TENEURS EN ÉLÉMENTS MAJEURS ET OLIGOÉLÉMENTS DANS UN SOL ET QUELQUES CULTURES MARAÎCHÈRES DE LA VILLE DE DSCHANG, CAMEROUN

In Dschang, market-gardening production intensifies with the utilisation of the organic and inorganic entrants which can have harmful effects on soil and plants. This study aimed at determining the macro and micro- nutrients content in a cultivated soil and in the vegetable produced. Three vegetable species including lettuce, eggplant and carrot were produced. Macro-nutrients elements monitored include Mg, Al, Si, Mn, Fe, P, K, Ca and Ti, while micronutrients elements were Nb, Zr, Y, Sr, U, Rb, Th, Pb, Ga, Zn, Cu, Ni, Co, Cr, S, Cl, V and Ba. Macro and micro-nutrient content in the soil and in the vegetables was determined using X-ray fluorescence spectrometry. The monitoring was done at three depths in the soil (0-10, 20-30, 40-50cm). Cr and Ni contents were higher than the threshold fixed by WHO. The Zn content in lettuces and carrots was higher than the threshold of 17 mg kg-1 and that of Cu in eggplant exceeded the acceptable limit of 15 mg kg-1 fixed by WHO. The vegetable production practices in Dschang town present major health risks due to the presence of heavy metals in the marshy soils and in the vegetable produced. This is a public health hazard which should be controlled.