Biochar amendment mitigates negative effects of controlled irrigation on paddy soil structure: Insights from micro-pore network analysis

作者：Jiazhen Hu, Shihong Yang, Wim Cornelis, Qian Huang, Suting Qi, Zewei Jiang, Haonan Qiu, Yi Xu · 发表于：Agricultural Water Management · 年份：2025 · DOI：10.1016/j.agwat.2025.109517 · 被引用次数：11 · 研究领域：Soil and Unsaturated Flow、Soil Carbon and Nitrogen Dynamics、Soil Geostatistics and Mapping

With increasing rice production demands and water scarcity, developing water-saving irrigation techniques for paddy fields is a global priority. The impact of these techniques on soil structure remains unclear, especially under varying water-carbon conditions. From 2022–2023, field experiments examined four biochar rates and two irrigation methods (controlled irrigation (CI) and flooding irrigation (FI)), resulting in five treatments: CK (0t/ha+CI), CA (60t/ha+CI), CB (30t/ha+CI), CC (10t/ha+CI), and FK (0t/ha+FI). Compared to FK, CK decreased mean weight diameter (19.73–25.54 %), soil organic matter (4.64–9.79 %), total nitrogen (2.68–10.59 %), dissolved organic carbon (1.90–9.48 %), water content at saturation (0.23–15.83 %) and permanent wilting point (3.69–7.87 %), while it increased unstable aggregates index (6.29–15.11 %) and fractal dimension (1.59–1.88 %). Biochar treatments (CA, CB, CC) mitigated CK's adverse effects on soil aggregate stability, total nitrogen, and water retention capacity and significantly improved these indicators. CA increased porosity across various effective pore diameters, while CB and CC primarily increased the proportion of porosity for diameters > 250μm. Simulation results indicated that compared to CK (3.879μm²), the intrinsic permeability (K) of soil under CA, CB, and CC treatments increased by 106.69 %, 77.77 %, and 3.31 %, respectively, while FK showed a contrasting decrease of 3.58 %. K correlated well with > 250μm porosity and connecte...