双季稻田根际土壤微生物群落结构及其多样性对长期施肥措施的响应机制

As soil microbial play key roles in soil fertility and plant nutrition, and there has a close interaction between soil microbial communities, diversity and fertilization practices. In preliminary studies, effects of long-term fertilization practices on soil microbial quantity and emzyme activity in double cropping paddy field systems were investigated. But its formation mechanism is still not clear. Based on a long-term fertilizer experiment over 30 years in Ninxiang of Hunan Province, we characterize of microbial communities and population in the rhizosphere soil by soil microbial cultivation method, analyze comprehensively the soil emzyme activity by soil enzymology during barley, early and late rice main growth stages. And the soil microbial communities and diversity in the rhizosphere soil under double rice cropping systems will be studied by Biolog-ECO, DGGE (denaturing gradient gel electrophoresis), PLFAs (phosphor lipid fatty acids) and pyrosequencing technology. In order to explored the mechanism of soil microbial communities and diversity in the rhizosphere soil with different long-term fertilization practices under double rice cropping systems. Meanwhile, we will be studying the response mechanisms of microbial community structure and diversity in the rhizosphere soil to long-term fertilization practices under double rice cropping systems. Therefore, we should be discovery the key effect factors of soil microbial communities and diversity in the paddy soil under double rice cropping systems. Hence, the outcome through this research would be of great practical significance to balanced fertilization and soil nutrient management, so as to realize sustainable utilization of farmland.

土壤微生物对土壤质量和作物营养极为重要，其群落结构和多样性与施肥的关系密切。前期研究已初步探明长期不同施肥模式下双季稻田土壤微生物数量和土壤酶活性存在明显差异，但其形成机理仍不清楚。本项目拟以长达30年施肥模式定位试验为基础，应用微生物培养和土壤酶学方法探明不同施肥模式下双季稻田根际土壤微生物生理类群、数量消长和土壤酶活性周年变化规律；应用Biolog微生物自动分析系统、变性梯度凝胶电泳技术、磷脂脂肪酸法和高通量测序相结合技术研究不同施肥模式对双季稻田根际土壤微生物群落结构和多样性的影响，阐明不同施肥模式下双季稻田作物根际土壤微生物群落结构、多样性的分子生态学机理；阐明土壤微生物对施肥模式的响应机制，揭示影响稻田土壤微生物群落结构、多样性的关键因子。研究成果对指导平衡施肥与土壤养分管理，实现农田的可持续利用具有重要应用价值。

土壤微生物对土壤质量和作物营养极为重要，其群落结构和多样性与施肥的关系密切。本项目运用微生物培养和土壤酶学方法、Biolog微生物自动分析系统、磷脂脂肪酸法和高通量测序相结合技术等，分析了长期不同施肥模式对双季稻田根际土壤微生物生理类群、数量消长和土壤酶活性、根际土壤微生物群落结构和多样性的影响。根据项目任务书的要求，本课题在长期施肥模式双季稻田定位试验基础上，探明了大麦、早稻和晚稻各个主要生育时期稻田耕层土壤微生物生物量碳、氮和微生物熵周年动态变化规律。明确了不同施肥模式条件下与稻田土壤肥力变化密切相关根际土壤微生物和土壤酶活性的生理类群、数量消长的变化规律，探明了长期施肥条件下各施肥处理间微生物群落结构差异机制。揭示了不同施肥处理之间土壤微生物群落结构平均颜色变化率、土壤微生物群落代谢多样性变化、土壤微生物群落代谢功能主成分，根际土壤微生物磷脂脂肪酸(PLFAs)的组成，根际与碳利用相关的土壤微生物群落变化。探明了在长期施肥条件下，双季稻田根际土壤微生物多样性与土壤养分、作物产量之间的关系及其变化规律。项目研究期间，发表研究论文11篇、出版学术专著2部，课题组2名成员职称晋升一级，全面实现了项目的设计，并完成了项目的研究目标。通过本项目研究实施，探明了不同施肥模式下双季稻田作物根际土壤微生物群落结构、多样性的分子生态学机理；其研究成果对指导平衡施肥与土壤养分管理，实现农田的可持续利用具有重要的应用价值。