Kurzzeittests zur Abschätzung langfristiger Wirkungen potentieller anorganischer Schadstoffe auf die mikrobielle Aktivität von Böden

Short-term experiments for the estimation of long-term effects of inorganic pollutants on soil microbial activity The purpose of the present study was to develope a short-term laboratory method to predict long-term effects of inorganic pollutants on soil microbial activity. Experiments were carried out on a sandy cambisol which had been used in a long-term field plot of the Biologische Bundesanstalt in Berlin. The perfusion technique was suitable to prove long-term effects of concentrations of 50 mg Cd/kg and 1000 mg Pb/kg dry soil on dehydrogenase activity of the test soil. 200 mg Cd/kg and 4000 mg Pb/kg caused higher reductions in the perfusion experiment than in the long-term field trial. Due to the desorption of OH-ions and the dissolution of organic material, effects of NaF-additions were partly compensated in the short-term experiment. The lysimeter technique used here seems to be of minor value to simulate long-term effects of cadmium, lead, and fluorine because unadsorbed portions of these elements and their accompanying ions (e.g. Cl, NO₃) are washed out of the system too slowly. The dehydrogenase activity was more valid to indicate long-term effects on soil microbial activity than ATP-contents and nitrification measurements did.