SOILS, FERTILIZERS AND INOCULATION 13 



plats and the tubercles counted, the result being 

 that there were nearly ten times as many on the 

 roots of the treated vines as on the untreated ones. 

 This shows decidedly favorable results through arti- 

 ficial inoculation by means of soil taken from a field 

 which bore peas. 



Ladd 19 conducted a series of experiments to ascer- 

 tain whether any advantage would be derived 

 through inoculation from especially prepared cul- 

 tures. He used the commercial culture known as 

 Nitragin. He reached the conclusion that where 

 the soil is well stocked with organic matter the gain 

 obtained is not sufficient to warrant use of the cul- 

 ture. However, in the case of light sandy soils and 

 for truck gardening, it may prove valuable. In re- 

 cent months another proprietary culture known as 

 Farmogerm is reported as having given excellent 

 results. 



One interesting experiment by Nobbe and Hilt- 

 ner 20 deals with the reciprocal inoculations of bac- 

 teria upon beans and peas. It was found that if 

 either plant were inoculated with germs from the 

 tubercles of the other, some nodules would be 

 formed, but the organism seemed to be without 

 power of nitrogen assimilation. If the inoculation 

 continued a second season, or through a second and 

 third series of culture, the bacteria became nearly 

 as efficient as those from the roots of the same 

 genus. The possibility of transfer of tubercle bac- 

 teria from the roots of one plant to those of the 

 other genus is affirmed. 



Whatever the method of inoculation, the grower 



19 N. D. Exper. Sta., Bui. 35. 



20 E. S. R., Vol. 12. 



