20 



BULLETIN 42, U. S. DEPARTMENT OP AGRICULTTJBE. 



the results secured should not be considered as unduly influenced 

 by irregularities due to nonuniformity of the soil in different plots. 

 The soil is inclined to be of an acid nature. 



The manganese sulphate was applied at the rate of 50 pounds per 

 acre. The untreated and treated plots received the same cultivation. 

 The corn, cowpeas, and potatoes were planted in the spring of each 

 year and harvested in the fall. The wheat and rye were planted in 

 the fall and harvested the next July. This experiment has now run 

 for six years, each crop on the same plot each year. That is, con- 

 tinuous culture of one crop on the same plot was practiced. The 

 manganese was applied each year after the ground was broken and 

 the land was cultivated before planting. 



EFFECT OF MANGANESE SULPHATE ON WHEAT. 



Manganese sulphate was applied to the plot, 1 square rod, in 

 September, 1907, at the rate of 50 pounds per acre shortly before it 

 was planted to wheat. The crop was harvested in July of the follow- 

 ing year and the soil was plowed and again prepared for wheat plant- 

 ing in September. The manganese sulphate was applied to the same 

 plot each year before planting. The results of five years are given 

 in Table XI. The weight of the unthr ashed straw and grain only 

 was taken. The first column gives the year. The second and third 

 columns give the yields of the manganese and untreated plots in 

 pounds per square rod. The yields of the two plots are calculated 

 to pounds per acre and given in the fourth and fifth columns. The 

 last column gives the increase or decrease of the manganese plot from 

 the untreated plot in pounds per acre. 



Table XI. — Showing the effect of manganese sulphate on wheat grown in soil treated five 



successive years. 





Yield of crop per 

 square rod. 



Calculated yield per acre. 



Year. 



Manganese 

 sulphate. 



Untreated. 



Manganese 

 sulphate. 



Untreated. 



Increase or 



decrease of 



manganese 



plot. 



1908 



Pounds. 

 27 

 23 

 22 

 21 

 15 



Pounds. 

 31 

 26 

 25 

 25 

 24 



Pounds. 

 4,320 

 3,680 

 3,520 

 3,360 

 2,400 



Pounds. 

 4,960 

 4,160 

 4,000 

 4,000 

 3,840 



Pounds. 



- 640 



1909 



— 480 



1910 



— 480 



1911 



— 640 



1912 



— 1,440 







In each year the manganese caused a decrease in yield. As shown 

 in the last column in the table, the decrease in 1908 was 640 pounds 

 per acre; in 1909 and 1910 the decrease was 480 pounds; in 1911 it 

 was 640 pounds; and in 1912 it was 1,440 pounds. 



