138 THE SOILS AND CROPS OF THE FARM, 



use. There is not enough heat and sunshine during 

 the growing season to mature the crop. 



In the United States the corn crop occupies one- 

 third the tillage area. There are 41 acres of corn 

 raised for each 1,000 acres of superficial area as 

 figainst 20 acres of wheat. 



The average annual production of Indian corn in 

 the United States for ten years, 1870-79, and for ten 

 years, 1880-89, is given below: 



1870-9. 1880-9. 



Area, acres 44,000,000 71,000,000 



Yield, bushels 1,184,000,000 1,703,000,000 



Value, dollars 505,000,000 669,000,000 



Value per bushel, doliars 0.43 0.39 



Yield per acre, bushels 27.1 24.1 



Value per acre, dollars 11.54 9.48 



It is a curious fact that the increase in yield of corn 

 during the past decade over that of the previous one 

 has been in the same ratio as that of wheat; namely, 

 44 per cent, and that the total value of the crops has 

 increased in nearly the same ratio as that of wheat, be- 

 ing but a fraction of a per cent less; namely, 13.3 per 

 cent. The value per bushel has decreased four 

 cents, and the yield per acre has decreased three 

 bushels. The average gross value of an acre of corn 

 has been less during both decades than that of wheat; 

 while the production of wheat has increased between 

 five and six times during the past fifty years, corn has 

 increased between four and five times during the same 

 interval. 



The seven states — Ohio, Indiana, Illinois, Iowa, 

 Missouri, Kansas and Nebraska, produce about two- 

 thirds the crop of the United States, and are known 

 as the corn surplus states, because they are practically 



