Soil salinization from shallow ground waters is problematic in numerous regions of the world. These ground waters can degrade soil physical properties and require special land management to maintain soil salinity levels ideal for crop and rangeland production. The objectives of this study were to evaluate how saline and sodic solutions changed soil hydrologic properties and how hydrologic parameters change with solution composition. Four soils ranging in texture from sandy loam to silty clay, were saturated with solutions ranging in electrical conductivities (EC) of 0.5 to 8 dS m⁻¹ and sodium adsorption ratios (SAR) of 0 to 20. The hydraulic conductivity and water retention were measured using pressure plates, HYPROP evaporation method, and a dewpoint potentiometer. Data was fit with the van Genuchten and dual porosity models and the model parameters were evaluated. There was an increase in water retention and decrease in hydraulic conductivity when soils were near saturation as solution SAR increased and EC decreased at potentials near saturation. Water retention method combinations agreed well for low salinity treatments, but fitting parameters did not agree well for the higher salinity treatments. The coarser textured soil had a stronger disagreement in fitting parameters for the different water retention method combinations and greater salt build up near soil surface. Capillary rise of salt bearing waters of low EC and high SAR increases soil water retention and decreases hydraulic conductivity near saturation which will slow rates of downward water movement and salt leaching.

中文翻译：

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钠盐溶液对土壤水力模型参数和方法的影响

在世界许多地区，来自浅层地下水的土壤盐渍化都存在问题。这些地下水会降低土壤的物理特性，需要进行特殊的土地管理，以保持土壤盐分水平，非常适合作物和牧场生产。这项研究的目的是评估盐溶液和苏打溶液如何改变土壤水文特性，以及水文参数如何随溶液组成而变化。质地从沙壤土到粉质粘土的四种土壤都被电导率（EC）为0.5至8 dS m ^-1的溶液饱和钠吸附比（SAR）为0至20。使用压力板，HYPROP蒸发法和露点电位计测量水力传导率和保水率。数据符合van Genuchten模型和双重孔隙度模型，并评估了模型参数。当土壤接近饱和时，随着溶液SAR的增加和EC在饱和附近的电势下降，保水性增加，水力传导率降低。保水方法组合对于低盐度处理非常吻合，但对于较高盐度的处理，拟合参数却不一致。对于不同的保水方法组合，较粗糙的质地土壤在拟合参数上存在较大分歧，并且在土壤表面附近积聚了更多的盐。