Effects of Different Fertilization Treatments on Soil Nutrient Availability and Microbial Response Mechanisms in the Baiyinhua Open-Pit Mining Area
Open-pit coal mining causes severe soil nutrient depletion, limiting vegetation restoration. This study, conducted in the Baiyinhua No.2 mining area (Inner Mongolia), evaluated the effects of different fertilization strategies on soil nitrogen (N) and phosphorus (P) availability and microbial community responses. A field experiment was established in May 2023 with five treatments: low (L), medium (M), and high (H) phosphorus inorganic fertilizers, green manure (GM), and a microbial fertilizer (MF) containing nitrogen-fixing and rhizobia bacteria, compared to a control (CK). Results showed that MF significantly increased total carbon (TC) from 8.47 to 10.17 g·kg⁻¹ and total nitrogen (TN) from 0.37 to 0.56 g·kg⁻¹, while H significantly increased available phosphorus (AP) from 9.78 to 26.28 mg·kg⁻¹. Both treatments significantly altered fungal community structure, with increased relative abundances of Gibberella and Alternaria. The study concludes that MF and H improve soil nutrient availability by modulating fungal communities, with MF offering a sustainable biological approach for mine reclamation. These findings provide targeted fertilization strategies for restoring degraded mining soils and advancing green mining practices.