BULLETIN 403JUE17

JUNE 1970

Me~hd aj r IfIJ24#0ty

NITROGEN PHOSPHORUS POTASSIUM Call

~

+°r. -a*~

AGRICULTURAL
gym'~

EXPERIMENT

STATION

AUB U RN
E. V. Smith, Director

U NI V ERS IT Y
Auburn, Alabama

CONTENTS
Page
NITROGEN EXPERIMENTS----------------------4
-

M e th o d s - - - - - - - - - - - - - - - - --- - - - - - - - - - - - - - - - - -

4 - 5

R es ults - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - P

AND KPLACEMENT

EXPERIMENT-----------------------8

R esults-------- -- ---- - -- -----

10

INTERPRETATION AND APPLICATION OF FINDINGS ON METHODS OF APPLYING P AND K------------------------12 C ON CLU SIO NS -- --------------- ---------------- - ---

12

ACKNOW LEDGM ENT------------------------------------13 LITERATURE CITED ------------------------------------

15

FIRST PRINTING

4M,

JUNE

1970

Methods of Applying Nitrogen, Phosphorus, and Potassium
for Cotton
CLYDE E. EVANS, Assistant Professor of Agronomy and Soils CLARENCE E. SCARSBROOK, Professor of Agronomy and Soils R. D. ROUSE, Associate Director

nitrogen needs of cotton be met by preplant application? Is a starter application of fertilizer for cotton necessary for top yields? Questions like these were of little interest a generation ago, but the advent of high analysis fertilizers, bulk handling, mechanization, and labor shortage has changed all that. Now these questions are of major economic importance for the cotton producer as he seeks to increase speed of planting and reduce costs of production. To provide information about effectiveness of preplant applications and necessity of starter applications of fertilizer, the study reported here was begun by Auburn University Agricultural Experiment Station. Results of fertilizer placement experiments in Texas had indicated a reduction in stand of cotton when fertilizer was placed with the seed (2). In Georgia, experiments comparing rates of complete fertilizer (N-P-K) showed no difference from method of application at one location but at another location yields were higher when all fertilizer was broadcast rather than banded (5). Zaslovsky and Mokady (7) indicated that a band application of P is not always advantageous because broadcasting may result in contact with a greater volume of roots and, therefore, more efficient uptake. Welch et al. (6) found that one-half banded and one-half broadcast was the best method of applying a high rate of P for corn on Illinois soils low in P. For low rates of P on soils
THE FERTILIZER

CAN

4

ALABAMA AGRICULTURAL EXPERIMENT

STATION

testing low, they indicated that banding was favored, as would be expected on soils with high P fixing properties. Maples and Keogh (3) compared broadcast and banded placement of fertilizer on Arkansas soils deficient in P and K. On sandy areas, soluble salts from banded fertilizer caused seedling injury in dry weather and broadcasting was better. Only on poorly drained soils was banded application superior, which may have been a result of reduced root growth and consequently less contact with broadcast fertilizers. Overton and Parks (4) compared rates and methods of applying fertilizer for cotton in Tennessee. On sandy loam or silt loam soils testing low or medium in P or K, there was a response to increasing rates of fertilizer but no response to methods of application. Uniform distribution of fertilizer would be an important consideration in broadcasting, particularly on soils of low fertility. In the experiments reported in this publication, methods of application were precisely controlled. Under practical field conditions spreading patterns may vary as a result of such factors as slope of ground, nature of fertilizer, equipment, and weather conditions
(1).

NITROGEN EXPERIMENTS Methods Field experiments on cotton were conducted at Prattville, Brewton, and Monroeville Experiment Fields and the Sand Mountain Substation. Soil type at each location was as follows:
Location Prattville Experiment Field Brewton Experiment Field Monroeville Experiment Field Sand Mountain Substation Soil type Lucedale sandy loam Norfolk sandy loam (formerly Kalmia) Magnolia sandy loam Hartsells sandy loam

The rates of N were 0, 30, 60, and 90 pounds per acre, applied

according to three schedules: (1) all broadcast ahead of planting, (2) 15 pounds drilled and remainder broadcast, and (3) 15 pounds drilled and remainder sidedressed. Different rates were used at the Sand Mountain Substation, 0, 60, 90 and 120 pounds N per acre. At this location, in addition to the 15-pound rate drilled, treatments included 30 pounds drilled and the remainder

METHODS OF APPLYING N, P, K, FOR COTTON

5

either broadcast or sidedressed. Adequate rates of P and K were applied for all N comparisons.
Results

At Prattville Experiment Field the yield was 1,390 pounds seed cotton per acre without applied N and increased with each increment up to 2,640 pounds at 90 pounds N per acre, Table 1. There
TABLE 1. YIELD OF SEED COTTON FROM THE RATES AND METHODS OF APPLICATION OF NITROGEN EXPERIMENT ON LUCEDALE SANDY LOAM SOIL, PRATTVILLE EXPERIMENT FIELD

Nitrogen treatment Drilled Broadcast Sidedressed No nitrogen 0 30 pounds N 0 15 15 60 pounds N 0 15 15 90 pounds N 0 15 15

1964 Lb. 1,440 2,120 2,160 2,280 2,500 2,490 2,470 2,670 2,650 2,710

Seed cotton yield per acre 1965 1966 1967 Lb. Lb. Lb. 1,480 2,110 2,060 2,100 2,640 2,470 2,730 2,940 2,730 2,910 1,590 1,800 1,840 2,060 2,390 2,370 2,530 2,430 2,290 2,480 1,080 1,740 1,780 1,980 2,300 2,110 2,270 2,530 2,230 2,450

Average Lb. 1,400a1 1,940b 1,960b 2,100b 2,460c 2,360c 2,500c 2,640d 2,470c 2,640d

0 30 15 0 60 45 0 90 75 0

0 0 0 15 0 0 45 0 0 75

'Yields
TABLE

with the same letter are not different at the 0.05 probability level.
YIELD OF SEED COTTON FROM THE RATES AND METHODS OF APPLICATION OF NITROGEN EXPERIMENT ON NORFOLK SANDY LOAM SoIL, BREWTON EXPERIMENT FIELD

2.

Nitrogen treatment Drilled Broadcast Sidedressed No nitrogen 0 30 pounds N 0 15 15 60 pounds N 0 15 15 90 pounds N 0 15 15
SYields

1964 Lb. 1,220 1,670 1,560 1,660 1,460 1,670 1,830 1,520 1,590 2,070

Seed cotton yield per acre 1965 1966 1967 Lb. Lb. Lb. 1,850 2,100 1,910 1,750 2,080 2,370 2,190 2,460 2,500 2,370 1,380 1,750 1,690 1,600 1,820 1,780 1,720 1,940 1,660 1,740 1,530 2,120 2,080 1,790 1,950 2,330 2,010 1,880 1,920 2,060

Average Lb. 1,8 7 0a1 1,910cd 1,810bc 1,700b 1,830bc 2,040d 1,940cd 1,950cd 1,920cd 2,060d

0 30 15 0 60 45 0 90 75 0

0 0 0 15 0 0 45 0 0 75

with the same letter are not different at the 0.05 probability level.

6

ALABAMA

AGRICULTURAL EXPERIMENT STATION

was no effect of method of applying N at the 30- and 60-pound per acre rates. All broadcast ahead of planting was just as good as applying part in the drill and either broadcasting or sidedressing the remainder. At the 90-pound rate the combination of 15 pounds drilled and 75 pounds N broadcast yielded less than the other methods of application. There is no logical explanation for this reduction in yield. Yields at Brewton Experiment Field indicated a response up to 60 pounds N per acre, Table 2. Overall, there were no consistent differences in yields from method of application. For example, at 90 pounds N, the rate recommended for cotton in the Coastal Plains, the three methods of application gave similar yields. Results at Monroeville Experiment Field show a response only to 30 pounds N, Table 3. Soil conditions and drought may account for the apparent poor response to N. At Sand Mountain Substation yields ranged from about 1,600 pounds to nearly 3,000 pounds seed cotton per acre as N was increased from none to 90 pounds, Table 4. There was no consistent response to more than 90 pounds at this location. Methods of applying N gave similar results. Broadcasting all the nitrogen was just as satisfactory as applying some in the drill and either broadcasting or sidedressing the remainder. In the fertilizer placement experiments reported later in this
TABLE 3. YIELD OF SEED COTTON FROM THE RATES AND METHODS OF APPLICATION OF NITROGEN EXPERIMENT ON MAGNOLIA SANDY LOAM SOIL, MONROEVILLE EXPERIMENT FIELD

Nitrogen treatment Drilled Broadcast Sidedressed 1964 Lb. 1,740 1,580 1,690 1,420 1,760 1,280 1,640

Seed cotton yield per acre 1965 Lb. 2,160 2,530 2,400 2,510 2,530 2,320 2,450 1966 Lb. 2,110 2,150 1,960 2,120 2,040 1,970 1,960 1967 Lb. 1,770 2,100 2,120 2,130 2,200 2,190 2,160 Average Lb. 1,9 4 0a 1 2,090b 2,040b 2,040b 2,130b 1,940a 2,050b

No nitrogen 0 0 30 pounds N 0 30 15 15 15 0 60 pounds N 0 60 15 45 15 0 90 pounds N 0 90 15 75 15 0 1 Yields with the same

0 0 0 15 0 0 45 0 0 75 letter are

1,450 2,580 2,110 2,090 2,060b 1,390 2,600 2,120 2,140 2,060b 1,580 2,360 2,050 2,190 2,040b not different at the 0.05 probability level.

METHODS OF APPLYING N, P, K, FOR COTTON
TABLE 4.

7

YIELD OF SEED COTTON FROM THE RATES AND METHODS OF APPLICATION OF NITROGEN EXPERIMENT ON HARTSELLS SANDY LOAM SOIL,
SAND MOUNTAIN SUBSTATION

Drilled

Nitrogen treatment Sidedressed Broadcast

Seed cotton yield per acre 1965 1966 Average Lb. Lb. 1,530 2,210 2,580 2,670 2,610 2,730 2,750 2,890 3,020 2,720 2,850 2,900 2,940 2,910 3,190 2,800 Lb. 1,610a' 2,370b 2,650b 2,640b 2,580b 2,730b 2,760c 2,810c 2,930c 2,750c 2,840c 2,900c 2,860c 2,940c 2,990c 2,820c

No nitrogen 0 60 pounds N 0 15 15 30 30 90 pounds N 0 15 15 30 30 120 pounds N 0 15 15 30 30
1Yields

0 60 45 0 30 0 90 75 0 60 0 120 105 0 90 0

0 0 0 45 0 30 0 0 75 0 60 0 0 105 0 90

1,690 2,530 2,720 2,610 2,560 2,740 2,760 2,730 2,850 2,780 2,840 2,900 2,780 2,970 2,790 2,830

with the same letter are not different at the 0.05 probability level.

bulletin, Tables 5-10, broadcasting the recommended rate of N can be compared with drilled + sidedressed N at several locations. Results were the same as reported above, indicating that broadcasting all N before planting was a satisfactory practice.
SUMMARY OF NITROGEN RESULTS.

Response to rates of N was

variable among locations. There was a response to only 30 pounds at Monroeville Field, 60 pounds at Brewton Field, and to 90 pounds N at both Prattville Field and Sand Mountain Substation. Method of applying N had little or no effect on yields. Cotton effectively utilized broadcast N as well as drilled N, and combinations were no better than drilling or broadcasting the fertilizer. If N broadcast ahead of planting had been less efficiently utilized by the cotton plant, then differences would have been expected at the lower rate of application. This did not occur. Results of these studies on fertile soils that had been well fertilized in the past indicate that the cotton producer can choose method of N application most suited to his management situation. It might not be advisable to apply all the N ahead of planting on very sandy soils or soils of low fertility.

8

ALABAMA AGRICULTURAL EXPERIMENT STATION P AND K PLACEMENT EXPERIMENT

Field experiments on cotton were conducted from 1964 to 1966 at six locations in the State, on these soil types :
Location Agronomy Farm, Auburn Prattville Experiment Field___ Monroeville Experiment Field_
Wiregrass

Soil type

.Chesterfield sandy

loam

_Lucedale sandy loam

Substation

-Magnolia

(formerly

Greenville)
sandy loam

________

.Dothan sandy loam
(formerly

Norfolk)

Sand Mountain Substation---. Tennessee Valley Substation___

_Hartsells sandy loam

-Decatur clay loam

TABLE 5. YIELD OF SEED COTTON FROM THE METHOD OF APPLICATION OF PHOSPHORUS AND POTASSIUM EXPERIMENT ON CHESTERFIELD SANDY LOAM SOIL, AGRONOMY FARM, AUBURN'

Treatmet Total number N-P-K 1 2 3 4 5 6 7 8

Fertilizer per acre, pounds Broadcast N-P-K Drilled N-P-K 20-18-50 20-9-15 20-9-15 0-0-0 0-0-0 20-0-50 20-18-0 0-0-0
dressed

Seed cotton yield per acre

Sie

N

1964

1965

1966

Av.'
Lb. 2,590 2,640 2,560 2,470 2,460 2,530 2,510

90-18-50 0-0-0 90-18-50 0-9-35 90-27-75 0-18-60 90-18-50 0-18-50 90-27-75 0-27-75 0-0-0 90-0-50 0-0-0 90-18-0 90-18-50 90-18-50

70 70 70 90 90 70 70 0

Lb. 3,030 3,000 3,200 2,860 2,850 3,050 3,030

Lb. Lb. 2,900 1,830 3,040 1,880 2,620 1,870 2,850 1,720 2,800 1,720 2,640 1,910 2,660 1,830 2,950 2,060

1Soil test P was high and K was medium.
2 Differences
TABLE

were not significant.

6. P

Treatn

YIELD OF SEED COTTON FROM THE METHODS OF APPLICATION OF AND K EXPERIMENT ON MAGNOLIA SANDY LOAM SOIL, MONROEVILLE EXPERIMENT FIELD'

o a Fertilizer per acre, rl e r a c s pounds

i e

Seed cotton yield per acre 1964 1965 1966

number

N-P-K

N-P-K

N-P-K

dressed

N 70 70 70 90 90 70 70 0 Lb. 1,900 1,970 1,970 1,910 2,010 1,990 1,890 Lb. 2,740 2,890 2,590 2,660 2,760 2,770 2,800 2,770 Lb. 1,940 2,100 1,980 1,890 2,020 2,050 2,090 2,030

Av.'

1 2 3 4 5 6 7 8
2

90-18-35~ 90-18-35 90-27-50 90-18-35 90-27-50 90-0-35 90-18-0 90-18-35

20-18-35 0-0-0 0-9-20 20-9-15 0-18-35 20-9-15 0-0-0 0-18-35 0-0-0 0-27-50 20-0-35 0-0-0 0-0-0 .20-18-0 0-0-0 90-18-35

Lb. 2,190 2,320 2,180 2,150 2,260 2,270 2,260,

' Soil tests for both P and K were high.
Differences were not significant.

METHODS OF APPLYING N, P, K, FOR COTTON

9

Trcatinei ts included three rates of P and K fertilizer based on soil tests: the recommilnded rate. 11* titnIs the reco)mmend~edl rote. and1( check treatnuie ts wXith no P or K. Com parisonts Xxere made of lbroadcast and diiill applications as XX(Ii as cominlationis inwhicli somei of the P an d K w\as applied as at st arter. Rates aid methods of application w xere (numbers correspoid to treatntii noiwil~rs ini Tables 5-10):

1 lBecomnieided

irate

1. llecom :3.
1.
112

nided rate

all drilledl starte di illed, remajider

1broacast
I (Wommlveide(I rate

b~roadclast
Hiecuoiiei (ed rate

all broadcltast

I.1 2 (lcolineinled raite

6. rlecommnieded r ate of K. inoP_

all drilled

7.

R~ecomnded rate ofI P, d r ate

no K

S. lR((o111cll

The d ri lied I ertilizer inctl uded 2(0 pouni ds N XXith the remntider of' N sidedressed: therefor c, treati ients 4 t ad 5 had all the N sidediressed Xx li treatmntit 8 had all the N b roadceast b efore plantitgi A\ 5jpeiall\ equiipped t~xo-r(oXX planter (slio~v in photo ) xx l as used iii all these e~periilcits. F~ertilizer for each rowX XXas XXeigt.hed and dIistibu ted uoiforlil I (IX r the length of tihd plot byx mlean s of sl\ mi)Xi op iii fertilizer b~elts mleteringt the f erti Ii /r to the appli '

This specially equipped, 2-row planter ensured uniform distribution of fertilizer over the length of the plot during the planting operation.

10

ALABAMA

AGRICULTURAL

EXPERIMENT

STATION

cators during the planting operation. The drilled fertilizer was placed 3 inches to the side and 2 inches below the seed. The comparisons were made at a different location on each field or substation each year. Soil pH was in the range of 6.0 to 6.5 and N and B (boron) were applied at recommended rates. Conventional methods of land preparation and weed and insect control were followed.
Results The tests were located intentionally on soils testing medium to

high in P and K. There was no response to P at any location, and yields were increased by the use of K at only two locations, Tables
TABLE

7.
P

YIELD AND

OF SEED COTTON

FROM THE

METHODS SANDY
1

OF APPLICATION LOAM SOIL,

OF

K

EXPERIMENT

ON LUTCEDALE

PRATTVILLE

EXPERIMENT FIELD

Treatnumber

Fertilizer per acre, pounds NTotaK N-P-K Broadcast N-P-K Drilled N-P-K

Sie dressed N

Seed cotton yield per acre 1964 Lb. 1965 Lb. 2,940 2,870 2,960 3,040 3,060 3,030 2,860 2,970 1966 Lb. 2,280 2,260 2,430 2,300 2,330 2,300 2,050 2,220 Av. Lb. 2,580abc 2,580abc 2,680c 2,530ab 2,560abc 2,630c 2,440a 2,620c

1 2 3 4 5 6 7 8
2 Yields
1

90-18-35 90-18-35 90-27-50 90-18-35 90-27-50 90-0-35 90-18-0 90-18-35

0-0-0 0-9-20 0-18-35 0-18-35 0-27-50 0-0-0 0-0-0 90-18-35

20-18-35 20-9-15 20-9-15 0-0-0 0-0-0 20-0-35 20-18-0 0-0-0

70 70 70 90 90 70 70 0

2,510 2,600 2,650 2,250 2,300 2,550 2,410 2,660

Soil tests for both P and K were high. with the same letter are not different at the 0.05 probability level.
YIELD OF SEED COTTON FROM
AND K EXPERIMENT ON

TABLE 8.
P

THE METHODS
SANDY
1

HARTSELLS

OF APPLICATION OF LOAM SOIL,

SAND MOUNTAIN SUBSTATION

Treatment number

Fertilizer per acre, pounds

N-P-K

Total

Broadcast N-P-K

DrilleK N-P-K

dS sd dressed

Seed cotton yield per acre 1964 1965 1966 Av2 Av.

1964

1965

1966

1 120-18-50 0-0-0 20-18-50 100 2 120-18-50 0-9-35 20-9-15 100 3 120-27-75 0-18-60 20-9-15 100 4 120-18-50 0-18-50 0-0-0 120 5 120-27-75 0-27-75 0-0-0 120 6 120-0-50 0-0-0 20-0-50 100 7 120-18-0 0-0-0 20-18-0 100 8 120-18-50 120-18-50 0-0-0 0 Soil test for P was high and K was medium. 2 Differences were not significant.

Lb. 1,710 1,800 1,860 1,740 1,680 1,720 1,810 1,630

Lb. 2,280 2,310 2,420 2,240 2,290 2,480 2,200 2,190

Lb. 2,320 1,620 2,150 1,970 2,400 1,890 1,960 2,000

Lb. 2,100 1,910 2,140 1,980 2,120 2,030 1,990 1,940

METHODS

OF

APPLYING

N,

P,

K,

FOR

COTTON

11

5-10. Broadcasting the P and K was just as satisfactory as applying all or some of the fertilizer in the drill. Likewise there was no advantage to using 112 times the recommended rate by the broadcast method. Even where there was a response to K, there was no indication that one application method was superior to the other.
At three locations, first-year treatments included one in which

all N, P, and K were broadcast ahead of planting. This treatment was added at the other three locations the second and third years.
Yields from this treatment were similar to the other P and K com-

parisons and also agree with the data reported previously on nitrogen application methods. Cotton yields in these experiments ranged between 11 and 2
TABLE 9. YIELD OF SEED COTTON FROM THE METHODS OF APPLICATION P AND K EXPERIMENT ON DECATUR CLAY LOAM SOIL,
TENNESSEE VALLEY SUBSTATION
1

OF

Treatment number

Fertilizer per acre, pounds

Seed cotton yield per acre

Total N-P-K

Broadcast N-P-K

Drilled N-P-K

dseed dressed

1964

N

1964
Lb.

1965

1965
Lb.

1966

1966
Lb.

Av.'
Lb. 2,340 2,330 2,290 2,180 2,370 2,190 2,290 2,330

Av.

1 2 3 4 5 6 7 8
2

70-27-50 70-27-50 70-40-75 70-27-50 70-40-75 70-0-50 70-27-0 70-27-50

0-0-0 0-18-35 0-30-60 0-27-50 0-40-75 0-0-0 0-0-0 70-27-50

20-27-50 20-9-15 20-9-15 0-0-0 0-0-0 20-0-50 20-27-0 0-0-0

50 50 50 70 70 50 50 0

2,780 2,400 2,580 2,470 2,650 2,170 2,650 2,760

2,640 2,750 2,630 2,350 2,810 2,640 2,620 2,620

1,600 1,830 1,650 1,730 1,650 1,770 1,600 1,620

1Soil tests for both P and K were medium.

Differences were not significant.

TABLE 10.
P

YIELD OF SEED COTTON FROM THE METHODS OF APPLICATION OF AND K EXPERIMENT ON DOTHAN SANDY LOAM SOIL, 1 WIREGRASS SUBSTATION

Treatment number

Fertilizer per acre, pounds Total N-P-K Broadcast N-P-K Drilled N-P-K Sied dressed

Seed cotton yield per acre 1964 1964 Lb. 2,780 2,680 2,700 2,690 2,860 2,560 2,390 1965 1965 Lb. 2,420 2,600 2,660 2,190 2,390 2,470 2,140 2,100 1966 1966 Lb. 2,570 2,200 2,850 2,470 2,580 2,630 2,430 2,400 Av.eAv. Lb. 2,590abc " 2,490abc 2,740c 2,450ab 2,610bc 2,550abc 2,320a

1 2 3 4 5 6 7 8
1 2

90-18-50 90-18-50 90-27-75 90-18-50 90-27-75 90-0-50 90-18-0 90-18-50

0-0-0 0-9-35 0-18-60 0-18-50 0-27-75 0-0-0 0-0-0 90-18-50

20-18-50 20-9-15 20-9-15 0-0-0 0-0-0 20-0-50 20-18-0 0-0-0

70 70 70 90 90 70 70 0

Soil test for P was high and K was medium. Yields with the same letter are not different at the 0.05 probability level.

12

ALABAMA AGRICULTURAL EXPERIMENT STATION

bales per acre most years. There appeared to be some early growth stimulation from drilled fertilizer some years, but this did not affect yield. INTERPRETATION AND APPLICATION OF FINDINGS ON METHODS OF APPLYING P AND K Experiments on several of the more extensive soil types on which cotton is grown in the State indicate that broadcasting P and K fertilizer for cotton is a satisfactory practice. These experiments were limited to soils testing high or medium in P and K, which are typical of fertility levels of soils on which most cotton is grown in Alabama. A summary of 1968 results from Auburn University's Soil Testing Laboratory' showed that 89 per cent of samples tested for cotton were medium or high in P and 94 per cent were medium or high in K. These findings agree with results from other states and show that broadcasting all fertilizer ahead of planting cotton is as good as other methods for soils with medium or high fertility levels. In this series of experiments there was no apparent stand damage and no yield losses from banding fertilizer. This pattern of response should be expected to differ on soils of low fertility. CONCLUSIONS Broadcasting fertilizer N ahead of planting on fertile soils gave similar results to drilling part and sidedressing remainder. Broadcasting all P and K was a satisfactory practice for soils testing medium or high in these plant nutrient elements. Rates of fertilizer recommended by soil tests were adequate to give maximum yields on soils representative of those producing much of the cotton grown in Alabama. No adverse effects from drilled fertilizer placed 3 inches to the side and 2 inches below the seed were encountered.
Alabama Soil Test Summary-1968.

METHODS

OF

APPLYING

N,

P,

K,

FOR

COTTON

METHODS OF APPLYING N, P. K, FOR COTTON

13

13

ACKNOWLEDGMENT Many people contributed information used in preparation of this publication. Substation and Experiment Field Superintendents where tests were conducted were F. E. Bertram (now retired), J. W. Richardson (retired), J. K. Boseck, S. E. Gissendanner, and C. A. Brogden. Members of the Agronomy and Soils Department who made important contributions to these studies were J. T. Cope, Jr., C. W. Jordan, and J. T. Eason.

METHODS OF APPLYING N, P, K, FOR COTTON

15

LITERATURE CITED

(1)

BOUAT, M. AND G. MANIERE. 1969. Spreading Patterns: A Study of Some of the Factors Influencing the Uniformity of Distribution of Bulk Fertilizers Applied with Conventional Spreaders. Agr. Chem. Vol. 24, No. 2. p. 25-26.

(2) DUDLEY,

R. H., E. HUDSPETH, AND H. WALKER. 1963. Fertilizer Placement Trials - Irrigated Cotton. Texas Agr. Exp. Sta. Prog. Rep. 2271.

(3) MAPLES, RICHARD AND J. L. KEOGH. 1968. Fertilizer Placement for Cotton. Ark. Farm Res. Vol. 17, No. 1. p. 2.

(4) OVERTON, J. R. AND W. L. PARKS. 1969. Fertilizer Rate and Placement
for Cotton. Better Crops with Plant Food. Vol. LIII, No. 2. p. 4-7.

(5) WALKER, MILTON

AND O. L. BROOKs. 1964. Comparative Response of Cotton to Broadcast Application versus Row Placement of Mixed Fertilizer. Ga. Agr. Exp. Sta. Mimeo Series n.s. 193. WELCH, L. F., D. L. MUJLVANEY, L. V. BOONE, G. E. MCKIBBEN, AND J. W. PENDLETON. 1965. Relative Efficiency of Broadcast versus Banded

(6)

Phosphorus for Corn. Agron. J. 58:283-287.

(7)

ZASLOVSKY, DAN AND R. S. MOKADY.

1967. Non-uniform Distribution

of Phosphorus Fertilizers: an Analytical Approach.

Soil Sci. 104:1-6.

AGRICULTURAL EXPERIMENT STATION SYSTEM OF ALABAMA'S LAND-GRANT UNIVERSITY

With an agricultural
research unit in every ii ajor soil area, Auibur n Uiniversity serves the

i

needs of field crop, liestock, forestr, and horticllti ral producers in
each egion in Ala,r lamna. Everv citizen ot the State has a stake in this research program. anv advantage from iew anid more cconomical vays of producing and handling farnmiproducts directl>9 bIeinefits the consumingo
silie

-

'

0
0

0
is 0

®0 ®
-

c

0

pubilic.

s

Research Unit Identification

*
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21.

Main Agricultural Experiment Station, Auburn
Tennessee Valley Substation, Belle Mina. Sand Mountain Substation, Crossville. North Alabama Horticulture Substation, Cullman. Upper Coastal Plain Substation, Winfield. Forestry Unit, Fayette County. Thorsby Foundation Seed Stocks Farm, Thorsby. Chilton Area Horticulture Substation, Clanton. Forestry Unit, Coosa County. Piedmont Substation, Camp Hill. Plant Breeding Unit, Tallassee. Forestry Unit, Autauga County. Prattville Experiment Field, Prattville. Black Belt Substation, Marion Junction. Tuskegee Experiment Field, Tuskegee. Lower Coastal Plain Substation, Camden. Forestry Unit, Barbour County. Monroeville Experiment Field, Monroeville. Wiregras Substation, Headland. Brewton Experiment Field, Brewton. Ornamental Horticulture Field Station, Spring Hill. Gulf Coast Substation, Fairhope.