WATER SOILS. 



871 



reduction. It appears, therefore, that a moderate siii)i)Iy of air would 

 tend to check the reductiou of nitrates iiuder the conditioii.s here 

 described. 



The denitrifying organisms are present in straw and niannie and are 

 probably widely distributed in the soil, bnt it is claimed that they 

 seldom occur in sutlicient numbers in any one phice to cause any con- 

 siderable reduction of nitrates. In the experiments in which such reduc- 

 tion was observed manure was added to the soil at the rate of about 

 17() tons per acre. It was found by the author that when manure was 

 incorporated in the soil in the proportion in which it is ordinarily used 

 in practice not only did the nitrates not disappear but they a(;tually 

 increased. The treatment of manure with sulphuric acid to destroy its 

 denitrifying power is condemned by the author as exj)ensive, harmful, 

 and useless. 



On the question of the nitrification of soils, Kochenovski {Selvs- 

 Icoe Kliozyaistvo I Lycsovodstro, 1S3 {1S9(J), May, pp. 455, -loG). — In 

 experiments in the agricultural laboratory of the Kiev University 

 observations were made on accumulation of nitric acid and ammonia in 

 the soil as affected by the humidity of the soil and the introduction of 

 fertilizers. 



In soils kept at a temperature of 30° R. ammonia was found to increase 

 with the humidity of the soil, the increase being more rapi<l during the 

 first week than during the second. The same was true to a less degree 

 of nitric acid, barely i)erceptible amounts being formed before the end 

 of the first week. 



The experiments with fertilizers were confined to marble and potas- 

 sium carbonate. The amounts of ammonia and nitric acid in 100 gm. 

 of soil at the end of different periods are shown in the following table : 



Effect of marble and potash on nitrification. 



Thus potash as well as marble promoted the accumulation of nitrogen 

 in the soil, but potash acted more rapidly than marble. 



In field experiments on oats, carried out in connection witii the al)ov(^ 

 laboratory investigations, it was observed that applications (»f calcium 

 carbonate were followed by greatly increased yields, while the use of 

 potasli was followed by a reduction in yield. — P. fireman. 



Virgin soils of Canada, F. T. Siiurr (Canada EspU. Farmx lipt. IS'.i.-,, pp. 199- 

 ,^(/,5). —Analyses with refoiciico to fertili/inj,' ooustitiioiits <»f i:{ saiiipli-s of soil from 

 (liHVreiit ])art.s of Canada aro rcjx.rtrd. The Haiuplen are descrilied and tho results 

 of the chemical exauiiuatious are discussed. 



