Effects of Eu and Ca on yield and mineral nutrition of wheat (Triticum aestivum) seedlings

Although fertilisers enriched in rare earth elements (REE) are widely used in agricultural practice, little is known yet about behaviour of the REE in soil–plant system. Among REE, europium (Eu) may be of highest interest. Eu may serve as an indicator of biogeochemical processes due to a change of its valence state under different environmental conditions. Since chemical characteristics of Ca and REE are similar, Eu may compete with Ca for organic ligands. In the present work we studied the influence of Eu and Ca on the growth and mineral nutrition of wheat seedlings. An application of Eu favoured germination and root growth, whereas in combination with Ca it produced a more sustained leaf growth. Eu affected uptake and distribution of certain nutrients in different parts of a plant. The content of Eu in all parts of wheat seedlings at the end of germination significantly increased. Transfer of the seedlings germinated in the Eu-rich medium into soil resulted in the release of Eu from the plants. Nevertheless, 9 days after the sowing, Eu concentration in the seedlings was still much higher than in the control plants.