60 Effective Farming 



In the northwestern part of the United States where wheat 

 has been grown continually on certain areas for more than 

 twenty years, these pieces are no longer profitable for wheat 

 and some other crop must be planted at least once every two 

 or three years. In the Central States where corn is the prin- 

 cipal crop, farmers have been able to continue raising this 

 grain by alternating it with some cereal crop, such as oats or 

 wheat. However, many progressive farmers in these regions 

 now include a legume on each piece of ground at stated inter- 

 vals and find that this method pays. In the cotton states 

 where the continual cropping of cotton has been practiced 

 a long time, planters are beginning to realize that they can 

 grow a larger product if they plant some other crop on the 

 land at intervals. Crimson clover, cowpeas, soybeans, velvet 

 beans, and corn are excellent crops to go with cotton. 



Rotation makes it possible to plant crops having different 

 length of root systems. For example, red clover, which has 

 deep tap-roots, and grains, which have fibrous roots, may be 

 planted in a crop rotation. Also, plants that make their chief 

 growth at different times of the year may be planted ; wheat, 

 for example, grows principally in early summer and corn in 

 the late summer. 



Rotation of crops helps to control weeds. In grain fields 

 weeds are usually destroyed when the ground is put into grass ; 

 a hoed crop like corn gets rid of weeds that may have been a 

 pest in the field when it was planted to other crops. 



Insect pests may be combated by changing the crop, for 

 certain insects will migrate or starve if their favorite food is 

 removed. For example the corn root- worm often becomes very 

 troublesome when land is continually cropped in corn, but this 

 pest can be practically destroyed by cropping the land in other 

 plants for a few years. 



Another advantage of rotation is that one or more legumes 

 can be included in the rotation. Even if the plants are not 

 plowed under for green-manure, which is often practicable, 



