Biochar amendment reduced microbial necromass carbon accumulation in a paddy soil profile

作者：Ruiling Ma, Suping Ji, Shuo Jiang, Dingyao Lei, Ying Cai, Xiulan Wu, Zhiwei Liu, Qi Yi, Shaopan Xia, Rongjun Bian, Xuhui Zhang, Jufeng Zheng · 发表于：Journal of Integrative Agriculture · 年份：2025 · DOI：10.1016/j.jia.2025.10.001 · 被引用次数：1 · 研究领域：Soil Carbon and Nitrogen Dynamics、Bioenergy crop production and management、Composting and Vermicomposting Techniques

• Biochar reduced fungal necromass carbon in the topsoil while decreasing bacterial necromass carbon throughout the paddy soil profile. • Biochar shifted the microbial community toward K -strategists to decrease microbial necromass carbon production. • Biochar intensified microbial nitrogen limitation to enhance microbial necromass carbon decomposition. Microbial necromass carbon (MNC) serves a crucial function in the formation and stabilization of soil organic carbon (SOC). Although biochar amendment is recognized as a promising approach for enhancing SOC sequestration, its impact on MNC accumulation across the paddy soil profile remains uncertain. Through a 4-year field experiment, this study examined the effect of biochar amendment on MNC accumulation across three soil layers (0–15, 15–30, and 30–45 cm) in a paddy soil profile by combining vertical soil profiling, microbial community dynamics, and biomarker analysis. The results showed that biochar amendment reduced MNC by 10.5% (0–15 cm), 7.5% (15–30 cm), and 9.6% (30–45 cm), respectively, compared to the unamended control. In the topsoil (0–15 cm), the reduction in MNC under biochar amendment was attributed to decreases in both fungal and bacterial necromass carbon (C), whereas in the subsoil (15–45 cm), it primarily resulted from the decrease in bacterial necromass C. Biochar amendment reduced MNC content by decreasing microbial biomass and increasing nitrogen (N) acquisition enzyme activities, mainly due to a shift in ...