In 1 90 1 the sweet potato series gave results as follows: 



Plot 7, without fertilization of any kind, per acre, 1,370 lbs. 

 Plot 3, with phosphoric acid and potash, per acre, 3,893 lbs. 

 Plot 4, with Nitrate, phosphoric acid and potash, 



per acre 10,810 lbs. 



Taking the average for the four years, the increase in 

 crops by applying phosphoric acid and potash only was 2^^ 

 per cent, but when 250 pounds of Nitrate of Soda was 

 added to this the increase amounted to 502 per cent. 



Tobacco was planted in 1898 and 1899, but the crop 

 of the latter year was a total failure. The following table 

 shows the yield in 1898, in pounds of green leaf per acre: 



T'be 2^0 pounds of Nitrate of Soda increased the crop 

 nearly 82 per cent. 



Food for 

 Plants 



119 



(Plot 21.) Cow Peas. No fertilizer 



