1906.] Inoculation of Leguminous Plants. 



659 



of the cultures accounts for many of the negative results. The 

 results indicate that even where the nodule-forming organism 

 is present considerable increase is sometimes produced, as in 

 the case of the lucerne, peas, and beans in pots of fertile soil 

 at Aberdeen, and in that of beans in fertile garden soil at 

 Kingston. Some of the virgin soils were rich in combined 

 nitrogen, but at Woburn with Melilotus, a crop new to the soil, 

 Dr. Voelcker reports a distinct gain due to inoculation, while in 

 this same poor soil beans showed an increased yield in the pots 

 inoculated with Hiltner's cultures. 



The third series of experiments should indicate the extent to 

 which these cultures are likely to be of practical value in this 

 country. The negative results exceed the positive in number, 

 both in plot experiments and under agricultural conditions. 



There are, however, some cases in which a considerable gain 

 resulted from inoculation. Such, for example, are the bean, pea, 

 and lucerne plots at Aberdeen ; the clover on peaty soil near 

 Aberdeen ; beans at Woodilee, reported in the Glasgow experi- 

 ments ; the peas at Diseworth, reported in the Kingston results ; 

 and the Melilotus at Woburn ; all of which were obtained with 

 American cultures. 



Very few experiments were tried with Hiltner's cultures, but 

 the lucerne at Kilmarnock gave very satisfactory results. 



As a result of all the reported experiments, it seems evident 

 that the cultures used were not uniform ; it is not possible, how- 

 ever, to determine the extent to which the failures are to be 

 attributed to this cause. It seems, however, from the positive 

 results recorded, that not only are these cultures sometimes able 

 to produce nodules on the roots of plants new to a neighbour- 

 hood, but that even in cases where the leguminous crop had 

 been grown in the previous year benefit may be derived from 

 inoculation. 



It is quite evident that the subject of plant inoculation in this 

 country has not yet passed the experimental stage, and more 

 work is required before one can feel at all justified in recom- 

 mending either method for adoption on a field scale ; neverthe- 

 less, the positive results obtained may lead farmers to hope that 

 in the future benefit may be derived, in some instances at least, 

 from the treatment of the soil or the seed before sowing, with 

 inoculating materials preparatory to growing leguminous crops. 



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