Background This study explores the impact of mineral resource development on regional soil quality, addressing challenges like soil structure damage and fertility decline in alpine mining areas. The proposed solution involves combining serpentine residue soil with raw soil from early mine construction, incorporating local materials like sheep manure, TG amendment, and water retaining agent. The goal is to enhance soil structure and nutrient conditions, establishing a suitable soil matrix for vegetation recovery. This approach aims to improve soil water and nutrient retention in mining areas, supporting soil restoration in high-altitude regions like Qinghai West Copper Mine

Methods In this study, samples representing storage raw soil and serpentine residue soil were collected from platforms 4290 and 4138 of Qinghai West Copper Mine using a three-mixed-one sampling method. The experiments included substrate formulation tests, potting tests, and field plot planting substrate amendment tests to assess their effects on soil properties and growth of one and six plant species. Physical and chemical indicators such as soil bulk weight, pH, porosity, EC, and nutrient content were measured using standard methods. Microsoft Excel and SPSS 26 were used to analyze the experimental data for statistics and to determine the significance of differences.

Results 1) Different ratios of serpentine residue soil and raw soil significantly affected the physicochemical properties of the substrate. When the ratio of serpentine residue soil to raw soil was 6∶4, the formulated soil bulk density, pH, and electrical conductivity decreased by 2.20%, 7.95%, and 19.88%, respectively, compared to the pure serpentine residue soil control (CK). Meanwhile, soil salt, soil capillary porosity, soil field water-holding capacity, available phosphorus, available potassium, total nitrogen, and hydrolyzable nitrogen contents increased significantly by 15.12%, 7.02%, 75.23%, 328.88%, 117.65%, and 32.38%, respectively, meeting the basic requirements of a greening substrate. 2) Pot planting results indicated that forage grasses like Elymus dahuricus showed increased emergence when planted alone or mixed with six grass seeds at a 6∶4 ratio of serpentine residue soil to raw soil, with a 10.34% and 25% increase, respectively. Additionally, the height, aboveground biomass, and belowground biomass of E. dahuricus increased by 7.25%, 87.00%, and 246.95% compared to the control CK. 3) The field plot planting test indicated that with a formulation ratio of 6∶4 for serpentine residue soil to raw soil, and the addition of 1 kg/m² TG amendment, 12 g/m² KM 3005 water retaining agent, and 3.12 kg/m² of goat slate manure, the seedling height and biomass in the gradient test of goat slate manure and TG amendment increased by 38.30% and 200.43%, and 21.43% and 358.02%, respectively, compared to the control. These findings have been applied in an engineering demonstration.

Conclusions The study concludes that a 6∶4 mix of serpentinite slag soil and local raw soil improves physicochemical properties in high-altitude mining areas. This ratio enhances soil structure, lowers pH and conductivity, and increases pore density and water retention. Enriched with nutrients, it supports better grass growth. Pot experiments confirm suitability for seedling emergence and overall growth. Field trials with serpentinite slag soil, raw soil, sheep manure, TG amendment, and KM 3005 water retaining agent promote superior ecological restoration in soil-deficient, high-altitude mining areas.