The present study aims to evaluate the growth and the phytoemediation effect of Medicago sativa, a forage and industrial plant, on soil irrigated with treated urban wastewater and/or amended with urban sewage sludge. Tap water was used for control. The seeds were brought from the oasis of Gabes in the southeast of Tunisia. The sewage sludge was tested at 5 and 25 t/h doses. Results showed that the best production was obtained when cultivating M. sativa on soil amended with 25 t/ha of sewage sludge and irrigated by tap water. Metal trace elements abatements were recorded in soils cultivated by alfalfa and irrigated by tap water; alfalfa thus exerts a phytoremediator power on the soil, it absorbs the metal trace elements and accumulates them in its aerial parts. However, this effect has not been demonstrated when alfalfa grown on soil amended with sewage sludge and irrigated with treated wastewater.
