190 Fruit-growing in Arid Regions 



preceding chapter what are some of the effects of plowing 

 under green-crops. But the importance of the subject 

 will warrant a repetition. The following summary has 

 been adapted in part from Bailey's writings on cover- 

 crops : 



1. Green-manures improve the physical condition of the 

 land : 



(a) Shade the surface soil from intense sun in summer, 

 thereby protecting the trunk and limbs from 

 the reflection of the sun from the soil; 



(6) Prevent the very rapid burning of organic matter in 

 the soil; 



(c) Conserve some of the surface moisture, and prevent 



crusts from forming; 



(d) Prevent soils from cementing and puddling; 



(e) Prevent the rapid drainage of water from loose, porous 



soils; 

 (/) Prevent one form of freezing dry. 



2. Green-manures modify or influence chemical ac- 

 tivities : 



(g) They catch and hold some of the leaching nitrates; 



(h) Render plant-food material available; 



(i) Appropriate nitrogen, if leguminous crops are grown. 



Shade-crops 



Cover-crops have become very popular in the East 

 in orchard management. The name is derived from the 

 fact that the seed is sown in the fall or late summer and 

 sufficient growth results so that the ground is covered 

 and protected during the winter. The crop is intended 



