Physico-chemical characterization of soils in two peri-urban lowlands: Implications for the sustainability of rice cultivation in Korhogo (northern Côte d’Ivoire)

In a context of heavy dependence on rice cultivation and intensifying land pressures in Ivorian peri-urban areas, this study analyzes the physico-chemical properties of two lowlands (Logokaha and Natio) located on the outskirts of Korhogo. The aim is to identify edaphic constraints likely to limit rice-growing productivity, and to propose sustainable management options. The methodology is based on stratified sampling according to longitudinal (upstream, median, downstream) and transverse (center, hydromorphic zones) topographical units. Samples were subjected to granulometric and chemical analysis, assessing texture, pH, nitrogen, phosphorus, potassium, organic matter and cation exchange capacity (CEC). The results reveal considerable textural variability between sites and topographical units. The soils of Logokaha, with their silty-clay texture, offer better rice-growing potential than those of Natio, which are sandier. Chemically, both lowlands have moderate acidity but marked deficits in total nitrogen, assimilable phosphorus and organic matter. CEC is generally low, reflecting limited fertility. In addition, some areas show high sodium levels, representing a risk of structural degradation, especially in hydromorphic conditions. We recommend boosting fertility with organic inputs (compost, manure) and targeted mineral fertilizers. Acidity correction and optimized water management should complement these interventions to sustainably improve the productivity and agroecological resilience of the lowlands studied.