Phytoremediation Potential of Maize (Zea mays L.). A Review

In most developing parts of the world, the rapid expansion of industrial areas leading to uncontrolled processing and utilization of industrial products, agricultural inputs, vehicular emissions and improper disposal of liquid and solid wastes may cause soil to become contaminated with chemical hazards such as heavy metals. Heavy metal contamination of soil may pose risks to humans and the ecosystem through direct ingestion or contact with contaminated soil, the food chain (soil-planthuman or soil-plant-animal-human), drinking contaminated ground water, reduction in food quality (safety and marketability) via phytotoxicity, reduction in land usability for agricultural production causing food insecurity and land tenure problems. Low-cost and ecologically sustainable strategies are needed to restore heavy metal-contaminated soils. Phytoextraction is considered a costeffective and publicly appealing remediation strategy that uses plants, associated microbiota and amendments to remove the heavy metals from the soil. A plant for this purpose needs be heavy-metal tolerant, grow rapidly with a high biomass yield per hectare, have high metal accumulating ability in the foliar parts, have a profuse root system, and a high bioaccumulation factor. Over 400 taxa of plant hyperaccumulators of heavy metals have been identified, but most of them are low biomass producers and exotic species. There’s need to supplement the list of plants available for phytoextraction. Maize (Zea mays L.) is a widely grown staple cereal with promising attributes of a heavy metal accumulator. The potential use of this robust tropical crop in phytoextraction technology is advocated especially for developing countries with scarce funds available for environmental restoration.