WATEE SOILS. 



729 



ence of the previous handling- of the manure on its subsequent behavior 

 in the soil. 



Of the various carbonaceous substances tested (pentosans and crude 

 liber from wheat straw, cotton, straw, peat, and pentosans from peat) 

 the first was most active in promoting denitrification and decreasing 

 the yield. 



The application of sterile fresh manure resulted in no increase of 

 3'ield, while well-rotted manure produced a decided increase. In the 

 field experiments, also, it was found that the use of fresh manure 

 resulted in a decided decomposition or transformation of the nitro- 

 genous compounds of nitrate of soda or of urine. On the plats 

 receiving applications of a mixture of solid and liquid cow manure 

 with straw there was a yield of 825 lbs. less of dry matter and 61.36 

 11)S. less of nitrogen than on the plats receiving only liquid manure 

 (urine). While the results of the field experiments agree in this case 

 with those of the pot experiments in showing that there is an important 

 decomposition or transformation of nitrates under certain conditions 

 of manuring, it is not considered safe to make too close an application 

 of the results of pot experiments in field practice. 



The chemical functions of certain soil bacteria, F. D. Chester 

 {Ddaware jSta. BjA. 1S99, pp. 76-85., Jigs. ,y).— This article records 

 observations on the production of ammonia and the reduction of 

 nitrates to nitrites by soil bacteria and on the relation of the growth 

 of these organisms to the reaction of the media. 



The apparatus used in studying the production of ammonia in neu- 

 tral l)ouillon and for determining the amount of anmionia produced 

 are described. The following tal)le gives the amounts of ammonia in 

 milligrams per 100 cc. of culture produced b}^ the diiferent organisms 

 xstudied during 7, 1-1, and 30 days' growth at room temperature: 



Ammonia found in cultures of soil organisms in neutral hnuillon. 



Amount per 100 cc. of culture. 



The bouillon used in these cultures contained 1.11 per cent of organic 

 matter and 0.18 per cent of nitrogen. "The largest quantities of 

 ammonia produced after 30 daj's' growth was for Bacterivm mi/coides 

 and Bacillus suhtilis, 45.5 and 46.2 mg. per 100 cc. respectively. In 



