Vegetative buffer zones as pesticide-filters for simulated surface runoff

Losses of pesticides from agricultural land to surface waters can cause environmental harm to fish and other aquatic organisms. Vegetated buffer zones (BZ) between agricultural land and surface waters have proved to be effective filters for sediments and sediment-bound nutrients. It is therefore likely that BZ also can be effective filters for pesticides, especially sediment-bound pesticides. The retention of glyphosate, fenpropimorph, propiconazole and soil particles was studied in short-term BZ experiments with simulated surface runoff. Runoff water containing pesticides and soil particles was added directly to the BZ. The BZ was 5 in wide and consisted of natural grass/herbaceous vegetation. To calculate retention efficiency of pesticides and particles through the BZ, surface runoff was collected before entering and after passing the BZ. The average removal efficiency was 39%, 71%, 63% and 62% for glyphosate, fenpropimorph, propiconazole and soil particles, respectively. AMPA (aminomethylphosphonic acid), which is a degradation product of glyphosate, constituted only a small part of glyphosate (about 10%) in this short-term experiment. Based on this study BZ can serve as contributors to reduce pesticide input to surface waters.