The role of wood-based biochar on growth, yield, and cadmium uptake in rice (Oryza sativa L.) grown under cadmium stress

Background and Objective: Rice (Oryza sativa L.) is prone to absorb cadmium (Cd), which is a vital environmental pollutant and a harmful threat to food security and human health. In general, the application of biochar mitigates the detrimental effect of Cd stress on the growth, yield and quality of plants. To address this effect a pot experiment was conducted to investigate the effect of wood-based biochar on plant growth, yield, and physiological status in rice plants under Cd stress.Methodology: The experiment was sequenced according to a completely randomized design with 3 replicates. Four different treatments namely control (0% biochar and no Cd stress), 25 ppm Cd stress, 2.5% wood-based biochar, and 25 ppm Cd stress + 2.5% wood-based biochar were used in the experiment. Data on plant height, tiller number, leaf area, and SPAD value were recorded 30 days after planting and analyzed statistically.Main Results: Cadmium had a negative impact on the growth and yield of rice. The results exhibited that under Cd stress plant height (79.9 ± 2.00 cm), leaf area (47.09 ± 5.11 cm2), SPAD value (36.08 ± 0.37), grains per panicle (136 ± 9) and grain yield (51.37 ± 8.09 g hill-1) of rice significantly (P < 0.05) decreased. Cd-stressed plants significantly (P < 0.05) increased sterility percentage (35.55 ± 2.15) and grains Cd concentration (1.56 ± 0.065 mg kg-1). In addition, soil pH was significantly (P < 0.05) increased (8.93 ± 0.24) in Cd-treated soil. The application of biochar in Cd-stressed plants significantly (P < 0.05) increased soil pH (9.15 ± 0.29), leaf area (54.83 ± 1.33 cm2), SPAD value (39.06 ± 1.50), grains per panicle (136 ± 9) and grain yield (70.78 ± 1.50 g hill-1), whereas Cd concentration significantly (P < 0.05) decreased (1.26 ± 0.14 mg kg-1).Conclusions: These results suggest that mitigation of Cd toxicity by wood-based biochar results from a decrease in the uptake of Cd, indicating the role of wood-based biochar in enhancing plant growth and yield as well as reducing the potential risks to humans.