During application of pesticides, the largest part of the active ingredients of herbicides directly enters the soil. For fungicides and insecticides, the immisions amount to about 20 to 50% of the active ingredients. Of the pesticides used for seed treatment, over 80% of the active ingredients are not taken up by the plants but directly enter the soil. However, little is known about the extent of pesticide residues in the soil and their long-term fate in the environment.
For selected NABO sites, the annual pesticides applications have been assessed (some of them in retrospective) since 1985 so that long-term data sequences are available. They allow a targeted selection and examination of soils with regard to potential pesticide residues and metabolites. The long-term monitoring allows performance checks and evaluation of the long-term behaviour of pesticides in the environment.