[Liming and biochar effects on soil pH and microbial properties in acidified soils: A meta-analysis].

). Overall, microbial diversity increased by 2.5% following amendment application. Biochar enhanced microbial diversity most strongly within 0.25-0.5 years (14.1%), while lime required more than two years to achieve significant improvement (8.5%). Lime was more effective in low-temperature, low-rainfall regions (up to 6.8%), whereas biochar was better suited to high-temperature, high-rainfall regions (5.5%). Biochar influenced microbial properties indirectly by regulating soil pH, with microbial biomass and diversity showing significant positive correlations with soil pH. In contrast, lime-induced changes in microbial properties were strongly affected by application rate, climatic condition, and initial soil pH. This study clarified the acid-neutralizing effects and soil microbial regulation mechanisms of different alkaline amendments, providing a foundation for further exploration of the coupled physical, chemical, and biological restoration processes in the amelioration of acidified soils.