The role of oxidases and hydrolases in enhancing carbon sequestration through soil management practices: A global meta-analysis across diverse ecosystems

Soil management practices (SMPs) enhance soil organic carbon (SOC) storage and/or components by regulating potential enzyme (PE) activities. Investigating PE activities and SOC components, along with their interrelationships in response to SMPs, can improve our understanding of how PE activities regulate SOC mineralization. Therefore, we conducted a meta-analysis based on 125 peer-reviewed studies to assess the effects of SMPs on PE activities and SOC components. Our results demonstrated that SMPs significantly increased SOC content, microbial biomass carbon (MBC), dissolved organic carbon (DOC), and the activities of β-glucosidase (BG), α-glucosidase (AG), cellobiohydrolase (CBH), β-xylosidase (XYL) and peroxidase (PER) by 22.96 %, 35.88 %, 22.26 %, 35.62 %, 31.06 %, 26.76 %, 29.94 % and 8.92 %, respectively. Significant positive correlations were observed between: (1) SOC and BG/CBH activities; (2) MBC and BG/AG/CBH/XYL/PER activities; and (3) DOC and BG/AG/CBH/phenol oxidase (PO) activities. These findings suggest that SMPs regulate SOC components through hydrolases and/or oxidases. Moreover, SOC levels were influenced by climatic conditions, initial SOC content, and soil pH. Higher SOC accumulation was observed when mean annual temperature (MAT) exceeded 20℃, initial pH > 7.7, and initial SOC < 10 g kg⁻¹ under SMPs. Our findings indicate that SMPs generally improve SOC storage, but the extent of enhancement depends on ecosystem types, initial soil properties, types of exogenous organic materials, and the effectiveness of treatment methods in providing energy and substrates for microbial activity and PE production. Overall, SMPs enhance SOC storage and its components, providing a scientific basis for optimizing fertilizer combinations and the application of exogenous organic materials in diverse ecosystems.