LEGUMINOUS PLANTS. 123 



Since alfalfa hay is exceedingly rich it must 

 be supplemented by foods containing the car- 

 bohydrates as, corn fodder, straw, or silage. 

 Alfalfa is adapted to a wide range of latitude. 

 It has been successfully grown as far north as 

 Central New York, Michigan, and Montana, 

 and as far south as California, Louisiana, and 

 Florida, and it stands the drouth of the western 

 plains better than any other forage crop. 



IV. Cow-peas ( Vigna catjang} . 



There are numerous varieties of cow-peas, 

 from the "bush-pea" to the prostrate runners, 

 with many gradations between them. Their 

 season of growth varies from a few weeks to 

 several months (see "Variation Induced by En- 

 vironmental Changes Climatic''). 



Cow-peas will grow on soil which is too poor 

 to support clover, and they are excellent soil- 

 renewers when plowed under green, and far less 

 expensive than commercial fertilizers for worn- 

 out or barren soil. This crop is best adapted 

 to the South, as it, like that of other beans, is 

 very sensitive to frost. Certain varieties, how- 

 ever, have been grown as far north as Wiscon- 

 sin also in the New England States, as soiling 

 crops. 



Much of the failure in the North has been 

 caused by planting when the ground was too 

 cold or wet. From the table it will be seen 

 that the hay of cow-peas yields a greater per 



