Declining agricultural fertility represent a major challenge to food security in the Sudano-Sahelian areas. In this context, it is essential to cultivate resilient cereals, such as sorghum, whose productivity depends heavily on the physical, chemical, and biological properties of the soil. This study aims to assess soil chemical fertility in order to improve soil management and optimize sorghum production. The spatial distribution of soils was determined using a Digital Elevation Model (DEM) from the ALOS PALSAR radar, with a spatial resolution of 12.5 meters. Soil data were analyzed using R software, applying descriptive statistics and principal component analysis (PCA). The soil prospecting identified three subgroups of soils: Haplic Cambisols located on the upper slope of the glacis, Ferric Lixisols on medium slopes and Gleyic Lixisols at the bottom of the glacis. Soil texture analysis showed a dominance of sandy fractions, varying from sandy-loam to sandy-clay, characteristic of soils in the Sudano-Sahelian zone. A gradient of organic matter, higher
in brown soils (1.11%), compared to ferruginous soils (0.59%) and hydromorphic soils (0.40%). A strong positive correlation was observed between organic matter, nitrogen and phosphorus, suggesting that improving OM could increase soil fertility. Low N (0.013–0.099%) and P (2.17–7.81 mg/kg) contents reveal significant nutritional limitations for agricultural productivity. OM, N, and P contents are mainly concentrated in the surface horizons. Although classified as medium, the fertility of all soil types studied varies depending on the topography. These results highlight the importance of knowledge of fertility parameters and the need for differentiated management of soils according to their agronomic suitability.

Fertility, topography, sorghum, agricultural potential, Sudano-Sahelian zone