ABSTRACT

A natural gradient field injection experiment of nine months duration has been performed with injection of Mecoprop (MCPP), Isoproturon (IPU) and bromide in the bottom of an adjacent hillslope. The spatial migration of the pesticides and bromide plumes were monitored over time along three transects instrumented with 85 vertical piezometers in a 6 × 10 × 2 m plot covering most of the discharge zone of the pesticides to the surface water in the riparian zone. Mass balance estimates of MCPP and IPU was evaluated and compared with sorption and aerobic degradation batch results. Results on flow characteristics and non-reactive transport processes of bromide are found elsewhere in this issue (Dahl, M., Christensen, B.S.B., Jensen, S. & Engesgaard P.: A field injection experiment to characterize flow and transport processes in a heterogeneous riparian wetland).