Impact of mixed plantations on soil physicochemical properties: Variations and controlling factors in China

Mixed plantations have emerged as a promising approach to improve soil health and contribute to sustainable land management. Despite the numerous field experiments conducted so far, there is no clear consensus on the impacts of mixed plantations on soil physicochemical properties due to the wide range of findings. This meta-analysis synthesizes findings from 252 studies across China to provide a comprehensive evaluation of these effects within both monoculture and mixed plantation contexts. We quantified the effects of mixed versus monoculture plantations on key soil physicochemical properties, including soil moisture content, bulk density, pH, and nutrient indicators such as soil organic matter, total nitrogen, available nitrogen, total phosphorus, available phosphorus, total potassium, and available potassium. Additionally, we identified the primary drivers of these changes, focusing on factors such as initial soil pH, elevation, mixing proportion, and plantation age. Compared to monocultures, mixed plantations significantly enhanced key soil physicochemical properties, with available potassium, soil organic matter, and available phosphorus each increasing by 18 %. However, soil pH only increased by 1 %. The magnitude of the response varied significantly across different analytes, influenced by factors including initial soil pH, elevation, mixing proportion, and plantation age, underscoring the complex interactions that affect soil dynamics under different plantation management strategies. •Mixed plantations significantly reduce soil bulk density.•Mixed plantations increased soil organic matter (SOM) by 44.91 %.•Mixed plantations increased soil available potassium and phosphorus by 17.72 % and 17.64 %.•A positive correlation between SOM and soil moisture and total N has been identified.