Accumulation and Translocation of Metals in Soil and Different Parts of French Bean (Phaseolus vulgaris L.) Amended with Sewage Sludge

A pot experiment was conducted to study the accumulation and translocation of metals in French bean (Phaseolus vulgaris L.). Plants were grown in soil amended with up to 100 % sewage sludge. Significant (p < 0.01) changes to soil characteristics were observed. The maximum growth of P. vulgaris was noted in the treatment with 40 % of sewage sludge. Metal concentrations were significantly (p < 0.05) higher in P. vulgaris after sewage sludge amendment where Fe > Zn > Cd > Cu > Cr > Pb. The translocation for Fe and Zn was in the order of leaves > shoot > root > fruits, for Cd, shoot > root > leaves > fruits, for Cu and Pb shoot > leaves > root > fruits and for Cr root > shoot > leaves > fruits of P. vulgaris. All accumulated metal concentrations except Cd in the fruit were below the FAO/WHO standard limits. Thus, the amendment of agricultural soil by sewage sludge might be feasible. However, a regular monitoring of metal levels in agricultural products is recommended to prevent their accumulation in the food chain.