Ecological restoration in semi-arid grassland mining areas is constrained by limited topsoil availability and arid climate, making the recovery of soil physicochemical properties critical for ecosystem reconstruction. This study was conducted in the Suancigou Coal Mine, Inner Mongolia, China, comparing soils reclaimed for 3, 7, and 11 years (R3, R7, and R11) with undisturbed land (UD). Differences in soil properties and their associations with vegetation biomass (BM) were analyzed using significance tests and Spearman correlation. Soil properties exhibited non-linear recovery trajectories. Under high-intensity anthropogenic intervention, soil organic matter (SOM) and soil total nitrogen (STN) at R7 recovered to levels comparable to UD, while soil water content, clay content, and soil available potassium were significantly higher than those in UD ( p < 0.05). With increasing reclamation age, soil structure transitioned from vertical homogeneity to differentiation. In R11 and UD, soil available phosphorus (SAP) was significantly enriched in the 0–10 cm layer relative to the 10–20 cm layer ( p < 0.05), whereas R3 and R7 showed weak stratification. Correlation analysis identified pH as a key regulator of nutrient availability, showing negative correlations with STN, soil available nitrogen , SAP, and SOM. BM was positively associated with STN (r s = 0.54) and SOM (r s = 0.53), indicating a re-established soil–vegetation feedback. These findings suggest that restoration in semi-arid grassland mining areas should move beyond natural succession toward integrated anthropogenic and biological strategies, with high-input interventions supporting rapid recovery and moderate, cost-effective measures better suited for large-scale restoration.
Fan et al. (2026) studied this question.