118 Peach-Growing 



producing capacity. These effects may be enumerated as 

 follows : 



1. The physical condition of the soil is improved when 

 the cover- and green-manure crops are plowed in : (a) by 

 giving more body to very light soils ; (6) by preventing the 

 heavier soils from cementing together or puddling. 



2. Soils may be deepened by the action of the roots of 

 some kinds of crops and by their decay when the crops 

 are plowed in or the plants die at the end of their natural 

 period of growth. 



3. The humus thus added increases the water absorb- 

 ing and holding capacity of the soil. Under some conditions 

 and with some crops, the snows of winter are held in posi- 

 tion, thus increasing the soil-moisture which in some sections 

 is of much importance. The growing crops also tend to 

 hold the rains, preventing a part of the run-off during heavy 

 showers, thus increasing the amount of water that soaks 

 into the ground. 



4. The humus added by these crops tends to induce or 

 promote chemical and bacteriological activities by means 

 of which plant-food is made available for the use of the 

 plants. 



5. ^Miere irrigation is practiced, it is made easier and 

 more effective by the presence in the soil of liberal quan- 

 tities of humus. 



6. Because of the effects, stated under item 1, among 

 other things, the roots of the trees are better aerated, which 

 is essential for vigorous, thrifty growth of tree. 



7. The soil is dried out in the spring by the early growth 

 of the hardy crops, thus making possible earlier tillage. 



8. Late fall growth of the trees is checked b}^ the growth 

 of the crops, thus many times inducing the ripening of the 



