24 
BULLETIN 42, U. S. DEPARTMENT OF AGRICULTURE. 
There was a decrease in the yield in the manganese plot in every 
year except 1909. In 1909 there was an increase of 40 bushels. In 
1907 there was a decrease of 69 bushels, in 1908 a decrease of 40 
bushels, in 1910 a decrease of 51 bushels, in 1911 a decrease of 91 
bushels, and in 1912 a decrease of 24 bushels per acre. 
ACIDITY OF THE SOIL IN THE VARIOUS PLOTS. 
Acidity tests of the various plots used in this experiment were 
made in May, 1912, after the experiment had been in progress for 
five years. All of the plots, both treated and untreated for each 
crop, were acid. Samples were taken of each plot and lime require- 
ment determinations made. 
The sampling was done with a soil auger to a depth of 6 inches. 
Five borings were made in each plot and a composite sample made 
from the individual borings. The determinations were made on air- 
dry soil. 
The lime requirement determinations were made by means of the 
Veitch method. 1 Table XVI shows the amount of lime required 
according to this method for each plot to produce a neutral condition 
in the soil. The soil in each plot required approximately a ton of 
lime per acre. Where wheat was grown the manganese and the 
untreated plots were equally acid. In the rye, corn, and cowpea 
plots the manganese plots had a higher lime requirement than the 
untreated plots. With rye the manganese plot required 2,492 
pounds of lime and the untreated 2,136 pounds per acre. With corn 
the manganese plot required 2,492 pounds and the untreated 1,780 
pounds. With cowpeas the manganese plot required 2,492 pounds 
and the untreated 2,136 pounds per acre. Where potatoes were grown 
the untreated plot had a greater lime requirement than the manganese 
plot. The manganese plot required 2,451 pounds of lime per acre 
and the untreated plot 2,743 pounds. 
Table XVI. — Showing the pounds of lime (CaC0 3 ) required per acre in the various plots. 
Wheat. 
Rve. 
Corn. 
Cowpeas. Potatoes 
Manganese plot. 
Untreated plot . 
Pounds. 
1,780 
1,780 
Pounds. 
2,492 
2,136 
Pounds. 
2,492 
1,780 
Pounds. 
2,492 
2,136 
Pounds. 
2,451 
2,743 
The results of these determinations show that the soil is an acid 
one and that the manganese tests were made under acid conditions. 
The results obtained on this soil are supported by the statements of 
other investigators, that the best effects of manganese can not be 
secured under acid conditions. 
Jour. Amer. Chsm. Soc, 24, 1120 (1902); 26, 637 (1904 ) 
