ACTION OP MANGANESE IN SOILS. 



21 



Some pot experiments were made in the greenhouse, using this 

 silty clay loam soil. Wheat was grown in soil in paraffined wire pots. 

 Manganese sulphate was used at the rate of 25, 50, and 100 pounds 

 per acre. Five pots were used for each treatment, six plants in each 

 pot. The wheat grew in the greenhouse for one month, from January 

 5 to February 6, when it was cut and the green weight of the plants 

 taken. The manganese caused no material difference in growth. 



The green weight was the same in the soil treated with manganese 

 at the rate of 25 and 50 pounds per acre as in the check. Manganese 

 at the rate of 100 pounds per acre caused a decrease; only 2 per cent, 

 however. There was no stimulation of growth in any case. 



EFFECT OF MANGANESE SULPHATE ON RYE. 



The result of the five-year test of manganese sulphate on plots of 1 

 square rod planted to rye are given in Table XII. Like the wheat, 

 the rye was planted in September and harvested the next July. The 

 manganese sulphate was applied each year at the rate of 50 pounds 

 per acre, shortly before the crop was planted. Five years' results 

 have been secured. The arrangement of the table is similar to that 

 of Table XI. The increase or decrease in pounds per acre due to man- 

 ganese is given in the last column. The weight of the unthrashed 

 straw and grain is given. 



In 1908 there was a decrease in the manganese plot of 1,120 pounds 

 per acre. The next year, 1909, there was an increase of 480 pounds 

 per acre; in 1910 there was a decrease of 320 pounds; in 1911 there 

 was an increase of 320 pounds, and in 1912 an increase of 480 pounds 

 per acre. 



Table XII. — Showing the effect of manganese sulphate on rye grown on 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. 

 26 

 ?9 

 10 

 25 

 17 



Pounds. 

 33 

 26 

 12 

 23 

 14 



Pounds. 

 4,160 

 4,640 

 1,600 

 4,000 

 2,720 



Pounds. 

 5,280 

 4,160 

 1,920 

 3,680 

 2,240 



Pounds. 

 —1,120 



1909 



+ 480 



1910 



— 320 



1911 



4- 320 



1912 



+ 480 







The results are somewhat inconsistent, some years there being an 

 increase from the manganese and in others a decrease. There is no 

 apparent reason for this. The decrease in 1908, the first year of the 

 treatment, was very large. In the following years the differences 

 were more moderate. 



