ACCLIMATION AND YIELD 



121 



TABLE XXI 



Table showing Comparative Yield op Native- and Im- 

 pobted-seed corn in western nebraska in bushels 

 PER Acre 



ADAPTATION OF THE SOIL 



89. The climatic and soil requirements of corn have been 

 stated in Section II. The climate cannot be controlled 

 or modified in a marked degree, hence corn production 

 is limited by climate to those regions where the natural 

 rainfall, temperature, and like conditions are favorable to a 

 profitable production. 



The soil, however, is subject to treatment, and almost 

 every soil can be brought to a high degree of productive- 

 ness by proper management. The subject of soil manage- 

 ment is so fully treated in special texts on this topic, that 

 it is not necessary to take up the matter in detail here. 



From a study of corn soils as classified according to 

 productiveness, it is apparent that a large proportion of 

 the soil likely to be cultivated in corn may be grouped in 

 two classes : first, soils that were once productive but 

 are now more or less deplete by 50 to 200 years cropping ; 

 and second, soils that never were productive. In both 

 cases the important factors to be modified can be grouped 

 under three general heads, as follows : (1) organic matter, 

 (2) mineral matter, (3) water. 



