ORGANIC MATTER 



and should be used to displace those found in the 

 farmer's fields. The chances are that, if soil con- 

 ditions are good, the bacteria present in the soil 

 are virile, and if the conditions are bad, the 

 pure cultures will not thrive. All eastern land is 

 supplied with red clover bacteria, just as some west- 

 ern land possesses alfalfa bacteria, and partial 

 clover failure has causes wholly apart from the 

 character of its bacteria. 



We do not have definite knowledge concerning 

 duration of inoculation nor the manner in which 

 it is maintained when legumes are not growing, 

 but we do know that when a legume has once 

 made vigorous growth in a field, the soil will re- 

 main inoculated for a long term of years. 



[45] 



