Application of CaCl2-Extraction for Assessment of Cadmium and Zinc Mobility in a Wastewater-Polluted Soil

During a field study of heavy metal pollution of plants and soil on a sewage farm in West-Berlin, soil extraction with calciumchloride was employed as a method for assessing the plant available fractions of cadmium and zinc (watersoluble ions and complexes, readily exchangeable cations). Total and extractable soil metal contents were set into relationship with pH, cation exchange capacity and organic matter content. - As far as is known, usually less than 5 per cent of the heavy metals in naturally enriched soils are plant available. This investigation shows, that in anthropogenically contaminated soils, especially those having received sewage sludge or wastewater, up to 30 per cent of the total content of cadmium and zinc can be plant available. In accordance with other studies it is confirmed that plants growing on such soils contain-higher amounts of heavy metals.