Modeling pesticide losses from diffuse sources in Germany

Area of Science:

• Environmental Science
• Hydrology
• Agricultural Science

Background:

• Diffuse sources are major contributors to surface water contamination.
• Pesticide application in agriculture poses risks to aquatic ecosystems.
• Germany utilizes extensive field crops, vineyards, and orchards in its agricultural landscape.

Purpose of the Study:

• To estimate pesticide losses from diffuse sources into German surface waters.
• To quantify inputs via tile drainage, runoff, and spray drift for 42 active ingredients.
• To validate model outputs against measured pesticide loads.

Main Methods:

• Geographic Information System (GIS)-based modeling approach.
• Application of 42 active ingredients across 11 crop types.
• Comparison of modeled water inputs with empirical data from catchments and river basins.

Main Results:

• Mean annual pesticide inputs: 1490 kg/year (tile drainage), 9060 kg/year (runoff), 3350 kg/year (spray drift).
• Model sensitivity analysis indicated high dependence on active ingredient properties.
• Model and measured data showed agreement in the order of magnitude of pesticide loads.

Conclusions:

• Runoff represents the primary pathway for pesticide entry into surface waters.
• Model results are valuable for comparative interpretations across different factors.
• Further research should focus on refining model parameters for specific active ingredients and regions.