还田秸秆碳在土壤中的转化分配及对土壤有机碳库影响的研究进展

农田土壤有机碳库是全球碳循环的重要组成部分.随着秸秆还田技术的广泛应用,作物秸秆成为土壤外源碳的主要来源.秸秆碳在土壤中的转化与分配直接影响土壤有机碳组成与含量,进而改变土壤养分循环.基于近年来的相关研究,本文探讨了还田秸秆碳转化与分配过程的影响因子,详细介绍了参与秸秆碳同化过程的土壤微生物组成,归纳与阐述了秸秆碳对土壤有机碳组成、含量及其周转的影响.同时,就非生物因子对秸秆碳的生物转化效应的影响、秸秆碳转化过程中的生物和非生物因子的互作、秸秆碳氮和土壤碳氮循环的耦合作用、秸秆碳向土壤活性有机碳库或稳定性有机碳库转化的有效调控技术等主要研究方向进行了展望,以期为准确揭示秸秆还田条件下各类土壤有机碳的变化特征,进而为实现秸秆还田的高效培肥与固碳效应提供理论依据和技术支撑.

Transformation and distribution of straw-derived carbon in soil and the effects on soil organic carbon pool: A review.

Farmland soil organic carbon (SOC) pool is a crucial component of global carbon cycle. Due to the widely-implemented straw returning, crop straws have become the primary exogenous carbon source for agricultural soils. The conversion and distribution of straw-derived carbon in soil directly affect the composition and contents of SOC, with further influence on soil nutrient cycling. Based on recent studies, this review investigated the factors impacting the transformation and distribution of straw-carbon; introduced the microbial composition that contributes to the assimilation of carbon from straw; and summarized the effects of straw-carbon on the composition, content, and turnover of SOC. Additionally, we proposed the future research regarding the effects of abiotic factors on the bio-transformation of straw-carbon; the interaction between biotic and abiotic factors during the straw carbon transformation processes; the coupling of carbon and nitrogen from straws into the soil carbon and nitrogen cycles; and the effective control over the transformation of straw-carbon that enters the active or stable soil organic carbon pool. The purpose was to reveal variation characteristics of SOC during straw returning, and provide theoretical basis and technical support for the efficient fertilization and carbon sequestration of straw returning.