Ground cover management improves orchard soil moisture content: A global meta-analysis.

• Ground cover management (GCM) overall increased soil moisture content (SMC) by 9.2% in orchards. • Effects of GCM on SMC change varied with management and environmental factors. • Climate and tree age were the dominant drivers of SMC responses to GCM. • High soil bulk density (greater than 1.4 g cm−3), full cover, and mowing could constrain the GCM-induced positive effect. Ground cover management (GCM) is an important practice for sustainable agricultural development, which has been garnering popularity in numerous orchards worldwide. It can effectively improve soil health, reduce soil erosion, and enhance carbon sequestration. However, the effects of GCM on soil moisture content (SMC) dynamics vary with management and environmental factors, and it remains unclear how these factors affect GCM-induced SMC. In addition, it remains unknown how SMC and influencing factors such as climatic, edaphic, and agronomic factors are inter-related in responding to mulching practices. Therefore, we performed a meta-analysis to identify the effect of these factors on SMC accumulation and elucidate the potential mechanisms involved under different environmental and management conditions. Results revealed that GCM practices significantly enhanced SMC (9.2%) compared with the effects of traditional clean tillage. The maximum benefits of SMC were observed when the average annual temperature was smaller than 8 ℃, initial soil organic carbon was 20 g kg−1, and tree age was greater than 20 yr. Further analysis using a random forest model revealed that sampling time, tree age, and soil depth were the predominant drivers of SMC change. Overall, these findings highlight the critical importance of GCM in increasing SMC in orchards worldwide. In addition, the results show that the corresponding changes are controlled by specific climatic, soil, and management factors. These findings provide insights and guidance that can assist practitioners and policy-makers to establish and manage site-specific GCM practices to maximize SMC benefits and promote sustainable agricultural development. [ABSTRACT FROM AUTHOR]