59 



No. 2 is from the Saskatchewan district, about 140 miles from 

 Winnipeg, and has probably been under cultivation a shorter time 

 than Wo. 1. The dry mould contained 0'3027 per cent, of nitrogen. 



No. 3 is from a spot about 40 miles from Fort Ellis, and may be 

 considered a virgin soil. The dry mould contained 0'2500 per cent, of 

 nitrogen. 



In general terms it may be said that these Illinois and North-west 

 Territory Prairie soils are about twice as rich in nitrogen as the average 

 of the Rothamsted arable surface soils ; and, so far as can be judged, 

 they are probably about twice as rich as the average of arable soils 

 in Great Britain. They indeed correspond in their amount of nitrogen 

 very closely with the surface soils of our permanent pasture land. As 

 their nitrogen has its source in the accumulation from ages of natural 

 vegetation, with little or no removal, it is to be supposed that, as a 

 rule, there will not be a relative deficiency of the necessary mineral 

 constituents.* Surely, then, these new soils are " mines " as well as 

 laboi-atories ? If not, what is the meaning of the term a fertile soil ? 



Assuming these soils not to be deficient in the necessary mineral 

 supplies, and that they yield up annually in an available condition an 

 amount of nitrogen at all corresponding to their richness in that con- 

 stituent, it may be asked — whether they should not yield a higher 

 average produce of wheat per acre than they are reported to do ? 



The exhausted experimental wheat field at Rothamsted, the sur- 

 face soil of which at the commencement of the experiments thirty- 

 nine years ago probably contained only about half as high a percentage 

 of nitrogen as the average of these four American soils, yielded over 

 the first eight years 17|; over the next fifteen years, 15| ; over the 

 last fifteen years (including several very bad seasons), only 11]| 

 bushels ; and over the whole thirty-eight years about 14 bushels per 

 acre per annum. 



So far as we are informed, the comparatively low average yield 

 of the rich North-west soils is partly due to vicissitudes of climate, 

 partly to defective cultivation, but partly, also, to the luxuriant 

 growth of weeds, which neither the time at command for cultivation, 

 nor the amount of labour available, render it easy to keep down. 

 Then, again, in some cases, the straw of the grain crops is burnt, and 

 manure is not retu ned to the land. Still, if there be any truth in the 



* Since the above was in type, we have seen Dr. Voelcker's report on the Illinois 

 Prairie soil above referred to, and find he caUed attention to its richness in potash 

 and other mineral constituents. He also called attention to the much higher per- 

 centage of nitrogen in it than in the soils of this country which he and others had 

 analysed. 



