Saline-sodic soils are susceptible to wind and water erosion when the dispersive effect of sodium overcomes inter-particle bonds. Rheological parameters of viscoelasticity can help to quantify inter-particle attractive forces and account for the effect of salinity in these soils. The main objective of the present study was to investigate the viscoelasticity behavior of saline-sodic soils of the Sirjan playa in south-central Iran. Three representative pedons were excavated and described by horizon. Soil physicochemical properties and rheological properties were determined, namely the micromechanical parameters flow point (γ_f), loss factor tan δ, and integral z, with samples analyzed at three matric potentials (0, −6, and −15 kPa). Results showed that soil microstructural stiffness was mainly influenced by soil texture, clay minerals, gypsum, calcium carbonate equivalent (CCE), and matric potential. The dispersive effect of sodium, as indicated by low integral z and γ_f values, decreased with increasing gypsum content in − 6 and − 15 kPa matric potentials (0.6 < r < 0.8) and CCE percentage in the quasi-saturated (0 kPa) condition (r > 0.8). However, greater microstructural stability (i.e., higher integral z and γ_f) was observed for fine-textured soils with relatively high amounts of smectite and palygorskite and low pH. Furthermore, integral z and γ_f increased with lower matric potentials due to the stabilizing effect of menisci forces. Therefore, the viscoelastic behavior of the saline-sodic soils was negatively associated with water content and high sodium concentration, while the presence of smectite, palygorskite, gypsum, and CCE improved the soil physical conditions and thus the rigidity of the porous system. These results demonstrate that rheological measurements can identify saline-sodic soils that have strongly degraded microstructural stability and would most benefit from active management and amelioration.

当钠的分散作用克服颗粒间键时，盐碱土很容易受到风和水的侵蚀。粘弹性的流变参数有助于量化颗粒间吸引力并解释这些土壤中盐度的影响。本研究的主要目的是调查伊朗中南部 Sirjan 海滩盐碱土的粘弹性行为。三个代表性的pedons被挖掘和描述了地平线。确定了土壤理化性质和流变性质，即微观力学参数流点（γ _f）、损失因子tan δ和积分z，在三个基质电位（0、-6 和 -15 kPa）下分析样品。结果表明，土壤微观结构刚度主要受土壤质地、粘土矿物、石膏、碳酸钙当量 (CCE) 和基质势的影响。钠的分散效应，如低积分 z和γ _f值所示，随着 - 6 和 - 15 kPa 基质势 (0.6 < r < 0.8) 中石膏含量的增加和准饱和 (0 kPa) 中 CCE 百分比的增加而降低条件 (r > 0.8)。然而，对于蒙脱石和坡缕石含量相对较高且pH 值较低的细质地土壤，观察到更大的微观结构稳定性（即，更高的积分z和γ _f）。此外，积分 z和γ _˚F具有较低电位基质增加，由于弯月面力的稳定作用。因此，盐碱土的粘弹性行为与含水量和高钠浓度呈负相关，而蒙脱石、坡缕石、石膏和 CCE 的存在改善了土壤物理条件，从而改善了多孔系统的刚度。这些结果表明，流变测量可以识别显微结构稳定性严重下降的盐碱土，并且最能从积极管理和改善中受益。