Modeling pesticide losses from diffuse sources in Germany

Abstract

A GIS-based model estimates the losses from diffuse sources in surface waters in Germany for 42 active ingredients applied to 11 field crops, vineyards and orchards. For the following pathways of entry: tile drainage, runoff and spray drift, the calculated mean pesticide input amounts to 1490 kg/year, 9060 kg/year and 3350 kg/year, respectively, in 1994. The model results are highly sensitive to the model parameters, primarily the chemical properties of the active ingredients. The modeled water inputs were compared with measured pesticide loads in smaller catchments and large river basins to validate model results. Both datasets agree as to the order of magnitude, nevertheless due to the scale of the study the results should be addressed mainly to comparative interpretations with the focus on the proportions between different active ingredients, soil regions, climates and application periods.

Risk mitigation measures for diffuse pesticide entry into aquatic ecosystems: Proposal of a guide to identify appropriate measures on a catchment scale

“…However, only a few mitigation measures are appropriate for managing drainage entry, including the reductions in the application rate and the restriction of pesticide use to specific soil types (Reichenberger et al ). Furthermore, pesticide entry via drainage is often of minor importance compared to spray drift and runoff in Germany (Bach et al ). Therefore, drainage was not included within the proposed guide; however, it may be an important input pathway in intensively drained regions, particularly for pesticides characterized by low adsorption coefficients.…”

“…2007). Furthermore, pesticide entry via drainage is often of minor importance compared to spray drift and runoff in Germany (Bach et al 2001). Therefore, drainage was not included within the proposed guide; however, it may be an important input pathway in intensively drained regions, particularly for pesticides characterized by low adsorption coefficients.…”

“…It should be noted that the guide is not a tool for identifying pesticide‐polluted surface water bodies on a national or regional scale. Large‐scale, geodata‐based models such as those used by Schriever et al () or Bach et al () are more appropriate for this purpose. The present guide focuses exclusively on water bodies that were already recognized as contaminated (e.g., as a result of a regional or national chemical or biological monitoring program or by modeling approaches).…”

Detachment of sprayed colloidal copper oxychloride–metalaxyl fungicides by a shallow water flow

“…This process depends on the influence of many factors that are difficult to control within a laboratory experimental design 2–4. A knowledge of the importance of the different factors governing foliar washoff is a key issue for modelling the losses of pesticide treatments and the optimisation of pesticide formulations for use in agriculture 5–7…”

Dissipation dynamics of terbuthylazine in soil during the maize growing season

“…Numerous distribution models have been developed to assess herbicide water contamination potential based on standard field scenarios, but to produce accurate assessments, all of them require sufficient data from field dissipation studies in agricultural soil under the most common conditions (6,9,(24)(25)(26). The objective of this field study was therefore to provide these data about the vertical distribution of TBA and DET in the uppermost 50 cm of silty clay loam soil under relatively humid and warm field conditions during a maize growing season.…”