我国旱作农田面积约占总耕地面积的56.84%，是农业生产过程中CO2和N2O的主要排放源。保护性耕作因其改良土壤、保持水土等优点，已在北方旱区得到了大面积的推广和应用。同时，长期保护性耕作可改变土壤微生境，影响土壤微生物群落结构组成和生态功能，进而影响土壤温室气体的排放。因此，研究长期保护性耕作下旱作农田CO2和N2O排放的微生物作用机理具有重要的生产指导意义和生态运用价值。本项目立足于旱作农业生产和农田生态现状，研究旱作农田主要温室气体CO2和N2O排放的变化特征，结合土壤微生物群落碳源利用多样性、碳氮功能微生物群落丰度和结构组成的变化，构建结构方程模型，揭示微生物在长期保护性耕作下旱作农田CO2和N2O排放中的作用机理，为构建高效、生态、可持续的保护性耕作技术体系提供理论支撑，并为保护性耕作技术的科学推广奠定理论基础。

Dryland area in our country accounts for about 56.84% of the total arable land area, is the main agricultural production in the process of CO2 and N2O emission source. Conservation tillage because of its advantage such as soil improvement, soil, it has been a large area of arid regions in the north extension and application. At the same time, long-term conservation tillage can change soil microenvironment, influence the soil microbial community structure and ecological function, and, in turn, affects the soil in greenhouse gas emissions. So the long-term conservation tillage under dryland farmland CO2 and N2O emissions of microbial mechanism has important guiding significance to the production and application of ecological value. This project base on dryland agricultural production and farmland ecological status quo, research on dryland farmland major greenhouse gas CO2 and N2O emission characteristics, combined with the soil carbon source utilization of the microbial community diversity, carbon and nitrogen function the change of the microbial community structure and abundance composition, constructing a structural equation model, revealing the microorganisms in long-term conservation tillage under dryland farmland and the functional mechanism of CO2 and N2O emissions, to build efficient, ecological and sustainable conservation tillage technology system to provide theoretical support, and for the science promotion of conservation tillage technology to lay the theoretical foundation.