Increasing Cd concentration in the two soils resulted in lower ryegrass yield (Figure 1), which is consistent with findings reported by other authors (Bolan and others 2003; Athar and Ahmad 2002; Prince and others 2002). This reduction was significant in some cases at 200 and 2000 mg/kg of Cd added to the uncultivated soil, and at 600, 1000, 4000, and 5000 mg/kg of Cd added to the cultivated soil.