Soil nutrient analysis is crucial for understanding the dynamics of agricultural fertility and productivity. Phosphorus (P) stands out among soil nutrients for its fundamental role in vital biological processes such as photosynthesis, respiration, and cell division. The study of variations in phosphorus content along toposequences, according to the specific topography of the lowlands, is proving to be a relevant approach to elucidate the complex interactions between abiotic factors and biogeochemical dynamics that govern soil fertility. This study aims to characterize spatial variations in soil assimilable phosphorus (P2O5) content as a function of edaphic parameters, using a multidimensional approach along the longitudinal and transverse axes of the lowland. This study was carried out in the locality of N’Zoupouri, in the department of Botro, about 40 km from Bouaké, in the Gbêkê region of central Côte d’Ivoire. The physicochemical analyses of the soil samples were carried out by French and international standard methods. The BORUTA algorithm used in this study can select the truly significant characteristics while ranking their importance. The result shows that potassium (K) content is a determining factor directly influencing this essential nutrient’s spatial variations and temporal changes. The close relationship between potassium and phosphorus in the soil highlights the importance of optimized agronomic management, in which potassium not only plays a supporting role but also acts as a key element in the release and stabilization of phosphorus that is available to plants.

The degradation followed by the disappearance of fertile land in a context of climate change affects agricultural production in the world and in sub-Saharan Africa. In Côte d’Ivoire, soil degradation and scarcity linked to demographic pressure lead the farmers of Bouaflé, in the center-west region of Côte d’Ivoire, to seek new cultivable land, in particular hydromorphic land in the lowlands. bottoms and banks of river tributaries. To this end, a study on the morphopedological and physicochemical characterization was conducted in order to determine the agronomic potential of the soils of the lower slope of a toposequence of the watershed of the Bandama River (Marahoué). On the bottom of the slope of the longest open toposequence on a 1000 m strip, three soil pits were opened under three vegetation covers characteristic of this topographic segment consisting successively of the top of the steepest slope to the river (lowest level of slope), wooded savannah, grassy savannah and prairie leading to the river. The profiles of these pits were described and sampled in the 0 – 20 cm and 20 – 40 cm layers and a composite sample was made and then analyzed in the laboratory. The types of soil encountered in the lower slope are impoverished ferralitic soils (Arenosols) and hydromorphic soils (Gleysols). The morphological characteristics of these soils offer an average agricultural potential while the low levels of assimilable phosphorus and the low cation exchange capacity (CEC) constitute the major chemical constraints for agriculture.