[Iron, manganese and cobalt levels in soil, pasture grass and bodies of young bulls after irrigation of the soil with waste water].

The effect of irrigation of meadows with the water of the river. Ner on the levels of iron, manganese and cobalt in the soil and vegetation was studied. Experiments were also carried out on 30 young bulls fed with the hay grown on these meadows. The levels of iron and cobalt were determined in the blood plasma, and the manganese level in the hair of the bulls. The experiments were carried out twice during 93 days. The animals were divided into 3 groups. Group I and II received the hay from the irrigated meadows (group II received the hay from the meadows more intensively irrigated). Group III (control) received hay from non-irrigated meadows. The daily diet consisted of 5 kg of hay and 3 kg of dried sugar beet residues. It was found that the irrigation caused an increase of iron content of the soil and the vegetation. This increase was proportional to the degree of irrigation. The iron level in the blood plasma of the bulls from group I, II and III did not show significant differences. The irrigation caused an increase of the manganese content the soil but the plants growing on this soil contained less manganese than those growing on non-irrigated meadows. There were no differences between the manganese content of the hair of the bulls from the three groups. The irrigation caused an increase of the cobalt content in the soil but it had no effect on cobalt content in the plants and the blood plasma of the bulls.