秸秆还田与加气灌溉对水稻泡田期温室气体排放的影响

Effect of Aerated Irrigation and Straw Incorporation on Greenhouse Gas Emissions from Paddy Field during Soaking Period

【目的】探讨秸秆还田与加气灌溉对水稻泡田期温室气体排放的影响。【方法】基于土箱模拟试验,设置3个处理(秸秆不还田+常规水灌溉,CK;秸秆还田+常规水灌溉,ST;秸秆还田+微纳米加气灌溉,SO),采用静态箱-气相色谱法对土箱中的温室气体排放浓度进行监测,分析CH_(4)、N_(2)O、CO_(2)的排放通量以及全球增温潜势的变化趋势,探讨温室气体排放对秸秆还田和微纳米加气灌溉的响应规律。【结果】秸秆还田可显著提高水稻泡田期N_(2)O、CH_(4)、CO_(2)累积排放通量,ST处理下3种气体排放通量分别可提高30.67%、167.08%、76.95%;秸秆还田条件下,微纳米加气灌溉下的CO_(2)累积排放通量相比常规水灌溉略有提高,而N_(2)O和CH_(4)的累积排放通量分别降低10.11%、32.63%;CK、ST、SO处理下的稻田温室气体全球增温潜势(GWP)分别为7.53、14.14、12.14 g/m^(2)。【结论】秸秆还田会促进稻田泡田期土壤温室气体排放,微纳米加气灌溉可以缓解这一负面效应,对秸秆还田背景下稻田土壤温室气体减排具有一定的积极作用。

【Objective】Soil stores more organic carbon than the atmosphere and biomass combined,and its change depends on a myriad of biotic and abiotic factors.This paper investigates the effect of aerated irrigation and straw incorporation on greenhouse emissions from paddy fields during soaking period.【Method】The experiments were carried out for rice grown in repacked soil pots.There were two irrigation treatments:conventional irrigation and aerated irrigation by mixing the irrigation water with micro-nano bubbles.For each irrigation,there were a straw incorporation treatment and a no-straw incorporation treatment.Emissions of CH_(4),N_(2)O,CO_(2)from the soils in all pots were measured using the static closed chamber method.【Result】Straw incorporation combined with aerated irrigation increased the cumulative emissions of N_(2)O,CH_(4)and CO_(2)by 30.67%,167.08%and 76.95%,respectively,compared with the control without straw incorporation and aeration.Combination of straw incorporation and aerated irrigation slightly increased CO_(2)emission,but reduced N_(2)O and CH_(4)emission by 10.11%and 32.63%,respectively,compared to straw incorporation without aeration.In terms of potential of global warming,conventional irrigation with and without aeration,and aerated irrigation combined with straw incorporation resulted in 7.53 g/m^(2),14.14 g/m^(2) and12.14 g/m^(2) of emission,respectively.【Conclusion】Straw incorporation under conventional irrigation during soaking period of the paddy field led to an increase in greenhouse gas emissions,and mixing the irrigation water with micro-nano bubbles can attenuate the emissions,especially N_(2)O and CH_(4).