There is a need to develop methods that can use data from standard lab toxicity tests to realistically predict response of organisms to metals under field condition. Therefore, the copper toxicity for microbial processes (nitrification and substrate induced respiration) will be measured for a selection of soils that are representative for the major soil types in Europe and varying in pH, texture and organic matter. The data will be used to develop an empirical relationship of toxicity as a function of soil bioavailability parameters. For three soils, the ageing of copper will be followed during 18 months after contamination in the lab and the results will be compared with results of field contaminated sites.