Current-use pesticides in vegetation, topsoil and water reveal contaminated landscapes of the Upper Rhine Valley, Germany
Ken M. Mauser, Jakob Wolfram, Jürg W. Spaak, Carolina Honert, Carsten A. Brühl
Abstract
Abstract Non-target areas in agricultural landscapes serve as invaluable refuges for organisms and safeguard biodiversity. This research aimed to examine the landscape-scale distribution of Current Use Pesticides (CUPs) in the Upper Rhine Valley in Germany, a region characterised by intensive agriculture in the valley and bordered by forested lower mountain regions. We sampled vegetation, topsoil, and surface water at 78 non-target, off-field sites during the pesticide application season in 2022. The sites were located in six 30 km long transects to cover both the valley and mountain regions. Samples were analysed for 93 CUPs. In total, 63 different CUPs (29 fungicides, 19 herbicides and 15 insecticides) were detected in all samples ( n = 186). CUPs were recorded in 97% of all vegetation and 97% of all topsoil samples (76 of 78 samples each). In total, 140 unique mixtures with ≥2 components were recorded. A prediction map using additional site parameters suggests a widespread presence of CUPs extending multiple hundred meters beyond CUP application areas. Landscape-scale mixture contamination is not addressed in environmental risk assessment for the regulation of pesticides. The study design could serve as a benchmark for evaluating landscape-scale pesticide contamination after implementation of pesticide reduction efforts in agricultural policies and practice.