The effect of ryegrass variety on trace metal uptake

Abstract

Trace metal deficiencies in soils can have adverse effects on plant production and animal health. Conversely, trace metals at elevated concentrations in soils can be phytotoxic. The exploitation of intraspecies variation in plant trace metal accumulation may be one way to manage both trace metal deficiency and phytotoxicity that can occur in some soils. An investigation was undertaken to determine the variation in Co, Cd, Ni, Cu, Zn, Mn, and Fe uptake in different ryegrass varieties. Eleven different ryegrass varieties were grown in a glasshouse experiment on two soils that contained elevated or background metal concentrations. We found that there was up to a 2.5‐fold range in trace metal concentrations between ryegrass varieties grown on the contaminated soil, with the short rotation/annual ryegrass varieties, i.e., ‘Flanker’, ‘Tabu’, and ‘Archie’, generally accumulating significantly smaller amounts of Cd, Zn, Ni, Mn, and Co than the other varieties tested. Metal uptake in the uncontaminated soil indicated much smaller differences between varieties. Dilution effects could in part explain the differences in metal concentrations between varieties for the contaminated soil, however there were no relationships between yields and trace metal concentrations for uncontaminated soil. It appears that there may be potential for selecting ryegrass varieties for the management of trace metal uptake in pasture soils, however further evaluation of results in field trials is required.