Abstract:
The effect of temperature and concentration of added NO-3 on the rate of denitrification was investigated by studying the rate of disappearance of NO-3-N and production of gaseous nitrogen products under flooded conditions. Three soils differing in their initial pH (Keld - pH 5.4, Wellwood - pH 6.3, and Morton - pH 7.8) were selected for this study. Three levels of NO-3- 100, 150 and 200 ppm - and three incubation temperature - 15, 25 and 35oC - were used. Nitrate disappearance rate was found to be independent of initial NO-3 level with the Morton soil. The rate was increased with increasing temperature. Nitrogen gas was the major gas produced and its production rate was independent of the level of NO-3. The temperature dependence of the zero order rate constant for N2 production followed the Arrehnius equation... Oxygen consumption and CO2 production increased with increasing temperature. The rates of O2 consumption and the production of CO2 were unaffected by concentration of NO-3. Liming the soil did not alter O2 consumption...
