文献类型： 外文期刊

作者： Zijing Zhong; Anxin Wang; Yanke Zhang; Kunkun Wang; Zhifeng Lu; Xiaokun Li; Tao Ren; Wenju Zhang; Rihuan Cong; Jianwei Lu

关键词： aggregation mechanism | biochar | carbon and nitrogen sequestration | microorganism | straw incorporation

期刊名称： EUROPEAN JOURNAL OF SOIL SCIENCE

ISSN： 1351-0754

年卷期： 2025 年

页码：

收录情况： SCIE（2025版）

摘要： Soil aggregates are fundamental structural units that host spatially distinct microbial communities, which drive carbon (C) and nitrogen (N) stabilization through niche-specific biotic and abiotic processes. Yet, the mechanisms underlying microbial-mediated C/N stabilization across aggregate size fractions under different organic inputs remain poorly understood. Here, we conducted a long-term field experiment in a rice–oilseed rape rotation system with three treatments: chemical fertiliser alone (NPK), straw incorporation (NPKS), and biochar application (NPKB). Soil aggregates were fractionated into > 2 mm (large macroaggregates, LA), 0.25–2 mm (macroaggregates, MA), 0.053–0.25 mm (microaggregates, SA), and < 0.053 mm (silt + clay, XSA). Results showed that biochar preferentially enhanced C and N concentrations in finer fractions (< 0.053 mm), indicating enhanced long-term stabilization due to chemical recalcitrance and physical protection. In contrast, straw incorporation promoted complex microbial co-occurrence networks, enriched nitrogen fixation functions, and higher microbial diversity in microaggregates (0.053–0.25 mm), identifying this fraction as a microbial hotspot for dynamic C/N turnover. Moreover, the reduced abundance of chitin-degrading taxa and upregulation of nitrogen-conserving functions under NPKS implied a shift in microbial functional strategies under labile carbon input. These findings reveal contrasting pathways of aggregate-scale C/N stabilization driven by straw and biochar, underscoring the critical role of microaggregates as ecological interfaces linking microbial structure, function, and soil chemistry under organic amendments. These insights offer guidance for optimising organic input strategies to balance short-term nutrient activation and long-term carbon sequestration in sustainable agriculture.

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