Nitrogen mineralization simulation dynamic in tobacco soil

Abstract

Laboratory and field culture experiments have been carried out at two sites which show that temperature and soil moisture significantly affected nitrogen mineralization in the soil in a tobacco field. Intermittent leaching under aerobic incubation conditions was adopted to develop dynamic simulation models of organic nitrogen mineralization under different temperature regimes (10, 15, 20, 25, 30, 35, 30, 25, and 20 °C) and soil gravimetric moisture content (0.1, 7%, 13%, 20%, 27%, 33%, 40%, 47%, and 53%). The results show that the highest N mineralization rate appeared at 35 °C and the lowest was 10 °C. Soil N mineralization rate, as affected by soil moisture, is a single peak curve with a peak at 40%. The interaction of temperature and moisture on soil N mineralization is significant. Based on the results of a field trial, the combined model given by governing equation:N=k(θ/θMax)m[∑(T−T0)n] has been established to simulate the dynamics of soil N mineralization under tobacco field conditions. A validation experiment showed that the measured values of mineralized N accumulation in the two experimental sites had a good correlation with the simulated values, indicating the practical value of the proposed model.