有机物料官能团在红壤中演变及其对红壤旱地有机碳稳定及固持影响的机理

The rapid decomposition and conversion of organic carbon is the main cause of low-fertility in upland red soil. Organic functional groups are the key factors affecting the decomposition and stabilization of organic carbon. There are few reports on the evolution of organic functional groups in upland red soil and the effects on the stabilization and retention of organic carbon in upland red soil. Those studies have great significance for the regulation of organic materials on the carbon pool and quality of upland red soil. Based on the long-term experiments with organic materials application in upland red soil, the methods of cultivation experiment and field experiment and the technologies of Fourier transform infrared spectroscopy, 13C nuclear magnetic resonance and transmission electron microscopy/energy dispersive X-ray spectroscopy will be used. Study contents include the correlation between functional groups of organic material and stabilization of organic carbon under the long-term experiment in upland red soil, the evolution of functional groups of organic materials driven by hydrothermal factors in red soil, and the numerical characteristics of stabilization and retention of organic carbon affected by organic material functional groups in upland red soil. The objective is to indicate comprehensively the mechanism of the functional groups of organic materials on the stabilization and retention of organic carbon in upland red soil from the perspective of "quality" and "quantity". Our results will provide new insights to soil organic carbon cycling, and provide scientific basis for improving upland red soil structure and fertility.

有机碳分解转化快是红壤旱地肥力贫瘠的主因。有机物官能团是影响有机碳分解转化及稳定固持的关键因子，其在红壤中演变规律及对红壤旱地有机碳稳定固持作用机理的研究少有报道。该研究对有机物料还田调控红壤旱地碳库和红壤旱地质量具有重要意义。本项目依托长期施用有机物料的红壤旱地定位试验，结合室内土壤培养及田间原位试验，采用同位素比质谱、傅里叶红外光谱及透射电镜/能量弥散X射线谱等光谱和能谱技术，研究有机物料官能团与红壤旱地有机碳稳定性的关联特征及水热因子驱动有机物料官能团在红壤中的演变特征，解析有机物料官能团影响红壤旱地有机碳稳定及固持的数值特征，旨在从“质”和“量”的角度揭示有机物料官能团在红壤中演变及其对红壤旱地有机碳稳定及固持影响的机理。本项目研究结果将丰富土壤碳循环的基础理论，为红壤旱地改良和培肥地力提供理论参考。

有机碳分解转化快是红壤旱地肥力贫瘠的主因。有机物官能团是影响有机碳分解转化及稳定固持的关键因子，其在红壤中演变规律及对红壤旱地有机碳稳定固持作用机理的研究少有报道。该研究对有机物料还田调控红壤旱地碳库和红壤旱地质量具有重要意义。本项目依托长期施用有机物料的红壤旱地定位试验，结合室内土壤培养及田间原位试验，采用同位素比质谱、傅里叶红外光谱及透射电镜/能量弥散X射线谱等光谱和能谱技术，研究了有机物料官能团与红壤旱地有机碳稳定性的关联特征及水热因子驱动有机物料官能团在红壤中的演变特征，解析了有机物料官能团影响红壤旱地有机碳稳定及固持的数值特征。结果表明有机物料官能团通过稳定团聚体，调控土壤理化特性及钙镁离子形态来影响有机碳的稳定，其中含氮烷基碳/甲氧基碳、芳香碳和酚碳是影响此过程的重要基团之一。水肥因子是调控有机物料官能团演化及土壤有机碳稳定的重要外在因素，有机物料结构中醇/酚类化合物，多糖，氨基化合物，烯烃类化合物和含磷/硫化合物随水分含量的增加逐渐降解，由多糖类为主演变为以芳香类结构为主。有机肥施用则通过促进细颗粒有机碳中脂肪类、多糖等活性有机碳的积累，促进真菌、放线菌、革兰氏阴性细菌的生长繁殖，增强微生物对有机碳官能团演变的贡献。数值解析表明，烷基碳、含氮烷基碳和羰基碳等官能团通过促进矿物氧化物的络合提高土壤有机碳稳定，含氧烷基碳和芳香基等官能团则通过提高腐殖质稳定性增强土壤有机碳稳定。该项目揭示了有机物料官能团在红壤中演变及其对红壤旱地有机碳稳定及固持影响的机理，为丰富土壤碳循环基础理论提供支撑。