ACTION OF MANGANESE IN SOILS. 
23 
Table XIV gives the yield of cowpea hay in pounds per square rod 
and pounds per acre. Columns 2 and 3 give the yield of the man- 
ganese and untreated plots in pounds per square rod; columns 4 and 
5 the yield of the two plots calculated to pounds per acre. The last 
column gives the increase or decrease of the manganese plot in pounds 
per acre. 
Table XIV 
-Effect of manganese sulphate on cowpeas grown in soil treated six suc- 
cessive years. 
Yield per square rod. 
Calculated yield per acre. 
Year. 
Manganese 
sulphate. 
Untreated. 
Manganese 
sulphate. 
Untreated. 
Increase or 
decrease of 
manganese 
plot. 
1907 
Pounds. 
42 
41 
28 
21 
35 
22 
Pounds. 
52 
55 
37 
27 
42 
21 
Pounds. 
6,720 
6,560 
4,480 
3,360 
5,600 
3,520 
Pounds. 
8,320 
8,800 
5,920 
4,320 
6,720 
3,360 
Pounds. 
-1,600 
-2,240 
-1,440 
— 960 
1908 
1909 
1910 
1911 
-1,120 
+ 160 
1912 
By an examination of the table it is seen that there was a decrease 
in the manganese-treated plots in each year except in 1912. In 1907 
there was a decrease in yield of hay of 1,600 pounds per acre, in 1908 
a decrease of 2,240 pounds, in 1909 a decrease of 1,440 pounds, in 
1910 a decrease of 960 pounds, in 1911 a decrease of 1,120 pounds, 
and in 1912 an increase of 160 pounds per acre. 
EFFECT OF MANGANESE SULPHATE ON POTATOES. 
The results of the six-year test of manganese sulphate on potatoes 
is given in Table XV. The details of the experiment and the arrange- 
ment of the table are the same as described in the test with cowpeas. 
In calculating from pounds of potatoes per square rod to bushels 
per acre the weight of a bushel of potatoes was taken as 60 pounds. 
Table XV. 
-Effect of manganese sulphate on potatoes grown on soil treated six successive 
years. 
Yield per square rod. 
Calculated yield per acre. 
Year. 
Manganese 
sulphate. 
Untreated. 
Manganese 
sulphate. 
Untreated. 
Increase or 
decrease of 
manganese 
plot. 
1907 
Pounds. 
57 
30 
83 
36 
57 
23 
Pounds. 
83 
45 
68 
55 
91 
33 
Bushels. 
152 
80 
221 
96 
152 
61 
Bushels. 
221 
120 
181 
147 
213 
85 
Bushels. 
69 
1908 
40 
1909 
+ 40 
-51 
—91 
-24 
1910 
1911 
1912 
