Localized Organic and PGPR Amelioration Improves Stratified Soil Multifunctionality by Reshaping Root Traits and Microbial Communities in Apple Orchard
This project investigates how localized amendment with apple branch residues and plant growth-promoting rhizobacteria (PGPR) regulates depth-dependent soil multifunctionality in orchard ecosystems. Field experiments were conducted with stratified soil layer treatments to explore the independent and synergistic effects of organic residue input and PGPR inoculation on root trait plasticity, soil microbial community assembly, and comprehensive soil multifunctionality. The study reveals distinct regulatory mechanisms governing topsoil and subsoil multifunctionality, in which root-driven rhizosphere processes dominate surface soil functions, while organic substrate supply and fungal community modulation primarily control subsoil multifunctionality. These findings provide a mechanistic basis for stratified, precise soil improvement and sustainable orchard management.