What is the purpose of filter strips in pesticide management?

• A. Untreated grass strips next to streams, ponds, etc., meant to trap pesticides
• B. Plastic barriers across fields
• C. Covered straw mulch on soil
• D. Painted lines on irrigation ditches

Answer: (A)

Filter strips are vegetated buffers placed along field edges next to water bodies to intercept and slow runoff, so pesticides, sediment, and nutrients are captured or degraded before reaching streams, ponds, or other waters. The grasses and soil act to filter chemicals, promote infiltration, and support adsorption and microbial breakdown, reducing the amount that leaves the field with runoff. This natural, grass-covered strip is the intended purpose of filter strips: to trap pesticides and protect water quality.

The other options don’t serve this function. Plastic barriers don’t provide a vegetation-based buffer to filter runoff; covered straw mulch is a soil cover that mainly addresses erosion and soil moisture, not interception of pesticide-laden runoff into waterways; painted lines on irrigation ditches don’t affect pesticide movement at all.