摘要
[ Objective] The study aimed to analyze greenhouse gases emission in rice fields at county level. [ Method] Based on GIS platform of soil system and greenhouse gas emission model, CH4 and N20 emission in rice fields of Chaohu City during 1990 -2009 were studied by using rice yield, fertilizer, climate and other data. [ Result] From 1990 to 2009, annual emission of CH4 emission in rice fields of Chaohu City varied from 6.47 to 11.67 Gg, and rice area, yield and the rate of straw returning to fields were the main factors influencing CH4 emission. For instance, when the rate of straw returning to fields rose to 30% and 45% respectively, CH4 emission increased by 14.4% and 27.4% separately. Annual emission of N20 in rice fields of Chaohu City from 1990 to 2009 was 0.119 -0.217 Gg. N20 emission rose slowly during 1990 -1998, then it enhanced fast and greatly as the rapid increase of chemical fertilizer and manure in their application after 1998; it reached the maximum value in 2000, then showed a decreasing trend after 2000. Thus, controlling nitrogen input and improving the utilization rate of nitrogenous fertilizer were the fundamental ways to decrease N20 emission in rice fields. [ Conclusion] The research could provide scientific references for the establishment of measures to reduce greenhouse gases emission in rice fields.
[ Objective] The study aimed to analyze greenhouse gases emission in rice fields at county level. [ Method] Based on GIS platform of soil system and greenhouse gas emission model, CH4 and N20 emission in rice fields of Chaohu City during 1990 -2009 were studied by using rice yield, fertilizer, climate and other data. [ Result] From 1990 to 2009, annual emission of CH4 emission in rice fields of Chaohu City varied from 6.47 to 11.67 Gg, and rice area, yield and the rate of straw returning to fields were the main factors influencing CH4 emission. For instance, when the rate of straw returning to fields rose to 30% and 45% respectively, CH4 emission increased by 14.4% and 27.4% separately. Annual emission of N20 in rice fields of Chaohu City from 1990 to 2009 was 0.119 -0.217 Gg. N20 emission rose slowly during 1990 -1998, then it enhanced fast and greatly as the rapid increase of chemical fertilizer and manure in their application after 1998; it reached the maximum value in 2000, then showed a decreasing trend after 2000. Thus, controlling nitrogen input and improving the utilization rate of nitrogenous fertilizer were the fundamental ways to decrease N20 emission in rice fields. [ Conclusion] The research could provide scientific references for the establishment of measures to reduce greenhouse gases emission in rice fields.
基金
Supported by Non-profit Research Foundation for Agriculture(201103039)
