Advance of Researches on Greenhouse Gases Emission from Chinese Agricultural Ecosystem
农田生态系统温室气体排放研究进展

Since 1985, the Institute of Atmospheric Physics, Chinese Academy of Sciences has carried out systematically field observation experiments with self-designed automatic observation system for 16 years continuously on regularities of methane emission as well as their relationship to soil texture, mete-orological factors and agriculture managements in the paddy field of China's four major rice culture regions. We have devoted to studies of production, oxidation and transportation of methane emission from rice fields. We have explored several practical steps for mitigating methane emissions from rice paddies, and developed numerical. A series of new rules in the temporal/spatial variations and investigations on transformation rate of methane emission were founded. Some new opinions about production and emission rates of methane from paddy field and their relations of environmental conditions have been formed. Based on ample evidences, the international estimates on total methane emission from China's and global paddies have been changed. In the light of a hard study of CH4, we have also conducted investigations on nitrous oxide (N2O) emissions form cropland since 1993, and acquired a batch of new achievements in the domain of production theory and experimental study concerning temporal/spatial variations and environmental factors governing N2O emissions from farmland, especially the relations of efflux to soil hu-midity and temperature , the interactions of fertilizer with emission fluxes, CHi emission with N2O e-mission fluxes, as well as their theoretical and experimental study on measures to reduce emissions. We review the research works of 16 years, summarize achievements, and offer further prospects of research on greenhouse gases emissions, especially carbon dioxide (CO2), from terrestrial ecosystem.