ate' ol Ferii um g ('ott on at Prattville,

Iullet in 624 B D~ecembher 1994( Alab~ama Agricultural Experiment Station Auburn U nix ersity L owell T. F~robish, D)irector Auiburn Uiix ersity, Alabama

CONTENTS

INTRODUCTION .......................... ... ................ METHODS .......................................................... RESULTS AND DISCUSSION ............................................ Yield Trends ................................... .......................... Nitrogen Rates Versus Yields ........................ .................... Rates of P and K Versus Yield .............................................. Soil-Test P Versus Relative Yield ........................................ Soil Test K Versus Relative Yield ....................................... Soil pH .......................................... ........................ ............... Solid Versus Skip-Row Planting .............................................. ................... CONCLUSIONS .............................................................................. ................... ACKNOWLEDGEMENTS ...................................................................... REFERENCES ................................................................................. ................... APPEND IX .........................................................................................................

3 4 6 6 7 8 9 11 12 13 14 14 14 17

First printing 3M, December 1994

Information contained herein is available to all persons without regard to race, color sex or national origin.

Rate of Fertilizing Cotton

at Prattville,
1934-1994
C.C. MITCHELL,

\

F.J.

ARRIAGA, AND D.A. MOORE

INTRODUCTION

IN 1934, A SIMPLE, COTTON TEST was established on the new Prattville Experiment Field (c. 1928). The test consisted of six, nonreplicated treatments comparing a 0-6-0 grade fertilizer, three rates of a 10-6-5 grade fertilizer, and two untreated controls. In 1962, seven nitrogen rate variables were added and the number of plots was expanded to 12. Although this test was originally designed to gather information and demonstrate cotton response to rates of fertilizers available to farmers in the area, no one intended for it to become one of the three oldest, continuous, cotton tests in the world and one of the oldest, continuous field crop tests in North America (5). The only cotton experiments older than the "Rate of Fertilizing Cotton" test at Prattville are Alabama's "Old Rotation" (c. 1896) and "Cullars Rotation" (c. 1911) at Auburn, Alabama. The "Rate of Fertilizing Cotton" test has always served as more of a test/ demonstration than as a scientific experiment since treatments are not replicated. It is located in a prominent, highly visible location next to the experiment field office. Farmers and other visitors can readily identify the rates-of-N treatments which range from severely N deficient plants to dark green, succulent cotton where 300 pounds N per acre per year have been applied. This test provides interesting insights into trends in long-term cotton yields in central Alabama and cotton's response to increasing and changing rates of nitrogen (N), phosphorus (P), and potassium (K). It is of particular interest as fertilization relates to sustainable production using only commercial fertilizer materials. Ironically, no formal research publications have been found which report or summarize cotton yields on this test. J. T. Cope, Jr., who served as project leader from 1951 until
.Mitchell is an Associate Professor of Agronomy and Soils; Arriaga is a graduate research assistant; and Moore is Superintendant, Prattville Experiment Field.

4

ALABAMA AGRICULTURAL EXPERIMENT STATION

his retirement 1984, noted that the test was maintained primarily because of its simplicity and visibility. No data were reported in Experiment Station publications during this time although complete yield and soil test records were maintained (J.T. Cope, Jr., personal communication). Therefore, the objective of this bulletin is to summarize 60 years of continuous cotton production on the "Rate of Fertilizing Cotton" test at Prattville and to document cotton response to rates of N, P and K.

METHODS
Soil at the site is a Lucedale sandy clay loam (fine-loamy, siliceous, thermic Rhodic Paleudult) which is a desirable, productive soil for cotton in Central and South Alabama. The plow-layer (0-8 inches) has a cation exchange capacity of 5.1 cmol/ kg. This test has always been planted using conventional tillage practices for cotton production which usually include (1) moldboard plowing in the late fall, (2) disking in the spring, (3) lime, fertilizer, and preplant incorporated fertilizer applications, and (4) final seedbed preparation. Fertilizer was broadcast on a total plot area. Cultivation, weed and insect control, and other cultural practices were standard recommendations and practices. Varieties planted on the "Rate of Fertilizing Cotton" test were selected based on cotton variety tests on the experiment field TABLE 1. COTTON VARIETIES (Table 1). A variety released by USDA and PLANTED, 1934-1994 the Alabama Agricultural Experiment Station, 'Auburn 56', remained on the test for Variety Year(s) 15 years-longer than any other variety. Cook 307 1934 Each plot is 21 feet wide and 86.5 feet Cook 1022 1935 long (1/24 acre). This allows six, 42-inch Cook 1006 1936-38 rows per plot. From 1977 through 1979, all Cook 144-16 1939-40 plots were planted in a 2x1 skip-row pattern Cook 144 1941-43 by planting the two center rows and the two Stoneville 061 1944-49 Coker 100 1950-52 outside rows in each plot. Since 1980, only Auburn 56 1953-67 the N-rate variable plots (6-12) have been McNair 1032 1968 planted in a skip-row pattern. This was McNair 1032B 1969 done in order to gather information on N Coker 201 1970 rates for skip-row cotton which had beDeltapine (DPL) 16 1971-73 Stoneville 213 1974-75 come the planting pattern used by most area DPL 25 1976-77 farmers. Seed cotton yields were estimated Stoneville 213 1978-79 by harvesting the two center rows in each DPL 61 1980-83 plot and calculating yield based on total DPL 90 1984-94 land area.

RATE OF FERTILIZING COTTON AT PRATTVILLE, 1934-1994

5

Several adjustments have been made in nutrients applied since the "Rate of Fertilizing Cotton" test began in 1934 (Table 2). Plot 1 has never received any fertilizer nutrients and plot 2 has not received any P fertilizer since 1936. Plot 6 has received P and K since 1962 but has never received any N fertilizer. Plot 4, the "no K" treatment, has not received any K fertilizer since 1971. Plots 3 and 5 are moderate and high rates of P and K. All P and K and half of the N are applied just prior to final seedbed preparation and planting. The complement of N is applied as a sidedressing at early squaring. TABLE 2. ANNUAL RATES OF N-P 20 5 -K20 APPLIED TO PLOTs, 1934-1994.
Years Plot 1 2 3 4 5 6 7 8 9 10 11 12 1934-35 0-0-0 0-36-0 30-18-12 60-36-24 90-54-36 0-0-0 1936-59 0-0-0 36-0-0 18-30-12 36-60-24 54-90-36 0-0-0 1960-61 1962-70 1971-76 0-0-0 120-0-60 120-30-60 120-60-0 120-60-30 0-60-60 30-60-60 60-60-60 90-60-60 120-60-60 150-60-60 300-60-60 1977-94 0-0-0 90-0-60 90-30-60 90-60-0 90-60-30 0-60-60 30-60-60 60-60-60 90-60-60 120-60-60 150-60-60 300-60-60

-

pounds N-P 205 -K20 per acre 0-0-0 0-0-0 48-0-0 120-0-60 24-24-24 120-30-60 48-48-48 120-60-48 72-72-72 120-72-72 0-0-0 0-60-60 30-60-60 60-60-60 90-60-60 120-60-60 150-60-60 300-60-60

Source of N during the early years of the test was nitrate of soda. However, since 1962, ammonium nitrate has been used. Superphosphate (0-20-0) or concentrated superphosphate (0-46-0) has been used as the source of P, and muriate of potash (00-60) has been the primary source of K. A major addition to the test occurred in 1962 when annual rates of N from 0 (plot 6) to 300 pounds N per acre (plot 12) were added. All N-rates (plots 6-12), have received 60 pounds P 20 5 and 60 pounds K20 annually since 1962. Soil test records date back to 1958. Mehlich-1 (dilute, double acid) extractable P and K have been determined on plow-layer soil samples taken in the fall (11 times since 1958). Lime was generally applied and incorporated into the top 6-8 inches of each plot whenever the soil pH dropped below 5.8. However, the records indicate that plot 12, 300 pounds N per acre per year, often had plow-layer pH values below 5.8 which may have resulted in reduced yields before lime was applied.

6

ALABAMA AGRICULTURAL EXPERIMENT STATION

RESULTS AND DISCUSSION
YIELD TRENDS The most striking observations in cotton yields from year to year since 1934 are wide, weather-dependent fluctuations (Figure 1). As would be expected, trends since 1934 have tended toward higher average yields with unfavorable weather or insect damage (as in 1993) reducing yields below those of the 1930's. Although this test was begun to look at the influence of N, P, and K fertilizers on cottonyields, trends indicate that any treatment effect can be overwhelmed by environmental conditions. High or low yield extremes rarely remain high or low for two consecutive years. Record yields during the 60 years of this test are in Table 3. In order to minimize the fluctuation in seed cotton yields from year to year so treatment effects can be compared, data can be presented as averages over a period of time or as a relative yield comparing each treatment with a standard treatment (3). Relative yields are used later in this bulletin. Seed cotton yield, Ib./acre

4,000
3,500

4,000 Annual yields S- - Five-year average

3,000
2,500
,

2,000 1,500
/

1,000 N rate applied, lb./acre/yr.

500
1930

901
I 1940

54
I 1950

I 1960

1721

120
I 1970

I
I 1980

90
I 1990 I 2000

Figure 1. Trends in seed cotton yield on plot no. 5 since1934.

RATE OF FERTILIZING COTTON AT PRATTVILLE,

1934-1994

7

TABLE 3. RECORD HIGH AND Low YIELDS DURING THE 60-YEAR HISTORY OF THE "RATES OF FERTILIZING COTTON" TEST AT PRATTVILLE. Record Plot Year 1985 1985 1946 1934 1946 1985 1986 Seed cotton yield Lb./acre 4,310 3,240 94 1,244 25 4,260 980

Highest plot yield ........................................ 11 Highest yielding year ................................... average Lowest yielding year ................................... average Highest control yield ........................................ 1 Lowest control yield ................................... 1 Highest yield for recommended N rate ........... 9 Lowest yield for recommended N rate ........... 9 NITROGEN RATES VERSUS YIELDS

Five-year running averages indicate that rates of 60 to 150 pounds N per acre produced maximum yields (Figure 2). However, when average yields were low such as the years around 1978 and again around 1989, 30 pounds N per acre were adequate.

Seed cotton yield, lb./acre 3,000
2,500

Five-year averages

2,000

1,500 1,000
500 0 906 3 90 0 ,

Q 60 -0300 1960 1965 1970 1975 1980 1985 1990

Figure 2. Effect of N rate on seed cotton yield since 1962 (plots 6-12). Each data point represents a 5-year running average.

8

ALABAMA AGRICULTURAL EXPERIMENT STATION

These data support the standard N recommendations made by the Auburn University Soil Testing Laboratory which suggests 90 pounds N per acre with a 30 pound adjustment up or down based on yield potential and field history (2). These standard recommendations were developed from numerous, replicated N-rate studies on cotton throughout Alabama. The 300 pounds N per acre rate usually resulted in excessive growth and increased difficulty controlling insects. This sometimes occurred on the 120 and 150 pounds N per acre rates, especially when rainfall was higher than normal. RATES OF PHOSPHORUS AND POTASSIUM VERSUS YIELD The first 28 years of the study compared increasing rates of a complete fertilizer (N, P, and K all increased simultaneously). Most cotton growers during this era fertilized in this manner. There was no soil testing program in Alabama until 1954. As expected, the highest yields were produced by the highest rate of fertilizer applied which was plot 5. During the 28-year period, this plot received as much as 90 pounds of N, 90 pounds of P20 5, and 72 pounds of K 20 annually (Table 2). The effects of N, P, and K cannot be separated because of the confounded variables. However, in 1962, three annual rates of P 20 5 (0, 30 and 60 pounds per acre) were established

Seed cotton yield, lb./acre
3,000

2,500

2,000

P205

rate, lb./acre

1,500-0

0

A030 Q 60 60 (skip row since 1980) 1,000 1960 I 1965

1970

1975

1980

1985

1990

Figure 3. Effect of phosphorus rate (plots 2, 3, 5, and 9 or 10) on seed cotton yield since 1962. Each data point represents a 5-year running average yield.

RATE OF FERTILIZING COTTON AT PRATTVILLE, 1934-1994

9

Seed cotton yield, lb./acre 3,000

2,500 -

2,000

F

K20 rate, Ib./acr 1,500 0 A 30 Q 60 60 (skip rows since 1980) 1,000 I I 1980 1985 1990 1980 1985 1990 1975 1970 Figure 4. Effect of potassium rate (plots 3, 4, 5, and 9 or 10) on seed cotton yield since 1971. Each data point represents a 5-year running average yield. in plots with equal rates of N and K (plots 2, 3, and 10). In 1971, three annual rates of K20 (0, 30 and 60 pounds per acre) were established in plots with equal rates of N and P (plots 4, 5, and 9 or 10). Since that time, we have been able to observe the effect of annual applications of these nutrients alone on yields (Figures 3, 4). However, by this time, previous P and K applications on these plots had increased residual soil P and K to the point that cotton yields were not increased by increasing rates of these nutrients. An apparent decrease in yield since 1980 where 60 pounds P2 0 5 and 60 pounds K20 per acre were applied is probably due to the skip-row planting pattern used only on plots 6-12.
SOIL-TEST P VERSUS RELATIVE YIELD

e

The soil testing program in Alabama created a need for as much soil test calibration information as possible. Therefore, by 1962, project leaders began altering the treatments to evaluate the effect of P and K separately and to gather data in support of soil test calibration research. Mehlich-1 extractable P since 1958 from the P variable plots indicates no correlation with relative seed cotton yield (Figure 5). Relative yield was calculated by dividing the yield on plots 1, 2, 3, and 4 by the yield of plot 9 or 10, a standard rate of N. Relative yields on the control (plot 1) are included

10

10 ALABAMA AGRICULTURAL EXPERIMENT STATION

Relative yield
1.6

[-

El

1.4
A

1.2 1.0 0.8 0.6-, 0.4 0.2

L~IULAk '
ALAI
Q

Ql Q 0.. 0l 0 m

A" A A'1 A

0'

ICritic

0'/ 0

!cal P
El 0 El

No fertilizer 30 lb. P 05/acre 2 P05/acre 2

So
0G 0o
'

A No P
60 lb.

0.0 Iii 0 20

I

II

40

60

80

100

120 140

160

180

200 220

Soil test P, lb./acre
Figure 5. There was no relationship between soil test (extractable) P and relative seed cotton yield -even though soil test P on the no P plots (plot 2) was considerably lower than the critical P level used by the Auburn University Soil Testing Laboratory of 50 pounds extractable Pper acre. Relative yields are yields on plots 1, 2, 3, or 5 compared to yields on plots 9 or 10 at the same N and K rate.Soil samples were taken following harvest inthe same year.
in Figure 5 for comparison only. Since the control plot does not receive any N, P, or K fertilizer, low yields are expected. Current soil test calibration for this soil would suggest applying P fertilizer if extractable P is less than 50 -pounds per acre (2). However, Figure 5 suggests that, in fact, a critical soil test P value may.be considerably lower than 50. Evans (4) has suggested a critical: value of 30 pounds per acre
extractable

Although yields do not indicate a response to soil-applied P fertilizer, the soil test

P.,

records clearly show a differentiation of soil-test P by long- term treatment (Figure 6). Continuopis application of t60 lb P2 05 K20 increased extractable P, and :K to :very high ;levels.}

and

RATE OF FERTILIZING COTTON AT PRATTVILLE, 1934-1994

11

Extractable P, Ib./acre

300250 Extremely high o No fertilizer A No P 0 30 lb. P20acre 60 lb. P2Os 5/acre

150
100 Very high

High
50Medium

-----Low 1960 1965

-------

----

0

1955

1970

1975

1980

1985

1990

1995

Figure 6. Effect of applied P on soil test (extractable) P compared to existing soil test calibration used in Alabama (2).The sudden decline in extractable P after 1968 cannot be explained but may be related to laboratory methodology which is not documented in the records of this test.

SOIL TEST

K

VERSUS RELATIVE YIELD

Surprisingly, soil test K was only weakly correlated with relative yield (Figure 7). However, the only relative yields below 1.0 are on the plots receiving no K since 1971 or only 30 pounds K20 per acre per year. Existing soil test calibration for cotton on Lucedale and similar soils with a cation exchange capacity between 4.6 and 9.0 cmol/kg by the Auburn University Soil Testing Laboratory uses 180 pounds extractable K per acre as the critical K value (2). Values above 180 are rated "high" and no additional K fertilizer is recommended. Although no yield increases were found in this test when soil test K was above 180 pounds per acre, soil test K values below this often resulted in yields lower than the plot receiving a complete fertilizer (plot 9 or 10). As with soil-test P, treatment effects of soil-test K is obvious, increasing with increasing rate of applied K (Figure 8).

12

ALABAMA AGRICULTURAL EXPERIMENT STATION

Relative yield 1.6 y = 0.0005x 1.4 1.2 r = 0.13
2

+ 0.88

Existing critical value /

1.0
0.8 -

°aA

*

O

O

0.6o 0.4 o
0

o o0

08
0
°460

o0 No fertilizer since1971 A No K O 30 lb. K 0/acre 2 lb. K20/acre

0.2
0.0
0.0

0o o I I
0

I

I

I

I

I

I

50

70

90

110

130

150 170 190 210 Soil test K, lb./acre

230

250

270 290

Figure 7. There was only a weak correlation between soil test (extractable) Kand relative seed cotton yield on plots 1,4, and 5 compared to plots 9 or 10 at the same N and P rate. The Auburn University Soil Testing Laboratory uses 180 pounds extractable K per acre as a critical K value for this soil.Soil samples were taken following harvest in the same year. SOIL PH Soil acidity as measured by soil pH was not a variable in this test. However, soon after the N-rate plots began in 1962, records indicate a problem maintaining a desirable pH on the high N-rate plots, especially where 300 pounds N per acre per year was applied (Figure 9). Ground, dolomitic agricultural lime was applied based on soil and buffer pH (1) in an attempt to maintain plow-layer pH in a range of 5.8 to 6.5. Figure 9 indicates that high N rates often resulted in rapid soil acidification and frequent pH values lower than desired in spite of regular liming. In some years, soil acidity may have actually reduced yields at the high N rate when lime was not applied. The standard N recommendation of 90 pounds per acre required 5.0 tons of lime per acre during the 32-year period compared to 15 tons per acre where 300 pounds N per acre per year was applied (Table 4). Interestingly, over the period from 1962 to 1994,

RATE OF FERTILIZING COTTON AT PRATTVILLE, 1934-1994
TABLE 4. TOTAL LIME APPLIED FROM 1962 TO 1994 ON THE 12 PLOTS OF THE "RATE OF FERTILIZING COTTON" TEST AT PRATTVILLE. Total no. of applications 1 5 5 4 4 0 1 3 4 6 8 9 Total lime applied Tons/A 1 .............. 2 .............. 3 ................. 4 ................. 5 ............. 6 ................. 7 ................. 8 ............ 9 .............. 10 ................. 11 ............. 12 .......... No fertilizer No P 30 lb P205/acre No K 30 lb K20/acre since 1971 No N 30 lb N/acre 60 lb N/acre 90 lb N/acre 120 lb N/acre 150 lb N/acre 300 lb N/acre 1.0 5.5 5.5 5.0 4.5 0 1.0 3.0 5.0 6.5 8.0 15.0 Total N applied Lb./A 0 3,420 3,420 3,420 3,420 0 990 1980 2,970 3,960 4,960 9,900 3.2 3.2 2.9 2.6 2.8 3.4 3.2 3.2 3.2 3.0 MEAN= 3.1 TABLE 5. COMPARISON OF SELECTED AVERAGE SEED COTTON YIELDS FROM PLOTS PLANTED TO SOLID-ROW COTTON AND SKIP-ROW COTTON'. Solid planted Plot 3, 1974-76 (120N) 2 Plot 3, 1983-88 (90N) Plot 5, 1974-76 (120N) Plot 5, 1983-88 (90N) Plots 8,9,10, 1974-763
1

13

Plot

Treatment

Lime: N ratio

Yield Lb./acre 2,130 2,300 2,300 2,400 2,360

Skip-row planted Plot 3, 1977-79 (90N) Plot 5, 1977-79 (90N) Plot 9, 1983-88 (90N) Plots 8,9,10, 1977-793 Plots 8,9,10, 1983-883

Yield Lb./acre 2,350 2,340 2,090 2,320 2,180

All plots were in solid cotton before 1977 and skip-row during 1977-1979. Since 1980, plots 1-5 have been in solid cotton and plot 6-12 in skip-row cotton. 2 Values in parentheses are the annual N rate applied during this period. 3 Nitrogen rate averaged 90 pounds N/acre during this period. the test received agricultural lime at the rate of 3.1 pounds lime per pound of N applied as ammonium nitrate. This is within the theoretical equivalent acidity range for ammonium nitrate (6). A value of 3 pounds agricultural lime per pound of N as ammonium nitrate is often recommended as a guide to neutralize the acidifying effects of ammonium nitrate. SOLID VERSUS SKIP-ROW PLANTING The non-replicated treatments, changing varieties, and the complicating N, P, and K variables make statistical analysis of the method of planting cotton (solid versus skip-row) impossible. However, comparing the yield records before skip-row and

14

ALABAMA AGRICULTURAL EXPERIMENT STATION

Extractable K, Ib./acre 350 o No fertilizer A No Ksince 1971 300 O 30 lb. K 0/acre 2 * 60 lb. K 0/acre 2 250

200High

150

100

Medum

0 1955

IIIIIII 1960 1965 1970 1975 1980 1985 1990

Low ! 1995

Figure 8. Effect of applied K on soil test (extractable) Kcompared with existing soil test calibration for soils with a C.E.C. of 4.6 to 9.0 cmol/kg. after skip row on the same plots and comparing similar plots planted to skip row after 1980 (plots 6-12) with those in solid cotton (plots 1-5), suggests that there is no yield advantage to planting skip-row cotton in this area (Table 5). All yields were calculated on a total area basis, not just planted area. While skip-row planting was popular during the late 1970's and 1980's, many area growers have returned to solid planted cotton. This test served to demonstrate to area growers that method of planting cotton does not affect the recommended N rate. CONCLUSIONS Records from the 60-year history of the "Rate of Fertilizing Cotton" test at Prattville have complemented and verified recommended fertilization practices of the Alabama Agricultural Experiment Station and Cooperative Extension Service. Weather and factors other than those studied can overwhelm treatment effects in this test and result in wide fluctuations in annual seed cotton yields. Extremes rarely follow patterns of two consecutive high-yielding years or two consecutive low-yielding years. Nitrogen rates had the most dramatic effects on long-term yields. Nitrogen

RATE OF FERTILIZING COTTON AT PRATTVILLE, 1934-1994

15

Relative yield 8.0 H
7.5710 6.5 6.0 5.5 5.0 4.5 4.01 1955 o A o " No fertilizer No N 90 lb. N/acre 300 lb. N/acre

1
1960

I

1965

t1 1970

I II

I

I

I

I

I

I I

1975

1980

1985

1990

1995

Figure 9. Soil pH tended to drop rapidly and more often in plots receiving high rates of fertilizer N. rates of 60 to 150 pounds per acre produced maximum yields. There were no longterm yield differences within these rates. Soils required liming at an average rate of 3.1 pounds lime for every pound N applied as ammonium nitrate. Surprisingly, neither P rates nor soil test P levels influenced long-term yield trends. Mehlich-1 extractable P on the plot receiving no P fertilization since 1936 is below the 50 pounds-per-acre critical value as used by the Auburn University Soil Testing Laboratory. However, long-term seed cotton yields were just as high on this plot as on plots receiving as much as 60 pounds P2 0 5 per acre annually. Yields were weakly correlated with Mehlich-1 extractable K on the plots receiving K variable rates since 1971. Although the test was not designed for statistical analyses of treatment effects, observations over the years suggest that there is little yield advantage to planting skiprow cotton over a solid-row pattern. The "Rate of Fertilizing Cotton" test has provided an interesting demonstration in fertilization management for local cotton growers. However, because it was not designed for statistical analysis, scientifically-based conclusions are difficult to make from the confounding variables. This test will not be continued beyond 1994.

16

ALABAMA AGRICULTURAL EXPERIMENT STATION

ACKNO WLEDGEMENTS
The fact that the "Rate of Fertilizing Cotton" test has been continued for over 60 years is a tribute to the dedication of the superintendents at the Prattville Experiment Field. They realized the need to share their research with local growers through a visible, non-replicated demonstration as well as collect scientific yield data. The following superintendents and project leaders have been responsible for this test: Project Leaders Superintendents 1934-1952 J.T. Williamson F.E. Bertram 1928-1967 J.T. Cope, Jr. 1952 - 1984 Fred Glaze 1968-1981 1984 - 1994 C.C. Mitchell Don Moore 1982-present

REFERENCES
(1 Adams, F., and C.E. Evans. 1962. A Rapid Method for Measuring Lime Requirement of Red-Yellow Podzolic Soils. Soil Sci. Soc. Am. Proc. 26:355357. (2) Adams, J.F., C.C. Mitchell, and H.H. Bryant. 1994. Soil Test Fertilizer Recommendations for Alabama Crops. Ala. Agr. Expt. Sta. Agron. & Soils Dep. Ser. No. 178. (3) Cope, J.T., Jr., D.G. Sturkie, and A.E. Hiltbold. 1958. Effects of Manure, Vetch, and Commercial Nitrogen on Crop Yields and Carbon and Nitrogen Contents of a Fine Sandy Loam Over a 30-Year Period. Soil Sci. Soc. Amer. Proc. 22:524527. (4) Evans, C.E. 1987. Soil Test Calibration. p. 23-29. In J.R. Brown (ed.) Soil testing: Sampling, Correlation, Calibration, and Interpretation. Spec. Pub. No. 21. Soil Sci. Soc. Amer., Madison, WI. (5) Steiner, R.A., and R. W. Herdt. 1993. A Global Directory of Long-Term Agronomic Experiments (Vol. 1: Non-European Experiments). The Rockefeller Foundation, New York, NY. (6) Tisdale, S.L., W.L. Nelson, and J.D. Beaton. 1985. Soil Fertility and Fertilizers. 4th ed. p.490-493. Macmillan Pub. Co., New York, NY.

APPENDIX TABLE 1. SEED COTTON YIELDS BY YEAR ON PLOTS OF THE "RATES OF FERTILIZING COTTON" TEST AT PRATTYILLE EXPERIMENT FIELD, 1934-1961, IN POUNDS PER ACRE Plot 1 2 3 4 5 6 1934 1,244 1,860 1,394 1,860 1,882 886 1935 1,056 1,508 1,279 1,567 1,747 868 1936 666 859 810 1,057 1,132 422 1937 666 1,111 975 1,212 1,345 555 1938 662 1,498 1,166 1,868 2,268 716 1939 720 1,526 1,235 1,912 2,318 583 1940 540 1,195 1,138 1,559 1,576 439 1941 252 1,357 ,303 1,768 2,329 425 1942 209 1,040 828 1,235 1,595 212 1943 472 1,436 1,145 1,634 2,081 432 1944 583 1,354 1,285 1,652 1,818 587

H

m 0
71 11

m
H

N_

z
0

0 0
z

H H 1945 428 1,292 1,123 1,699 1,922 396 1946 25 115 104 184 122 14 1947 216 778 569 918 1,094 148 1948 302 911 792 1,177 1,282 223 1949 216 1,091 828 1,328 1,627 126 1950 313 990 900 1,411 1,512 256 1951 742 1,354 1,289 1,462 1,314 432 1952 461 1,116 965 1,156 1,238 310 1953 367 976 940 1,148 1,321 169 1954 515 936 925 1,123 1,040 360 1955 374 1,318 1,192 1,991 2,351 295

Plot 1 2 3 4 5 6

It

H

H H

m
1957 331 871 763 972 1,066 209 1958 396 1,368 1,123 1,746 2,171 306 1959 230 918 785 1,231 1,620 187 1960 533 1,670 1,397 1,951 2,156 446 1961 (revised) 245 1,397 1,170 1,840 2,221 259
-4 CA)

Plot 1 2 3 4 5 6

1956 310 792 929 1,325 1,368 252

APPENDIX TABLE 2. SEED COTTON YIELDS BY YEARS ON PLOTS OF THE "RATES OF FERTILIZING COTTON" TEST AT THE PRATTYILLE EXPERIMENT FIELD, 1962-1993 (IN POUNDS PER ACRE) Plot 1 2 3 4 5 6 7 8 9 10 11 12 1962 162 1,174 1,539 1,620 1,616 369 1,516 1,562 1,534 1,570
1,602

1963 missing data

1964 missing data

1965 292 2,743 2,963 3,020 2,945 508 1,724 2,408 2,851 3,028 3,026 2,765

1966 374 2,203 2,491 2,563 2,502 392 1,638 1,958 2,250 2,124 2,153 2,300

19.67 328 1,350 2,228 2,174 2,221 511 1,883 2,174 2,196 1,958 1,793 1,591

1968 1 641 2,221 2,477 2,390 2,369 943 1,922 2,563 2,887 2,830
2,578

1969 662 2,682 2,938 2,758 2,884 1,130 2,279 2,628 2,797
2,815

1970 (revised) 857 2,722 2,556 2,275 2,639 886 1,670 2,261

W
2n

2,891

2,790
2,768 2,596

0 C 1980 554 1,065 1,245 1,050 1,252 795 1,203 1,068 1,049 1,078 1,160 1981 942 2,453 2,432 2,165 2,381 1,271 1,966 1,957 1,904 1,971 2,067 H C

1,512

2,437

2,887 2,617

Plot 1 2 3 4 5 6 7 8 9 10 11

1971 1,530 3,625 3,409 3,028 2;905 1,343 2,610 3,316 3,467 3,546 3,722

1972 800 2,120 2,370 2,300 2,280 730 1,740 2,100 2,080 2,040 1,970

1973 762 l,636 1,640 1,557 1,866 902 1,697 1,758 1,712 1,730 1,658

1974 993 2,568 2,273 2,396 2,885 1,504 2,417 2,950 2,777 2,777 2,741

1975 583 2,619 2,755 2,014 2,597 554 1,611 2,417 2,511 2,525 2,374

1976 935 1,611 1,352 1,489 1,417 957 1,746 1,806 1,806 1,662 1,755

1977 978 2,324 2,208 2,093 2,525 964 2,432 2,626 2,366 2,474 2,582

1978 1,214 2,581 2,755 2,535 3,051 1,746 2,717 2,391 2,414 2,520 2,603

1979 1,071 2,158 2,079 2,057 2,230 1,158 2,014 2,022 2,000 2,086 2,129

m

X

m m
z H H H 0 z

APPENDIX TABLE

2, CONTINUED. SEED COTTON YIELDS BY YEARS ON PLOTS OF THE "RATES OF FERTILIZING COTTON" TEST AT THE PRATTVILLE EXPERIMENT FIELD, 1962-1993 (IN POUNDS PER ACRE)
1983 496 2,360 2.496 2,417 2,345 897 1;611 1,559 1,655 1,482 1,439 1,583 1984 626 3,057 3,280 2,806 3,518 1,156 1,986 2,451 2,921 3,122 3,151 3,180 1985 638 3,407 3,049 3,282 3,796 1,328 2,433 3,955 4,259 4,259 4,314 4,135 1986 406 1,245 1,178 1,145 1,245 697 1,029 1,001 913 979 1,134 1,173 1987 232 2,315 2,547 1,883 1,950 1,325 1,770 1,737 1,593 1,676 1,471 1,632 1988 415 1,684 1,468 1,435 1,568 940 1,289 1,438 1,189 1,195 1,162 929 1989 307 1,776 2,074 1,767 2,000 1,045 1,610 1,604 1,460 1,610 1,455 819 1990 738 2,456 2,630 2,614 2,779 1,007 1,742 1,676 1,770 1,726 1,742 1,184 1991 448 1,859 2,423 2,398 2,008 631 1,123 1,504 1,433 1,554 1,361 1,333 1992 70 2,717 3,144 3,109 3,057 865 1,673 2,114 1,998 2,050 1,922 1,800 1993 522 1,846 1,620 1,533 1,463 854 1,423 1,284 1,330 1,284 1,475 1,376 1994 840 3,520 3,640 3,480 3,860 1,070 2,020 2,780 2,580 2,380 2,980 2,710

H m
-1

Plot 1 2 3 4 5 6 7 8 9 10 11 12

1982 no yield

m

Ri'
O 0 H H H

m C--.

CO

20

ALABAMA AGRICULTURAL EXPERIMENT STATION
APPENDIX TABLE 3. ANALYSES OF THE YOUNGEST, MATURE, COTTON LEAF BLADES TAKEN AT EARLY BLOOM ON 16 JULY 1991.

Plot 1 .............. 2 ................. 3 ................. 4 ................. 5 ................. 6 ................. 7 ................. 8 ................. 9 ................ 10 ............... 11 ............... 12 ............... Sufficiency range*

N Pct. 3.40 4.64 5.26 5.00 4.87 4.06 4.33 4.74 5.21 5.22 5.17 5.30 3.504.50

P Pct. 0.64 0.50 0.52 0.53 0.50 0.36 0.53 0.50 0.49 0.54 0.57 0.47 0.300.50

K Pct. 0.88 1.12 1.09 1.06 1.07 1.26 1.08 1.15 1.29 1.30 1.25 1.25 1.503.00

Mg Pct. 0.43 0.44 0.40 0.56 0.39 0.36 0.30 0.39 0.43 0.47 0.47 0.52 0.300.90

Ca Pct. 2.03 1.89 1.97 2.48 1.96 2.53 1.93 2.37 2.34 2.42 2.12 2.15 2.003.00

Mn mg/kg 10 72 90 90 69 153 84 97 83 78 61 150 25350

Zn mg/kg 328 28 28 26 25 29 29 27 30 27 60 25 20200

B mg/kg 39 43 46 36 55 42 36 48 50 53 49 52 2060

*Plank, C.O. 1988. Plant analysis handbook for Georgia. Georgia Coop. Extension Service. Athens, GA.

l\iaiaama's

Aricultural N

".xpri ntent Station Sstem

AUBURN UNIVERSITY

With an agricultural research unit in every major soil area. Auburn University serves the needs of field crop, livestock, forestr. and horticultural

producers in each region in Alabama. Every citizen of the state has a stake in this research program.
since any advantage

from new and more economical ways of prlucing and handling farm products directlN benefits the consuming public.

I:r~ t.

i

i

(l cI I~i I

i

Main Agricultural Experiment Station, Auburn. E. V. Smith Research Center, Shorter.
Tennessee Valley Substation. Belle Mina Sand Mountain Substation. Crossville North Alabama Horticulture Substation. Cullman Upper Coastal Plain Substation. Winfield. Forestry Unit. Fayette County Chilton Area Horticulture Substation. Clanton Forestry Unit. Coosa County Piedmont Substation. Camp Hill Foresty Unit. Autauga County Prattville Experiment Field, Prattville 11 12 13 14. 15 16 17. 18. 19 Black Belt Substation. Marion Junction The Turnipseed-Ikenberry Place. Union Springs Lomer Coastal Plain Substation. Camden. Forestry Unit. Barbour County. Monroeville Experiment Field. Monroeville Wiregrass Suostation Headland Bremton Experiment Field, Bremton Ornamental Horticulture Substation. Spring Hill. Gulf Coast Substation. Fairhope