Assessing the Relative Effectiveness of Organic Amendments in Alleviating Cadmium Toxicity

Background: Cadmium (Cd) contamination in soils poses a significant threat to plant growth and human health, particularly in agricultural regions. Organic amendments, such as biochar and compost, have been explored as potential solutions to mitigate Cd toxicity by immobilizing the metal and enhancing plant growth. Objective: This study aimed to evaluate the effectiveness of biochar and compost, individually and combined, in reducing Cd toxicity and promoting the growth of Spinacia oleracea in contaminated soils. Methods: A controlled experiment was conducted in which Spinacia oleracea was grown in soil treated with 1% biochar, 1% compost, or a combination of both. Growth parameters, including root and shoot length, biomass, and leaf area, were measured. Physiological attributes, such as photosynthetic pigments and antioxidant enzyme activities, were assessed. Cd content, translocation, and bioaccumulation in plant tissues were analyzed using atomic absorption spectrophotometry. Statistical analysis was performed using SPSS 25.0, with significance set at p<0.05. Results: The combined application of biochar and compost significantly increased root length (by 49.75%), shoot length (by 36.73%), and biomass (by 42.85%) in Spinacia oleracea. Cd content in roots and shoots was reduced by 40.41% and 51.16%, respectively, compared to control. Conclusion: Biochar and compost, when combined, effectively mitigate Cd toxicity and enhance plant growth, offering a promising strategy for managing contaminated soils.