Cadmium contents of oats (Avena sativa L.) in official variety, organic cultivation, and nitrogen fertilization trials during 1997-1999

The cadmium (Cd) contents of oats (Avena sativa L.) in Finland were examined over a 3 year period in three types of trials: official variety, organic vs conventional cultivation, and nitrogen fertilization trials. Large seasonal and regional variations were found in the Cd concentrations. In official variety trials, the mean Cd contents in 1997, 1998, and 1999 were 0.046, 0.029, and 0.052 mg kg -1 dry weight (dw), respectively, ranging from 0.008 to 0.120 mg kg -1 dw. The concentrations were generally well below the maximum permitted level of 0.100 mg kg -1 fresh weight. No significant differences were found between the organic and the conventional cultivation techniques. Nitrogen (N) fertilization increased the Cd contents of oats especially at high nitrogen rates (160 kg N hectare -1 (ha)). Significant cultivar differences (p < 0.001) were determined in all trials. Cultivars Salo and Kolbu had consistently higher contents, and Belinda and Roope had lower Cd contents among the different growing conditions. Hence, it is possible to cultivate and develop oat cultivars less likely to accumulate Cd.