Phytoremediation potential of Phalaris arundinacea, Salix viminalis and Zea mays for nickel-contaminated soils

The aim of this study was to evaluate the usefulness of Phalaris arundinacea, Salix viminalis and Zea mays to the phytoremediation of the soil contaminated with nickel. A 2-year microplot experiment was carried out with plants growing on Ni-contaminated soil. Microplots (1 m2 × 1 m deep) were filled with Haplic Luvisols soil. Simulated soil contamination with Ni was introduced in the following doses: 0—no metals, Ni1—60, Ni2—100 and Ni3—240 mg kg−1. The phytoremediation potential of plants was evaluated using a tolerance index, bioaccumulation factor, and translocation factor. None of the tested plants was a species with high Ni phytoremediation potential. All of them demonstrated a total lack of usefulness for phytoextraction; however, they can be in some way useful for phytostabilization. Z. mays accumulated large amounts of Ni in the roots, which made it useful for phytostabilization, but, at the same time, showed little tolerance to this metal. For this reason, it can be successfully used only on soils medium-contaminated with Ni, where a large yield decrease did not occur. Its biomass may be safely used as cattle feed, as the Ni transfer from roots to shoots was strongly restricted. P. arundinacea and S. viminalis accumulated too little Ni in the roots to be considered as typical phytostabilization plants. However, they may be helpful for phytostabilization due to their high tolerance to Ni. These plants can grow in the soil contaminated with Ni, acting as a protection against soil erosion or the spread of contamination.