Effects of hybrid giant napier biochar on cadmium migration in a cabbage-soil system contaminated with cadmium and butachlor

We investigated the effects of high-productivity plant hybrid giant Napier (HGN)-derived biochars prepared at different pyrolysis temperatures on Cd migration in a soil-cabbage system contaminated with Cd and butachlor. The results showed that with the enhancement amount of biochar applied, soil pH and electrical conductivity (EC) increased, whereas the available Cd content dropped significantly (P<0.05). The maximum decreasing value (66.08%) of the available Cd content was observed, while with 5% biochar prepared at 400ºC. Further application of this biochar caused a significant biomass increase and a Cd content decrease of cabbage (P<0.05). Notably, the cabbage biomass even increased to 573.58%. The application inhibited Cd migrations from the soil to the underground part and, successively, the overground part of the cabbage, leading to reduced bioaccumulation of Cd. With 5% biochar prepared at 400ºC, the maximum decrease of the Cd content reached up to 90% in the aboveground part and 70% in the underground part of cabbage, respectively. Hence, the investigation demonstrates that high-productivity HGN-derived biochar can be a good candidate for immobilizing Cd and reducing its bioaccumulation.