382 SOIL PHYSICS AND MANAGEMENT 



In the corn and wheat belt and corresponding latitudes oats are 

 almost universally seeded after corn. Even in the southern states 

 this is practiced. If they should follow clover or potatoes, lodging of 

 the crop would almost certainly occur, with consequent loss. They 

 will follow wheat, millet or cotton well. 



Barley does well in the southern oats helt and under practically 

 the same conditions. It may follow wheat, oats or corn. 



Rye may be grown under practically the same climatic conditions 

 as wheat, but it is a better forager and produces more on poorer 

 soils. In the middle west it is a common crop for very sandy lands. 



The clovers are almost universally seeded with wheat, oats or 

 barley as nurse crops. Occasionally they may be seeded in corn or 

 cotton after the last cultivation, but the catch is uncertain. 



Soybeans and cowpeas follow almost any crop, but there is noth- 

 ing gained by having these succeed other legume crops. A non- 

 leguminous crop should intervene or at least be grown in conjunc- 

 tion with one of the legumes. 



SOME PRACTICAL ROTATIONS 



1. For the Corn and Winter Wheat Belt. In this belt corn 

 and wheat are the money crops, and they should be given the most 

 favorable places in the rotation. If any crop is grown that is of 

 special benefit to the soil, these should have the advantage of its 

 effect. The best place for corn is following the legume. If two 

 important money crops are placed in the rotation, each should be 

 given the best place possible. This belt is characterized by hot 

 summers and cold winters, with the annual rainfall varying from 

 20 to 48 inches. Corn, wheat, oats, and rye are the principal 

 cereals (Fig. 189). 



A short-cycle rotation that is sometimes practiced is : first year, 

 corn; second year, oats, seeded to clover; and third year, clover. 

 This is a good rotation to maintain organic matter, but it is not as 

 profitable as some others. 



An excellent four-year rotation is made by adding another year 

 of corn to the former, making (1) corn; (2) corn; (3) oats 

 (clover) ; and (4) clover. This exhausts the soil more rapidly than 

 the former and is best adapted to fertile soils- well supplied with or- 

 ganic matter. If it is desired to grow wheat, a four-year rotation 

 is as follows: (1) corn, (2) oats, (3) wheat (clover), (4) clover. 

 This is well adapted to a rich soil such as black clay loam or a 



