Ion Exchange Capacity of Mountain-Forest Soils of the Lankaran Economic Region and its Dependency Patterns
Tural Ahadov 
Abstract. The Lankaran‒Astara region is one of the transitional areas of Azerbaijan’s subtropical zone, characterized by complex relief, high precipitation, and rich forest cover. These natural factors lead to the intensive development of complex geochemical processes in the soil profile, including ion-exchange reactions. The article provides detailed information on the cation exchange capacity (CEC) and anion exchange capacity (AEC) of mountain-forest soils in the region and analyzes their dependence on soil texture, mineralogical composition, organic matter content, and soil reaction (pH). The research results showed that the CEC of soils in the region ranges from 12.5 to 35.8 cmol/kg, while the AEC varies between 150 and 450 mg/kg. The ion-exchange properties differ significantly across altitudinal zones, reflecting the diversity of soil formation processes in the region.
Keywords: cation exchange capacity, anion exchange capacity, mountain-forest soils, Lankaran‒Astara region, pH, humus, clay minerals