CORN 59 



V. PLACE OF CORN IN CROP ROTATION 



Reasons for rotation. At the basis of all successful farm- 

 ing is an intelligent practice of crop rotation. Early in our 

 study of corn, therefore, it is well to learn its place in sys- 

 tems of crop rotation. 



A few of the more particular reasons for the rotation of 

 crops are as follows: 



1. Different crops make different demands upon the soil. 

 The grain crops are able to use a large part of the available 

 phosphorus and potassium of the soil, but less of its nitro- 

 gen ; therefore it is well to follow the grains with crops which 

 use nitrogen more extensively and do not draw much upon the 

 supply of phosphorus and potassium in the soil. 



2. Root systems differ. The small grains are shallow- 

 rooted, and so utilize the fertility from the surface portion 

 of the soil. Other crops, such as clover and alfalfa, send 

 their roots deep into the soil, and so secure plant-food that 

 is out of reach of such crops as wheat and oats. Besides, 

 clover, alfalfa, and other leguminous crops when plowed 

 under leave the soil richer in nitrogen than they find it. 

 This adds greatly to the productiveness of the soil for 

 crops of a different character. 



3. The culture of one crop prepares for a succeeding crop 

 of a particular kind. It is common in the wheat sections to 

 follow corn with wheat because summer cultivation of corn 

 makes it possible to sow the wheat without plowing. Besides, 

 the well tilled corn ground enables the wheat to get a good 

 start in the fall, and to make use of a considerable part of 



