xt7hx34mn39d https://exploreuk.uky.edu/dips/xt7hx34mn39d/data/mets.xml   Kentucky Agricultural Experiment Station. 1957 journals 059 English Lexington : Agricultural Experiment Station, University of Kentucky Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Progress report (Kentucky Agricultural Experiment Station) n.59 text Progress report (Kentucky Agricultural Experiment Station) n.59 1957 2014 true xt7hx34mn39d section xt7hx34mn39d IN KENTUCKY, 1948 -1956
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AGRICULTURAL EXPERIMENT STATION
UNIVERSITY OF KENTUCKY
L E X I N G T O N

 CONTENTS
Page
INTRODUCTION .°..... D D D D D D D D D D D D D D 3
LOCATION OF FERTILITY EXPERIMENTS ............. D 3 V
ROTATION EXPERIMENTS WITH GENERAL GROPS ..... D D D D D D D 3
GENERAL FERTILITY EXPERIMENTS ,... D D D D D D D D D D 3
Berea Soil Experiment Field D D D D D D D D D D D D D D 3
Campbellsville Soil Experiment Field D D D D . D D D D D D 5
Greenville Soil Experiment Field D D .... D D D D D D 7
Mayfield Soil Experiment Field D D .D D D D D D D D D D D 9
Western Kentucky Substation D D D D D D D D D D D D D D 12
TWO-YEAR ROTATIONS OF CORN AND WHEAT D D D D D D D D D" D D D 14
Greenville Soil ExperimentField D D D D D D D D D D D D D lh
Western Kentucky Substation D D D D D D D D D D D D D D 16
LEGUMES IN ROTATION D D D D D ..... U ..,.... 17
Western Kentucky Substation D D D D D D D D D D D D D D 17
Greenville Soil Experiment Field D D D D D D D D D D D D 18
EXPERIMENTS COMPARING VARIOUS SOURCES OF PHOSPHORUS D D D .¤..¤ 18
ROTATTON EXPERIMENTS ..... D D D D DD D D D D D D D 19
Campbellsville Soil Experiment Field D D D D D D D D D D D 19
Western Kentucky Substation D D D D D D D . D D D D D D 20
Greenville Soil Experiment Field D D D D D D D D D D D D 22
Residual Effects of Phosphorus from Various Sources D D D D D D 23
ANNUAL EXPERIMENTS D D D D D D D D D D D D D D D D D D 2¤
Sources of Phosphorus for Corn D D D D D D D D D D D D D 2U
Sources of Phosphorus for Wheat D D D D D D D D D D D D D 28
Sources of Phosphorus for Sudan Grass .... D D D D D D D 30
Sources of Phosphorus for Pasture D D D D D D D D D D D D 32
Sources of Phosphorus for Alfalfa ..... D D D D D D D 32
Effectiveness of Various Sources of Phosphorus D D D D D D D D 33
RASTURE EXPERIM NTS °.,°.. D ....¤¤. D D D D D 33
Greenville Soil Experiment Field D D D D D D D D D .... 33
Simpson County Pasture Experiment D D D D D . D D D D D D D 3U
ALFALFA EXPERIMENTS D D D D D D D D .......¤.» 37
Greenville Soil Experiment Field D D D D D D D .».° D D 37
Western Kentucky Substation D D D D D D D D D D D D D D D 37
Simpson County D D D D D D D D D D D D D D D D D D D 39
TOBACCO EXPERIM NTS D D D D D D D D D DD D D D D D D D D D 39
BURLEY TOBACCOD D D °¤¤¤....... D D D D D D 39
Campbellsville Soil Experiment Field D D D D D D D D D D D 39
Greenville Soil Experiment Field D D D D D D D D D D D D Ml
Western Kentucky Substation D D D D D D D D D D D D D D U5
Dm TOBACCO D.DD.,.............. *+8
Western Kentucky Substation D D D D D D D D D D D D D D UB
FERTILIZER TESTS WITH CORN DDDDDDDD D DDDDD DD D #9
River Bottoms DDDDDDDDDDDDD D D D D D D #9
Upland Soil D D D D D D D D D D D D D D D D D D D D D 53
Creek Bottoms D D D D D D . D D D D D D D D D D D D D 54
GRAIN SORGHUM EXPERIM NTS D..DD.DD D DDDDDDD D 55
2

 SUMMARY QF FERTILITY EXPERIMENTS IN KENTUCKY, lQb8-56
By E. C. Doll, L. A. Link, and A. L. Hatfield
.` INTRODUCTION
A Proper use of commercial fertilizers is essential for profitable crop pro-
duction on most Kentucky soils. The Agronomy Department of the University of Kentucky
Agricultural Experiment Station, carries on an extensive program to determine the best
fertilizer and soil management practices for the production of most of the common
field crops grown in Kentucky. Results obtained from l9U8 through 1956 are presented
in this summary. In most cases the data are self—explanatory, but a brief statement
describing the results is generally given. Since this is only a summary, no discus-
sions of the results or recommendation are included. V
I LOCATION OF FERTILITY EXPERIMENTS
Long—time fertility and soil management experiments are being conducted on the
‘ Campbellsville Soil Experiment Field in Taylor county, the Greenville Soil Experiment
Field in Muhlenberg county, and at the Western Kentucky Substation in Caldwell county.
Long—time experiments have recently been discontinued at Berea in Madison county and M
at Mayfield in Graves county. In addition to these permanent locations, numerous
experiments are conducted on leased land throughout the state for shorter periods.
V ROTATION EXPERIMENTS WITH GENERAL CROPS ·
A number of experiments have been conducted to determine the general ferti-
lizer requirements of crops grown in a rotation, and some have been designed primarily
to evaluate the effectiveness of various sources of phosphorus.
GENERAL FERTILITY EXPERIMENTS
· Berea Soil Egperiment Field: Work on the Berea Soil Experiment Field was conducted
in cooperation with Berea College. All experiments were discontinued after yields
were obtained in 1955. The soil type has been tentatively correlated as Honongahela
silt loam, and is similar to a number of soils found at the base of the cnain of
Knobs surrounding the Bluegrass regions. These soils are light in color, quite acid,
and low in both phosphorus and potash.
A four—year rotation of (l) corn, (2) wheat, and (3.b) two years of grass-
legume hay was followed on four series of plots, so that each crop in the rotation
was grown every year. Until l9¤8, manure was applied to all plots prior to planting
corn in an amount equivalent to the crops removed from all series the previous year ,
3

 (except wheat grain). After 19M8, the use of manure was discontinued on all but two
plots in each series. On plots ¤a, 5a, 7a, and 9a, phosphate applications were
discontinued starting with corn in 1930. Rates and time of fertilizer applications
per four-year rotation are given below: 1
L — Limestone — 0 tons per acre between 1913 and 1921 ~
— 1 ton per acre between 1928 and 1930
- 2 tons per acre between 1908 and 1951
M - Manure — 10 tons per acre for corn -
N - Nitrogen - Ammonium nitrate at the rate of 60 pounds of
N per acre for corn, and 30 pounds for wheat
(15 pounds in the fall and 15 pounds in the spring}.
SP — Superphosphate - 20% superphosphate at the rate of 120 pounds of
P 0 per acre for wheat.
2 5
BP - Rock Phosphate — 200 pounds of P2O5 per acre applied for wheat
FRP — Rock Phosphate - 2UO pounds of P20 per acre applied as finely
ground rock phospgate for wheat.
-K - Muriate of Potash - 60 pounds of K20 per acre for corn and 30 pounds
for wheat. -
All of the phosphorus was applied in the fall for the wheat, and all of the manure in ‘
the spring for corn. Average yields from 19U8 until the experiment was discontinued _
in 195U are given below:
Corn Wheat Hay
Plot Treatment bu bu lst year 2nd year
lb lb -
 
1 0 2.3 1.0 170 010
la 0 2.7 0.6 120 290
2 L N S P K M5.8 20.5 2590 3100
2a L N F R P K U2.0 16.M 2580 3010
3 O 2.5 0.7 360 500
3a M S P 23.7 5.U 1150 1320
M N S P K 18.5 5.5 1170 890
ba N (SP) K* 12.3 1.3 720 800
5 N R P K 39.0 9.2 1750 2010
5a N (RP) K* 3¤.@ 7.6 1390 1050
6 L N S P 22.1 17.8 1790 2300
es L N * 2¤.s 10.7 1500 1960
7 L N R P 21.1 15.8 2260 2230
7a L N (HP)* 23.8 15.5 1750 1960
8 0 8.0 1.¤ 300 9bO
8a M L S P 39.1 13.2 2730 3310
9 L N S P K ¤3.¤ 22.2 2960 3¤20
9. 1. N (sp) 1<·· 33.6 12.5 1610 2290
10 L N R P K M5.8 19.6 3150 3MlO
10a L N (RP) K* 00.2 15.7 2700 2790
* Phosphate applications discontinued in 1930. Q A
M

 These results show the striking responses obtained at this location for limestone,
phosphorus, and potash.
Campbellsville Soil Experiment Field: Experiments at this field were started in 1919,
and fertility tests have been conducted continuously since that time. The major soil
types on the field have been tentatively correlated as Bedford and Dickson silt loams,
The soil is moderately acid (about pH 5.5), and responds well to applications of lime-
stone and phosphate. After a period of intensive cropping, potash usually becomes
. limiting. The general fertility experiment is designed primarily to determine the
A effects of applications of limestone and phosphate on crop yields, although other
comparisons are included. A three-year rotation of corn, wheat, and mixed grass legume
hay is followed, with each crop in the rotation being grown on one of the three series
each year. Recommended varieties of corn and wheat are seeded, and the hay crop consists
A of a mixture of Kenland red clover, Atlantic alfalfa, Korean lespedeza, orchardgrass,
and red top. When this experiment was begun, manure was applied to all plots (except
one in each series) in an amount equal to the crops removed (except wheat grain);
starting in l9¤8, the use of manure on all plots except 8 and 15 was discontinued. The
following table gives the rates of fertilization and the crops to which the fertilizer
are applied;
L — Limestone — U tons per acre applied between 1919 and 193b
- l ton per acre between l9U8 and 1950
· - 2 tons per acre between 1955 and 1957
M - Manure — 8 tons per acre for corn
N - Nitrogen - Ammonium nitrate at the rate of 90 pounds of -
N (270 pounds ammonium nitrate) per acre for
corn, and 30 pounds per acre for wheat (15 in
the fall, 15 in the spring)
P - Superphosphate - 20% superphosphate at the rate of 90 pounds of
PZO5 per acre rotation; all applied prior to
1 seeding wheat
Bs — Basic slag - Applied prior to seeding wheat at a rate to
supply 90 pounds of PZO5 per acre rotation,
K — Muriate of Potash — Applied at the rate of 90 pounds of K2O per acre
per rotation: 60 pounds of K20 per acre for the
corn and 30 pounds for the wheat
All of the phosphorus is applied in the fall just prior to seeding wheat,
and all the manure (plots 8 and 15) is applied for the corn, The hay is not fertilized,
Every third plot in each series is a check plot, on which no fertilizers are
applied, No fertilizer or manure have been applied to Plot 2 since the experiment
was started in 1919, but all the check plots received applications of manure prior to
the revision in 19b8. The average annual yields obtained since the use of manure was
discontinued in l9¤8 are given in the following table:
5

 Fertilizer Corn (bu) Wheat (bu) Hay (lb)
Plot Treatment 9 crops 8 crops 7 crops
1 O 17.7* 2.8 850
2 0 l1.i+ 1.8 560
» 3 L 19.7 M.1 1050
u 0 16.7 2.5 860 `
5 P 53.6 17-5 3090
6 P K 58.3 18.Q 33bO
7 0 28.3 *+.2 1520 V
8 M P 71.2 22.6 3990
9 N P K 67.9 26.7 3670
10 O 27.7 3.9 1650
11 N Bs K 60.2 30.b ¤760
· 12 L P u5.b 19.2 MO7O
13 O 23.7* M.3 l¤9O
lb L P K 63.2 2M.7 u990
15 L M P 70.5 23.8 1+660 L
16 0 32.8 6.9 1790
17 L N P K 67.9 28.2 5990
18 L N Bs K 65.u 27.0 5730
19 0 38.1 6.5 1830
* Average of 8 crops. _
The greatest response obtained in the experiment has been for the application ,
of phosphate. While the addition of ground limestone has resulted in increased yields,
a comparison of plots 3 and 5 shows that limestone alone is not nearly as effective
in increasing the yields as is phosphate alone. When potash was applied (Plot 6),
yields were increased somewhat (as compared with the yields of Plot 5). When the
yields of Plots 6 and 9 are compared, a very definite response to nitrogen is obtained
for corn and wheat; as would be expected, the nitrogen applications have very little
effect upon the hay yields. This may be explained in two ways; first, nitrogen is
fixed by the legumes in the hay, and second, because of their extreme solubility, ni-
trogen not used by the corn and wheat crops may be readily leached from the soil and
thus usually has a very small residual effect. Other experiments conducted at Lexington
indicate that losses of nitrogen through leaching occur mainly in January, February,
and March.
A comparison of plots 5 and l2 shows that limestone and phosphate together are
verylittle, if any, more effective, than phosphate alone in increasing the yields of
corn and wheat. However, the hay yields are definitely better when both limestone and
phosphate are applied. When the yields obtained on plots l2, lh, and 17 are compared,
it is apparent that approximately the same responses to nitrogen and potash are ob-
tained on the limed as on the unlimed plots.
Basic slag is applied as a source of phosphorus on plots ll and 18. When the
yields of these plots are compared with those of plots 9 and 17. it is evident that
basic slag is equally as effective as superphosphate as a source of phosphorus.
Furthermore, the neutralizing value of basic slag is approximately 80% of that of
pure limestone. The much better hay yields on plot ll as compared with plot 9 are
mostly due to the neutralizing effect of basic slag.
6

 Manure is applied to plots 8 and 15 at the rate of 8 tons per acre prior to
plowing the series for corn. The treatments on plots 8 and 9 and plots 15 and 17 are
designed to determine the relative effectiveness of manure as compared to commercial
fertilizer. The yields of corn are approximately the same on all these plots, but the
wheat yields are definitely poorer on the manured plots. This is mostly due to the
lack of sufficient nitrogen on the plots which receive manure.
Greenville Soil Experiment Field: The Greenville Soil Experiment Field was established
, in 1913. The soil on this field, classified as Tilsit silt loam, is fairly representa-
tive of the upland soils of the Western Coal field and the sandstone area on its borders.
Tilsit silt loam is described as a light yellowish brown, strongly acid silt loam,
underlain by a mottled yellow. brown, and gray silty clay loam hardpan which is 10 to
20 inches thick and lies at depths of from 17 to 25 inches: this soil is moderately well
drained. Under natural conditions, available phosphorus is very low, and potash usually
becomes limiting after the soil is cropped for a short time. Because this soil is
naturally strongly acid, applications of ground limestone are absolutely essential.
These soils respond well to fertilization, and when properly managed, are capable of
producing fairly good crop yields.
In the general fertility experiment, a four—year rotation of (1) corn, (2) wheat,
and (3.G) two years of mixed legume—grass—hay is followed. The main objective is to
V determine the effects of lime and phosphate (supplied as either 20% superphosphate or
raw rock phosphate) upon the yields of the various crops in the rotation. Four series
· of plots enable each crop of the rotation to be grown each year. The various symbols
p used to designate the plot treatments are given in the following table:
L - Ground Limestone - Approximately 6 tons of limestone have been `
applied since 1913-19MB
2 tons applied between 1955 and 1957
fL — Finely—ground
Limestone - 1 ton per acre
M — Manure — 10 tons per acre plowed under for the corn crop
N - Ammonium Nitrate - Applied at the rate of 90 lb of N (or 270 lb of
ammonium nitrate) per acre per rotation; 60 lb of
N for the corn, and 30 lb of N for the wheat.
One—half of the N for the wheat is applied in the
fall, and the other half as an early spring topdressing.
P — 20% Superphosphate - Applied at the rate of 120 lb of P205 (600 lb of
superphosphate) per acre per rotation, except on
plots 1 and 9. Phosphate is applied to plot 1 at
twice the regular rate, and to plot 9 at the rate
of 80 lb of P205 (uoo lb of superphosphate) per acre per
rotation. A11 the phosphate is applied for the
wheat crop.
RP — Rock Phosphate — Applied at the rate of 2UO lb of P205 per acre per
rotation (approximately 720 lb of rock phosphate),
except on plot 5a which receives 200 lb of P205 per acre,
per rotation. All rock phosphate is applied for the
wheat.
7

 RP — Finely ground
Rock Phosphate - One ton of fine rock phosphate applied 1929-32, L
another ton between 19¤8 and 1951. _
K - Muriate of Potash — Applied at the rate of 120 pounds of KgO per
acre per rotation. (200 pounds of 60% muriate of 9
potash). 80 pounds of K20 is applied for the corn
and no pounds of K2O for the wheat. .
Phosphate applications have been omitted on plots 7a, 8a, and 13a since 1929.
When this experiment was initiated in 1913, manure was applied to all plots, except
plot 1, in an amount equal to the total weight of the crops (less wheat grain) removed
during the entire rotation. In 19¤8 the use of manure was discontinued on all plots
except 3a, 5a, and 9. The average annual yields obtained since the revision in 19NB
are given in the following table€
Corn Wheat Hay lb/acre
Plot Treatment bu/acre bu/acre lst year 2nd year
1 L 2(NPK) 06,:. 37.6 U160 3380
la O 8.8 2.3 1190 1070 ·
2 L N K 23.6 9.3 2320 1900 ‘
2a L N {RP K 52.9 26.9 3880 0080
3 0 18.6 5.2 1820 1900
3a M ¤O.6 11.3 2370 2590 ·
0 P . 39.9 17.2 2730 2900
ua £L N P K 56.5 31.6 36MO 3¤60 '
5 R P 38.5 18.M 3190 3100
5a M RP 61.1 23.5 3900 38¤0
6 P K 52.8 18.8 3180 2910
6a N P K 53.*+ 26.i+ 3000 3090
7 L N P K 58.1 3M.M M060 3510
7a L N (P) K L»2..¢+ 16.7 2600 3130
8 L N RP K 63.8 29.8 M000 3800
8a L N (RP) K 58.7 25.2 33bO 3900
9 M L P 61.9 26.7 MONO 3870
9a L N P K 55.9 31.3 UO20 0020
10 0 lb.9 ¤.4 1380 2090
11 L P K 56.9 zu.3 3990 3630
11a I N P K 6¤.9 3u.3 b180 3960
12 RP K 63.0 20.7 MO30 3660
12a N RP_K 68.0 30.9 ul50 U3lO
13 L N RP K 71.9 32.6 u330 0220
13a L N (BP) K 72.2 31.3 M52O QNMO
 
8

 The following table shows the average responses obtained from the different soil
treatmentsz
Increase in Yield
Increase in . Corn Wheat lst year 2nd year
yield due to: Plots compared bu bu Hay,lb Hay,lb
Limestone 6a,7 U.? 8.0 1060 U20
‘ Superphosphate 3,b 21.3 12.0 910 1000
Rock Phosphate 3.5 19.9 13.2 1370 1200
Potasn 1+,5,6,12 18.7 2.0 650 290
Nitrogen 12a,l2,ll,1la 6.5 10.1 160 ¤90
Manure alone 3,3a 22.0 6.1 550 690
Manure as compared with
Nitrogen and Potash 9,9a 6.0 -¤.6 20 -150
When this experiment was started in 1913, rock phosphate was applied to the
proper plots at a rate to supply four times as much P205 as was applied to those plots
` receiving superphosphate. The rate of application of rock phosphate has since been
reduced, and at the present time approximately 2 l/2 times as much P O has been applied
as rock phosphate as has been applied as superphosphate. When phospgage was applied at
` the above rates, no appreciable yield differences were obtained between plots to which
_ superphosphate or rock phosphate has been applied. Up until l9¤8, however, manure was
· applied to all plots (except plot 1), and undoubtedly had some effect upon the yield
comparisons. `
The results of this experiment, as shown by the yield data, clearly show the
value of rock phosphate used in a long—time soil building program. Data obtained from
V other experiments, however, indicate that when used without applications of manure or
crop residues, superphosphate is much more effective than rock phosphate for the first
few years. Nearly all the phosphorus in rock phosphate is unavailable to most crop
plantsin its original form, however, a chemical reaction between the rock phosphate
and the soil slowly takes place and results in the release of phosphorus in an avail-
able form. This reaction is retarded by applications of limestone, and several years
may be required under some conditions before enough phosphorus is released in avail-
able form to supply the needs of crop plants. When it is desired to use rock phosphate,
supplemental phosphorus added as superphosphate would usually be advisable until suf-
ficient available phosphorus has been accumulated from the reaction of rock phosphate
with the soil.
Mayfield Soil Experiment Fie1d8 The Mayfield Soil Experiment Field, in Graves
county, was established in 1913. Most of the soil on the field has been classified
as Grenada silt loam, which is the most extensive upland soil type in the Purchase
region of Kentucky. This experiment was discontinued in 1950 after the plot yields
had been obtained. A four—year rotation of (1) corn, (2) wheat, and (3,U) two years
of mixed legume—grass-hay was followed. The main objective was to determine the
effects of lime and phosphate (supplied as either 20% superphosphate or raw rock phos-
phate) upon the yields of the various crops in the rotation. Four series of plots
V enabled each crop of the rotation to be grown each year. The various symbols used to
designate the plot treatments follow:
9

 L — Ground Limestone — Approximately 6 tons of limestone per acre —
applied during 1913-1919, and 2 tons per
acre during 19U8—195l (except plots lh and 16). a
M - Manure — 10 tons per acre for corn p
N — Ammonium Nitrate - Applied at the rate of 90 lb of nitrogen (or Y
270 lb of ammonium nitrate) per acre per ro-
tation; 60 lb of nitrogen (180 lb of ammonium
nitrate) for the corn, and 30 lb of nitrogen
(90 lb of ammonium nitrate) for the wheat. One-
half of the nitrogen for the wheat is applied in
the fall, and the other half as an early spring
topdressing.
P — 20% Superphosphate - Applied at the rate of 120 lb of PgO5 (600 lb
of superphosphate) per acre per rotation, ex-
cept on plots ¤ and 6, and to plots M and 6
at the rate of 80 lb of P2O5 (Moo lb of super-
phosphate) per acre per rotation. A11 the
phosphate is applied for the wheat crop, p
RP — Rock Phosphate — Applied at the rate of 2¤0`1b of P205 per acre V
per rotation (approximately 720 lb of rock
phosphate), except on plot 5 which received
200 lb of P205 per acre, per rotation, All ~
the rock phosphate was applied for the wheat
crop. ‘
RP - Finely ground
Rock Phosphate - 2UO lb P2O5 per acre per rotation as on other
RP plots,
K - Muriate of Potash - Applied at the rate of 120 pounds of X20 per
acre per rotation. (200 pounds of 60% muriate
of potash) 80 pounds of K20 is applied for the
corn crop and no pounds of K2O for the wheat
cropo
Phosphate applications have been omitted on plots 6a, Ba, and 9a since 1929»
When this experiment was initiated in 1913, manure was applied to all plots except
plot 1, in an amount equal to the total weight of the crops (less wheat grain) re-
moved during the entire rotation. In l9¤8 the use of manure was discontinued on
all plots except 9, 5 and 6. Approximately 2 1/2 times as much phosphorus was
applied as rock phosphate as was applied as superphosphatet The average yields of
7 corn, 6 wheat, M first-year hay and 2 second—year hay crops since 19¤8 are given
in the following table:
10

 , Plot Treatment Corn Wheat Hay lb/acre
bu/acre bu/acre lst year 2nd year
1 O 19.3 2.5 1270 1720
2 L 30.6 9.5 2520 2530
3 0 25.7 0.8 1300 1780
. 0 M P 09.1 17.3 2390 2530
0a P 37.7 10.5 2010 2900
5 M RP 55.3 20.0 3110 3810
5a RP 07.0 17.2 2800 3900
6 M L P 60.2 20.0 0110 , 3800
6a M L (P) 58.2 22.2 3000 3670
7 0 32.3 9.2 1630 2060
8 L N RP K 58.1 29.7 3970 3280
8a L N (RP) K 58.1 29.7 3970 3280
9 L N P K 56.8 29.6 3870 3050
9a L N (P) K 08.8 23.9 3190 2820
10 L N P 39.8 26.8 3550 2580
1Ca L N P K 52.2 27.7 3930 3000
ll O 32.1 11.8 1700 2810
' 12 L N P K 53.1 28.8 0050 3050
12a L N RP K 55.0 23.0 0000 3800
13 L N K 07.1 21.0 2380 2990
10 (L) P K"‘ 57.9 28.5 3930 3670
10a L P K ---- 21.3 3550 3520
. 15 O 33.7 12.1 1020 2620
16 (L) RP K* 59.3 21.1 3090 3960
16a L HP K ---- 22.0 0200 3900
17 L N P K 60.0 30.2 0390 0010
_ * Not Relimed 1908-51.
The following table gives the average responses obtained for the different soil treatments:
Yield decrease Plots _________ Qngrgage_ig Xiglg _ _ _ _ »g_ _
due to: Compared Corn Wheat lst year Hay 2nd year Hay
bu bu lb lb
Limestone 2,3 8.9 0.7 1180 750
. Superphosphate 3,0a 12.0 9.7 670 1160
Rock Phosphate 3,5a 21.3 12.0 1500 2160
Potash 10,lOa 12.0 0.9 380 020
Nitrogen 102,17 6.5* 8.9 800 090
° Plot 10 used in comparison
Prior to 1908, when manure was applied to all plots. greater yield increases were
- obtained for limestone applied alone than for phosphorus applied alone. Since that time,
however, greater yield responses have been obtained for phosphate applications. Responses
11

 have been obtained at this location for all of the fertiliser elements, showing the V
need for a complete fertilization program on the major upland soils of the Purchases
Western Kentucky Substation: Experiments at the Western Kentucky Substation, in Caldwell V
county, have been conducted on two different soil types;`one derived from limestone and
the other from sandstone. ZTwo major limestone soils, Pembroke silt loam and Crider silt
loam, have been identified; the only difference between them is that the thickness of the
loess (windblown material) cap is thicker on the Crider soils Both are deep. well-drained. V
highly productive soils and are characteristic of the well-drained upland soil of the
limestone section of the Western Pennyroyalo Theother.s0il types Tilsit silt loam, is
located on the sandstone area and is similar to that which occures on the Greenville Soil ‘
Experiment Fields
Limestone Soilé From 1927 to l9¤¤ an experiment was,oondncted comparing the effects of
ground limestone on crops with respect to different times of application and different
particle sizesn A 3-year rotation of (1) corny (2) wheate and (3) legume and grass hay -
was followedu There was very little difference in crop_yields9 whether the limestone
(2 tons) was all applied at the beginning of the 18-year period, l ton each 9 years, or
1/3 ton in each 3—year rotations For the l/3 ton applications, there was no advantage
in having the limestone finer than l0-20 meshs In those tests, the amount of manure
applied was equal to the weight of crops removed, (encept wheat grain)¤
This project has been revisedt Beginning with the l9U9 corn crop, manure has
been omitted from all but one treatment, Fertilizer treatments are given below:
L - Ground Limestone‘ . A ,
M — 8 tons manure per acre applied for corn
N - 65 pounds per acre of N applied as ammonium nitrates
50 pounds applied for corn, 15 pounds as spring
topdressing on wheatn
SP - 90 pounds of PZO5 per acre applied as 20% super-
phosphate prior to seeding wheatq
CSP - 90 pounds of P2O5 per sees applied as Uji concen-
trated supgpphosphate
FP - 90 pounds of P2O· per acre applied as 28% fused
tricalcium phospgate
RP ~ 180 pounds of PZO5 per acre applied as raw rock
phosphate I T
K ~ 60 pounds per acre of K2O applied as 60% muriate of
potash for the wheat cropt
l2

 - The average yields from plots of certain treatments in the present project are shown
in the following table:
Treatment Treatment Corn — bu Wheat — bu Hay - lb
Number 8 crops 6 crops N crops
 
1 0 R200 17.3 l¤89
v` 2 L 50,9 22.M 2180
x 3 SP 53,0 29.1 2265
h SP K 53.7 27,7 2390
5 L sr 56..3 32»5 3255 "
6 L SP K 59,9 35.1 _ 3825
7 L N sp K 60.,6 37.6 31+65
8 L CSP K 56,8 34,7 3825
9 L FP K 55,0 3¤,5 3U6O
_ 10 RP K 55.7 29.8 2910
ll L RP K 56,7 31,1 3525
l2 M L SP 58,1 3¤,3 3635
The treatments in which 20% superphosphate, concentrated superphosphate, and
fused tricalcium phosphate are applied show no important differences among the various
sources of phosphorus. A comparison of the first three treatments indicate that a
‘ greater response is obtained for phosphate alone than for limestone alone, but that the
application of both (treatment 5) results in even higher yields.
Sandstone Soil: In 1929, a lime and fertilizer test was begun on the Substation's
_ sandstone soil, using a 3—year rotation of (1) corn, (2) wheat, and (3) grass and le- {
_ gume hay, All plots received an application of farm manure for the corn crop through
l9¤8, Beginning with the l9¤9 corn crop, manure was omitted from all but one of the
p plots.
The soil was very unproductive when experimentation started, However, it has
, responded remarkably well to liming, fertilization and good management, Limestone and
phosphate applied together have given large increases in crop yields, The potassium
and nitrogen applications probably would have increased crop yields also, had not rather
_ liberal amounts of manure been used on the plots previous to l9U9¤
There is also a comparison between applying all the phosphate and potash for
the rotation for the corn or applying it for the wheat, In some individual comparisons,
. l corn yields were slightly greater when the fertilizer was applied for this crop, but
wheat and hay yields were not so good, Considering all the crops, it has been
appreciably better to apply phosphate and potash for the wheat crop, The average
adjusted yields of the crops in the rotation from l9U9 to 1953 are shown in the follow-
· ing table:
13

 The various symbols used to designate treatments are given below:
M - Manure at the rate of 8 tons per acre applied
. ahead of corn. s .
P - Superphosphate, 20 percent, at the rate of 90 —
pounds PZO5 per acre for wheat on all plots
except where specified for corno
K - Muriate of potash, 60 percent, at rate of 90
pounds KZO per acre for wheat on all plots
except where specified for corn. ·
N — Ammonium nitrate at rate of 15 pounds N as a
topdressing on wheat and 50 pounds of N per
acre broadcast for corn.
L — Limestone. a total of N tons per acre applied
since 1929. i _
Treatment Corn — Bu Wheat — Bu Hay - lb
M crops 3 crops 3 crops
None (Av. 7 checks) 16.2 1.7 1010
L P ‘ *+7-%+ _ 19 @5, 3*+70
L P K @9.8 2lp3 bO50 _
M L P 55.2 2l.b U230
L P K N 51.6 21.8 MO50
P K bl.l 12.9 2U90 ,
L P* 50.3 lh.? 3170
T L P K' 55.M 15.M 3¤l0
L P N* jb.9 19.7 3180
L P K N* 57.2 21.3 3150
 
* Phosphate and potash broadcast before corn was planted on these plots.
Two~Year Rotations of Corn and Wheats
Two experiments are being conducted in which corn and wheat are grown in a 2-
year rotation, with a legume seeded in the wheat to serve as a cover and green manure
crop. ,
Greenville Soil Experiment Field; This experiment was started in its present form in
1952. The soil type is the same as that described in the General Fertility Experiment
at the Greenville Soil Experiment Field. Corn and wheat are grown in a 2—year rotation
on two series of plots, so that each crop is grown each year. An application of 320
pounds of P2O5 per acre per rotation is broadcast on all plots. one—half for the corn,
lb

 and one-half for the wheat. Sweet clover and lespedeza are seeded in the wheat in the
spring to serve as a green manure and cover crop. None of the sweet c1over—1espedeza
cover crop is removed. Each of four rates of nitrogen (0, NO, 80, and 120 pounds of
N per acre per rotation) is combined with each of five rates of potash (O, N0, 80, 160,
and 320 pounds of K20 per acre per rotation) to give a total of 20 treatments. One-
half of the potash is applied for each crop, and 5/8 of the nitrogen is applied for the
corn and the remaining 3/8 for·the wheat.
The average yields of five corn and four wheat crops are given in the following
’ tables:
- - _·°·x¤;¤s¤.Yield.¤£ Q<>;¤.(?iushs1.s pe; Acre). - ..
Rate of Potash (Lb K2O per acre)
Rates of Nitrogen 0 no 80 160 320
(Lb N per acre) (0)* (20) (UO) (80) (160) Average
_ (gy, 30.6 311.6 1+2.7 52.6 52.3 1+2.6
· (NO 20.9 31.1 96.2 56.1 55.M M1.9
25)
BO 18.0 36.7 uu.7 55.8 56.u ¤2.3
· (50)
` 120) 12.’-P 311.6 1+5.3 51+.11 51+.5 1+1.9
(75
U * Figures in parenthesis refer to amount applied for corn crop.
* - _ _Axe;¤se..Yie1d.¤;£ Hhae-1 1Bashe1s.par.Aare)_ _
(3), 16.7 22.3 2¤.1 19.3 18.5 20.2
#0
601 10 D On 0 O
(15) 2 3 7 31 2 3 3 26 5 29 2
‘ 80
2600 aq {ILP 0 0 Ou
(BO) 3 3 36 32 5 28 0 31
` I 120 1 M 1
(M5) 9.9 35. 36.5 33.6 31·9 3115
Average 22.2 30.9 32.1 28.9 26.2 28.1
 
* Figures in parenthesis refer to applications for wheat crop.
15

 The corn yields show that an increase in yield owing to the application of potash
was obtained up to the rate of l60 pounds of Kzp per acre.per year. For wheat, an ins - -
crease in yield was obtained only-for the rate of 20 pounds oi K80, after which there was
no increase. The decrease_dn“r&e1g of wheat for the higher rates of K20 is probably due
mostly to soil variation. insofar as nitrogen is concerned; B0 fnqrea