Abstract
The stability of arid soils can be affected by their chemical and mineralogical properties. A study was
conducted to investigate the influence of soil chemical and mineralogical properties on soil stability
indices in the Shamil-Ashkara Catchment area of Iran. Eight soil profiles were dug and all the soils were
classified as Entisols and Aridisols. These soils are calcareous in nature with high amounts of basic
cations. There was a significant positive correlation between water-stable aggregates (WSA) and
organic carbon (OC), exchangeable Ca2+ and kaolinite contents with r-values of 0.70, 0.45, and 0.62,
respectively. Soil pH affects stability indices the most as indicated by the highest significant correlation
between pH and water-dispersible clay (WDC) (r = 0. 87). Among the minerals present, palygorskite
significantly influences the WSA (r = -0.46) and WDC (r = 0.68) the most, while chlorite has the least
significant effect. The results indicated that the significant positive factors affecting WDC are in the
order of: pH > Fe2O3 > CEC > palygorskite > Na+
> SAR > Mg2+ and the positive factors affecting WSA
are: OC > kaolinite > Ca2+
, respectively.
Key words: Mineralogical properties, aggregate stability, arid region soils, soil properties
