Schwermetallgehalte verschiedener Gemüsepflanzen und Möglichkeiten zu deren Verminderung durch ackerbauliche Maßnahmen - Teilergebnisse aus Freilandversuchen

In a field trial carried out at a site with heavy metal soil load in the Stolberg area (Rhineland) the plant availability of lead, cadmium, and zinc became markedly reduced by certain measures of soil management; in this way it was possible to decrease the contents of toxic heavy metals within the test plants ( esp. vegetables) to a considerable degree. Exceeding the diminishing effect of increasing soil reaction by liming, applications of high rates of phosphates, partly in combination with silicatic soil adjuvants, resulted in additional decreases of heavy meta! contents in plants. Application of ion exchangers on the basis of synthetic resins was most effective in decreasing the heavy meta! contents, however, potassium-magnesium-phosphate (esp. in combination with silicate) produced nearly equally good effects after a longer hold-up-time, i.e. during the 2nd and 3rd year after application. The various lest plants indicated considerable differences in their uptake patterns with respect to different heavy metals as well as regarding to the diminishing effects of soil treatments. Compared with leaf and/or sprout vegetables root crops indicated markedly pronounced tendencies in their uptake and accumulation patterns for soil contaminating metals.