THE NICKEL UPTAKE FROM DIFFERENT SOILS AND ITS PREDICTION BY CHEMICAL EXTRACTIONS

The uptake of Ni by 13 plant species was investigated from two soil types containing Ni in different concentrations and forms. Absorption was highest from NiCl2, less from Ni containing sewage sludge or industrial filter dust, and least from a soil containing geogenic Ni. The 13 species grown can be classified into four groups differing in Ni uptake and toxicity. The Ni contents in grain and in storage organs were larger than in the vegetative plant parts. The highest Ni contents were found in the roots. Plants grown in pots absorbed more Ni than from the same soils in the field. During consecutive years the Ni availability did not decrease. Only soil extractions with unbuffered salt solutions reflected the availability of pollution-derived Ni sufficiently well.