秸秆还田和根系及其分泌物对潮土有机质累积和团聚体形成的协同作用机制

项目名称： 秸秆还田和根系及其分泌物对潮土有机质累积和团聚体形成的协同作用机制

项目编号： No.41471182

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 张丛志

作者单位： 中国科学院南京土壤研究所

项目金额： 84万元

中文摘要： 我国粮食重要产区黄淮海平原潮土地区土壤有机质含量普遍较低且难于累积，土壤砂粒含量高使得土壤结构差且团聚体难以形成。前期长达20多年的长期定位施肥试验表明依赖于作物根系及其分泌物，有机质只能达到10g/kg而难以继续增加，而增施秸秆堆腐而成的有机肥则能进一步显著提升土壤有机质，改善土壤结构。因此，本项目通过野外盆栽、室内模拟以及大田长期定位试验，采用同位素示踪来研究秸秆和根系及其分泌物对土壤有机质的协同累积作用；利用同位素示踪、扫描电镜-X射线能谱仪结合技术(SEM-EDX技术)、高分辨魔角核磁共振（HR-MAS NMR）、高通量测序和实时定量PCR等技术来研究秸秆和根系及其分泌物协同作用下土壤有机质和土壤微生物对土壤团聚体形成机制的影响。以期在不同空间及时间尺度上阐明秸秆还田和根系及其分泌物对潮土有机质累积和团聚体形的协同作用机制，为黄淮海平原地区土壤地力的培育提供理论基础和技术支持。

中文关键词： 秸秆还田；根系及其分泌物；土壤有机质；团聚体；协同作用

英文摘要： Huang-Huai-Hai Plain locates in the northern China and is an important food supply area in China. In this area, the typical soil is classified as fluvo-aquic soil，the soil properties are generally presented as lower soil organic matter and poor soil structure with high sand, therefore, it is difficult to accumulate soil organic matter and to form aggregates in fluvo-aquic soil. A long-term fertilization experiments lasted for more than 20 years showed that soil organic matter could only reach to 10g/kg when only depending on the inputs of crop root and its exudates, however, application of organic fertilizers from straw decomposition could further significantly improve soil organic matter and soil structure. In this proposed project, pot experiments, laboratory culture experiments and field experiments will be conducted, via isotope labeling to study the cooperative effects of straw return and root and its exudate on soil organic matter accumulation. A series of modern techniques such as scanning electron microscope-X energy dispersive spectrometer(SEM-EDX), High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR), high-throughput sequencing, and polymerase chain reaction (PCR) will be applied together to investigate the effects of soil organic matter and soil microbiology on the formation of aggregates. The aim of this study is to reveal the cooperative effects of straw return and root and its exudate on soil organic matter accumulation and aggregate formation in fluvo-aquic soil, Such efforts not only contribute to our further understanding of the soil organic matter and soil structure in different spatial and temporal scales, but also provide theoretical basis and technical support for the soil fertility cultivation of the Huang-Huai-Hai Plain.

英文关键词： straw return;root and its exudate;soil organic matter;aggregate;cooperative effect