CROPPING SYSTSM 



125 



cornstalks, and clover were all plowed under, and this 

 system was designated as " grain farming " since no live 

 stock to produce manure was needed. 



Fig. 38. — Good land, continuously cropped with grain, until it is in an 

 unproductive state. 



In a second series, designated "live-stock farming," the 

 crops have been removed but equivalent manure returned. 



' Legume catch-crops and crop residues. 



' Manure applied in proportion to previous crop yields. 



Growing legumes and returning all residues has main- 

 tained yield, and when in the form of manure has increased 



