FACTORS IN WHEAT PRODUCTION 113 



10 minutes. 1 This difference is due largely to the 

 increased use of machinery. In 1830 the plow was 

 a clumsy wooden affair, the seed was sown by hand 

 and was harrowed into the ground by drawing brush 

 over it. Furthermore the grain was cut by cradles 

 and hauled to the barn, where it was threshed some 

 time during the winter by beating it with flails, 

 and separated by hand fanning mills. Now the 

 ground is turned by steel plows and pulverized by 

 discs, the seed is sown mechanically, and the grain 

 is cut and threshed by steam-driven machines of 

 great capacity. All this change has come in less 

 than a century. 



The Yield of Wheat.- -The United States and 

 Russia are the greatest wheat-growing countries in 

 the world. The United States in 1914 produced 

 891,017,000 bushels of wheat, and Russia in 1913 

 produced 962,587,000 bushels. In both of these 

 countries wheat farming is carried on extensively 

 and large fields are common. But the yield per 

 acre is much less in these countries than is the 

 average in some other regions. Note for example 

 the average yield per acre in the following countries 

 for the years 1901-1911 inclusive: 



United Kingdom 32.8 bushels 



Germany 30.7 



France 20.1 



twelfth Census Report, Vol. X, p. 352. 



