DENITRIFICATION IN SEVERAL ALBERTA SOILS: INHIBITION BY SULFUR ANIONS

Publisher Website
Google Scholar
Abstract
The microbial potential for denitrification and the effects of S anions on this process were assessed in 5 Alberta soils. The denitrification potential of the various soils was ranked as follows: Black > Dark Brown > Brown .simeq. Gray Luvisol .simeq. Solodized Solonetz. The rate of denitrification in any soil was dependent on the chemical characteristics of that soil and the availability of a suitable C substrate for the denitrifying microorganisms. Denitrification was stimulated in 3 of the last 4 soils by adding 300 .mu.g glucose-C/g of soil. Addition of 100 or 500 .mu.g SO42--S/g of soil had little or no effect on the rate of denitrification. In contrast, soils with added Na2SO3, Na2S2O3 and Na2S had reduced rates of denitrification and nitrite accumulated. Microbial reduction of these S anions to S2- apparently occurred, and S2- apparently blocked the terminal steps of the enzyme pathway for denitrification, resulting in the accumulation of NO2-. The inhibition of denitrification by the S anions could be overcome by adding 900 .mu.g glucose-C/g of soil.

This publication has 16 references indexed in Scilit: