1912] The Work of the Dominion Experimental Farms. 27 



legumes. We have noted the increase of yield in crops succeeding 

 them; we have ascertained the increase of soil nitrogen due to their 

 growth, and we have investigated the merits of the various cultures put 

 upon the market for inoculation of the soil with the nitrogen-fixing bac- 

 teria. The results of these researches would occupy several volumes, 

 but I must try to condense them into two or three sentences. 



Analyses have shown that from 75 to 150 lbs. of nitrogen may be 

 stored up in a season, per acre, by the more common legumes. This is 

 very largely from the atmosphere if the roots of the crop are nodule- 

 bearing. The ploughing under of such a crop adds to the soil's store of 

 reserve nitrogen, we may say, as much as would be furnished by an 

 application of 10 tons of good barnyard manure. And this is but one 

 of many advantages of this system of soil improvement. The plan of 

 sowing clover with the cereal crops is now common in the older parts 

 of the Dominion, and it is proving a very valuable one in the enrichment 

 of our soils. The adoption of this method is, I believe, very largely 

 due to the teachings of the Experimental Farms. 



As regards increase in crop yields after clover, I may cite one of 

 our many experiments. Series I comprised two adjacent plots, the one 

 carrying clover the other carrying wheat. In the succeeding year both 

 were planted with fodder corn; the crop from the clover plot exceeded 

 that of the adjoining by 8 tons 480 lbs. per acre. In the following 

 year both plots were sown with oats; the original clover plot gave 23 

 bus. 18 lbs. more per acre than its neighbour. Further, the third year 

 after clover, both were planted with sugar Deets ; the yield from the plot 

 that had borne the legume was 13 tons 1400 lbs. per acre more than that 

 of the wheat plot. We invariably obtained an increased yield on the land 

 that had carried the clover or other legume, for at least three years to 

 a marked degree. Evidence of this practical nature is overwhelm- 

 ingly convincing of the manurial value of the legumes. 



In the determination by direct analysis of the soil of the amount 

 of nitrogen that might become part and parcel of the soil through the 

 continuous growth of clover, the results of one experiment may be 

 cited. This plot of very poor sandy soil was first sown with clover in 

 1902, ten years ago, and has been continuously under that crop since 

 that date. The soil was enriched at the outset with phosphoric acid 

 and potash but no nitrogen was added. The nitrogen content was 

 taken at the beginning of the experiment and every second year since. 

 The net gain in organic nitrogen at the end of the ten-year period was 

 approximately 500 lbs. in the first 4 inches of soil per acre. From other 

 work we assume that the loss of nitrogen from various causes in such a 

 light soil as that under experiment — almost a pure sand — must at least 



