Metal uptake by tall fescue (Festuca arundinacea) as affected by poultry litter application

Poultry litter is commonly applied to pastures as an organic fertilizer. However, poultry litter also typically contains numerous heavy metals that may accumulate in soil and can pose an environmental threat when it is applied to pastures. The objective was to ascertain uptake characteristics of heavy metals by tall fescue (Festuca arundinacea Schreb.) from soil with a history of poultry litter additions as affected by subsequent applications of poultry litter. Poultry litter was applied to small plots at rates of 0, 2·2 and 4·5 t dry litter ha⁻¹. In the 7·5 months following application of litter, cumulative dry-matter (DM) production of herbage was higher (P < 0·05) in the plots that received poultry litter compared with the control plots where no litter was applied. However, concentrations of Al, Cu, Fe, Mg, Mn, Se and Zn in herbage were unaffected by the rate of application of poultry litter. All metal tissue concentrations, except for Fe, were affected by sampling date. While tall fescue responds to poultry litter with increased DM production, it does not appear to accumulate excessive quantities of micronutrients associated with the application of poultry litter.