Ecological soil-oriented utilization of phosphorus tailings: Targeted stabilization, nutrient retention, and...

Phosphorus tailings (PTs) accumulate in large quantities and demand safe, scalable management. Targeting the water-soluble hazardous constituents in PTs (phosphate, fluoride, and heavy metals), we applied targeted solidification/stabilization (S/S). PTs-based soils were implemented using FeSO₄ and polyaluminum salts (PAC/PAS) combined with humic acid and organic wastes. An integrated assessment covered physicochemical properties, nutrient release, plant performance, microbial communities, and ecological functions. A 4% targeted stabilizer achieved immobilization efficiencies of 95.1% for fluoride and 88.24% for phosphate. With PTs >85.25% and 40-day ambient incubation, co-amended substrates outperformed PTs controls in structural attributes, pH buffering, EC management, and controlled nutrient release. Notably, in PPS and PHS treatments, combining humic acid with organic manures elevated pak-choi germination to 93%, increased microbial diversity, and enriched plant growth-promoting functions, demonstrating strong synergy with the targeted S/S regime and improving the ecological adaptability and sustainability of PTs-based soils. Collectively, these results establish both a theoretical basis and a practical pathway for the ecological valorization of PTs.