Root mucilage (RM), a soil-born biohydrogel, affects the physical stability of the rhizosphere. One reason for this is attributed to the present polysaccharides which contribute to the formation of aggregates by acting as interparticulate glue. The aim of this study was to explore how physico-chemical properties of polymers of interparticulate gels influence this gluing and thus soil microstructural stability. We hypothesized that the microstructural stability of sand increases with the viscosity of the amended biohydrogel, which depends on the content of carbohydrate polymers and non-esterified uronic acids which themselves determine the amount of absorbed calcium. Therefore, natural RM of maize and wheat were compared with higher viscous chia seed mucilage (SM) as a widely used model for RM, and with industrial pectin rich in uronic acids partially methylated. Results show that additionally to Ca binding by uronic acids, binding by proteins is a further possible mechanism of Ca adsorption in RM. Upon Ca addition, the viscosity increased upon intermolecular associations (pectin) and decreased upon suppression of intermolecular charge–charge repulsion (chia SM, maize RM). Amount of high-molecular weight material in the amendment affected strongly soil microstructural stability. Results further suggest the creation of gel micro-zones upon Ca addition, which increase the viscosity of interparticulate gel and sand microstructural stability. Finally, the study outlines several physico-chemical mechanisms through which interactions between biotic (roots and seed) and abiotic components (mineral particles) influence soil structure, which control the water, air and nutrient flow through the rhizosphere and is, thus, an important soil quality parameter.

中文翻译：

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根粘液和模型物质理化性质对沙子微观结构稳定性的影响

根粘液 (RM) 是一种土生生物水凝胶，会影响根际的物理稳定性。其原因之一归因于本发明的多糖，其通过充当颗粒间胶而有助于形成聚集体。本研究的目的是探索颗粒间凝胶聚合物的物理化学性质如何影响这种胶合，从而影响土壤微观结构的稳定性。我们假设沙子的微观结构稳定性随着改良的生物水凝胶的粘度而增加，这取决于碳水化合物聚合物和非酯化糖醛酸的含量，它们本身决定了吸收的钙的量。因此，将玉米和小麦的天然 RM 与较高粘性的奇亚籽粘液 (SM) 作为广泛使用的 RM 模型进行比较，和富含糖醛酸的工业果胶部分甲基化。结果表明，除了糖醛酸与 Ca 的结合外，蛋白质的结合是 RM 中 Ca 吸附的另一个可能机制。添加 Ca 后，粘度因分子间缔合（果胶）而增加，并因抑制分子间电荷 - 电荷排斥（chia SM，玉米 RM）而降低。改良剂中高分子量物质的含量对土壤微观结构的稳定性影响很大。结果进一步表明在添加 Ca 后会产生凝胶微区，这增加了颗粒间凝胶的粘度和砂的微观结构稳定性。最后，该研究概述了几种物理化学机制，通过这些机制，生物（根和种子）和非生物成分（矿物颗粒）之间的相互作用影响土壤结构，