蚯蚓是农田生态系统的重要组成部分,对土壤的碳氮循环和微量气体代谢有重要作用,但相关研究仍较缺乏。通过采用静态箱-气相色谱法研究田间条件下蚯蚓在农田生态系统中主要温室气体的排放通量；采用密闭气室红外分析法测量蚯蚓农田季节间和昼夜间的土壤呼吸及CO2排放速率变化特征；采用Biolog微平板法及分子生物学方法明确接种蚯蚓后土壤反硝化过程中的重要功能菌（Nar,Nir,Nor,Nos）生物量及生物多样性变化，旨在揭示蚯蚓对CO2和N2O排放的影响、对农田生态系统固碳能力、N代谢及反硝化作用的影响。采用培养实验研究施加不同C/N比秸秆后蚯蚓对温室气体排放产生的短期效应，重点观察N素矿化和利用情况，土壤有机碳形态及变化，明确蚯蚓对N2O排放的影响、机理，为正确评价土壤动物的生态功能提供依据。本项目的实施将有助于深入了解蚯蚓在农田生态系统中的管理固碳能力及其在土壤硝化、反硝化作用中的角色及调控因素。

Soil trace gas metabolism has been one of the important research subjects about interaction between the Earth's spheres. Pedosphere, biosphere and atmosphere come into being interrelatively and mutually dependently in the cycling and dynamic process of soil C, N biogeochemistry. Earthworms, the most important macro-fauna in agroecosystem play an important role in nutrient cycling. Earthworms are one of the most important members of soil fauna in terrestrial ecosystem. However, little information of the impact of soil fauna especially earthworms on the generation of trace gases in agro-ecosystem is available so far. To identify the effects of soil fauna on greenhouse gases (CO2,CH4 and N2O) emissions from agro-ecosystem, the outdoor field experiments assisted with laboratory incubations will conducted under the same climate condition and agricultural management. The CO2, CH4 and N2O fluxes will be measured in situ using the static chamber technique and analyzed with gas chromatogram, soil respiration will be measured by using the closed-chamber IRGA method to determine the seasonal and diumal (24h) dynamic pattern. We will use Biolog, PLFA and molecule biology measurements to determine soil microbial (especially function genes in denitrifiers) properties, such as microbial biomass and microbial diversity. The primary objectives will be to examine the effect of earthworm on greenhouse gases emissions with residues applied (incorporation or mulching), to explore their processes and relevant mechanisms in agro-ecosystem, and to study soil carbon sequestration and its potential by earthworm inoculation in cropland ecosystems. The microcosm experiments throughout a short-term incubation will be conducted to assess effects of straw application and active earthworm inoculation on greenhouse gases emission, and to make clear the denitrification pathway and chemical composition of soil organic carbon fractions. This project will be conducive to deeply understand the role of earthwom on soil carbon carbon sequestration, soil nitrification and denitrification, and will provide a firm foundation for strategy of greenhouse gas emission reductions measures in agro-ecosystem.