Progress Report Series No. 89 y, 1968
Progress Report Series No. 89 February, 1968
Agricultural Experiment Station
AUBURN UNIVERSITY
2. V. Smith, Director
Auburn, Alabama
LIIMARYk
SOIL FERTILITY EX .TS
WITH EANUTS IN 1967
DALLAS HARTZOG and FRED ADAMS, Department of Agronomy and Soils
A COOPERATIVE RESEARCH PROGRAM between farm-
ers and Auburn University was begun in 1967 to
better define soil fertility requirements of peanuts
and to improve correlation between fertilizer require-
ments and soil-test values. The success of the pro-
gram was made possible by the cooperation of many
county Extension personnel.
Experiments were located on farmers' fields after
peanuts had emerged to a stand. Each area selected
had a uniform stand on reasonably uniform soil.
Each farmer fertilized, planted, and handled peanuts
within the test-area the same as those in the re-
mainder of the field throughout the growing season.
Each selected area was divided into 8 plots, each
being 4 rows wide and 100 ft. long. The experi-
mental treatment consisted of topdressing with either
calcium, potassium, magnesium, or boron on 4 of
the 8 plots, with nothing added to the other 4. Cal-
cium was used as a topdressing at early blooming
time and potassium, magnesium, and boron were
applied immediately after emergence of seedlings.
Twenty-nine experiments were conducted in 1967
it niine counties 
(Barbour, Bullock, 
Coffee, Coving-
ton, Dale, Geneva, Henry, Houston, Pike). Seven-
teen experiments were partially or completely har-
vested (6 in Geneva, 3 in Covington, 2 each in Bul-
lock, Coffee, Dale, and Pike). Some experimental
plots were only partially harvested because of irregu-
lar stands in some or because the farmer's harvesting
equipment was unsuitable for obtaining accurate
yields from small areas.
CALCIUM (Ca) EXPERIMENTS
Six experiments were harvested in which calcium
was applied as a topdressing at early blooming; five
at a rate of 1,000 lb. of gypsum per acre and one at
500 lb. (This is considered to be in excess of the
amount usually needed). Soil-test Ca ranged be-
tween low (225 lb./A) and high (484 lb./A), and
soil pH ranged between 5.0 and 6.4. Calcium was
added either as lime or as gypsum by farmers on
the entire test areas of two experiments, but only
experimental calcium was added in the other four.
Results of the calcium experiments are summarized
in Table 1.
The Early Runner variety failed to respond to
extra calcium. Two soils initially tested "high" in
TABLE 1. THE EFFECT OF TOPDRESSING CALCIUM AT RATE OF 1,000 POUNDS PER ACRE OF GYPSlUM ON YIELD AND PER 
CENT SOUND
MATURE KERNEL (SMK) OF PEANUTS IN 1967
County
Coffee
Geneva
Covington
Soil type
Norfolk sandy loam
Norfolk sandy loam
Tifton sandy loam
Soil pH 
Soil-test
Ca
Lb./A.
Early Runner variety
5.0 254(L)
5.3 484(H)
6.4 448(H)
Florigiant variety
R. E. Bryant Covington Tifton sandy loam 5.5 240(L) 1,700
H. Thompson Dale Norfolk sandy loam 5.2 225(L) 2,850
E. C. Brooks Coffee Tifton sandy loam 5.4 2483(L) 
1,600
* Farmer added 500 lb. of gypsum per acre to all plots; experimental rate was 500 lb./A.
** Farmer added 1,500 lb. of lime per acre to all plots.
Farmer
G. Hataway
G. Shields*
J. Goolsby**
Yield
No extra
Ca
Lb./A.
2,280
2,560
3,060
Extra
Ca
Lb./A.
1,950
2,510
3,020
1,910
2,980
1,770
SMK
No extra
Ca
Pct.
70
74
71
67
78
71
Extra
Ca
Pct.
70
73
72
67
74
73
calcium and each received a calcium application by
the farmer. Although the third soil contained a
"medium" level of calcium, it had a pH probably
too low for peanuts. A fact that is frequently mis-
understood about soil pH and calcium is that gypsum
does not neutralize soil acidity but tends to lower
soil pH.
Yields of the Florigiant variety were not increased
by extra calcium, even though soil-test calcium meas-
ured "low" and no calcium was added by the farmers.
The extra calcium had no effect on per cent SMK,
per cent fancies, or per cent extra large kernel.
POTASSIUM (K) EXPERIMENTS
Four experiments were harvested in which potas-
sium fertilizer was used as topdressing in the row
soon after seedling emergence at the rate of 50' lb.
per acre of K (60 lb. K
2
0). This was in addition to
potassium used by farmers, which varied from none
to 60 lb. per acre of K(72 lb. K
2
0). Soil-test K varied
from "low" (52 lb./A) to "high" (129 lb./A). Re-
sults of the potassium experiments are summarized
in Table 2.
nesium experiments are summarized in Table 3.
Relatively high yields were obtained in both ex-
periments, and extra magnesium had no effect on
yield or quality of nuts.
BORON (B) EXPERIMENTS
Five experiments with boron were harvested, three
in Geneva County and two in Pike County. Boron
was applied as topdressing in the row soon after
planting at the rate of 1 lb. per acre of B. Accurate
yields were obtained from only two experiments,
but accurate measurements of per cent sound ma-
ture kernel and "hollow-heart" were obtained from
all five experiments. Since boron deficiency appears
in peanuts as "hollow-heart," this is an important
measurement to make in boron experiments. Results
of the boron experiments are summarized in Table 4.
Boron fertilizer did not affect yields in the two
experiments harvested for yields, but apparently in-
creased per cent SMK in one experiment (L. Davis
farm). Per cent SMK was not affected by boron
fertilizer in other experiments. However, boron fer-
tilizer greatly reduced the incidence of hollow-heart.
TABLE 2. THE EFFECT OF EXTRA POTASSIUM AT RATE OF 50 POUNDS PER ACRE OF K (60 POUNDS K
2
0) ON YIELD AND PER CENT
SOUND MATURE KERNEL (SMK) OF PEANUTS IN 1967
Farmer County
A. Barnes Geneva
T. Seay Geneva
W. L. Piland Covington
Soil type
Orangeburg sandy loam
Norfolk sandy loam
Ruston sandy loam
W. F. Morton Dale Ruston fine sandy loam
11 Multiply pounds of K by 1.2 to obtain pounds of
Farmers
Soil-test 
Farmer
K 
ffert.
K K*
Lb./A. Lb./A.
Early Runner variety
129(H) 35
102(M) 41
52(L) 0
Florigiant variety
71(M) 60
K20.
Yield
No extra Extra No extra
K K K
Lb./A. Lb./A. Pct.
1,550
2,530
1,930
1,110
Iffl
I~Lilo
1,730
2,750
1,660
1,140
74
74
74
74
Extra potassium fertilizer failed to increase yields
or affect SMK values of peanuts in any of the experi-
ments, regardless of soil-K level or yield level.
MAGNESIUM (Mg) EXPERIMENTS
Two experiments with magnesium were harvested,
both with the Early Runner variety and both in
Bullock County. Magnesium sulfate was used as
topdressing in the row soon after planting at the
rate of 20 lb. per acre of Mg. Results of the mag-
Hollow-heart was identified by splitting a sample of
peanuts and visually estimating the presence or ab-
sence of hollow-heart in each nut. By this rapid
visual procedure, peanuts are considered to be free
of boron deficiency and hollow-heart, and the grower
is not penalized, if the sample contains less than 1%
hollow-heart.
Soil boron and per cent hollow-heart were also de-
termined on all other experiments in 1967. Hollow-
heart was found in four other experiments (Brooks,
Morton, Piland, and Mitchell farms). It was not
TABLE 3. THE EFFECT OF ADDING MAGNESIUM SULFATE AT THE RATE OF 20 POUNDS PER ACRE OF MG ON YIELD AND 
PER CENT SOUND
MATURE KERNELS (SMK) OF PEANUTS IN 1967
County Soil type
Bullock Ruston sandy loam
Bullock Susquehanna stoney sandy loam
Soil-test
Mg
Lb./A.
18(L)
42(H)
Yield
No Mg Added Mg
Lb./A. Lb./A.
2,860 2,740
2,750 2,850
SMK
No Mg Added Mg
Pct. Pct.
75 74
73 74
SMK
Extra
K
Pct.
74
75
75
74
Farmer
J. R. Mitchell
B. East
111 1\ V 1 1111~ 1111 111~
found where farmers applied boron to peanuts in
1967.
SUMMARY
Results of experiments in 1967 strongly suggest
that peanut yields were limited by factors other than
fertilizer rates. In no case did the surface applica-
tion of gypsum, potassium, magnesium, or boron ap-
preciably increase yields.
Similar experiments on farmers' fields are planned
for 1968 in the continuing effort to improve the basis
for fertilizer recommendations for peanuts.
TABLE 4. THEEFFECT OFBORONAPPLIED ATRATE OF 1 POUND PER AcROF BON YIELD,, PER CENT SOUND MAmmI KERNEL (SMK),
AND PER CENT HOLLOW-HEART OF PEANUTS IN 1967
Yield
No B Added B
Lb/1A. Lb./A.
SMK
No B Added B
Pct. Pct.
Hollow-heart
No B Added B
Pct. Pct.
Norfolk sandy loam
Norfolk sandy loam
Kalmia fine sand
Pike Orangeburg coarse sanc
Early Runner variety
0.18 ---
0.10 2,100
0.07 1,60
Virginia Bunch 67 variety
0.11 ---
Dixie Runner variety
,980
1,760
71
64
65
71
65
72
0
0
0
65 62 1 0
M. Barron" Pike Orangeburg sand 0.07- 46 48 3
'~ Peanuts exposed to inclement weather for long period between digging and harvesting, resulting in unusually low-quality nuts and
much internal damage.
Farmer County Soil type
Soil-test
B
T. Davis
M. Austin
L. Davis
T. Harden
Geneva
Geneva
Geneva
Lb./A.