Ability of lead phytoremediation by sorghum (Sorghum bicolor L.) under the application of biochar and salicylic acid

In order to investigate the effect of biochar and salicylic acid on phytoremediation of sorghum (Sorghum bicolor L.) to lead heavy metal (Pb), a factorial experiment was conducted in a completely randomized design with 4 replications in the greenhouse of Sari Agricultural Sciences and Natural Resources University in 2019. Treatments were five levels of lead (0, 400, 800, 1200 and 1600 mg Pb kg-1 soil), two levels of biochar (no-consumption and consumption of 20 g biochar kg-1soil) and two levels of salicylic acid (no-foliar application and 2 mM foliar application). Shoot and root dry weights, tolerance index, Pb concentration in shoot, root and soil, transfer and bioaccumulation factors and Pb uptake in the shoot were measured. The results showed that the application of biochar and salicylic acid reduced the negative effect of Pb on dry weight of sorghum and improved traits related to phytoremediation. The highest Pb concentration in shoot and root (671.17 and 398.70 mg Pb kg-1 dry matter, respectively) were obtained in the combined treatment of biochar and salicylic acid application at 1600 mg Pb kg-1 soil. Generally, the results showed that biochar and salicylic acid application in sorghum improves Pb phytoextraction in contaminated soil.