52 EXPERIMENTAL FARMS 



6-7 EDWARD VII., A. 1907 



Voluminous data Lave been obtained as to tbe relative values of the more com- 

 monly grown legumes as fertilizers from the standpoint of their nitrogen-content. 

 The list includes Common Ked Clover, Crimson Clover, Alfalfa, Hairy Vetch or Sand 

 Vetch, Peas, Soja Beans and English Horse Beans. In this work, in addition to the 

 analyses, the weights per acre were also taken of the foliage and of the roots (to a 

 depth usually of 9 inches) separately, so that the manurial value of the roots could 

 be estimated when the crop was cut and cured. The reader is referred to the reports 

 of this Division and to a bulletin issued in 1902 by the Director and the writer entitled 

 ' Clov*3r as a Fertilizer,' for further details of this valuable research. It may be briefly 

 stated, however, that the evidence shows that from 75 to 150 lbs. of nitrogen per acre 

 can be added to the soil by this means of ' green manuring.' 



Experiments of a somewhat more direct nature than the foregoing have a^so been 

 made, viz. : the analysis of the soil before and after the growing of clover. The results 

 are of a very satisfactory character, indicating that a very large proportion of the 

 nitrogen-holding organic matter from the turned under clover becomes part and parcel 

 of the soil. 



The value of clover as a fertilizer has also been ascertained by determining the 

 increase of yield of various farm crops following the growth and turning under 

 of clover. Many series of such experiments have been made during the past fourteen 

 years under the immediate supervision of the Director. These field tests have confirmed 

 in the most emphatic manner the results obtained by chemical research and have 

 proved beyond dispute the great benefit to be derived from the legumes as soil enrichers. 



INOCULx\TION FOR THE GROWTH OF LEGUMES. 



For several years we carried on experiments, both in pots and in the field, with 

 cultures or preparations of these nitrogen-fi:sing bacteria, using both seed and soil 

 inoculation. At first the cultures prepared in Germany, and known as Nitragin, were 

 tested. It was shown that in certain instances the cultures had distinctly favoured 

 the growth of the legumes, but their action was more or l^s uncertain, and we con- 

 cluded that there was not sufiicient evidence to justify us in recommending this pre- 

 paration for general use. These cultures (there being at that time 17 in all upon the 

 market) were found particularly susceptible to light and heat, and under the best con- 

 ditions of preservation their vitality could only be guaranteed for six weeks from the 

 date of preparation. It was felt, therefore, that the matter was still in the experi- 

 mental stage and that further investigation and more satisfactory results would be 

 necessary before the process could be considered one of practical utility. 



More recently, the new cultures of Dr. George T. Moore, of the Bureau of Plant 

 Industry, "Washington, D.C., U.S., have been tried. These it was claimed were more 

 potent and less susceptible to unfavourable conditions than the German cultures by 

 reason of special modification in the method employed in their preparation. Our 

 results were not, on the whole, satisfactory, and though in certain instances larger 

 yields were obtained from the inoculated crop than from the untreated crop grown 

 under similar conditions of soil and climate, the effect was either so uncertain or so 

 slight that we did not feel justified in reporting favourably on the cultures for general 

 use. It is quite possible, however, that in eertain isolated areas inoculation is valuable 

 in inducing a more vigorous growth of clover and alfalfa. For such areas we believe 

 that the most direct and surest plan is to secure soil containing the bacteria, i.e., 

 from a field that has recently grown clover or alfalfa, and either to broadcast it oni 

 the field to be treated, and thoroughly harrow in, or to place the bacteria-holding soil 

 in a vessel (tub or barrel) and pour on water. After stirring and allowing to stand 

 a little time, decant the supernatant soil extract and thoroughly moisten therewith 

 the seed of the legume. This treated seed should be sown as soon as it is sufficiently 

 dried. 



