CHAPTER VII 



Jfcrbittg tbr ipianl 



^JTHE corn crop thrives well on a wide variety 

 ill of soils, ranging from a light sand to a heavy 

 \r clay. A typical soil for the crop may be 

 described as a medium loam, well supplied 

 with vegetable matter, and overlying a subsoil of 

 good texture. The chief needs for the crop are 

 an abundance of moisture and of available plant 

 food during the season of its growth. The fact 

 that the average yield for the United States is reported 

 as only about twenty-five bushels per acre, shows that 

 notwithstanding the very high yields that are obtained 

 under perfect conditions, there is a large area grown 

 under conditions which are so imperfect as to result in 

 a small and generally unprofitable yield, and in many 

 cases, particularly in the eastern and southern states, 

 this is due to a lack of available food during the season 

 of growth. This need of food is due to two causes, 

 first, the impoverished character of the soil, both nat- 

 ural and artificial, the latter due to long years of crop- 

 ping, without adequate return of manure ; and second, 

 to improper methods of management. That a large 

 crop cannot be grown on a very poor soil is clearly 

 indicated by the composition of the plant. A crop of 

 fifty bushels of shelled corn per acre, with the accom- 

 panying stalks, will remove from the soil, on the aver- 

 age : Nitrogen, eighty pounds ; phosphoric acid, twenty- 

 nine pounds ; potash, fifty-five pounds. 



From the standpoint of the removal of the fertility 

 elements, therefore, it is an exhaustive crop ; neverthe- 

 less, because of the period of growth, and because of 



