耕作方式对土壤团聚体微生物及有机碳矿化的影响研究进展及展望

Effects of Tillage Methods on Soil Aggregate Microorganisms and Organic Carbon Mineralization:A Review

农业碳排放约占全球年均总排放量的25%,为实现中国2060年碳中和的目标,农业对CO_(2)的吸收与排放需达到自然平衡。土壤有机碳(SOC)矿化是具有碳降解功能的微生物分解SOC为作物生长提供养分,向外界释放CO_(2)等温室气体的生物化学过程。农田SOC矿化与作物养分供给、CO_(2)形成和排放紧密相关,但SOC矿化受多种因素影响。土壤耕作是驱动农田土壤碳固定的关键因素,耕作方式对SOC的影响是农业生态系统碳循环研究的重要内容。土壤不同粒径团聚体被视为微生物碳矿化产生CO_(2)的生化反应器,SOC的矿化分解离不开其对微生物以及对应酶的利用。可见,耕作方式通过直接作用改变土壤团聚体结构,进而改变土壤中的微生物类群,最终对SOC矿化产生影响。就此归纳总结了关于耕作方式、土壤团聚体及关联土壤微生物对农田SOC矿化的影响,以期从改良土壤团聚体结构入手,减少农田SOC矿化,为中国实现“双碳”(碳达峰、碳中和)目标提供理论支撑。

Agricultural carbon emissions account for about 25%of the annual global CO_(2) emissions.To achieve the goal of carbon neutrality in China before 2060,the absorption and emissions of CO_(2) in agriculture need to reach a dynamic balance.Soil organic carbon(SOC)mineralization is a biochemical process of microbial decomposition of SOC which provides nutrients for crop growth and releases greenhouse gases such as CO_(2) to the environment.SOC mineralization in farmland is closely related to crop nutrient supply,carbon sequestration and CO_(2) emission,but SOC mineralization is affected by many factors.Soil tillage is the key factor driving farmland soil carbon fixation,and the impact of tillage methods on SOC is an important part of agricultural ecosystem carbon cycle research.Soil aggregates with different particle sizes are regarded as biochemical reactors for microbial carbon mineralization to produce CO_(2).The mineralization and decomposition of SOC can not be separated from the use of microorganisms and corresponding enzymes.Therefore,the tillage methods directly change the structure of soil aggregates,then change the microbial groups in soil,and ultimately affect SOC mineralization.This review summarized the effects of tillage methods,soil aggregates and associated soil microorganisms on SOC mineralization in farmland,aiming to reduce the occurrence of SOC mineralization in farmland,and provide theoretical support for China to achieve the goal of“double carbon”(peaking carbon emissions and achieving carbon neutrality).