ORGANIC MATTER 



Explanations offered for any phenomenon may 

 later become embarrassing in the light of new 

 knowledge. We do not really need to know why 

 an occasional soil is supplied with the bacteria 

 of a legume new to it. We have learned that the 

 bacteria of sweet clover serve alfalfa, and this 

 accounts for the inoculation of some regions in 

 the east. We believe that some bacteria are 

 carried in the dust on the seed, and produce par- 

 tial inoculation. Other causes are more obscure. 

 The cowpea trails on the ground, and carries its 

 bacteria more successfully than the soybean. 

 Most legumes require a soil artificially inoculated 

 when brought into a new region, failing otherwise 

 in some degree to make full growth. 



Method of Inoculation. The bacteria can be 

 transferred to a new field by spreading soil taken 

 from a field that has been growing the legume 

 successfully. The surface soil is removed to a 

 depth of three inches, and the next layer of soil 

 is taken, as it contains the highest percentage of 

 bacteria. They develop in the nodules found on 

 the feeding roots of the plants. The soil is pul- 

 verized and applied at the rate of 200 pounds 

 per acre broadcast. If the inoculated soil is near 

 at hand and inexpensive, 500 pounds should be 



[43] 



