TYPES OF FARMING 



11 



a farmer plants a certain area of wheat or cotton, he 

 knows little about what his yield will be. In the ten 

 years, 1901 to 1910, the yield of potatoes in New Jersey 

 has varied from 59 to 132 bushels per acre. Corn in 

 Illinois has varied from 21.4 to 39.8 bushels. Wheat in 



NO.RM AL 



FIG. 20. Rainfall for June, July, and August and yield of corn per acre. 1 



Average yields of corn 1888 to 1902. 

 Average rainfall for June, July, and August. 



Kansas has varied from 10.4 to 18.5 bushels. Cotton in 

 Texas has varied from 125 to 225 pounds. 2 Such varia- 

 tions are to be regularly expected for all crops. The 

 chief cause for them is the variation in rainfall. It is 

 this great uncertainty that makes the opportunities for 

 speculation in farm products, and for gambling on future 

 prices. 



The relation of rainfall to yield of corn in the corn-belt 



1 U. S. Dopt. Agr., Yearbook, 1903, pp. 215-244. 

 * U. S. Dapt. Agr.. Yearbook, 1910. 



