ACTION OP 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 



1908 



-2,240 



1909 



-1,440 



1910 



- 960 



1911 



-1,120 



1912 



+ 160 







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 

 243 

 85 



Bushels. 

 —69 



1908... 



—40 



1909 



+40 

 51 



1910 



1911 



91 



1912 



24 







