Integrated geochemical and spatial analysis of trace element redistribution in salinized arid agro-landscapes: Evidence from the Turyanchay River basin (Azerbaijan)

Arid agro-landscapes are highly vulnerable to the soil degradation caused by long-term irrigation and climatic constraints.This study investigated the spatial patterns and geochemical characteristics associated with trace element redistribution in salinized irrigated soils of the Turyanchay River basin (Azerbaijan).A geochemical dataset comprising 22 depth-specific sampling units from representative sampling sites was analyzed for trace element composition using energy-dispersive X-ray fluorescence spectrometry (EDXRF).A separate physicochemical dataset comprising 22 depth-specific sampling units was used to characterize soil salinity, major soluble ions, organic carbon, and humus conditions.Geochemical indices, including the contamination factor (CF) and geoaccumulation index (Igeo), together with statistical analysis and descriptive geochemical landscape mapping, were used to evaluate relative geochemical enrichment and spatial variability.The results indicate pronounced vertical differentiation and considerable spatial variability in trace element distribution.Nickel (Ni) exhibited the highest relative enrichment (CF = 28.23;Igeo = 4.23), followed by arsenic (As; CF = 6.88;Igeo = 2.20) and bromine (Br; CF = 5.12; Igeo = 1.77), whereas Fe, Rb, Y, and Zr had CF values below 1. Salinity analysis indicated substantial spatial and depth-related variability in soluble-ion composition, dry residue, and total soluble salts across the investigated soils.Statistical analysis identified significant relationships among major ions and salinity-related soil properties; the strongest relationship occurred between dry residue and total soluble salts (ρ = 0.99, p < 0.001); however, these correlations were interpreted as supporting physicochemical context rather than as direct evidence of salinitydriven trace element redistribution.The descriptive geochemical landscape map illustrated spatial differences in trace element associations across the study area, while the conceptual soil-water-geochemical interaction model provided a framework for interpreting the observed patterns.The findings indicated that trace element redistribution occurs within a spatially heterogeneous environment characterized by variations in soil salinity, alkalinity, and landscape conditions across the investigated irrigated agro-landscapes.The integrated methodological framework developed in this study may support soil quality assessment, environmental monitoring, and sustainable irrigation management in the arid and semi-arid regions affected by salinization.