Screening High-Biomass Grasses for Cadmium Phytoremediation

Area of Science:

• Environmental Science
• Plant Biology
• Soil Science

Background:

• Assessing non-hyperaccumulator plants for phytomanagement of cadmium (Cd)-polluted soils is crucial.
• Phytomanagement strategies include phytostabilization (immobilizing contaminants) and phytoextraction (removing contaminants).

Purpose of the Study:

• To evaluate the Cd tolerance of high-biomass grasses.
• To determine their suitability for phytoextraction or phytostabilization on moderately Cd-polluted land.
• To assess the impact of Cd on biomass production and element accumulation.

Main Methods:

• Ten high-biomass grass species were grown on soil with 7.5 mg kg^-1 Cd.
• Biomass production, element accumulation, Cd bioconcentration factor (BCF), and translocation factor (TF) were measured.
• Cd concentrations in roots and shoots were analyzed.

Main Results:

• Cd exposure reduced root biomass in *Panicum maximum* cv. Massai and *Pennisetum glaucum* cv. Purpureum Schum.
• Element accumulation (P, K, Mg, Ca, Fe, Zn, B) was altered in some species but not always correlated with biomass reduction.
• Cd concentrations were significantly lower in shoots than roots, with Cd TF < 0.4 for all species.

Conclusions:

• The tested grasses are generally better suited for Cd phytostabilization than phytoextraction.
• *Panicum maximum* cv. Massai and *Pennisetum glaucum* cv. Purpureum Schum may be less effective long-term due to inhibited root growth.
• Further research is needed to optimize phytomanagement strategies for specific grass species and pollution levels.