Mechanisms of functional reconstruction in saline-alkali soil and plant growth responses

Functional impairment in saline-alkali soils critically constrains ecological functions and plant establishment, necessitating advanced remediation technologies. This investigation engineered a novel soil conditioner through stoichiometric integration of coal gasification ash (CFA), cow dung (CD), and wine pomace (WP) (5:4:1 w/w) to reconstruct edaphic functionality. Multivariate analysis elucidated governing factors in soil microhabitat restoration and concomitant alfalfa physiological responses. Results demonstrate that the ternary amendment significantly enhanced soil structural integrity and chemical equilibrium. The composite mediates multidimensional regulation of heavy metal speciation (Cd, Pb, As), cation-anion homeostasis, and electrolytic conductivity via pH-buffering mechanisms, establishing a phytocompatible rhizosphere. Crucially, we reveal multifunctional coupling between physicochemical modulation and microbiome-mediated ecological feedback. This mechanistic insight advances the theoretical framework for functional reconstruction of degraded saline-alkali ecosystems while establishing a waste-valorization pathway for coal gasification residues.