Hyperaccumulator plants as industrial crops for sustainable metal recovery and biomass utilization on marginal lands: A comprehensive review

The deliberate cultivation of hyperaccumulator plants for phytomining represents a promising industrial crop strategy for extracting valuable metals from marginal, metal-rich soils while simultaneously generating biomass for energy and materials. These specialized plants can tolerate and accumulate exceptionally high concentrations of metals such as nickel (Ni), cobalt (Co), thallium (Tl), and gold (Au), offering an innovative, dual-purpose approach to non-food crop production. This review examines the agronomic, physiological, and economic dimensions of using hyperaccumulators as industrial crops within sustainable cropping systems. Key species such as Alyssum corsicum and Streptanthus polygaloides (Ni), Haumaniastrum spp. (Co), and Iberis intermedia (Tl) demonstrate the ability to produce metal-rich, low-sulfur biomass ("bio-ore") that can reduce downstream processing costs and energy demands. Economic viability depends on multiple factors, including biomass yield, metal content, site conditions, and global metal prices. Gold phytomining is particularly attractive; for example, Daucus carota L. grown for industrial purposes can produce 16 tons/ha biomass with 48.3 mg/kg Au, yielding up to $85,690/ha under current market values. Additionally, the combustion of harvested biomass provides energy and concentrates metals in ash, enabling storage and delayed metal extraction—an advantage under volatile market conditions. The review highlights potential for integrating these crops into sustainable land management practices, especially in tropical regions that support year-round growth. By converting unproductive or contaminated land into productive systems, hyperaccumulators support circular economy goals through combined metal recovery, energy production, and environmental restoration. This review positions hyperaccumulators as viable industrial crops for marginal lands, contributing to the development of low-input, metal-yielding biomass systems with strong potential for further agronomic optimization and commercialization. • Phytomining extracts valuable metals (Ni, Co, Tl, Au) from low-grade soils using hyperaccumulators. • Gold phytomining can yield up to $85,690/ha. • Biomass combustion provides energy and metal-rich ash, lowering costs and risks. • Tropical climates support year-round biomass growth. • Hyperaccumulators absorb metals at concentrations much higher than those in the soil, enabling effective metal recovery