102 The Ottawa Naturalist. [August 



ON THE COMPOSTION OF CANADIAN VIRGIN 



SOILS.* 



By Frank T. Shutt, M.A., F.I.C., F.C.S., 

 Chemist, Dominion Experimental Farms. 



The soil investigations carried on in the Laboratories of the 

 Dominion Experimental Farms, at Ottawa, have included the 

 chemical and physical examination of certain typical virgin 

 (uncropped and unmanured) soils. The samples, over lOO, 

 were carefully collected in the various provinces of the Dominion 

 and may be regarded as types or representatives of areas of fair 

 uniformity and considerable magnitude. 



The majority of these samples are surface soils, but in a 

 large number of instances the results upon their respective sub- 

 soils have also been obtained. The paper is accompanied by 

 six tables of analytical data. 



The exact value of an ordinary soil analysis in ascertaining 

 the fertility or productiveness of a soil, is considered, and while 

 it is admitted that hot hydrochloric acid sp. g. rii5 dissolves 

 larger amounts of mineral plant food than are of immediate 

 availability to crops, it is pointed out that a knowledge of the 

 " maximum" amounts shows decisively deficiencies, if any exist, 

 and thus indicates lines for rational and economic treatment o^ 

 the soil with fertilizers. Further, it is pointed out that soils 

 possessing large " maximum " amounts will in all probability 

 prove more fertile than those showing smaller percentages, the 

 climatic influences in both cases being equally favourable. 



The diagnosis of a soil as regards productiveness cannot be 

 made from a chemical analysis alone — even if such includes a 

 determination of the so-called "available" plant food. The 

 physical condition of the soil, drainage, rainfall, mean tempera- 



*Abstract of a paper read before the Chemical Section of the British Association 

 for the Advancement of Science, Toronto, August, 1897. 



