Biochar Improved Growth of an Important Medicinal Plant(Salvia miltiorrhiza Bunge) and Inhibited its Cadmium Uptake

Effects of biochar on the growth of Salvia miltiorrhiza Bunge and heavy metal accumulation in plant tissues were evaluated in artificially Cd-polluted soil. Results showed that plant biomass increased with the proportion (0 to 32%) of biochar in the soil mix. However, the impacts of biochar on plant physiological indicators were not clear. Compared with the control, the addition of biochar decreased Cd content in leaves and roots of S. miltiorrhiza by 52.8% and 43.6%, respectively. Correspondingly, the bioaccumulation coefficient of Cd was reduced, and the Cd transfer coefficient decreased with the increase of biochar indicating that biochar inhibited Cd to transfer from soil to plant. Therefore, biochar has potential for remediation of Cd or possibly other heavy-metal polluted soils in agricultural crop production.