Soil salinisation and sodification are two principal processes in arid and semi-arid regions which have been irrigated with poor-quality waters. A laboratory experiment was carried out to study the effect of soil texture, salinity (EC) and sodicity (SAR) of irrigation water and matric potential on soil friability. Intact soil aggregates/clods with different size ranges of 4–8, 8–15, 15–20, and 20–40 mm were collected from two texturally-different soils of sandy loam (SL) and clay loam (CL). Undisturbed soil samples were also taken for determination of soil water contents at matric potentials (h) of –30, –100, –200, and −400 kPa. All of the soil samples were subjected to five wetting/drying cycles using twelve different water quality treatments, combinations of four levels of EC (0.2, 1, 6, and 10 dS m⁻¹) and three levels of SAR [1, 5 and 12 (meq L⁻¹)^1/2]. The tensile strength of aggregates/clods was determined by the indirect Brazilian test. Then, the soil friability was calculated by employing three methods of coefficient of variation (F₁), ranking order (F₂), and volume-dependence (F₃). The results showed that the F values varied considerably depending on the friability calculation method and matric potential. Soil friability was not affected by the treatments at the wet range because of the dominant effect of high water content on soil mechanical behavior; whereas soil aggregates/clods of 4–8, 8–15 and 15–20 mm at h of −400 kPa showed the highest friability. Soil friability decreased with an increase in SAR and increased with an increment in EC at low matric potentials (i.e., –200 and −400 kPa) due to the negative and positive effects of sodium and soluble ions on soil microstructure, respectively. The effects of SAR on soil stability, dispersion clay and tensile strength and as a consequence on soil friability was more pronounced at low EC values. Results showed more influence of water quality (EC and SAR) in clay loam than sandy loam soil due to its higher clay content. Comparison of the F values with well-known classification revealed that F₁ and F₂ were about 2–4 orders of magnitude higher than F₃, especially for aggregates size ranges of 4–8 and 8–15 mm at h of –200 and −400 kPa and air-dry condition; and the coefficient of variation and ranking order methods were more acceptable and reliable than the volume-dependence method for characterizing the soil friability.

在干旱和半干旱地区，土壤盐碱化和增糖化是两个主要过程，这些地区已经用劣质水灌溉了。进行了一项室内实验，研究了土壤质地，灌溉水的盐度（EC）和碱度（SAR）以及基质势对土壤脆性的影响。从两个质地不同的沙壤土（SL）和黏土壤土（CL）中收集了大小范围分别为4-8、8-15、15-20和20-40 mm的完整土壤聚集体/土块。还采集了未扰动的土壤样品，以测定基质电势（h）为–30，–100，–200和-400 kPa时的土壤水分。使用十二种不同的水质处理方法，对所有土壤样品进行五个润湿/干燥循环，将四种水平的EC（0.2、1、6和10 dS m^-1）和三个级别的SAR [1、5和12（meq L ^-1）^1/2 ]。骨料/凝块的抗张强度通过间接巴西试验测定。然后，采用变异系数（F ₁），等级顺序（F ₂）和体积依赖性（F ₃）三种方法计算土壤脆性。结果表明，F值随脆性计算方法和基质电势的不同而有很大差异。土壤脆性不受湿地处理的影响，因为高水分含量对土壤力学行为的主要影响。而在4-8、8-15和15-20mm的土壤聚集/凝块-400 kPa的h显示最高脆碎度。在钠盐势较低时（–200和-400 kPa），土壤脆性随SAR的增加而降低，随EC的增加而增加，这分别归因于钠和可溶性离子对土壤微结构的负面和正面影响。在低EC值下，SAR对土壤稳定性，分散性粘土和抗张强度以及对土壤脆性的影响更为明显。结果表明，由于粘土壤土中较高的粘土含量，其对水质（EC和SAR）的影响比砂壤土更大。将F值与知名分类进行比较发现，F ₁和F ₂比F ₃高约2-4个数量级。，特别是在–200和-400 kPa的h以及风干条件下，骨料尺寸范围为4–8和8–15 mm的情况下；变异系数和等级排序方法比体积相关性方法更易接受和可靠。