CROPS AND SOIL IMPROVEMENT 



conditions, but they are the same favorable con- 

 ditions that our plants require. A fact of im- 

 portance to the farmer is that the bacteria which 

 thrive on the roots of some legumes will not serve 

 other legumes. This is a reason for many failures 

 of alfalfa, crimson clover, the soybean, the cow- 

 pea, hairy vetch, and other legumes new to the 

 region. 



Soil Inoculation. The belief that the right 

 kind of bacteria may be absent from the soil 

 when a new legume is seeded, and that they should 

 be supplied directly to the soil, has failed in ready 

 acceptance because examples of success without 

 such inoculation are not uncommon. Even if 

 the explanation of such success is not easy, the 

 fact remains that legumes new to a region usually 

 fail to find and develop a supply of bacteria ade- 

 quate for a full yield, and some of these legumes, 

 of which alfalfa is an example, make a nearly total 

 failure when seeded for the first time without soil 

 inoculation. Experiment stations and thousands 

 of practical farmers have learned by field tests 

 that the difference between success and failure 

 under otherwise similar conditions often has been 

 due to the introduction of the right bacteria into 

 the soil before the seeding was made. 



[42] 



