CHAPTER XXVIII 



ROTATION 



A CROP rotation is the growing of two or more crops in regular 

 sequence on the same land. Scientific rotation is the systematic 

 growing of crops on the same soil in regular succession such that 

 each crop bears a useful and somewhat vital relation to some or all 

 of the others grown. Rotation is very closely related to and be- 

 comes the basis of soil improvement. The object of a rotation is to 

 utilize, to the very best advantage in the production of maximum 

 crops, the favorable conditions of soil with respect to tilth, moist- 

 ure, temperature and food, produced by other crops, and to elimi- 

 nate any unfavorable conditions produced by any crop. A legume 

 should form one of the crops of the rotation because of its value in 

 bringing about these favorable soil conditions. 



Major crops in rotations are the main crops grown. Minor crops 

 are those grown for catch, cover, or green manure purposes. 



In nature no very distinct rotation of plants occurs because 

 the same thing is accomplished in a measure by the growing to- 

 gether of different plants on the same land. Yet we see that nature 

 has its own system of rotation. Certain plants may grow luxuri- 

 antly for a few years and then be almost entirely replaced by some 

 more favored one. Sweet clover has be<en observed growing along 

 ditch banks for several years and then has been crowded out by some 

 other plant without any apparent cause. As a result of weather 

 conditions some weeds are very abundant for a year or two and 

 then almost entirely disappear. Fires sometimes aid nature in 

 bringing about a rotation of plants, as do also birds and other 

 animals. Any natural agency of seed distribution lends its assist- 

 ance in accomplishing this purpose. 



In agricultural practice it has been found very essential to 

 'rotate crops. The object of farming is to grow crops and it has 

 been found in general farm practice and determined through num- 

 erous experiments that more grain and other crops may be produced 

 in a regular rotation than by growing any one crop year after year 

 on the same land. 

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