Yuan Hechong, Wu Yaman, Sun Yuanyuan, Liu Juying, Lin Li, Xia Fan, Su Xu, Sun Qiang, Meng Jun
Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, Shenyang, 110866, China; National Biochar Institute, Agronomy College, Shenyang Agricultural University, Shenyang, 110866, China.
Key Laboratory of Biochar and Soil Improvement, Ministry of Agriculture and Rural Affairs, Shenyang, 110866, China; National Biochar Institute, Agronomy College, Shenyang Agricultural University, Shenyang, 110866, China.
J Environ Manage. 2025 Aug;390:126284. doi: 10.1016/j.jenvman.2025.126284. Epub 2025 Jun 23.
The accumulation of soil organic carbon (SOC) is critical for maintaining soil fertility and mitigating climate change. The incorporation of organic amendments is a common practice for improving SOC, but the SOC dynamics affected by biochar and straw in rice cultivation still remain unclear. This study focused on paddy ecosystems in cold regions of Northeast China. Through a two-year field experiment (with three treatments: conventional fertilization (CK), biochar application (BC), and straw incorporation (SR)), combined with amino sugars and lignin phenols as biomarkers, the differential soil organic carbon dynamics were revealed. The results revealed that biochar and straw incorporation significantly increased the soil organic carbon content by 10.4 % and 3.4 %, respectively (P< 0.05), among which straw incorporation increased the accumulation of plant-derived carbon by 2.6 % and microbial necromass carbon by 4.8 %, and the contribution rate of bacterial necromass carbon reached 12.8 %. The SR and BC treatments increased the proportion of macroaggregates by 6.1 % and 10.1 %, respectively. Biochar treatment significantly changed the origin of SOC, reducing the proportion of plant-derived carbon by 2.9 % while increasing the fungal/bacterial necromass carbon ratio (F/B) to 3.2. These results demonstrate that straw incorporation enhances carbon conversion efficiency by synergistically increasing plant-derived and microbial necromass carbon, whereas biochar enhances carbon pool stability by promoting plant-derived carbon conversion and reconstructing the proportion of the carbon fraction dominated by fungal necromass carbon. Overall, this study highlights the different carbon sequestration pathways between biochar and straw incorporation and reveals the function of carbon sequestration in biochar application.
土壤有机碳（SOC）的积累对于维持土壤肥力和缓解气候变化至关重要。添加有机改良剂是提高土壤有机碳的常见做法，但在水稻种植中，生物炭和秸秆对土壤有机碳动态的影响仍不明确。本研究聚焦于中国东北寒冷地区的稻田生态系统。通过为期两年的田间试验（设置三个处理：常规施肥（CK）、施用生物炭（BC）和秸秆还田（SR）），结合氨基糖和木质素酚作为生物标志物，揭示了土壤有机碳动态的差异。结果表明，施用生物炭和秸秆还田分别显著提高了土壤有机碳含量10.4%和3.4%（P<0.05），其中秸秆还田使植物源碳积累增加了2.6%，微生物残体碳增加了4.8%，细菌残体碳的贡献率达到12.8%。秸秆还田和生物炭处理分别使大团聚体比例增加了6.1%和10.1%。生物炭处理显著改变了土壤有机碳的来源，使植物源碳比例降低了2.9%，同时使真菌/细菌残体碳比（F/B）提高到3.2。这些结果表明，秸秆还田通过协同增加植物源和微生物残体碳来提高碳转化效率，而生物炭则通过促进植物源碳转化和重建以真菌残体碳为主的碳组分比例来增强碳库稳定性。总体而言，本研究突出了生物炭和秸秆还田不同的碳固存途径，并揭示了生物炭应用中的碳固存功能。
