Influence of the topographic gradient on the physico-chemical properties of soils in a tropical agroecosystem in southern Côte d'Ivoire

This study aims to analyze the influence of the topographic gradient on the variability of soil physicochemical properties in a tropical agroecosystem in southern Côte d'Ivoire. Three soil profiles were described along a projected toposequence in the village of Ahoué, respectively at the upper, middle, and lower slopes. Soil samples were collected at different depths and analyzed in the laboratory to assess pH, cation exchange capacity (CEC), and organic matter (OM) content. The results show a marked variability in soil characteristics depending on the topographic position. Soils at the lower slopes have hydromorphic horizons rich in OM and CEC, while those at the upper slopes are more impoverished, acidic, and susceptible to erosion. This differentiation reflects a redistribution of elements linked to erosion, runoff, and deposition dynamics. Topography thus appears to be a determining factor in soil fertility and their cultural suitability. These results highlight the interest of differentiated land management based on pedotopographic conditions, with a view to more sustainable agriculture.