CHAPTER XI. 

 CROP ROTATIONS 



143. What a Crop Rotation is. — A crop rotation is a 

 more or less regular succession of crops of different 

 kinds on a given field or farm, designed to result in a 

 larger net return or some improvement of the soil. 



In the older agricultural areas the crop rotations 

 always make liberal use of leguminous crops. In fact, 

 no rotation is considered rational that does not include 

 them. The ancient Romans appreciated the value of 

 legumes for the effect upon the soil and succeeding crops. 

 Writing in the first century A. D., Columella said, 

 "Where no kfnd of manure is to be had — the cultivation 

 of lupines (legume plants) will be found the readiest 

 and best substitute." At an earlier date Saserna wrote, 

 "Some of the leguminous plants manure the soil and 

 make it fruitful, whilst other crops exhaust it and make 

 it barren.'^ 



144. The World's Best Evidence on Rotations. — The best 

 information the modern world affords of the value of 

 suitable crop rotations is to be found in (a) the results 

 of the long and accurately conducted tests at Rotham- 

 sted in England and at different places in America, 

 and (b) the practice of crop rotations in all the old 

 agricultural regions of the world. - 



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