秸秆还田模式及其减氮增效机制研究进展OA

Straw returning is a key technology for promoting green and low-carbon agricultural development and achieving the strategic goal of chemical fertilizer reduction.Its core value lies in the synergistic realization of nitrogen reduction,crop yield increase,and nitrogen use efficiency improvement.This article summarized the practical modes of straw returning for nitrogen reduction in different major agricultural regions of China and elucidated the intrinsic mechanisms of nitrogen reduction and efficiency enhancement through multi-interface processes.Practical evidence demonstrated that region-specific straw returning modes,such as deep ploughing in Northeast China,rotary tillage in the Huang-Huai-Hai Region,and rapid decomposition in southern China,when being combined with optimized water and fertilizer management,could generally reduce the nitrogen application by 10％to 25％for rice,wheat,and maize,while maintaining or even increasing the crop yields by 10％and improving nitrogen use efficiency.The core mechanism involves a multi-pathway synergistic coupling process:1)Straw acts as a natural slow-release nutrient pool,directly supplementing and partially replacing nitrogen fertilizer,with release patterns aligned with crop nutrient demand;2)Straw returning increases soil organic matter and promotes aggregate formation,significantly improving soil structure and strengthening water retention,fertility preservation,and nitrogen immobilization capacity;3)Exogenous carbon input drives the restructuring and functional activation of soil microbial communities,such as enhancing the abundance of nitrogen-fixing(nifH)genes and suppressing nitrification activity,thereby optimizing carbon and nitrogen cycling and facilitating efficient nitrogen transformation and retention in the soil-microbial system;4)Straw returning optimizes the rhizosphere microenvironment to promote root development and enhances the activities of key enzymes,such as Rubisco and glutamine synthase,in functional leaves,thus strengthening photosynthetic carbon assimilation and nitrogen metabolism efficiency;5)Straw returning reduces environmental risks such as nitrogen runoff,ammonia volatilization,and N2O emissions through multiple pathways,including physical coverage,chemical adsorption,and biological immobilization.Future research should focus on the molecular mechanisms of straw-soil-microbe interactions,precise integration of regionally adapted technical models,comprehensive assessment of long-term ecological effects,and the development of intelligent decision-support systems to promote the large-scale and efficient application of straw returning in advancing green and high-quality agricultural development in China.