to reduced leaching of
the nitrogen, or possibly because better utilization is obtained when grass had
a relatively large proportion of leaves and, or, roots at the time of fertili-
zation. Results indicated that better nitrogen absorption and retention oc-
curred when the grass was allowed to grow without fertilization until it had
produced several to many leaves. Fertilization after this had occurred re-
sulted in more efficient movement of nitrogen into the grass tops than when
nitrogen was applied immediately after clipping.

In a review of the effect of defoliation on root growth Throughton (3)
stated that the main effect was to retard growth for a period of time depending
upon the severity of defoliation and other factors. Also, the number of roots
initiated and the root volume is reduced. Root growth was found to be reduced
more than shoot growth, the difference between the growth of the root and shoot
decreasing as the plant recovers from the defoliation. Defoliation not only
decreases the life of roots but roots of defoliated plants have been shown to
die back from the tips. In most experiments, height of cutting had a greater
influence on the severity of root damage then frequency of cutting.

Throughton (3) also discusses nitrogen nutrition. In general he states,
"It appears that plants grown in conditions where available nitrogen was a
factor limiting growth have a well developed root system, but a poorly deve-
loped shoot system. Plants grown with an excess of nitrogen exhibit the
opposite relative development".

From the above facts, pangolagrass in the 1956 test where the grass was
cut twice (the second time immediately prior to fertilization) would have been
expected to have a weaker root system than that of the other tests where it was
mowed once and then fertilized sometime later after roots and shoots had re-
grown more fully. If this phenomenon proves to be true it would have consi-
derable practical significance because of the much better utilization of the
nitrogen obtained when the grass was allowed to regrow prior to fertilization.

Except for the 1960 experiment, the yield responses to potassium applica-
tions in the fall were not large, even though the soil levels of this element
were very low (Table 2.). The effect of these low soil levels, however, was
pronounced on the late spring yields obtained in certain of the tests where
the grass was refertilized with nitrogen (and without potash) in the spring.






Grass growth in the fall (when responses to potash were slight or non-existant)
presumably was limited more by cold weather than by lack of potash. In the
spring, when the growth was more rapid potash deficiency severely limited pro-
duction. In both fall and spring when yields were limited by a lack of potash,
the protein contents were higher than where potash had been applied.

Under conditions of grazing, the fall fertilization date should be about
the same as those suggested earlier for either production of tonnage or pro-
duction of quality of feed. Under conditions of grazing rotationally or almost
continuously throughout the winter it might be best to initiate grazing in the
middle of November to the middle of December. When planning to make hay or
green-chop the harvest date might be slightly later than these grazing dates.
Aphids or frost can upset plans for delayed grazing, therefore, provision
should be made for those years when it might be impossible to reserve the
pasture until the need for feed reaches its peak.

SUMMARY

1. Maximum yields were obtained when pangolagrass was fertilized before October
1. Protein contents were about 2.5 to 4.0o.

2. Grass fertilized between October 15 and November 15 generally yielded less
but contained more protein than that fertilized earlier.

3. The quantity of protein (or nitrogen) found in the tops of the pangolagrass
became greater as fertilization was progressively delayed in the fall.

4. The percent nitrogen utilization varied from about 20 to 80% and depended
upon the year and date of fertilization.

ACKNOWLEDGEMENTS

Acknowledgement is due Mr. L. E. Hostetler, Field Assistant without whose
help, the work reported could not have been completed, and to Dr. C. T. Ozaki
former Assistant Soils Chemist, Everglades Experiment Station, for supervision
of some of the protein analyses and for his valuable suggestions.

LITERATURE CITED
1. Methods of Analyses of A. O. A. C. Washington 4, D. C. 6th Ed. p. 25. 1945.

2. Patterson, D. D. Statistical Technique in Agricultural Research. McGraw-
Hill, New York. 1939.

3. Throughton, Arthur. The Underground Organs of Herbage Grasses. Bul. 44.
Commonwealth Bureau of Pastures and Field Crops, Hurley, Berkshire. p. 94-102,
105-111. 1957.
(Continued from page 6)
i/ All plots were clipped on July 19 and all plots were clipped again prior to
fertilization except those of Aug. 1 which were harvested on Sept. 4. Values
not in parenthesis represent harvests prior to fertilization (except Aug.)
while those data in parenthesis were obtained after fertilization (except the
Aug. plots).
2/ Yields during entire period without fertilization,
IRFL Mimeo 62-1
200 copies







TABLE 1. The Effects of Different Fall Fertilization Dates on Dry weight Yields, Dry Matter
Pounds of Protein Removed and Utilization of the Nitrogen Applied to Pangolagrass.


and Protein Contents,


Fertilization
Date


Yields

Ibs./A
harvested
prior to (1-7-57)


Dry Matter


Crude Protein


Crude Protein
removed
Ibs./A


Total Nitrogen
removed
% of N
applied


1956--60 lbs.N/A fertilization
1. August 1 3070 (630)1/ 17.7 (40.3)!/ 8.7 (3.7)1 268 (23 )/ 77.6
2. September 5 600 (1480) 28.3 (39.9) 5.9 (2.9) 35 (43) 20.8
3. October 3 870 (1310) 33.1 (33.3) 3.3 (4.3) 28 (55) 22.1
4. November 2 1360 (630) 39.8 (25.2) 2.7 (7.2) 37 (44) 21.6
5. December 3 1010 (410) 40.5 (18.9) 2.7 (13.2) 27 (53) 21.3
L.S.D. .05 (530) ( 1.6) (0.5) (11)

1957--60 lbs.N/A Harvested 11-4-57
1. Check 2/ 2650 41.1 2.2 57 -
2. August 5 5630 40.7 2.1 116 30.9
3. September 4 4230 38.3 2.4 101 26.9
4. October 4 3830 30.6 4.6 174 46.4
L.s.D. .05 910 1.8 0.5 34

1957--75 Ibs.N/A Harvested 12-17-57
1. August 20 4990 39.8 2.7 134 28.6
2. September 3 5120 40.6 2.9 148 31.6
3. September 17 3810 40.9 3.4 129 27.6
4. October 1 2820 37.1 3.9 109 23.3
5. October 15 4150 31.7 6.9 288 61.5
6. October 29 3390 34.5 7.4 247 52.8
7. November 12 2270 31.0 11.0 256 54.7
L.S.D. .05 760 4.8 0.6 65

1960--60 Ibs.N/A Harvested 1-16-61
1. August 29 5050 46.6 2.8 140 37.3
2. September 19 4020 43.7 3.4 137 36.5
3. October 11 5010 36.4 4.2 210 56.0
4. November 1 3930 29.8 6.3 247 65.9
5. November 23 2650 24.0 11.3 297 79.2
L.S.D. .05 430 1.9 1.2 25 -


_/2/ See page 5.











Table 2. The Effects of Potash Fertilization on Pangolagrass Dry Weight
Yields, Dry Matter and Protein Contents, Crude Protein Removed
and Utilization of the Nitrogen Applied.


Soil K
contents
prior to
Fertilization


Potash
Fertilization
rate


Yields Dry matter


Crude protein


Crude protein-l
removed


Nitrogen-/
removed
4 of IT


Year Ibs./A Ibs./A lbs./A % % Ibs./A applied

1. 1956 24 a. 0 1530 31.6 6.5* 92 25
b. 60 1470 31.5 6.0 85 23

2. 1957 30 a. 0 3730 38.1 2.9 108 29
b. 60 3860 38.6 2.7 109 29

3. 1960 27 a. 0 3180 39.5** 6.8** 196 52
b. 60 4130** 36.1 5.6 206 55


1/ Not analysed statistically.

* Statistically significant at the 56 level.

** Statistically significant at the 1% level.









HISTORIC NOTE


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

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Cooperative Extension Service.






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