Electrostatic repulsive forces among soil particles control the intensity of soil loss in runoff and are controlled by the coupling of cation surface reactions (e.g., the Hofmeister effect), electrolyte concentration, and soil particle size composition. In this study, we used different concentrations of Li⁺, K⁺, and Cs⁺ to adjust the cation surface reaction or Hofmeister effect and electrolyte concentration of a neutral purple soil (Entisol). The mechanical composition of the soil was adjusted by adding 0.55–1 mm diameter quartz particles, and the mean surface potential of the soil particles was used to indirectly express the electrostatic repulsive force between particles. The results show that the Hofmeister effect, electrolyte concentration, and mechanical composition are strongly coupled during soil loss, of which the Hofmeister effect plays the most critical role. The physical mechanisms of the coupling effects can be summarized as follows. The electrostatic repulsive force among soil particles depends on the coupling of the Hofmeister effect and electrolyte concentration. Breaking intensity of the soil aggregate, which influences soil loss intensity in runoff, is determined by the electrostatic repulsive force and the production rate of the electrostatic repulsive force-which is controlled by the soil mechanical composition. We conclude that: (1) soil cation surface reactions are a key factor for determining the electrostatic repulsive forces and thus soil loss intensity in runoff; (2) for a given soil, the mechanical composition provides the basic factors that determine the production rate of the electrostatic repulsive force to break soil aggregates; and (3) increasing the soil’s large particle content enhances soil loss intensity but not necessarily soil loss quantity.

土壤颗粒之间的静电排斥力控制径流中土壤流失的强度，并受阳离子表面反应（例如霍夫迈斯特效应），电解质浓度和土壤粒径组成的耦合影响。在这项研究中，我们使用了不同浓度的Li ⁺，K ⁺和Cs ⁺调整阳离子表面反应或霍夫迈斯特效应以及中性紫色土壤（Entisol）的电解质浓度。通过添加直径为0.55-1mm的石英颗粒来调节土壤的机械成分，并使用土壤颗粒的平均表面电势间接表达颗粒之间的静电排斥力。结果表明，在土壤流失过程中，霍夫迈斯特效应，电解质浓度和机械成分密切相关，其中霍夫迈斯特效应起着至关重要的作用。耦合效应的物理机制可归纳如下。土壤颗粒之间的静电排斥力取决于霍夫迈斯特效应和电解质浓度的耦合。土壤团聚体的破坏强度，影响径流土壤流失强度的因素，是由静电排斥力和静电排斥力的产生速率决定的，而静电排斥力的产生速率则由土壤的机械组成决定。我们得出以下结论：（1）土壤阳离子表面反应是决定静电排斥力和径流土壤流失强度的关键因素；（2）对于给定的土壤，机械成分提供了决定静电排斥力使土壤团聚体破碎的速率的基本因素；（3）增加土壤大颗粒含量会增加土壤流失强度，但不一定会增加土壤流失量。我们得出以下结论：（1）土壤阳离子表面反应是决定静电排斥力和径流土壤流失强度的关键因素；（2）对于给定的土壤，机械成分提供了决定静电排斥力使土壤团聚体破碎的速率的基本因素；（3）增加土壤大颗粒含量会增加土壤流失强度，但不一定会增加土壤流失量。我们得出以下结论：（1）土壤阳离子表面反应是决定静电排斥力和径流土壤流失强度的关键因素；（2）对于给定的土壤，机械成分提供了决定静电排斥力使土壤团聚体破碎的速率的基本因素；（3）增加土壤大颗粒含量会增加土壤流失强度，但不一定会增加土壤流失量。