34 



thereby giving rise to larger crops, but the physical conditions are 

 most favorably modified. Cover crops also conserve soil nitrogen 

 and they prevent to a large extent the soil from washing during 

 winter. A soil enriched by organic matter will retain more moist- 



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HORSE BEAN. RED CLOVER. 



Pig. I. — Nodules on the Roots of Legumes. 



ure, and hence is better able to withstand drought. No small 

 compensation for the trouble of green manuring consists in keep- 

 ing the weeds down. A field of corn sowed with any crop during 

 July is the best guarantee the farmer can have against weeds. A 

 field not sown down will, as is too often the case, be covered with 

 Roman wormwood, pigweed and other undesirable growths. The 

 plowing in of green crops should be practised on all land sub- 

 ject to cultivation whenever there is a possibility of so doing. 

 With corn, a crop of red clover, mustard or melilotus (sweet 

 clover) can be sown after the last cultivation, and this can be cut 

 and utilized for feeding and the roots plowed under just before 



