【摘要】 晚稻稻田的甲烷排放呈现前高后低特点 ,稻田甲烷的日排放速率与日均气温具有良好的正相关。稻草翻施使稻田甲烷排放量上升 5 1 .1 1 % ,而采用稻草表施的方法甲烷排放量仅增加 33.98%。水稻分蘖期是稻田甲烷排放的重要时期 ,其甲烷排放量占水稻全生育期排放总量的 65 .6% ,施用稻草进一步加大水稻分蘖期的甲烷排放比例。与稻草翻施相比 ,稻草表施的甲烷减排突出表现在水稻分蘖期及一天中 1 2∶0 0～ 1 6∶0 0的甲烷排放高峰时段。土壤 5cm处温度的昼夜周期性变化与稻田甲烷排放的昼夜周期性变化具有高度相关性。稻草表施可明显降低稻田耕层土壤水溶解甲烷含量更多还原

【Abstract】 Methane emission in the late-rice paddy field is characterized by a declining trend with growth of the rice and a positive relationship between daily emission rate and air temperature. Application of rice straw in soil (ARSS) could increase methane emission by 51.11%, and application of rice straw on soil surface (ARSSS) only by 33.98%. The rice tillering stage is a peak period for methane emission. At this stage, the methane emitted amounted to 65.6% of the total emitted throughout the whole growth stage of rice. Applying rice straw could increase the proportion of methane emitted at the rice tillering stage. Compared with ARSS, ARSSS decreased methane emission more significantly in the rice tillering stage and at daily peak emission time of 12∶00～16∶00. The diurnal change in soil temperature at 5 cm depth was highly related with content of methane dissolved in the soil water. ARSSS could remarkably reduce the content compared with ARSS in the layer of cultivated soil of paddy field.\;更多还原