有机质促进土壤团聚体稳定性中的离子特异性效应

The formation and stability of soil aggregate are closely related to organic matter and its content, and are affected by the interactions of soil particles. Specific ion effects can influence aggregate stability through changing the surface properties and interactions of organic matter and soil particles, while its mechanisms are not clear enough. This proposal will build single and mixed electrolyte conditions, measure the surface properties of soil with different contents of organic matter, and clarify the specific ion effects on the particle interactions. Then combining the aggregation kinetics and structure feature of aggregation with the strength of aggregate breakdown, this study would develop the relations among interface-ion reaction (microscale), particle interactions and behavior (mesoscopic scale) and aggregate stability (macroscale), and elucidate the specific ion effects on organic matter improving aggregate stability. This project provides theoretical supports for aggregate conformation and soil fertility development.

土壤团聚体的形成和稳定与有机质及其含量密切相关，同时也受到土壤颗粒间相互作用的影响。离子特异性效应可以通过改变有机质与土壤颗粒的表面性质及其相互作用进而影响到团聚体的稳定性，但其作用机制仍不完全清楚。本项目拟通过构建单一和混合电解质条件，测定不同有机质含量土壤的颗粒表面性质，明确颗粒间相互作用力的离子特异性效应；结合颗粒凝聚动力学参数、凝聚体结构特征和土壤团聚体破裂强度，建立界面离子反应（微观）、颗粒相互作用与行为（介观）和团聚体稳定性（宏观）之间的内在联系，阐明有机质促进土壤团聚体稳定性中的离子特异性效应，为团聚结构构建和土壤肥力提升提供理论支撑。