THE IMPACT OF MINERAL-SOLUBILIZING MICROBES ON SOIL AGGREGATE STABILITY THROUGH MODULATION OF SOIL SURFACE ELECTROCHEMICAL PROPERTIES

Purpose: The number of abandoned mines in the world is rapidly increasing, and external soil spray technology has become a common method for their regreening. Due to the unique environmental conditions of rocky waste mining areas, characterized by widespread rocks, externally sprayed soil only acts on the rock surface and is prone to detachment, making it difficult to maintain in the long term. The purpose of this study is to enhance the stability of soil aggregates through the addition of mineral-solubilizing microbes. Methods: In this study, we simulated the soil microenvironment in the presence of exposed rocks and added microbes that dissolve minerals. Evaluating the effects of soluble microbes on soil aggregate stability from the perspective of soil charge properties and their relationships with soil physicochemical and electrochemical properties. Results: The results indicated that soil pH, clay content, cation exchange capacity, surface potential and soil surface electric field strength were the key drivers of soil aggregate stability. The addition of microbes reduced soil pH, increased soil cation exchange capacity, and clay content. Structural equation modeling results showed that soil physicochemical properties ultimately affected soil aggregates through their influence on soil electrochemical properties. Conclusions: The results suggest that the use of microbes that dissolve minerals could be a viable strategy for the ecological restoration of abandoned mining areas, providing a possible long-term solution for maintaining the efficacy of external soil spray technology. This method addresses the challenges posed by the unique environmental conditions of rocky waste mining areas.