Section III., 1905 [ 53 ] Trans. R. S. C 



VI. — Recent Experiments in the Nitrogen-Enrichment of Soils. 

 By Frank T. Shutt, M.A., F.I.C., and A. T. Charron, M.A. 



(Read May 24, 1905.) 



Among the fundamental problems studied in the fields and 

 laboratories of the Experimental Farms, no one has received greater 

 attention or yielded more valuable results to Canadian agriculture than 

 that relating to the economic maintenance and increase of soil fer- 

 tility. The basis of successful farming is a productive soil, 'and since 

 irrational and wasteful methods have lead to loss of 'productiveness in 

 many of the older districts in the Dominion it needs no argument to 

 show the importance of the work we have been 'engaged upon. 



Our analyses of exhausted, or more correctly speaking, partially 

 exhausted, soils from cultivated areas 'have shown unmistakably that 

 in the majority of instances the constituents that have more particu- 

 larly been dissipated through successive cropping and poor farming, 

 are organic matter (humus) and its concomitant, nitrogen. Again, 

 we have found invariably 'that virgin soils of great productiveness are 

 well supplied with these constituents, and that accompanying a ifair 

 humus-content there is almost always a goodly proportion of the min- 

 eral elements of plant food — phosphoric acid, potash and lime — in avail- 

 able and readily assimilable forms for the nourishment of crops. 



Loss of humus means not only loss of nitrogen — the most expen- 

 sive form of plant food 'upon the market — ^but a deterioration in the 

 physical condition of the soil. The land becomes less retentiver of 

 moisture, less mellow, less suitable for the development of those micro- 

 organisms that prepare the food of higher plants, and hence, on all 

 grounds, less suitable 'for successful farming. 



In the present paper we purpose to present, first, the results of 

 certain recent researches that 'demonstrate the extent and rapidity of 

 the depletion of soil "nitrogen imder what is evidently an irrational 

 method of fanning, and secondly, to bring forward data to show the 

 value of the 'legumes, especially clover, as a means of maintaining and 

 increasing fertility through the addition of nitrogen and humus. 



Depletion of Soil Nitrogen. 

 Throughout the whole of the Dominion, areas of greater or less 

 extent of unsurpassed fertility are to be found. Among these, the 

 plains of Manitoba and the North-west Territories stand out promin- 

 ently, for they have gained for Canada a world-wide reputation as an 

 agricultural countrj-. Many soils in these north-western provinces 

 have been held to be of practically inexhaustible richness ; for, after cul- 

 tivation for a quarter of a centur}' without any addition of manure or 



