SOILS H9 



of planting corn, and the question of threshing from the 

 stack or after stacking. 



One method of procedure in the beginning of a system of 

 permanent soil fertility is to spread one ton of finely ground 

 rock phosphate per acre on pasture land or clover meadow 

 and plow it under; then apply twe to four tons of limestone 

 per acre, mix it with the soil in preparing the seed-bed, sow- 

 ing wheat in the fall and clover the next spring; or apply 

 rock phosphate where manure has been spread, and plow 

 both under for corn; then apply the limestone before plant- 

 ing the corn. Both phosphate and limestone are then in the 

 soil ready to benefit oats and clover which may follow the 

 next year after corn. 



After the first rotation, half of these quantities of fer- 

 tilizer once every four or five years is sufficient to main- 

 tain permanently the supply of both limestone and phos- 

 phorus. While limestone and phosphate, when properly used, 

 increase the yields of wheat, oats, and corn, their most im- 

 portant use in permanent agriculture is to make possible 

 the production of large yields of clover and other legumes 

 which may be returned to the soil in large part, either with 

 crop residue or in farm manure, in order to provide both 

 nitrogen and organic matter, and thus complete a system of 

 permanent soil fertility. Benefits are also insured from 

 the physical improvement of the soil which is brought about 

 by the addition both of organic matter and of limestone. 



The important question remains, how much clover or 

 manure must be returned to the soil to maintain the supply 



