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SCIENCE 



[N. S. Vol. XXVI. No. 661 



was then removed and in its place a strictly 

 Itomogeneous but very poor sandy loam 

 substituted— the nitrogen content of which 

 was .0437 per cent. This was dressed with 

 the following chemical fertilizer: 

 Superphosphate at the rate of ... . 400 lbs. per acre. 

 Muriate of potash at the rate of 200 lbs. per acre. 

 It was then sown with red clover, May 

 13, 1902. During each succeeding season 

 the growth has been cut twice, and the ma- 

 terial allowed to decay on the soil. At the 

 end of every second season the crop has 

 been turned under, the soil being stirred to 

 a depth of approximately four inches, and 

 the plot resown the following spring. From 

 the subjoined table, it will be seen, four 

 collections and analyses of this soil have 

 been made since the experiment began, and 

 each successive collection has shown a 

 marked increase in nitrogen— an increase 

 which I think very satisfactory for such 

 an open, sandy soil. 



NITKOGEN-ENEICHMENT OF SOILS DUE TO GROWTH 

 OF CLOVEB 



In two seasons we enriched this soil in 

 nitrogen to the amount of 175 pounds per 

 acre; in five years, despite losses, the land 

 is richer by 308 pounds per acre. 



EVIDENCE OF SOIL ENBICHMENT PROM SUB- 

 SEQUENT CROP YIELDS 



To conduct experiments in the field to 



* The season of 1905 was an exceedingly poor 

 one for clover and the growth on the plot was 

 consequently very meager. 



prove that the growth of clover has a bene- 

 ficial influence upon succeeding crops might 

 seem to some as superfluous and unneces- 

 sary. The knowledge of the value of clover 

 in this particular is truly a matter of ancient 

 history. Nevertheless, to bring home in a 

 very practical way to the Canadian farmer 

 the fact that he could find in clover and 

 other legumes the very cheapest and best 

 of manures, and to show that our laboratory 

 results would receive confirmatory evidence 

 in the field, we instituted several series of 

 experiments on the Dominion Experimental 

 Farms in the growing of various crops after 

 clover. I shall only present data from two 

 series, but they are typical and may, there- 

 fore, very well serve to illustrate the results 

 we have obtained regarding the after-effect 

 of the legume. Each series consisting of 

 two plots, one with and one without clover, 

 was continued for three seasons after the 

 growth of the clover and it will be noticed 

 that there was an increased yield from the 

 plots that had carried the clover— right to 

 the end of the experiment period. The in- 

 creases are truly phenomenal. All our 

 results have been of an equally convincing 

 nature and it seems almost impossible to 

 comment upon the data without appearing 

 to use extravagant language regarding this 

 method of green manuring. I will, there- 

 fore, let the figures tell their own story. 



This table requires but a word of ex- 

 planation. The plots in each series are 

 contiguous, the soil uniform in character 

 with the same history and of an open, sandy 

 nature. In series I. the clover was sown 

 without any nurse crop, one cutting made 

 and removed; in series II. oats were sown 

 with the clover and no cutting of the latter 

 made. In each case the clover was turned 

 under in the following spring. 



Perhaps I may have already overstepped 

 the bounds set me and encroached on the 

 valuable time of this convention. I am 



