Progress Report Series No. 110
Agricultural Experiment Station
AUBURN UNIVERSITY
R. Dennis Rouse, Director
Auburn, Alabama
ON-FARM LIME AND FERTILIZER 
EXPERIMENTS
WITH SOYBEANS AND 
COTTON IN
NORTHERN ALABAMA, 1975-1976'
C.C. MITCHELL, 
S.M. EICH 
and FRED 
ADAMS 
2
A COOPERATIVE RESEARCH PROGRAMwith farmers was
begun in 1975 in the following counties 
of northern
Alabama: Cherokee, Colbert, DeKalb, 
Franklin, Jackson,
Lauderdale, Lawrence, Limestone, Madison, 
Marshall,
and Morgan. This program has a two-fold 
purpose: (1) to
provide up-to-date fertilizer and lime 
requirements for
major crops of the area, particularly cotton 
and soybeans,
and (2) to improve Auburn University's 
soil testing
program and service to farmers in the area. 
This program
is needed because Auburn University's 
Agricultural Ex-
periment Stations at Belle Mina and Crossville 
do not ade-
quately represent the variety of soil 
types and growing
conditions that exist in this major agricultural 
area of the
State.
Experiments were located primarily 
on the fine-
textured soils of the Tennessee River 
Valley, the silty soils
of the Highland Rim area north of the 
Tennessee River, the
loamy soils on stream terraces, and the sandy soils 
of the
Appalachian Plateau south of the River. 
Small areas were
selected in farmer's fields that 
were representative of soil
types for the region. Each of these chosen 
areas was then
divided into 8, 12, 16, 20, or 24 plots, 
depending upon the
number of liming treatments or fertilizer 
treatments
planned for the individual experiment. 
Each lime or fer-
tilizer rate was repeated four times 
at each location. Each
cotton plot consisted of six 35-foot 
rows; each soybean
plot consisted of eight 100-foot rows. 
Cotton was
harvested by hand; soybeans were machine combined.
The experimental areas received no special 
attention
other than the planned lime or fertilizer 
treatments. Each
farmer followed his normal practices 
of land preparation,
planting, cultivation, and control of weeds, diseases, 
and
insects.
'Financial assistance of Gold Kist, Inc., Alabama Farmers 
Cooperative,
and TVA for this project is gratefully acknowledged.
2
Former Research Associate, Department of Agronomy and Soils; Area
Cotton Specialist, Cooperative Extension Service; and Professor 
of Soils,
Department of Agronomy and Soils, respectively.
LIME EXPERIMENTS WITH SOYBEANS
A total of 17 lime experiments with soybeans 
was
harvested on farmers' fields in 1975 and 1976, 
Table 1.
Varieties planted were Bragg, Dare, Essex, Forrest, 
and
Lee. Six of the experiments were on Highland 
Rim soils
(Mountview and Dickson series), three were on Tennessee
Valley soils (Decatur and Dewey series), two were 
on
stream terrace soils (Holston and Sequatchie series), 
and
six were on Appalachian Plateau soils (Wynnville 
and
Hartsells series).
The Mountview and Dickson series are loamy soils 
that
cover extensive areas of the ighland Rim 
north of th
icultura xlgian Rir nort ofnese Ri.
Tennessee River. They are locally called "gray lands". 
The
Decatur and Dewey series are important agricultural 
soils
of the Tennessee Valley and are called "red lands" 
because
of their dark reddish color. The Holston and Sequatchie
series are brown loamy soils that occupy terrace positions
along streams of the limestone valleys. The Wynnville 
and
Hartsells series are common on Sand Mountain and other
areas of the Appalachian Plateau; they are highly produc-
tive when properly fertilized, limed, and managed.
Soil pH of the test areas before liming ranged from 
4.5 to
5.7. Soil pH after liming was 6.0 or above. Because 
drought
limited yields in some fields, yields on limed plots 
ranged
between 22 and 45 bushels per acre. Yield increases 
from
liming ranged from none to 20 bushels per acre. 
In general,
liming was less effective where yields were 
limited by
drought; some of these showed no yield increase 
from
lime even where soil pH was as low as 4.9 or 5.0. 
However,
where yields were not severely limited by drought 
(35-45
bushels per acre), liming increased yields considerably 
at a
soil pH of 5.2 or less.
FERTILIZER EXPERIMENTS WITH SOYBEANS
Eleven experiments were harvested in 
which
phosphorus and potassium fertilizers were applied 
broad-
cast prior to planting soybeans, Table 2. Varieties 
were
Bragg, Essex, Forrest, Lee, Mack, and York. 
Four ex-
September 1977
periments were on Highland Rim soils (Dickson and
Mountview series), three were on Tennessee Valley soils
(Allen and Bewleyville series), and two each on stream
terrace soils (Capshaw and Sequatchie series) and Ap-
palachian Plateau soils (Wynnville and Townley series)
None of the soils was "low" in potassium, but several
were "very low" or "low" in phosphorus. In spite of the
low soil-test phosphorus level of several soils, only one
showed a marked increase in yield from fertilizer. On a
Bewleyville silt loam in Limestone County (E. Black's
farm), the soil fertility index for P was only 30 percent, and
fertilizer increased yield by 10 bushels per acre. The other
experiments failed to show a statistically significant yield
increase from fertilizer.
LIME EXPERIMENTS WITH COTTON
Unfavorable weather, diseases, and insects combined to
make 1975 and 1976 very disappointing years for Alabama
cotton farmers. The on-farm experiments suffered the
same fate, and many had to be abandoned because of poor
stands, excess weeds, or early freeze.
Yields of the different experiments ranged from a low of
800 pounds to a high of 2,000 pounds of seed cotton per
acre, Table 3. Soil pH of the unlimed plots ranged
between 4.9 and 5.6, but yields were not greatly affected
by liming. The greatest yield increase was 290 pounds of
seed cotton per acre on a Mountview silt loam (a Highland
Rim soil) at pH 4.9.
NITROGEN RATE EXPERIMENTS WITH COTTON
Four experiments were harvested in 1976 in which
nitrogen as ammonium nitrate was added at four different
rates: 30, 6090, and 120 pounds per acre of N, Table 4.
The recommended nitrogen fertilizer rate for cotton on
these soils is 90 pounds per acre of N.
As noted earlier, yields were relatively low in 1976 in all
experiments with cotton in northern Alabama. This may
help explain why 30 pounds of N produced just as much
cotton as did higher N rates in every instance. Certainly,
the use of higher N rates was not profitable on these farm
sites in 1976.
Cotton was picked twice on three of the experimental
sites in order to obtain a measure of the effect of N rate on
earliness. In general, it has been observed over the years
that opening of cotton is delayed by increasing N rates.
Two of the experiments in 1976 showed this expected
result, while the third experiment showed the reverse
effect. No explanation is offered for the results on the J.W.
Jeffries farm in Colbert County where cotton receiving
the lowest N rate (30 pounds per acre) was the latest to
open.
The results with 
cotton in these 
two "poor cotton" 
years
are not expected to be a good measure of the nitrogen re-
quirement for high cotton yields during "good" years. Past
experience suggests that future experiments in "good"
years will show a definite yield advantage for more than 30
pounds of nitrogen per acre.
TABLE 1. EFFECT OF LUIME ON SOYBEAN YIELDS, 1975-1976
Soil Unlimed Per-acre yield
Farmer County Soil type group' 
soil pH Unlimed Limed
Highland Rim soils
J. LeGrand Lawrence Mountview silt loam 
2 4.9 27.22 35.12
H. Ruf Limestone Mountview cherty silt loam 2 
5.1 29.8 33.4
J.E. Blankenship Madison Mountview silt loam 2 4.7 
26.22 41.02
F. and E. Austin Lauderdale Dickson silt loam 5 4.9 17.92 
25.42
W. Ridgeway Limestone Mountview cherty silt loam 2 5.0 21.8 
22.6
E. Zirbel Limestone Dickson silt loam 2 5.6 26.2 
26.5
Tenn. Valley soils
O. Sockwell Colbert Dewey silt loam 5 
4.9 24.2 22.3
Moore and
Hollingsworth Limestone Decatur silt loam 2 5.1 19.4 
22.3
D. White Limestone Decatur silt loam 2 4.5 13.62 22.02
Stream Terrace soils
C. Burton Marshall Holston loam 2 4.8 27.4 41.6
C. Jacobs Jackson Sequatchie sandy loam 2 5.7 41.7 43.0
Appalachian Plateau soils
L. Beck Marshall Wynnville sandy loam 2 5.0 30.1 33.6
A.G. Miller Marshall Wynnville sandy loam 2 5.0 32.92 44.62
R. Sloman Marshall Wynnville sandy loam 2 4.9 31.52 44.42
P. Bartlett Marshall Hartsells sandy loam 2 4.9 28.1 29.7
R. Rhoades Marshall Wynnville sandy loam 2 5.2 22.92 43.42
L.D. Whisenant Marshall Wynnville sandy loam 2 4.8 7.22 23.42
'Based on soil texture and cation-exchange capacity, as classified by Auburn's Soil Testing Laboratory.
2
Yield is statistically greater on limed plots.
TABLE 2. EFFECTS OF PHOSPHORUS AND POTASSIUM FERTILIZER ON SOYBEAN YIELD, 1975-1976.
Soil-test values
Soil P K Fert. rate' Per-acre yield
Farmer County Soil type group Lb/A Rating Lb/A Rating P
2 
0
5
-K
2
0 No fert.Fert.
Lb/A Bu. Bu.
Highland Rim soils
W. Darby Lauderdale Dickson silt loam 5 8 60L 132 80M 120-120 21.7 24.6
J. Black Limestone Mountview silt loam 2 8 40L 98 80M 80-80 25.1 27.9
F. and E. AustinLauderdale Dickson silt loam 2 10 40L 116 80M 130-130 22.4 25.4
E. Zirbel Limestone Dickson silt loam 2 46 100M 128 90H 80-80 22.5 24.8
Tennessee Valley soils
E. Black Limestone Bewleyville silt loam 2 5 
30L 134 90H 120-120 19.42 29.72
L. Hitt Morgan Allen sandy loam 2 15 60L 129 90H 100-100 29.2 32.8
J. Clift Madison Bewleyville silt loam 2 25 70L 86 70M 150-150 34.9 34.9
Stream Terrace soils
J. Rowe Morgan Capshaw loam 2 17 60L 76 70M 80-80 41.0 42.6
C. Jacobs Jackson Sequatchie sandy loam 2 118 240VH 156 100H 100-100 45.2 43.0
Appalachian Plateau soils
L.D. Whisenant Marshall Wynnville sandy loam 2 18 60L 98 80M 80-80 20.2 23.4
J.L. Beck Marshall Townley loam 2 28 80M 118 80M 80-80 31.2 27.0
'All fertilizer broadcast prior to planting.
2
Yield is statistically greater on fertilized plots.
TABLE 3. EFFECT OF LIME ON YIELD OF SEED COTTON, 1975-1976.
Soil Unlimed Per-acre yield
Farmer County Soil type group soil pH Unlimed Limed
Lb. Lb.
Highland Rim soils
P. and T.
Williamson Limestone Mountview silt loam 2 4.9 1,3801 1,6701
Tenn. Valley soils
G. Johnson Lawrence Dewey silt loam 2 4.9 830 840
J. Newby Limestone Decatur silty clay loam 5 5.1 950 1,100
D. Bridgeforth Limestone Emory silt loam 5 5.2 2,060 1,970
M. Haney Limestone Decatur silt loam 5 5.4 1,560 1,580
P. Byrd Lawrence Waynesboro sandy loam 2 5.6 560 630
Stream Terrace soils
G. Brown Cherokee Holston silt loam 2 5.5 1,390 1,490
'Yield is statistically greater on limed plots.
TABLE 4. EFFECT OF NITROGEN (N) RATES ON YIELD OF SEED COTTON, 1976.
Soil Per acre Bolls open
Farmer County Soil type group N rate yield' at 1st pick
Lb/A Lb. Pct.
Tenn. Valley soils
30 1,060 33
Mauldin Farms Lawrence Emory silt loam 5 60 1,010 29
90 1,020 27
120 940 25
30 960 49
J.W. Jeffries Colbert Dewey silt loam 2 60 930 60
90 750 67
120 930 69
30 1,050 -
B. Lovelady Jackson Decatur silt loam 
5 60 1,010 -
90 1,160 -
120 1,160 -
Stream Terrace soils
30 1,740 52
W. Davis Cherokee Holston loam 2 60 1,760 44
90 1,710 37
120 1,520 37
7
Nitrogen rates had no effect on 
yields.
t o all W th O u t Le r n is .orforigiat