【摘要】 根据对贵州玉米 -油菜轮作田、大豆 -冬小麦轮作田和休耕地N2 O释放通量的田间观测 ,研究了气候、农业活动和土壤性状对田间N2 O释放通量季节变化的影响。结果表明 ,当温度适宜于反硝化作用进行时 ,降雨事件与N2 O季节释放峰间存在明显的驱动 -响应关系 ;形成N2 O释放峰的最佳WFPS在 48%～ 80 % ,气温在 1 5～2 5℃ ;自然土壤冬春季N2 O释放通量与温度间存在指数函数关系。施肥增加了土壤N2 O释放峰的强度 ,而翻耕能形成弱的N2 O释放峰 ,农业活动在一定程度上改变了释放通量的季节变化模式。土壤有机质含量的微弱差异对N2 O的释放产生长远影响 ,三试验田N2 O释放通量季节变化与土壤有效N含量间不存在直接的定量关系。更多还原

【Abstract】 Based on the measured N 2O fluxes from fallow land, corn rape seed rotation field and soybean winter wheat rotation field in Guizhou Province, the effects of climate, farming practice and soil properties on seasonal variations of N 2O fluxes were discussed. The results showed that during suitable temperature range for denitrification, N 2O flux peaks were driven by rainfall event. The optimal range of soil’s WFPS and air temperature for forming N 2O flux peaks were 48%～80% and 15～25℃, respectively. N 2O flux from natural soil in spring and winter was in exponential function with the temperature. Fertilizing increased N 2O flux peaks and tilling could produce a new weak N 2O peak. Agricultural practices could partly change the seasonal variation pattern of N 2O flux. Soil’s organic matter content had a long potential impact on N 2O flux. No quantitative relation between the seasonal variation of N 2O fluxes and available nitrogen concentration in soil was found.更多还原