382 



LEGUMES 



to scatter the bacteria and sown a second time, usually thorough 

 inoculation is secured. 



Need of Inoculation. Some legumes have greater need of 

 inoculation than others. When alfalfa or red clover is sown on 

 fields where there are no bacteria, the plants usually live for three 

 or four months, then begin to die. Soy beans and cow peas, while 

 greatly benefited by bacteria, will do very well on good soils when 

 there is no evidence of nodules on the roots. Field peas, vetch, 

 white clover, and alsike clover are all grown with little difficulty 

 on good soils, without inoculation. However, the bacteria are bene- 



FIG. 167. Plot on right had lime applied, on left no lime. Note difference in amount and 



growth of red clover. 



ficial in most cases. If no bacteria are present the legume exhausts 

 the nitrogen supply of the soil the same as other plants. 



SOILS FOR LEGUMES 



Certain legumes are well known as crops that can be grown on 

 poor soils, as field beans and cow peas, the old adage " too poor to 

 sprout black-eye peas " being the last word on poor soil. Other 

 legumes require good soils, notably alfalfa, which seldom succeeds 

 except on good, productive soils. The common legumes may be 

 roughly grouped as follows : 



1. Legumes that will grow on poor soils: Beans, field peas, 

 cow peas, alsike clover, lespedeza, burr clover. 



2. Legumes requiring better soils : Red clover, sweet clover, 

 vetches, white clover, soy beans. 



