CHAPTER VI 

 RELATION OF SOILS TO GROWTH 



Most of the good corn soils of the United States are 

 deep black loams, well drained, well supplied with organic 

 matter, and rich in available nitrogen, phosphates, and 

 potassium. 



52. The soil may be regarded as a medium for holding 

 minerals and water in an available form for the plants as 

 needed. Natural productive soils are those that in a 

 state of nature contain all the mineral elements and organic 

 matter necessary, and are supplied with sufficient natural 

 rainfall. 



In some virgin soils, as the deep black loam soils of the 

 Mississippi, Ohio, and Missouri river drainage basins, 

 there is sufficient of all mineral elements in an available 

 form for the maximum production of corn. Even in 

 these soils, however, maximum production is seldom at- 

 tained, as the rainfall is not always properly distributed, 

 nor even sufficient. 



Corn especially enjoys a large supply of nitrogen and 

 will flourish in soils so rich in available nitrogen that other 

 cereal crops would produce an excessive amount of straw, 

 probably lodging and making a poor yield of grain. Corn 

 is able to make use of fertility furnished through the de- 

 caying of coarse organic matter, as manure or sod land ; 

 while other cereals, as wheat and oats, require for best 

 results a more advanced state of decomposition, with 

 the elements more easily available. 



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