This study comprised a comprehensive evaluation of the morphogenetic characteristics, diagnostic features, and classification of alluvial-hydromorphic soils formed within river basins of the northeastern slope of the Lesser Caucasus, Azerbaijan. However, these soils developed under complex geomorphological conditions, heterogeneous microrelief, and periodic seasonal flooding, resulting in dynamic pedogenic processes, stratified profiles, and variable clay formation intensity. The subsequent research aimed to identify the key morphogenetic and diagnostic indicators of soil types and subtypes within the Kura River basin. It also sought to define their classification based on principles of the World Reference Base (WRB) for soil resources and assess the rational use of conditionally unsuitable stony alluvial soils. Field investigations transpired from 2015 to 2025, including detailed surveys, laboratory analyses, statistical evaluations, and large-scale soil mapping. The results revealed humid subtropical soils exhibited intensive carbonate leaching, higher humus content, and the formation of active clay, whereas dry subtropical soils showed a surface carbonate accumulation, salinization tendencies, and lower humus reserves. Clay formation intensity had a close association with moisture regime, redox potential (Eh), and mobile iron oxides, contributing to improved soil classification and sustainable land use.
Alluvial-hydromorphic soils, morphogenetic diagnostics, soil classification, clay formation process, river floodplains, WRB system, soil mapping, bioclimatic zones
The results provided a scientific basis for the improved diagnosis, mapping, and passporting of alluvial-hydromorphic soils, support for the development of soil-related GIS databases, and a contribution to the sustainable and efficient use of these soils in agricultural systems.