Progress Report Series No. 101
Agricultural Experiment Station
AUBURN UNIVERSITY
R. Dennis Rouse, Director
Auburn, Alabama
Soil Fertility Experiments .with Peanuts 
in 19721.
Dallas Hartzog 
and Fred Adams
2
T HE COOPERATIVE RESEARCH PROGRAM, which be-
gan in 1967, to better define soil fertility require-
ments of peanuts was continued in 1972. This pro-
gram is especially intended to improve correlation
between fertilizer requirements and soil-test values.
This is accomplished by conducting experiments on
farmers' fields throughout the peanut growing area
of southeastern Alabama. The selection of experi-
mental sites is based on soil testing. Thirty-three
experiments in eight counties were initiated in 1972
and 23 were harvested (7 in Dale, 4 in Barbour, 3
in Henry, 2 each in Crenshaw, Geneva, Houston,
and Pike, and 1 in Coffee).
The experimental area on each farm was divided
into the required number of plots, each plot being
4rows wide and 100 feet long. Each farmer planted,
cultivated, sprayed, and harvested peanuts within
all plots the same as those in the remainder of his
field.
All experimental materials were applied by the
researchers. Four plots in each experiment received
no treatment; the remaining plots consisted of four
replications of one or more of the following treat-
ments: (1) a phosphorus-potassium fertilizer, (2)
gypsum, (3) basic slag, (4) "Magi-Cal," (5) boron,
or (6) lime..
FERTILIZER (P AND K) EXPERIMENTS
Five experiments were conducted to determine if
fertilizer applied in the spring would increase pea-
nut yields on soils testing "low" or "medium" in
either phosphorus (P) or potassium (K). In three
of these experiments, the fertilizer was broadcast
and then disked-in (Croft, Martin, and Buie farms).
In the other two, the fertilizer was broadcast and
then turned under (Baker and Deloney farms). The
crop preceding peanuts was corn on two fields; the
other three had been idle in 1971.
Financial assistance of the Alabama Peanut Producers Associa-
tion for this project is gratefully acknowledged.
' Research Associate and Professor, respectively, Department of
Agronomy and Soils.
Each fertilizer experiment consisted 
of eight plots.
Four plots in each experiment received 400 
pounds
per acre of 0-10-20 fertilizer broadcast; 
the other
four plots received no fertilizer.
Three experiments were with the 
'Florigiant'
variety and two were with the 'Florunner'. Three
soils tested "low" in phosphorus (P) 
and two "med-
ium"; three tested "low" in potassium 
(K) and two
"medium"
The results of these experiments are given in Table
1, and they continue to confirm results 
from previous
years. Although some yields were 
relatively low be-
cause of an extended drought, they show that ferti-
lizer did not increase yield or grade of peanuts in a
single experiment. These experiments 
show once
again that a direct application of fertilizer 
to peanuts
is not a profitable practice. They support 
Auburn's
recommendation that fertilizer should be applied to
the crop that precedes peanuts in the rotation 
and
not to peanuts directly. Even previously idle land
needed no additional fertilizer to give maximum
peanut yields.
CALCIUM (Ca) EXPERIMENTS
Topdressing gypsum at early bloom is a common
and effective practice of supplementing the soil's
supply of available calcium to peanuts. This is a
money-making practice on soils with too little avail-
able calcium but a bothersome and uneconomical
practice on soils with adequate calcium. Conse-
quently, a major objective of soil testing for peanuts
is to identify those soils that need supplemental cal-
cium to produce maximum yields of top-quality nuts.
Fifteen such experiments with gypsum topdressed
at 500 pounds per acre were harvested in 1972. Four
of these experiments simply compared gypsum with
"no calcium". 
Four others compared 
basic slag as
well as gypsum with "no calcium". Three others com-
pared "Magi-Cal" as well as gypsum with "no cal-
cium". (Magi-Cal is the trade name of a concentrated
suspension of extra fine gypsum that its manufacturer
recommends be sprayed onto peanut foliage). Four
February 1973
TABLE 1. EFFECT OF BROADCAST FERTILIZER ON YIELD AND SMK OF 'FLORIGIANT AND FLORUNNER PEANUTS, ALABAMA, 
1972
Variety and farmer County Soil type
1971
crop
Soil-test values Yield per acre'
pH P K No fert. Fert.
Lb./A. Lb./A. Lb. Lb.
SMK'
No fert. Fert.
Pet. Pct.
Florigiant
P. L. Baker Dale Lucy loamy sand 
corn 6.1 40(M) 32(L) 1,550
G. Croft-------------- Dale Fuquay loamy sand 
corn 5.4 15(L) 17(L) 2,350
F. C. Martin Barbour Blanton loamy sand 
idle 6.3 7(L) 29(L) 2,150
Florunner
W. Buie--------------- Houston Unclassified 
rye-idle 6.2 32(M) 43(M) 1,590
B. Deloney, Jr. Dale Lucy loamy sand idle 
5.8 14(L) 47(M) 3,240
' Fertilizer did not statistically increase or 
decrease yield or percentage SMK.
additional experiments compared 
spring-applied lime
as well as gypsum with 
"no calcium".
These 15 experiments were on soils that 
ranged
in soil Ca from a low of 140 
pounds per acre to a
high of 528. The soils also 
ranged in pH from a low
of 5.0 to a high of 6.3. The experiments are 
grouped
as follows: (1) gypsum alone, 
(2) gypsum and basic
slag, (3) gypsum and "Magi-Cal", 
(4) gypsum and
lime.
Gypsum alone. Each of the 
four experiments in
Table 2 consisted of 
four plots with topdressed
gypsum and four plots 
without. With soil Ca 
at
194 pounds per acre (medium) 
gypsum increased
yield of 'Florigiants' on F. C. Martin's 
farm by 990
pounds and grade (SMK) 
by 14 percentage points.
'Florunner' yield and 
grade were increased 
similar
amounts on the "low" Ca 
soil of the Deal Brothers.
The experiment on the 
Baxley Farms was located
on an area with two distinctly 
different levels of
soil Ca. Consequently, the 
results of this experi-
ment are divided 
into "A" and "B" 
parts. The "A"
soil had 528 pounds of Ca and yield was unaffected
by gypsum;- the "B" 
soil had only 140 pounds 
of Ca
and yield was increased more 
than 1,600 pounds by
gypsum.
Gypsum versus 
basic slag. Of 
the four experiments
comparing gypsum and 
basic slag, three were
"medium" and one was 
"low" in Ca, Table 3. 
The
"low" Ca soil was on the Thrash farm with soil Ca
at 174 pounds per acre 
and soil pH at 5.0. On 
this
soil, neither gypsum nor slag increased yield. How-
ever, both increased grades - gypsum 
by six points
and basic slag by four points. Neither 
gypsum nor
slag affected yields or grades on the 
three "medium"
Ca soils.
Gypsum versus "Magi-Cal". There 
have been
numerous claims that liquid, sprayed-on 
calcium ma-
terials are effective sources of available calcium to
peanuts. Such claims are contrary to the scien-
tifically established fact that calcium cannot be sup-
plied to the nuts via the leaves. Nevertheless, farm-
ers continue to buy and use these spray-on ma-
terials. One such material is "Magi-Cal", and its
use by farmers prompted three experiments with
it in 1972. The results are given in Table 4. Two
of the soils proved to be deficient in Ca. Yield was
increased 860 pounds by gypsum on the 
Deloney
farm. Correspondingly, grade (SMK) was 
increased
19 percentage points. Although yield was unaffected
by gypsum on the Croft farm, grade was increased by
12 points. In contrast to these results, "Magi-Cal"
was worthless, increasing neither yield nor grade.
The third soil was not deficient in Ca because
gypsum failed to increase yield or SMK. Neither did
"Magi-Cal" affect yield or grade.
Gypsum versus lime. Four experiments were har-
vested in which the effect of spring-applied lime
was compared to that of topdressed gypsum. A fifth
experiment simply measured the effect of lime. Lime
was applied in each case at the rate of 1 ton of dolo-
TABLE 2. EFFECT OF TOPDRESSING CALCIUM AT RATE OF 500 POUNDS 
PER ACRE OF GYPsuM ON YIELD AND PER CENT SOUND
MATURE KERNELS (SMK) OF PEANUTS, ALABAMA, 1972
Soil Soil-test Yield per acre SMK
Variety and farmer County Soil type 
pH Ca No Ca Gypsum No Ca Gypsum
Lb./A. Lb. Lb. Pct. Pet.
Florigiant
F. C. Martin ------------ 
Barbour Blanton 
loamy sand 6.3 
194(M) 1,0501 2,0401 
462 602
Florunner
Deal Bros-... Dale 
Blanton sand 5.8 152(L) 
640' 1,8401 58' 70'
Baxley Farms--A------------------ Geneva Dothan 
loamy sand 5.8 528(H) 2,500 2,260 
68 68
Baxley Farms-B - Geneva 
Dothan loamy sand 5.4 140(L) 7301 
2,3501 59 67
Bolin Farms Geneva 
Dothan loamy sand 5.7 310(H) 
3,220 3,100 70 70
1 Yield is statistically greater on plots receiving 
gypsum.
SPercentage SMK is statistically greater on plots receiving gypsum.
63
67
69
1,640
2,460
2,210
1,770
3,220
62
64
67
62 65
77 76
TABLE 3. EFFECT OF TOPDRESSING CALCIUM AT RATE OF 500 POUNDS PER ACRE OF GYPSUM OR BASIC SLAG ON YIELD AND
PER CENT SOUND MATURE KERNELS (SMK) OF PEANUTS, ALABAMA, 1972
Variety and farmer
County Soil type
Soil Soil-test Yield per acre SMK
pH Ca No Ca Gypsum Basic slag No. Ca Gypsum Basic slag
Lb./A. Lb. Lb. Lb. Pct. Pct. Pct.
Florunner
G. Holmes Crenshaw Norfolk loamy sand 5.4 240(M) 3,700 3,700 3,910 73 76 74
F. Thrash Pike Dothan loamy sand 5.0 174(L) 3,490 4,080 3,800 67' 
731 711
J. Bagents Crenshaw Brodgen loamy sand 5.2 296(M) 1,650 1,770 
1,410 70 72 68
L. Long ............................. Pike Norfolk loamy sand 5.1 210(M) 3,600 3,680 3,650 68 70 70
1Percentage SMK is greater on plots receiving gypsum or basic slag.
TABLE 4. EFFECT OF "MAGI-CAL"' IN COMPARISON TO GYPSUM (500 LB. PER ACRE) ON YIELD AND PER CENT SOUND
MATURE KERNELS (SMK) OF PEANUTS, ALABAMA, 1972
Soil Soil-test Yield per acre 
SMK
Variety and farmer County 
Soil type SH 
C Ye p a
Variety and farmer pH 
Ca No Ca Gypsum Magi-Cal No Ca Gypsum 
Magi-Cal
Lb./A. Lb. Lb. Lb. Pct. Pct. Pct.
Florigiant
B. Deloney, Jr.------------------ Dale McLaurin loamy sand 5.5 179(M) 6702 1,530 
310 43' 62' 413
G. Croft .--------------------------. Dale Fuquay loamy sand 5.8 205(M) 1,840 
2,250 1,390 48' 60' 41
Florunner
G. Holmes ........................ Crenshaw Norfolk loamy sand 5.4 240(M) 3,700 3,700 3,640 73 76 74
1 "Magi-Cal" was applied at 2-week intervals, beginning at early pegging, at rate of 5 qt. per spray; 'Florunners' were sprayed twice;
'Florigiants' were sprayed three 
times.
'Yield is statistically greater on plots receiving gypsum.
3 Percentage SMK is statistically greater on plots receiving gypsum.
mite per acre on turned and disked land in the plot yields in some of the other experiments. Con-
spring. The lime was disked-in prior to planting sequently, apparent 
differences in yields are no
peanuts. The results of these experiments are given more than random variation in those cases. Grade
in Table 5. Liming increased yields in two of the was increased by both gypsum and liming only on
five experiments (Hartzog and Blankenship farms), the Blankenship farm. In the two experiments where
even though yields were severely limited in both lime increased yield, lime was beneficial on the
instances by unusually droughty conditions. The Hartzog farm because it raised pH and on the
droughty conditions also caused unusually erratic Blankenship 
farm because it supplied Ca.
TABLE 5. EFFECT OF LIME AND GYPSUM ON YIELD AND SMK OF PEANUTS, ALABAMA, 1972
Soil Soil-test Yield per acre SMK
pVariety and farmer County Soil type H Ca No lime Lime Gypsum No lime Lime Gypsum
Florunner Lb./A. Lb. Lb. Lb. Pct. Pct. Pct.
J. Hartzog------------- Barbour Sunsweet sandy loam 5.0 213(M) 770 1,350' 1,070 68 72 
72
P. W. Blankenship Dale Lucy loamy 
sand 5.3 174(L) 1,2501 1,730 1,980' 
61' 66' 692
T. Kirkland Dale Faceville sandy loam 5.3 254(M) 1,360 1,770 1,690 67 68 
67
R. Ward-------------- Henry Varina sandy loam 5.4 160(L) 1,070 1,580 1,500 63 68 68
G. Paramore Houston Dothan loamy sand 5.6 292(M) 3,450 3,520 - 74 74
1 Yield is statistically greater on plots receiving lime or gypsum.
SPercentage SMK is statistically greater on plots receiving lime or gypsum.
TABLE 6. EFFECT OF BORON FERTILIZER ON YIELD AND PER CENT SOUND MATURE KERNELS (SMK) OF PEANUTS, ALABAMA, 1972
Variety and farmer County Soil type 
Soil-test Yield per acre 
SMK
Soil-test Herb. Fung. Herb. Fung.
Variety and farmer County 
Soil type B No B +rb 
F+R No B +Rb
1  
+B
2
Lb./A. Lb. Lb. Lb. Pct. Pct. Pct.
Florigiant
F. C. Martin Barbour Blanton loamy sand 0.11 
2,080 1,900 2,240 66 67 70
Florunner
Mobley Bros. Henry Fuquay loamy sand 0.11 
2,610 2,620 69 69 67
Wiregrass Substation Henry Dothan sandy loam 0.29 
3,110 3,430 3,210 69 70 68
' Mixture of 1 lb. boron + 3 qt. Balan ? 3 pt. Vernam in 20 gal. water applied 
per acre as preplant and incorporated.
_ Mixture of 0.15 lb. boron + 6 oz. Benlate in 10 gal. water per acre applied 
as first two sprays for leafspot control.
BORON (B) EXPERIMENTS
Three experiments were harvested in which boron
was added to peanuts. In each of these tests, there
were two methods of boron application.
(1) Boron mixed with herbicide: preplant incor-
poration of 1 pound of boron in a tank mixture of
3 quarts of Balan and 3 pints of Vernam using 20
gallons of water per acre.
(2) Boron mixed with fungicide: 0.15 pound of
boron sprayed-on twice in June in 6 ounces of Ben-
late fungicide at 2-week intervals using 10 gallons
water per acre for each spraying.
These experiments were intended primarily to de-
termine the feasibility of adding boron by these pro-
cedures. Since adding boron to peanut fertilizers is
a general practice that has about eliminated boron
deficiency, no special effort was made to locate B-
deficient soils for these tests. A significant finding of
these tests is that no problems were encountered in
applying boron by either method. The yields and
grades are given in Table 6 and show no effect from
the applied B. Although no boron deficiency-"hol-
low-heart"-was found in these experiments, the
most significant result was that there was no evi-
dence of boron toxicity from the herbicide-boron
mixture or from the Benlate-boron experiments.
SUMMARY OF 1967-1972
The last 6 years of experimentation on farmers
fields have shown the following:
There have been no yield increases from 
directly-
applied P and K fertilizers in 34 experiments.
Gypsum in 57 experiments increased yields only
on soils with soil-test Ca at about 200 pounds per
acre or less.
Boron in 23 experiments increased quality of nuts
on soils very low in boron.
Neither basic slag nor Fairfield slag appears to
be a satisfactory source of calcium when applied at
blooming time.
"Magi-Cal" sprayed on peanuts during blooming
and pegging time is not a satisfactory source of
calcium.