如何让农田土壤变身“碳银行”？中国农业科学院农业资源与农业区划研究所、国家绿肥产业技术体系首席科学家曹卫东研究员团队利用我国南方稻区10点联网试验，发现绿肥与秸秆联合施用可减少土壤碳损失，通过微生物“碳泵”将植物残体高效转化为稳定有机碳，这一发现为农业固碳和土壤健康管理提供了全新策略。相关研究结果近期以“Green Manure Coupled With Straw Returning Increases Soil Organic Carbon via Decreased Priming Effect and Enhanced Microbial Carbon Pump”为题发表于《Global Change Biology》。
论文重要发现如下??
1+1>2的固碳效果:绿肥施用、单独秸秆还田和二者联合（MR处理）每年分别使土壤有机碳(SOC) 储量增加了 119.7、477.0 和 830.2 kg/ha，MR处理显著提高SOC积累效率（23.1%），远超单独秸秆还田（17.7%）或绿肥施用（13.3%）。固碳机制:MR处理通过抑制K策略微生物，减少对顽固性土壤原有SOC（如木质素、蛋白质类分子）的分解，降低正激发效应（PE），从而减少碳损失；MR处理促进r策略微生物和真菌活性，增强微生物碳泵（MCP）路径，将更多植物残体转化为微生物残体（MNC），特别是真菌残体；秸秆（高C/N）提供持久碳源，绿肥（低C/N）激活微生物活性，协同减少碳损失。
????该研究揭示绿肥与秸秆联合施用调控SOC动态的微生物机制，提出“低质量+高质量残体组合”的农田土壤碳库增效模式，为绿肥-稻秸联合利用这一“碳氮互济”举措全方位推广应用提供重要科学依据，也为我国当前实施的农田减排固碳行动提供有效技术支撑。
Abstract
Green manuring and crop straw returning are widely used to increase soil organic carbon (SOC) sequestration, while the pathways and drivers in native SOC mineralization and new SOC formation after implementing these practices remain unclear. Here, through a 10-locations' network field experiment in southern China, the effects of green manuring (Mv), rice straw returning (Rs), and their combination (MR) on soil C sequestration efficiency (CSE) were evaluated. A microcosmic experiment was performed to trace the components and participants of SOC mineralization and formation under the three practices. The network experiment showed that Mv, Rs, and MR annually improved SOC stock by 119.7, 477.0, and 830.2?kg?C?ha?1, respectively, with MR having the highest CSE of 23.1%, followed by Rs (17.7%) and Mv (13.3%). The microcosmic experiment further revealed that the highest CSE in MR most likely resulted from the low mineralization of native SOC (positive priming effects, PE) and great formation of new SOC through microbial C pump (MCP). Therein, MR mainly downregulated the K-strategists of the microbial community (e.g., Gaiellales) to yield negative PE on recalcitrant native SOC, such as protein/amino sugar- and lignin-like molecules; meanwhile, MR had the highest bacterial and fungal MCPs, which were, respectively, led by r-strategists (e.g., Sporobacter) and molds (e.g., Cladosporium). The study highlights the advantages of mixing low- (Rs) and high-quality (Mv) residues for efficiently increasing SOC sequestration and firstly discovers the core microbes that dominate the mineralization and formation of SOC in paddy fields.
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参考文献：
Zhou, G., Li, G., Liang, H., Liu, R., Ma, Z., Gao, S., Chang, D., Liu, J., Chadwick, D.R., Jones, D.L. and Cao, W. (2025), Green Manure Coupled With Straw Returning Increases Soil Organic Carbon via Decreased Priming Effect and Enhanced Microbial Carbon Pump. Glob Change Biol, 31: e70232
文献链接：
https://doi.org/10.1111/gcb.70232
