Effects of no-tillage and fertilization on paddy soil CH_4 and N_2O emissions and their greenhouse effect in Central China
免耕施肥对稻田甲烷与氧化亚氮排放及其温室效应的影响

By using static chamber-gas chromatographic techniques, the CH_4 and N_2O emissions from the paddy soil in southeast Hubei were measured. Four treatments were installed,i.e.,no-tillage plus no-fertilization (NT_0),conventional tillage plus no-fertilization (CT_0),no-tillage plus fertilization(NTC),and conventional tillage plus fertilization(CTC).In all treatments, the CH_4 emission had a seasonal variation of increasing first and decreasing then, while the N_2O emission had no significant seasonal variation. Fertilization increased the CH_4 and N_2O emissions significantly.NT_0 increased the CH_4 emission and decreased the N_2O emission significantly, compared with CT_0;NTC only decreased the CH_4 emission and increased the N_2O emission slightly, compared with CTC. The analysis on the integrated greenhouse effect of CH_4 and N_2O showed that NT_0 increased the effect by 25.9%,compared with CT_0,while NTC decreased the effect by 10.1%,compared with CTC. Therefore, a reasonable arrangement of fertilization and no-tillage could reduce the integrated greenhouse effect of CH_4 and N_2O from paddy field.