Evaluation of Granulometric Characteristics and Biogenic Element Diagnostic Indicators of Mountain Gray-Brown Soils in the Gazakh-Tovuz Economic Region According to the Wrb System
Ramil Sadigov1* , Matanat Huseynova2 , and Nargiz Baghirova3
Abstract. This article presents the results of comprehensive investigations conducted between 2020 and 2025 on mountain gray-brown soils within the Gazakh-Tovuz economic region of western Azerbaijan, focusing on the Shamkir administrative district. The research covered an area of 10,522.55 ha and aimed to evaluate the morphological, physicochemical, and spatial characteristics of these soils using conventional soil survey methods integrated with modern geospatial technologies. Detailed field and laboratory analyses were carried out on representative soil profiles, particularly sections 12, 19, 25, and 98, supplemented by observations from additional target sites. Morphological assessments were supported by analyses of key diagnostic indicators, including humus content, total nitrogen, available phosphorus and potassium, granulometric composition, soil reaction (pH), and calcium carbonate (CaCO₃) content. Statistical methods were applied to determine the variability and relationships among soil properties. Geographic coordinates of representative soil sections were established using a Garmin GPSMAP 62s device to ensure accurate spatial referencing. A high-resolution digital elevation model (DEM) was generated through interpolation of elevation data obtained from topographic maps, and a detailed relief model of the study area was developed using ArcGIS 10.3 software. The integration of soil analytical data with GIS-based spatial modeling enabled a comprehensive characterization of mountain gray-brown soils. The findings provide a scientific basis for soil classification, land evaluation, sustainable land management, and agricultural planning aimed at improving land-use efficiency and agricultural productivity in the region. Key finding: The study revealed that mountain gray-brown soils in the Shamkir region exhibit moderate humus content, slightly alkaline pH, and variable nutrient distribution, with noticeable differences across soil profiles influenced by relief and parent material. Spatial analysis based on DEM and GIS modeling confirmed that topography plays a significant role in shaping soil properties and their distribution patterns. Overall, the integration of field data and geospatial techniques provided a reliable basis for accurate soil classification and more efficient land use planning in the Gazakh-Tovuz economic region.
Keywords: mountain gray-brown soils, granulometric composition, biogenic elements, WRB soil classification, soil diagnostics, Gazakh-Tovuz economic region