3.4. Metal concentrations in plants
The concentrations of Cu, Zn, and Pb in the shoots and roots of vetiver and common reed in Pb/Zn tailings are shown in Table 7. The results showed that concentrations of Cu and Pb in both the shoot and root tissues of vetiver in tailings amended with manure compost (PZM) or sewage sludge (PZS) were significantly decreased (p ⩽ 0.05). Vetiver accumulated significantly higher Zn in the shoots when grown in PZM20, PZM10 + F, and PZS10 + F substrata than that of grown in control tailings (PZ) ( Table 7).