Synergistic Enhancement of Heavy Metal Phytoextraction in Okra (Abelmoschus esculentus) Using Biochar and Chelating Agents

Abstract

Okra (Abelmoschus esculentus) is an annual vegetable consumed for its pleasant and spicy flavor. Heavy metal stress adversely affects human health, ecological balance and biodiversity throughout the globe. A pot experiment was conducted using heavy metal-contaminated soils to assess the phytoextraction potential of A. esculentus. To create the biochar, we pyrolyzed rice husk, peanut shell, Asphodelus tenuifolius, and Suaeda fruticose in a locally fabricated pyrolysis machine at 500–550°C under anaerobic conditions. Our research suggested that the application of biochars and chelating agents significantly enhanced the absorption and transport of heavy metals into plant tissues as compared to untreated plants. Further, all treatments indicated that the root-to-shoot translocation factor was >1, indicating the significant improvement in metal mobilization, plant biomass production, plant height and chlorophyll contents. These findings suggested that the integration of biochar with chelating agents can serve as an effective strategy for the remediation of heavy metal-contaminated soils via phytoextraction using A. esculentus. This research will help to develop a sustainable approach for managing agricultural and plant-based waste materials through biochar production.