Spatial Variability of the Physicochemical Properties of Cotton-growing Soils at Six Locations in Northern Côte d’Ivoire (Boron, Boundiali, Diawala, Ferkessédougou, Kasséré and Korhogo)

Cotton-growing soils in northern Côte d’Ivoire differ in their physical and chemical properties, potentially affecting soil fertility management. This study assessed the spatial variability of selected physicochemical indicators at six locations: Boron, Boundiali, Diawala, Ferkessédougou, Kasséré and Korhogo. Composite soil samples were collected from the 0–20 cm layer under cotton cultivation. Laboratory analyses included particle size distribution, soil pH, soil organic carbon, total nitrogen, available phosphorus, exchangeable bases, cation exchange capacity (CEC) and base saturation. Differences among locations were examined using statistical and multivariate analyses. Soil pH ranged from 6.45 at Korhogo to 7.12 at Diawala, indicating slightly acidic to neutral conditions. Mean soil organic carbon ranged from 0.7 to 1.8 g kg⁻¹, total nitrogen from 0.07 to 0.16 g kg⁻¹ and available phosphorus from 9 to 30 mg kg⁻¹. CEC ranged from 5.64 to 15.32 cmol₊ kg⁻¹, while base saturation ranged from 22.9% to 59.4%. Sandy textures predominated at four locations; Diawala had a sandy loam texture and Kasséré a loam texture. The first two principal components explained 71.84% of the observed variability. Coarse silt, fine sand, pH, total nitrogen and CEC were important differentiating variables, and four relatively homogeneous soil groups were identified. These findings indicate that fertility management should consider the contrasting soil properties of the locations studied, particularly nutrient availability, soil texture and exchange capacity.