Rice straw biochar differently influences the availability and uptake of cadmium and lead by wheat ( Triticum aestivum L.)

Present research aimed to investigate the interactive effects of rice straw biochar (RSBC) and heavy metals (cadmium (Cd) and lead (Pb)) on agronomic parameters, soil properties, gas exchange characteristics and metal uptake by wheat (Triticum aestivum L.) plants. The experiment involved a factorial design with two factors: biochar (No-BC and RSBC at a rate of 1%) and heavy metals (control, Cd, Pb, and Cd + Pb). The pre-analysis of RSBC showed high nutrient and mineral contents, especially silica rich minerals. Results indicated that RSBC application significantly improved plant growth parameters and mitigated negative effects of Cd and Pb on growth as compared to the control. The gas exchange characteristics were greatly improved with RSBC application under metal stress as compared to no-BC treatments. The RSBC reduced the concentrations of bioavailable Cd (24%) and Pb (18%) in soil. A significant reduction in metal accumulation was observed in grains (36 and 30% for Cd and Pb, respectively) and straw (55 and 88% for Cd and Pb, respectively) of wheat plants. The uptake of Cd and/or Pb was lower when applied alone as compared to Cd + Pb treatment. Results demonstrated the safe utilization of RSBC for enhancing crop resilience in metal-contaminated soils.