358 FIELD CROPS 



largely replaces clover in the Rocky Mountain states, though 

 occasionally large crops of clover are grown in valleys where 

 alfalfa does not thrive. 



The principal states in the production of clover and 

 mixed clover and timothy are Iowa, with three and one- 

 half million acres; New York with three million acres; 

 Michigan, Missouri, Wisconsin and Pennsylvania with about 

 one and three-quarters of a million acres each; and Illinois 

 and Ohio with more than a million acres each. 



In the region north of the Ohio River and east of the 

 Missouri, to the Atlantic Ocean, red clover is more widely 

 grown than any other legume, and is probably sown on a 

 larger acreage than all other legumes combined. White 

 clover is very common in pastures over this area, but is not 

 generally sown, for, like Kentucky blue grass, it rapidly 

 establishes itself on fields which lie undisturbed for a few 

 years. In the South, where it does not thrive, red clover is 

 replaced by numerous annual legumes and to some extent 

 by alfalfa, while in the irrigated sections alfalfa is much more 

 commonly grown because of the greater number of crops it 

 produces in a season and its longer period of life. 



454. The Best Soils for Red Clover. Red clover makes 

 its best growth on a deep, fertile loam, though the soil does 

 not need to be rich in nitrogen because of the power of this 

 plant, through the nitrifying bacteria, to utilize the nitrogen 

 in the air. In common with other legumes, red clover will 

 store up little nitrogen on soils which are already well stocked 

 with it, but the bacteria do much more effective work on 

 soils with a low nitrogen content. Some nitrogen is neces- 

 sary in order to give the plants a start and allow time for the 

 bacteria to establish themselves, but the supply need not be 

 large. A deep soil is desirable for clover, since the root 



