ÉVALUATION DE L’ÉTAT DE DÉGRADATION DE LA FERTILITÉ CHIMIQUE DES SOLS DANS LA COMMUNE RURALE DE KOUKA (BURKINA FASO)

Human activities are the main factor in soil degradation, with climatic conditions exacerbating the phenomenon. These activities are characterized by the clearing of land for cultivation and the overexploitation of soils. These actions lead to both a significant reduction in vegetation cover and a decrease in the stock of organic matter and, in turn, nutrients, particularly nitrogen, phosphorus and potassium. This study aims to assess the state of chemical soil fertility degradation in the rural commune of Kouka, in north western Burkina Faso. The methodological approach adopted is based on a physico- chemical analysis of soil samples. These samples were an alyzed at the BUNASOLS laboratory using the KJELDAHL method for total nitrogen, the BRAY method for assimilable phosphorus, the photometric method for available potassium and the potentiometric method for pH. The results show four classes of soil chemical fertility degradation. These are the low, medium, high and very high class. Of the 72628.42 ha in the rural commune of Kouka, the low level degradation class occupies 1.76%, the medium level degradation class occupies 13.73%, and the high level class occupies 63.09%. The very high level of degradation affects 21.42% of the study area. Production systems and cultivation methods combined with climatic variability are the main causes of this degradation.