CHAPTER 14 

 CROPPING SYSTEMS 



ROTATION of crops means that the crops grown on each 

 field are changed from time to time in a fairly regular way. 

 Practically every farmer does change crops occasionally on 

 at least part of his farm, but the changes are often more or 

 less haphazard. There are many fields in America that 

 have been in cotton, corn, or wheat for 10 to 50 years. As 

 the country grows older, the enemies of crops increase, and 

 the need for rotation becomes more apparent. The ma- 

 jority of farmers will ultimately come to use more or less 

 definite rotations. 



The advantages of having a variety of crops are often 

 confused with the advantages of crop rotation. There 

 are many reasons why diversified farming pays best. 

 Some of these are given in Chapter 3. But one may have 

 a diversity of crops and yet not do much rotating of crops. 

 There are many farmers who grow corn, alfalfa, and 

 wheat, but who do not do much rotating. 



248. Reasons for crop rotation. There are many 

 reasons why crop rotation is a good thing. The final 

 factor that forces farmers to change crops is usually 

 either weeds, insects, or diseases. Crop rotation (1) helps 

 to control these enemies ; (2) may provide for keeping 

 up the humus supply of the soil ; (3) may provide for the 

 growth of grass and legumes on each field ; (4) often 

 saves labor ; (5) may keep the land occupied with crops 

 a greater part of the time ; (6) allows for the alternation 



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