农田生态系统温室气体排放研究进展

Advance of Researches on Greenhouse Gases Emission from Chinese Agricultural Ecosystem

自1985年起,中国科学院大气物理研究所利用自行设计制造的自动观测仪器系统,历时十六年先后对我国四大类主要水稻产区的甲烷排放规律及其与土壤、气象条件和农业管理措施的关系进行了系统野外观测实验,并对稻田甲烷产生、转化和输送机理进行了理论研究,探讨了控制稻田甲烷排放的实用措施,建立了估算和预测稻田甲烷排放的数值模型。在甲烷排放的时空变化规律和转化率研究方面有一系列新的发现,在稻田甲烷产生率、排放率及其与环境条件的关系方面取得一系列新的成果,以充分证据改变了国际上关于全球和中国稻田甲烷排放总量的估算。在对稻田甲烷深入研究的基础上,从1993年起又开展了对农田氧化亚氮排放的研究,并在农田氧化亚氮排放的时空变化及环境控制因素,特别是排放量与土壤湿度及温度的关系、施肥与排放、CH_4与N_2O排放相互消长关系及减排措施选择的理论与实验研究方面取得了新的研究成果。

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.