162 The Commercial Apple Industry 



event, shade-crops should seldom be allowed to remain 

 more than four or five years. Cultivation for a year or 

 two will preserve a judicial balance. 



The quantity of seed to the acre for cover-crops may vary 

 somewhat with the region. However, the following table 

 will serve as a rough guide : 



TABLE IX. QUANTITY OF SEED TO THE ACRE 



Mammoth clover 10 pounds 



Common red clover 10 " 



Alsike clover 8 " 



Crimson clover 15 



Alfalfa 20 



Cowpeas 75 



Soybeans 75 



Hairy or winter vetch 50 



Summer vetch 60 



Canada peas 90 



Rye 75 " 



Buckwheat 60 " 



Rape 6 



Turnips 1 pound 



VALUE OF CULTIVATION ANT) METHODS 



The philosophy of tillage and its absolute necessity in 

 maintaining soil fertility need as much emphasis in apple- 

 growing as in any other phase of agriculture. Above all, 

 tillage is the principal determining factor in moisture con- 

 servation. It increases the availability of plant-food by 

 promoting the decomposition of organic matter ; it fines the 

 soil and thereby increases the feeding surface for the roots 

 and it promotes many favorable chemical and biological 

 activities. 



Hard, lumpy, untilled soil will no more produce profit- 

 able apple trees than any other crop. The bad effects of 

 continued clean cultivation have been emphasized, but the 



