Kentucky Agricilltural Experiment Station. 11
` It will be 11oted that there is very little response to any of
the treatments, by the crops in this rotation. On this field acid
phosphate was used at the rate of 800 lbs. per acre per rota- 4
tion, sulfate of potash 400 lbs., and limestone 4 tons, at a cost
of $23.40 per rotation. The only appreciable increase over the
untreated land was from a combination of all these materials
which gave an increase valued at $7.97. However, it has been
found necessary to add limestone to this soil in order to grow
alfalfa and sweet clover successfully. `
The following results from the London Experiment Field
in the western part of the Eastern Coal Field are quite instrue- `
tive in showing what supplying deficiencies in 2111 unprodue- '
I tive soil will accomplish. The average yields include five eorn
g crops, four soy bean and eowpea hay crops, three wheat crops,
and two clover crops.
Acid phosphate was used at the rate of 800 lbs. per acre, ,
for the four year rotation, Ellld limestone at the rate of 4 tons
per acre.
Table II. Average Yields Per Acre. London Experiment Field.
Value of Increase
Soy Bean Clover for Rotation
Treat- Corn and Cowpea Wheat Hay Less Cost of
ment* Bus. Hay Lbs. Bus. Lbs. Ferts.
O ............ 17.4 1383 3.2 230 ..........
AP ........ 29.4 1778 6.8 1100 $12.59
LAP ...... 42.5 3390 10.1 3380 41.36
*O—No treatment; AP—Acid Phosphate; L—Limestone.
Small applications of manure were used on the 1912 and
19].5 corn crops, it being applied to the different plots in pro-
portion to the production their treatments gave the preceding
year. Potash in addition to acid phosphate increased the 11et
gain $9.86 per rotation, but when used in addition to limestone
and acid phosphate. it did not return a profit. This field was