PESTICIDE LEACHING DATA TO VALIDATE SIMULATION-MODELS FOR REGISTRATION PURPOSES

A data set originating from three pesticide leaching experiments conducted in undisturbed soil monoliths is described. Leaching of the herbicides dichlorprop and bentazon was measured in five different soils, ranging from loamy sand/sand through sandy loam to silty clay. Information on degradation and adsorption of the herbicides and soil physical and hydraulic properties is also included in the paper. This data was used for a model validation exercise, aimed at comparing and evaluating existing pesticide leaching models from the point of view of regulatory purposes. Larger amounts of dichlorprop were leached than bentazon reaching an average amount of 3.22 g a.i./ha (0.20% of applied dichlorprop) during the eight month study period. The largest leaching loss was found in a day soil, which was explained in terms of macropore flow.