Soil hydraulic properties are important for water management in salt and sodium (Na) affected soils. The soil saturated hydraulic conductivity (Ksat) has been found to decrease when high soil solution Na adsorption ratio (SAR) is coupled with low solution electrical conductivity (EC). Soil clay type plays an important role in changes to soil Ksat when the soil solution composition has a high SAR and low EC. Little is known about how soil water retention changes from solution EC and SAR. The objective of this study was to determine the impact of a range of solution EC and SAR values on soil Ksat, and water retention for soils containing swelling and nonswelling clay minerals. The soil Ksat and water retention were measured on four smectitic soils, a kaolinitic soil, and an illitic soil. Smectite swelling caused large changes in soil hydraulic properties in smectitic soils at high exchangeable Na percentage (ESP) and low EC levels, whereas there was a reduced effect on soils with little smectite clay. Increasing soil solution ESP and decreasing EC level caused the Ksat to decrease and the water content at a given pressure head to increase on soils that contained smectite. A narrower range of EC and SAR of waters suitable for use on smectitic soils are required to prevent changes in soil water flow rates and soil water retention.

中文翻译：

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可交换钠和粘土矿物学对土壤保水和导水率的影响

土壤水力特性对于受盐和钠 (Na) 影响的土壤中的水分管理很重要。已发现当高土壤溶液 Na 吸附率 (SAR) 与低溶液电导率 (EC) 相结合时，土壤饱和导水率 (Ksat) 会降低。当土壤溶液成分具有高 SAR 和低 EC 时，土壤粘土类型对土壤 Ksat 的变化起着重要作用。关于溶液 EC 和 SAR 对土壤保水量的变化知之甚少。本研究的目的是确定一系列溶液 EC 和 SAR 值对土壤 Ksat 以及含有膨胀和非膨胀粘土矿物的土壤的保水性的影响。在四种蒙脱石土壤、高岭土和伊利石土壤上测量了土壤 Ksat 和保水性。在高交换钠百分比 (ESP) 和低 EC 水平下，蒙脱石膨胀导致蒙脱石土壤的土壤水力特性发生很大变化，而对蒙脱石粘土含量低的土壤影响减弱。在含有蒙脱石的土壤上，增加土壤溶液 ESP 和降低 EC 水平导致 Ksat 降低和给定压头下的含水量增加。需要更窄范围的适用于蒙脱石土壤的水的 EC 和 SAR，以防止土壤水流量和土壤保水的变化。在含有蒙脱石的土壤上，增加土壤溶液 ESP 和降低 EC 水平导致 Ksat 降低和给定压头下的含水量增加。需要更窄范围的适用于蒙脱石土壤的水的 EC 和 SAR，以防止土壤水流量和土壤保水的变化。在含有蒙脱石的土壤上，增加土壤溶液 ESP 和降低 EC 水平导致 Ksat 降低和给定压头下的含水量增加。需要更窄范围的适用于蒙脱石土壤的水的 EC 和 SAR，以防止土壤水流量和土壤保水的变化。