1 lO 



AGRICULTURE. 



upon this vetch. This inoculation may be done 

 by a light application of the soil in which these 

 bacteria are known to be. Their presence is 

 indicated by the luxuriant growth of the vetch 



FIG. 31. — ROOTS OK YELLOW SOY-BEAN. 



Grown at the Kansas Agricultural Experiment Station in 1S96, on land inocu- 

 lated with an extract containing the tubercle-forming bacteria. 



and the presence of nodules on its roots (see 

 Fig. 30). If any considerable area is to be in- 

 oculated, this method of inoculation is too ex- 

 pensive to be practical, as it requires from 500 

 to 1,000 pounds of soil to an acre. 



Recently, through investigations in the labo- 



