Soil Surface Electrochemical Properties in a Karst Ecosystem and Its Response to Rocky Desertification Evolution, SW China

Rocky desertification control is an effective way to reconstruct degraded ecosystems and restore soil function in karst areas.Soil surface electrochemical properties, including soil surface potential, surface charge density, surface electric field strength, specific surface area, and surface charge number are important indicators for evaluating agricultural soil quality and environmental carrying capacity.However, little attention has been paid to the effect of rocky desertification succession on soil electrochemical properties.In this study, we selected a sequence of rocky desertification succession (nil, slight, moderate, and severe) to study the changes in soil surface electrochemical properties during the succession of rocky desertification.Our results showed that with increasing rocky desertification intensity, soil surface charge density, surface charge intensity, specific surface area, and the numbers of surface charge decreased, while the soil surface potential increases.The results showed that humus composition, soil particle size composition, and metal oxide content were important environmental factors that determine the electrochemical properties of soil surface in a karst rocky desertification area.In terms of impact on surface charge properties, soil properties displayed an order of humus>particle size composition>metal oxides.In addition, through the comparative analysis of soil physical properties and surface electrochemical properties, it was found that the surface soil aggregates of severe rocky desertification were more likely to disintegrate when precipitation occurs, thus facing a higher risk of soil erosion.Our results showed that the electrochemical properties of soil surface decrease with the increase of rocky desertification grades, which contributed to the decline of soil water and fertilizer