Objective The ecological restoration of mining area slopes in the Qinling Mountains faces significant challenges due to harsh environmental conditions, including fragile geology, vegetation degradation, and severe soil erosion. Conventional slope protection methods often lack sufficient ecological integration and effective soil retention capacity. In response, this study focuses on enhancing the greening effect and erosion resistance of hydroseeding slope protection by selecting optimal vegetation species and evaluating the erosion resistance of slopes under different treatment conditions.

Methods Seven common slope protection plants—Festuca elata, Lolium perenne, Cynodon dactylon, Robinia pseudoacacia, Lespedeza bicolor, Amorpha fruticosa, and Medicago sativa—were cultivated in an outdoor experimental setup. Growth performance and soil-fixing capacity were measured to evaluate species adaptability to hydroseeding substrates. Based on superior growth and soil stabilization performance, L. perenne was selected for further study. Using a laboratory rainfall simulation system, this study investigated runoff generation and erosion resistance under four hydroseeding times (24 h, 7 d, 21 d, 35 d) and three rainfall intensities (10, 30, 50 mm/h), simulating real slope conditions.

Results 1) The outdoor trials revealed that L. perenne and F. elata exhibited excellent growth and adaptability, while M. sativa showed high soil stabilization potential. Therefore, they can be considered as preferred plant species for hydroseeding-based slope protection in the Qinling mining area. 2) Indoor rainfall simulation demonstrated that runoff rates were significantly and positively correlated with rainfall intensity. The average runoff rates at 30 mm/h and 50 mm/h were approximately 2.1 and 4.5 times those at 10 mm/h, respectively. Runoff rates decreased progressively with longer curing time, with reductions of about 8.0%, 18.6%, and 29.4% at 7 d, 21 d, and 35 d, respectively, compared to 24 h. The erosion resistance coefficient increased with curing time, with the value at 35 d being approximately 1.47 times that at 24 h. However, under high-intensity rainfall (50 mm/h), the erosion resistance coefficient dropped sharply to only 42% of the value under 10 mm/h. 3) Power function models were developed to describe the relationships between runoff, erosion resistance, rainfall intensity, and curing time, with high fitting accuracy (R² > 0.94).

Conclusions For hydroseeding-based slope protection in the Qinling mining area, plant selection should consider both rapid early-stage vegetation cover and root-induced soil reinforcement. Ryegrass, tall fescue, and alfalfa therefore show good application potential, while the post-hydroseeding maintenance period is an important factor in improving slope resistance to runoff erosion. These findings provide a useful reference for plant configuration, hydroseeding scheduling, and rainfall-induced erosion risk control in the ecological restoration of mining slopes.