施用有机肥对土壤微生物群落结构及功能均具有重要影响，对于维护农田土壤健康、提升土壤质量具有重要意义。然而，施用有机肥后哪些碳源因子发挥着关键作用，其在不同土壤生态系统中的作用机理如何还有待进一步阐明。本项目拟依托我国红壤、潮土、水稻土的长期定位施肥实验平台，选取多类有机肥处理的土壤，在耦合BIOLOG与微量热技术基础上，甄别提高土壤微生物代谢活性的关键碳源因子，明确它们与土壤及有机肥种类的关系；再通过温室盆栽实验，利用BIOLOG、微量热、酶活性及高通量测序等方法，从微生物功能和多样性角度揭示关键碳源因子对土壤微生物的影响；最后通过培养实验，利用稳定同位素核酸探针等技术，揭示关键碳源因子作用下具有代谢活性的关键微生物菌群。研究结果对于优化施肥方案、调控土壤微生物养分循环功能、促进农业可持续发展具有重要的理论价值和实践意义。

The application of organic fertilizer has profound influences on soil microbial community structure and function. This strategy is of great importance for maintaining soil health and promoting soil quality in agriculture. However, little is known about the key carbon sources that play vital roles in enhancing microbial metabolism in the organic fertilizations, and the functioning mechanism of those carbon sources in soil ecosystems. In this proposed project, based on the long-term fertilization experiments that include varying organic fertilization treatments in red-soil, Fluvo-aquic-soil and paddy-soil regions, we will determine the key carbon sources responsive for the elevated soil microbial metabolic activity in organic fertilization treatments by combining BIOLOG and microcalorimetric techniques. A pot experiment will be further conducted to evaluate the impacts of those key carbon sources on soil microbial function and community structures by using multiple approaches, including BIOLOG, microcalorimetry, soil enzyme assays and high-throughput pyrosequencing. Finally, by laboratory cultivation, the soil microbes driving the metabolism of those key carbon sources will be investigated by high-throughput pyrosequencing and stable isotope probing techniques. Those results will be helpful for making rational fertilization strategy, regulating soil microbial process of nutrient cycling, and promoting agricultural sustainable development, which are of significantly theoretical and applicative significance.