Abstract: Changes in land use patterns have marked effects on soil surface electrochemical properties, which are directly related to key soil functions such as nutrient absorption, pollutant migration, and soil aggregate stability. We examined surface electrochemical properties of soils and the influencing factors across five typical land use types on the Loess Plateau, including forest, shrubbery, grassland, abandoned land, and farmland. A combination of methods was used to measure soil surface electrochemical properties. The results showed that soil surface charge quantity, surface potential, surface charge density, specific surface area, and surface electric field across in the five land use types ranged from 6.52 to 11.44 cmol c·kg^-1, -157.26 to -104.12 mV, 0.17 to 1.36 C·m^-2, 19.30 to 144.72 m²·g^-1, and 2.35×10⁸ to 19.14×10⁸ V·m^-1, respectively. Soil surface potential, surface charge density, and surface electric field in forests were significantly lower than those in farmland, while soil surface charge quantity and specific surface area in forests were significantly higher than those in abandoned land and farmland (P<0.05). The independent contribution rates of root characteristics and soil physicochemical properties to the variations of soil surface electrochemical properties were 25.2% and 44.8%, respectively, and the relative contribution of their interaction was 26.9%. Among all the root characteristics, root length density was the major factor influencing soil surface electrochemical properties, with a contribution rate of 87.1%. In terms of soil physicochemical properties, clay and organic matter contents were the primary factors influencing soil surface electrochemical properties, with contribution rates of 83.2% and 11.1%, respectively. Soil physical and chemical properties significantly influenced soil surface electrochemical properties, with path coefficients of -0.82 and -0.83, respectively, and the direct effects being dominant. In conclusion, soil surface electrochemical properties on the Loess Plateau differed significantly with land use types, and were regulated jointly by roots and soil physicochemical properties. Our results enhance the understanding of soil surface electrochemical properties on the Loess Plateau and provide theoretical support for soil management and regulation as well as for the assessments of ecological benefits.

Key words: land use type, root system, soil surface electrochemical property, Loess Plateau