CHAPTER XIV 



MINERAL MATTER FOR CORN LAND 



As pointed out heretofore (p. 42), about 1 per cent of 

 the green weight or 5 per cent of the drj^ weight of corn is 

 ash or mineral matter, talven directly from the soil. For 

 the production of 50 bushels of corn the mineral ash found 

 in composition would be as follows : — 



TABLE XXVI 



Mineral and Nitrogen Requirements op a 50-bdshel Corn 



CROPI 



97. Soils in regard to mineral supplies may be classed as : 



1. Soils in which sufficient mineral matter in available 

 form is present. 



2. Soils in which sufficient minerals are present, but one 

 or more of those minerals are unavailable or available in 

 very limited amounts. 



3. Soils in which one or more minerals are so deficient 

 that even with good soil management a sufficient amount 

 cannot be made available for a crop, the total supply 

 being sufficient for only a few crops. 



1 Hopkins, C. G. 



Soil Fertility, pp. 154 and 603. 

 135 



