ROTATIONS FOR THE NORTH CENTRAL STATES 275 



south, as in the Central Atlantic States of the Coastal Plain section, 

 the following rotation is considered a good one for soil improvement : 



1. Cowpeas (plowed under), followed by rye (plowed under 

 about May 1). 



2. Cowpeas (cut for hay), followed by crimson clover (sown in 

 the fall and plowed under about May 1). 



3. Corn followed by crimson clover (sown at last cultivation 

 and plowed under for other crops). 



Rotations for the North Central States. This group of states 

 comprises Ohio, Indiana, Michigan, Wisconsin, Minnesota, Iowa, 

 Missouri, Illinois, North Dakota, South Dakota, Nebraska 

 and Kansas. 



The important crops, named in the order of their importance 

 on the basis of acreage are : Corn, oats, hay, winter wheat, spring 

 wheat, barley, rye, flax, potatoes, peas, and tobacco. 



FIG. 170. The alfalfa acreage. Fio. 171. Timothy and clover mixed. 



The important legumes and their adaptation are: 



Medium red clover for general use for hay and pasture. 

 Grows best on soils well supplied with lime. 



Alsike clover adapted for low lands and for acid soils. 



Mammoth clover best for sandy soils and for green-manuring. 

 Grows best on non-acid soils. 



Alfalfa grows best on well-drained rich uplands, well supplied 

 with carbonate of lime (Fig. 170). 



Soybeans grow well on soils of slight to medium acidity. 



Cowpeas for southern portion of this section grow well on 

 acid soils. 



A few common rotations are given, each being lettered. The 

 crops in the rotation are numbered. 



A 1. Corn. 2. Oats, wheat or barley (seeded). 3. Clover. 

 Some other cultivated crop may take the place of corn. Clover 

 is commonly mixed with timothy (Fig. 171) and other grasses 

 to produce hay or pasture for the fourth year. 



