Impact of urban gardening in an equatorial zone on the soil and metal transfer to vegetables
Résumé
This study was aimed at assessing the impact of urban agriculture on physicochemical properties of the soil and the metal uptake by some leafy vegetables cultivated in urban soils of Libreville, Gabon. Cultivated and uncultivated topsoil and vegetable samples were collected from two urban garden sites, and analyzed. The results showed that there was strong acidification and a decrease in the concentrations of nutrients and metals in soils due of agricultural practices. The metal transfer to plants was important, with the exception of iron. The non-essential metals cadmium and lead were not detectable in the plant tissues. Amaranth accumulated more metals than other vegetables. Amaranth and Roselle were vegetables that preferentially concentrated metals in their leaves and could, therefore, be used for metal supplementation in the food chain.