A global meta-analysis of management practices on soil available and total zinc

Aim: To investigate the effects of eight fertilization strategies on soil available and total zinc content, as well as to identify their key driving factors.Location: Global.Time Period: 1993-2024.Major Taxa Studied: soil available and total zinc.Methods: This study integrated a global dataset comprising 1,240 paired observations of soil available zinc and 364 paired observations of soil total zinc. The effects of eight fertilizer types (chemical fertilizer [CF], composting, manure, zinc fertilizer, CF combined with composting [CFC], manure [CFM], zinc fertilizer [CFZn], and composting plus zinc fertilizer [CZn]) on the soil available and total zinc content were assessed by meta-analysis. Subsequently, environmental variables were then grouped into five categories, namely climate, biological factors, topographic factors, management measures, and soil properties, to determine which categories had the most significant influence on soil zinc content under different fertilization treatments.Results: The results indicated that soil available zinc content increased significantly under CZn (158.26%), CFZn (134.36%), zinc fertilizer (133.24%), CFM (83.57%), manure (77.89%), CFC (43.29%), and composting (35.40%). Additionally, manure, CFM, zinc fertilizer, CFZn, and CZn treatments significantly enhanced soil total zinc content, with increases ranging from 25.04% to 32.29%. Soil available zinc content increased with fertilizer rates of CFC, CFM, and zinc fertilizer. Among crops, wheat responded more strongly to the enrichment of soil available zinc, whereas rice showed a great tendency to accumulate soil total zinc. Fertilization intensity, crop types, soil organic carbon, and soil pH emerged as key drivers influencing soil available and total zinc content. Regulating soil zinc through fertilization strategies requires careful consideration of soil organic carbon and pH to promote sustainable agricultural development.