Biological exudates, such as plant mucilage, can greatly stabilise soils but as the mechanical and hydrological drivers depend much on soil particle size composition, eroding and depositional areas of a slope may respond differently. Soils from an eroded midslope and a depositional footslope in an arable farm were amended with chia (Salvia hispanica) seed mucilage at concentrations of 0 g C kg−1, 0.46 g C kg−1 and 2.3 g C kg−1 mucilage, formed into cores, and then imparted with wetting and drying (WD) cycles. Mucilage increased the stability of these inherently stable soils from 80% to >98% water stable macroaggregates at 0WD cycles regardless of slope position. Aggregate stability was maintained after 5WD cycles by mucilage, whereas the stability of unamended soil dropped by 66.7% in the footslope and 30.1% in the midslope compared with 0 WD. Underlying physical stability properties were measured by tensile strength and penetration resistance for mechanical, water sorptivity and repellency for hydrological, and micro‐, meso‐, macro‐ and total porosity for structural properties. Almost every soil physical property measured changed less with WD cycles if mucilage was present. Compared to unamended soil, 2.3 g C kg−1 mucilage amendment decreased water sorptivity from 0.289 mm s‐1/2 to 0.122 mm s‐1/2 in the midslope and 0.230 mm s‐1/2 to 0.182 mm s‐1/2 in the footslope after 5 WD cycles. Aggregate stability, total porosity and water sorptivity were correlated. In the midslope, hydrology and penetration resistance were affected most, likely driven by mucilage deposition in the macropores of this more coarsely textured soil. In the footslope, the greater impact of mucilage on tensile strength was likely driven by buffering of macroporosity formation by WD cycles in this finer textured soil.

中文翻译：

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通过植物粘液在斜坡侵蚀区和沉积区之间解开土壤稳定的水文、机械和结构机制的实验室研究

生物分泌物，例如植物粘液，可以极大地稳定土壤，但由于机械和水文驱动因素在很大程度上取决于土壤颗粒大小的组成，斜坡的侵蚀和沉积区域可能会有不同的反应。来自可耕农场中被侵蚀的中坡和沉积脚坡的土壤用 0 g C kg-1、0.46 g C kg-1 和 2.3 g C kg-1 粘液浓度的奇亚（Salvia hispanica）种子粘液修正，形成芯，然后进行润湿和干燥 (WD) 循环。无论斜坡位置如何，在 0WD 循环中，粘液都将这些固有稳定土壤的稳定性从 80% 增加到 >98% 的水稳定大团聚体。5WD 循环后通过粘液保持集料稳定性，而与 0 WD 相比，未改性土壤在脚坡和中坡的稳定性下降了 66.7%，在中坡下降了 30.1%。基本物理稳定性特性通过机械的拉伸强度和抗渗透性、水文的吸水性和排斥性以及结构特性的微观、中观、宏观和总孔隙率来衡量。如果存在粘液，则几乎所有测量的土壤物理特性随 WD 周期变化较小。与未改良土壤相比，2.3 g C kg-1 粘液改良剂使中坡的吸水率从 0.289 mm s-1/2 降低到 0.122 mm s-1/2，从 0.230 mm s-1/2 降低到 0.182 mm s-1/ 2 个在 5 个 WD 循环后的脚坡上。聚集体稳定性、总孔隙率和吸水率是相关的。在中坡，水文和渗透阻力受到的影响最大，可能是由于这种质地更粗糙的土壤的大孔隙中的粘液沉积所致。在脚下，