Accumulation of Phosphorus and Arsenic in Two Perennial Grasses for Soil Remediation

Abstract

Rice cutgrass (Leersia oryzoides Sw.) and tall fescue (Festuca arundinacea Schreb.) were assessed for potential for phytoremediation of arsenic (As) in a soil-based medium amended with phosphorus (P) in a greenhouse experiment. Arsenic was added at 30 mg kg⁻¹, and P concentrations ranged from 0 to 120 mg kg⁻¹. Plants were grown for 8 weeks. Rice cutgrass accumulated greater concentration and total amount of As in shoots or roots than fescue. Only the first increment of P fertilization increased As in shoots above that which accumulated without P fertilization. Phosphorus fertilization did not stimulate growth of either species. Most of the As remained in the roots of either species. Plant–soil accumulation ratios suggest that rice cutgrass has more potential in phytoremediation than fescue. Above a minimal amount, P fertilization did not enhance As accumulation in shoots and may not be useful in increasing the potential of either species to remediate soils.

Keywords:

• Festuca
• Leersia
• phytoremediation
• rice cutgrass
• soil contamination
• tall fescue