160 



EXPERIMESTAL FARAHS. 



64 VICTORIA, A. 190r 



period, the young plants must rely largely on the nitrates produced the previous sea- 

 son. Unfortunately for the agriculturist, nitrates are extremely soluble compounds 

 and consequently are washed down out of the reach of the roots of the young plants, 

 if heavy rains have prevailed the previous autumn or winter. 



On the supposition that there was excessive leaching of the nitrates from the 

 surface soil in the North-west during the autumn and winter months, it has been 

 suggested by an English agricultural writer that an application of nitrate of soda, 

 in the spring to the growing grain would be of much value and greatly increase the 

 yield. While this may be true in part in certain, what we may term, exceptional 

 seasons, as the past one — which was characterized by a heavy rainfall in the late 

 summer months — it is not, in all probability, the case usually, for in Manitoba and 

 the North-west Territories the rains of the year, as a rule, are during the latter part 

 of May and in June, and the autumn is fair and dry. Further, the winters are usu- 

 ally very cold and dry, and consequently not conducive to leaching. To this we may 

 add, the soils generally over the wheat-growing areas are a heavy clay loam of a re- 

 tentive character. 



Be this as it may, it was thought desirable to determine from month to month the 

 amount of nitrates in the surface soils (1 to 8 inches) already referred to as examined 

 for their moisture content. The method adopted was to weigh out 100 grams of the 

 fresh soil and add thereto 1,000 c.c. of ammonia-free distilled water and shake the 

 mixture well for one hour. It was then allowed to settle for one hour and thei free 

 ammonia in an aliquot part at once determined. A further quantity was at the same 

 time set aside in contact with a zinc-copper couple (by means of which nitrates are 

 reduced to ammonia) and at the expiration of twenty-four hours distilled. From the 

 free ammonia in the distillate the amount previously found deducted and the re- 

 mainder calculated to nitrogen, and recorded as nitrogen, in nitrates in one million 

 parts of the water-free soil. The results are set forth in the subjoined table : — 



Nitrogen in Nitrates and Nitrites — Results recorded in parts per million of water- 

 free soil. 



