INFLUENCE OF CASSIA SIEBERIANA DC (SIEBERS CASSIA, FABACEAE) ON SOIL PHYSICOCHEMICAL PROPERTIES IN FANDENE, SENEGAL

Senegal is facing increasing soil degradation, particularly in arid and semi-arid zones. This degradation is largely due to climate change and inappropriate farming practices, which have led to a decline in soil fertility and lower agricultural productivity. To enhance soil fertility, legumes such as Cassia sieberiana DC are considered a potential solution. Although these species are socio-economically, ecologically, and medicinally important, research on their specific impacts on soil fertility remains limited and inconsistent. This study aims to assess the influence of C. sieberiana on soil physicochemical properties. Soil samples were collected from natural stands of C. sieberiana in Fandene across three diameter classes, both under and above the crown, at two depths. Soil physicochemical parameters were assessed. The results indicated that the soil texture beneath C. sieberiana was sandy loam. The results showed significant effects of diameter class, radius, depth, and interactions between class and depth, and between radius and depth, on carbon (C), organic matter (OM), and nitrogen (N). However, pH varied with depth. Electrical conductivity (EC) varied with depth and interactions. The results showed that OC and OM contents were higher at 2/3R of the crown, in diameter class C2 and at a depth of 0-20cm. These results underline the importance of sustainably managing these trees in agroforestry systems to mitigate soil degradation and improve agricultural productivity. However, it would be interesting to study the effect of the species on soil cation exchange capacity, and minerals such as calcium, potassium, magnesium, sodium and sulfur.