Soil sodicity, salinity, clay dispersion, and clay soil cracking are significant issues for modern agriculture, especially in arid and semi-arid regions of the world. Sodium adsorption ratio (SAR) has traditionally been used to estimate potential changes in infiltration rates or hydraulic conductivity when sodium cations dominate irrigation water quality. Recent research indicates that the cation ratio of soil structural stability (CROSSf and CROSSopt) provides better predictive capabilities for soil structure and threshold electrolyte concentration than SAR, especially when water used for irrigation or aquifer recharge contains both potassium and sodium cations. In this study, soil columns filled with clay loam were used to assess the impact of recycled water reuse on soil structure stability and saturated hydraulic conductivity. Ten treatments were prepared using chloride solutions of sodium, potassium, calcium, and/or magnesium to create a broad range of synthetic recycled water qualities with varying SAR, CROSSf, and CROSSopt values. After a pre-saturation process, the columns were maintained to have a constant 1 cm head of treatment solutions with a salinity of 1.5 dS/m. The results showed that CROSSf had a stronger correlation with saturated hydraulic conductivity and soil aggregate stability in comparison to CROSSopt and SAR. The R2 for saturated hydraulic conductivity and soil structure were 0.90 and 0.94 for CROSSf, 0.41 and 0.60 for CROSSopt, and 0.75 and 0.78 for SAR, respectively. Notably, the treatments that received solutions with 0-SAR values but contained potassium had significantly more dispersible clay throughout the entire soil column than the treatment that received calcium chloride solution. It was concluded that the CROSSf model could offer enhanced accuracy and insight into predicting the impact of recycled water reuse for irrigation on soil infiltration rate and soil aggregate stability.

中文翻译：

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评估循环水再利用对渗透和土壤结构的影响


土壤钠含量、盐度、粘土分散和粘土开裂是现代农业的重要问题，尤其是在世界干旱和半干旱地区。钠吸附率 （SAR） 传统上用于估计当钠阳离子主导灌溉水质时渗透率或水力传导率的潜在变化。最近的研究表明，土壤结构稳定性的阳离子比 （CROSSf 和 CROSSopt） 比 SAR 更好地预测土壤结构和阈值电解质浓度，尤其是当用于灌溉或含水层补给的水同时含有钾和钠阳离子时。在本研究中，使用填满粘壤土的土柱来评估循环水再利用对土壤结构稳定性和饱和导水率的影响。使用钠、钾、钙和/或镁的氯化物溶液制备了 10 种处理，以产生具有不同 SAR、CROSSf 和 CROSSopt 值的广泛合成循环水质量。在预饱和过程后，色谱柱保持恒定的 1 cm 水头处理溶液，盐度为 1.5 dS/m。结果表明，与 CROSSopt 和 SAR 相比，CROSSf 与饱和水力传导率和土壤团聚体稳定性的相关性更强。饱和导水率和土壤结构的 R2 分别为 CROSSf 的 0.90 和 0.94、CROSSopt 的 0.41 和 0.60、SAR 的 0.75 和 0.78。值得注意的是，与接受氯化钙溶液的处理相比，接受 0-SAR 值但含有钾的处理在整个土柱中的可分散粘土明显更多。 得出的结论是，CROSSf 模型可以提高准确性和洞察力，以预测循环水再利用灌溉对土壤渗透率和土壤团聚体稳定性的影响。