270 



CROP ROTATION 



Proper Rotation With Use of Fertilizers Increases Productive Power of a 



Depleted Soil 



(Yield of corn grown in a 5-year rotation) 



* Rotation consisting of corn, oats, winter wheat, clover and timothy grown in the 

 order named. 



t Sixty pounds of acid phosphate, 30 pounds of muriate of potash and 160 pounds of 

 nitrate of soda applied annually. 



t One hundred sixty pounds of acid phosphate and 80 pounds each of muriate of potash 

 and nitrate of soda applied to corn and oats crop; and 160 pounds acid phosphate, 100 

 pounds muriate of potash, 25 pounds dried blood and 60 pounds nitrate of soda applied 

 to each wheat crop. 



It is interesting to note that the yield of corn decreased thirty 

 per cent in twenty years when grown continuously, even though 

 manure was applied at the rate of twenty-five tons for each five- 

 year period. In the rotation, on the other hand, the yield increased 

 thirty-seven per cent during the same period, manure being applied 

 at the rate of only sixteen tons for each five-year period. Similar 

 results were secured in the use of commercial fertilizers. 



The above results also show that rotation without fertilization 

 does not permit so rapid a reduction in the yield of corn as con- 

 tinuous cropping. Moreover, rotation gives greater returns from 

 manure and commercial fertilizers than a one-crop system. 



In the same series of experiments it is interesting to note how 

 rotation increased the yield of winter wheat. 



