CBOPPING SYSTEM 



127 



The Indiana results confirm the lUinois experiments, 

 showing : (a) a rapid decrease for continuous grain culture ; 

 (b) a maintenance of yield for longer period when a 

 rotation including legumes and grass is included ; (c) an 



Fig. 39. — Compare with Fig. 38. The same kind of land near by, but 

 properly managed to maintain productivity. (Minn. Exp. Sta.) 



actual increase in productivity when fertilizer is added. 

 However, fertilizer did not maintaiyi yield in a grain rotation. 



ROTATIONS FOR CORN GROWING 



93. The above tables suggest the type of rotations 

 and fertilizer treatment for the Corn Belt. Other stations 

 have suggested rotations including corn, as follows : ^ — 



" A rotation for dairy farms recommended by the New 

 Jersey station consists of (1) field corn, seed to crimson 

 clover in July or August ; (2) crimson clover followed by 



1 U. S. Dept. Agr., Farmers' Bui. lU: H- 



