Effect of Straw Retention on Crop Yield, Soil Properties, Water Use Efficiency and Greenhouse Gas Emission in China: A Meta-Analysis

Crop straw retention to field (CSRF) is a technology to impact the crop yield, soil properties and greenhouse gas (GHG) emission and plays a critical role in sustainable agriculture system. Based on the literatures published, a meta-analysis was performed to evaluate actual impact of CSRF on crop yield, soil properties and GHG emission compared with straw no-retention (NSR). The results indicated that compared with NSR, yield of wheat, maize and rice under CSRF was significantly higher by 4.11, 7.22 and 7.62% respectively; CSRF enhanced the water use efficiency (WUE) and soil organic carbon (SOC) by 14.60 and 7.59%, respectively, reduced the bulk density of 0-20 cm soil layer by 3.06%., while it had no significant effect on the SOC of 20-40 cm; For GHG emissions, the soil emissions of CO2, N2O and CH4 were significantly improved under CSRF by 23.64, 12.21 and 27.34% respectively. Categorically, results on meta-analysis and regression indicated that large variation in crop yield, SOC content and bulk density in 0-20 cm soil layer, WUE and GHG emission under CSRF compared with NSR because of different straw retention mass, retention regions, and crop species. For example, the increased rate of large straw retention mass (LA) on crop yield was the highest. Adoption of CSRF under appropriate site-specific conditions can safeguard China's food security, alleviate soil-related constraints and slightly increase GHG emissions.