CROP ROTATIONS 



183 



Wheat grown continuously at Rothamsted, England, 

 for sixty years has produced an average yield of 14 bus, 

 per acre. On adjoining land in a rotation of turnips, 

 barley, clover and wheat, the wheat produced an aver- 

 age yield during the same time of 25 bus. In the same 

 rotation barley yielded almost 25 bus. per acre while on 

 a continuously cropped plot it yielded only a fraction 



Fig. 72. — Wheat After Alfalfa on Brandon Experimental Farm. 



over 14 bus. During the last 20 years of the sixty-year 

 period wheat in the rotation averaged 24 bus. while on 

 the continuously cropped land it averaged only 12 bus. 

 This is probably the best information the world affords 

 on the relative values of a good crop rotation and con- 

 tinuous cropping. 



Corn grown continuously at Urbana, 111., for 29 years 

 produced an average yield of 27 bus. On adjoining 

 land in a rotation of corn and oats it gave an average 

 of 46 bus., while in a rotation of corn, oats and clover 



