Die Nickelaufnahme von Pflanzen aus verschiedenen Boeden und Bindungsformen und ihre Prognose durch chemische Extraktionsverfahren Abschlussbericht

The nickel update from different soils and Ni-bondings has been compared with chemical soil extraction. NiCl_2 proved to be most available, followed by an artificially Ni-enriched sludge. The Ni-uptake from industrial sludges and filter dust, as well as from geogeneously Ni-containing soils, was very low. Wheat, barley, rapeseed and mustard absorbed little Ni and did not exhibit toxicity symptoms. Spinach, lettuce carrots, kohlrabi and oats accumulated higher Ni-amounts and reacted with yield depressions. Bush beans, radish and corn salad showed especially high Ni-concentrations and were visibly damaged. Rye gras took up equally much Ni but did not suffer from its toxicity. Regarding the natural Ni of many soils, the present limit value of 50 mg/kg is unnecessarily low, but nonetheless can not be increased due to the toxicity of anthropogeneous Ni-contamination. Extractants with pronounced dissolution capacity reflect the Ni-availability as poorly as the total Ni-contents do. The same also applies for buffered solutions because of their changing the pH-status during the extraction. Only salt solutions are able to indicate the actual plant availability, although even there the extraction values have to be corrected to some exent.(orig.)Available from TIB Hannover: RN 8422(1995,33) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman