Hemp Cultivation in Soils Polluted by Cd, Pb and Zn in the Mediterranean Area: Sites Characterization and Phytoremediation in Real Scale Settlement

Abstract

Polluting activities affect, directly or indirectly, large areas of agricultural lands. Metal polluted soils could be managed by phytoremediation using hemp (Cannabis sativa L.). To know the phytoremediation capability of industrial hemp in metal polluted soils under semiarid environments, an experimental project with the support of local farmers was conducted in Sardinia (Italy). This work was carried out in three main steps: (i) identification and selection of the study sites, (ii) field trials, at local farms, both on contaminated and non-polluted sites, (iii) evaluation of heavy metals contents accumulated in the different parts of the plants. Five study sites were chosen. Three of them were severely polluted by heavy metals. Concentrations of Zn and Cd in plants generally were positively correlated with soil content and were different in each part of the plant. The higher values of Zn and Cd were detected in leaves of plants grown in polluted sites (Zn > 950 mg kg−1 and Cd > 6.8 mg kg−1). High values of Pb were also detected in plants grown in non-contaminated soils: this contamination may be due to atmospheric deposition related to polluting sources far to the cultivation.