Understanding the influence of soil‐borne hydrogels (e.g., bacterial extracellular polymeric substances [EPS] and biofilm or root‐derived mucilage) on soil hydraulic properties is crucial for accurate modeling of flow and transport in porous media. The underlying mechanisms of how hydrogels modify soil physical and hydraulic properties, however, remain unclear. In this study, we applied a roughness‐triangular pore space model (R‐TPSM) to simulate water retention curve and hydraulic conductivity of hydrogel‐affected soils. The model considers the effective soil pore size distribution and physicochemical properties (e.g., surface tension and surface roughness) of soil and soil solution. The modeling results are in good agreement with measured water retention curves and hydraulic conductivity for different textured soils. Comparison of the fitted model parameters between control and hydrogel‐treated soil samples indicates that hydrogels reduce surface tension and shift the effective pore size distribution to a narrower size range. Hydrogels generally increase water retention in the form of adsorptive films and reduce film flow under relatively dry conditions. This study highlights the importance of considering reduced surface tension and mean pore size by hydrogels in changing soil hydraulic properties, which has important implications for accurate modeling of water distribution and flow in the rhizosphere.

中文翻译：

---

使用粗糙度-三角形孔隙空间模型揭示土壤水凝胶对土壤水力学的影响

了解土壤传播的水凝胶（例如细菌细胞外聚合物[EPS]和生物膜或根源黏液）对土壤水力学特性的影响，对于在多孔介质中精确模拟流动和运输至关重要。然而，水凝胶如何改变土壤物​​理和水力性质的潜在机制仍不清楚。在这项研究中，我们应用了一个粗糙的三角形孔隙空间模型（R-TPSM）来模拟水凝胶影响的土壤的保水曲线和水力传导率。该模型考虑了土壤和土壤溶液的有效土壤孔径分布和理化性质（例如表面张力和表面粗糙度）。模拟结果与不同质地土壤的保水曲线和水力传导率非常吻合。对照样品和水凝胶处理过的土壤样品之间拟合模型参数的比较表明，水凝胶降低了表面张力并将有效孔径分布转移到较窄的尺寸范围内。水凝胶通常以吸附膜的形式增加保水性，并在相对干燥的条件下减少膜的流动。这项研究突显了在改变土壤水力特性时考虑通过水凝胶降低表面张力和平均孔径的重要性，这对于准确模拟根际中的水分布和流量具有重要意义。水凝胶通常以吸附膜的形式增加保水性，并在相对干燥的条件下减少膜的流动。这项研究突显了在改变土壤水力特性时考虑通过水凝胶降低表面张力和平均孔径的重要性，这对于准确模拟根际中的水分布和流量具有重要意义。水凝胶通常以吸附膜的形式增加保水性，并在相对干燥的条件下减少膜的流动。这项研究突显了在改变土壤水力特性时考虑通过水凝胶降低表面张力和平均孔径的重要性，这对于准确模拟根际中的水分布和流量具有重要意义。