Lead Remediation by Urochloa brizantha in Microcosms: Phytoextraction Versus Phytostabilization

ABSTRACT

Lead (Pb) is a highly toxic metal that threatens environmental and human health by impairing soil functioning and plant development and potentially entering the food chain. However, some plant species possess Pb tolerance mechanisms, making them promising candidates for the remediation of contaminated soils. This study aimed to evaluate the phytoremediation potential of Urochloa brizantha cv. Marandu cultivated in Pb‐contaminated soil microcosms by assessing its capacity for Pb absorption, accumulation, translocation, and tolerance. A greenhouse experiment was conducted using 100 dm ³ microcosms filled with Typic Quartzipsamment and four Pb levels (0, 72, 180, and 300 mg kg ⁻¹ ), under fertilization and liming conditions recommended for the species. At 180 days after the uniformity cut, the dry mass production of the aerial part and root (SDM and RDM), the concentrations and accumulation of Pb and nutrients in the soil and plant tissues, bioconcentration factor (BCF), and the translocation factor (TF) were evaluated. U. brizantha maintained biomass production under increasing levels of soil Pb contamination, demonstrating high tolerance to the metal. TF values <1, together with shoot BCF values <1, indicated restricted Pb translocation from roots to shoots and limited bioconcentration in aboveground tissues, supporting the phytostabilization potential of U. brizantha rather than its use for phytoextraction. Its high Pb tolerance and ability to maintain biomass production in contaminated soil further support its potential use in assisted revegetation strategies. However, its long‐term phytostabilization effectiveness should be confirmed by assessing root bioconcentration and changes in soil Pb mobility and availability.