Phytoremediation capability of nickel and manganese polluted soil by Sorghum biocilor L.

A pot experiment was conducted based on a factorial study and complete random block design with three replicates to investigate the phytoremediation potential of Sorghum biocilor L. in soils polluted with nickel and manganese during 2017-2018. The first factor was nickel nitrate (0, 60, and 120 mg kg-1 soil) and the second factor comprised of manganese sulphate (0, 50, and 100 µM). The characteristics under investigation were shoot height, root length, shoot dry weight, root dry weight, nickel concentration of shoots and roots, manganese concentration of shoots and roots, and nickel and manganese translocation factors. Findings suggested that under nickel and manganese stress, shoot height, root length, shoot dry weight, and root dry weight reduced. Also, with an increase in the soil nickel and manganese, so did the concentration of these heavy metals in roots and shoots of the plants under study. Maximum effect of nickel and manganese were recorded in the treatments comprising 120 mg Kg-1 Nickel and 100 µM manganese sulphate, respectively while compared with nickel, manganese caused less damage to the plants under study. Application of nickel to the soil increased the translocation factor while there was no difference between the two levels of nickel applied. On the other hand, application of manganese did not affect the translocation factor compared to the control and the translocation factors for both elements were less than 1. Therefore, based on the findings of the study, sorghum showed a relatively good tolerance to nickel and manganese, the absorbed nickel and manganese were mostly concentrated in the plant root, and Sorghum biocilor L. is not recommended for phytoremediation.