崇明岛稻麦轮作系统稻田温室气体排放研究

通过静态箱-气相色谱法,研究了崇明岛稻麦轮作地水稻生长季及收割后休耕期（2011年6月至2011年11月）温室气体CO2、CH4和N2O的排放、吸收规律及交换量,并运用增温潜势进行了温室效应估算。3种温室气体通量在水稻不同生长阶段有明显差异：稻田除成熟收割期外,其他期均表现为CH4排放源,并在分蘖期达到最大值;N2O除幼苗期表现为汇,其他期均为排放源,并在拔节期达到最大值。温室效应分析得出：水稻田温室气体以CH4和N2O排放为主,二者对全球温室效应的贡献为3.255×103kgCO2·hm-2;由于光合作用,稻田表现为对CO2固定,固定量为2.462×103kgCO·2hm-2;崇明水稻生长季排放温室气体综合GWP值为793kgCO·2hm-2,为温室气体排放源。

Emission of Greenhouse Gases from Paddy Fields of Rice-wheat Rotation System in Chongming Island, China

During rice growth season and the fallow period（from June 2011 to November 2011）, static chamber technique was used to investigate the emission and consumption of CO2, CH4 and N2O at paddy field in Chongming Island, and the greenhouse effect of there three gases were assessed using global warming potentials（GWPs）. Results showed that the fluxes of greenhouse gases had obvious difference in different period of rice growth. Except ripening stage, paddy fields were sources of CH4 emission through the whole study period, and the peak appeared at tillering stage. Rice field was the sink of atmospheric N2O in seedling stage, but changed into the sources in other stages and the peak of N2O emission was observed at elongation stage. According to the analysis of the greenhouse effect, CH4 and N2O were the major greenhouse gases from rice fields. The GWPs of CH4 and N2O was 3.255×103 kgCO2·hm-2. The whole rice field acted as a sink of atmospheric CO2 due to photosynthesis（2.462×103 kgCO2·hm-2）. Total GWPs of there three greenhouse gases from rice fields in Chongming Island was 793 kgCO·2hm-2. Paddy field in Chongming Island is a solid source of greenhouse gases.