Determining the Dissipation and Potential Offsite Movement of Pendimethalin through a Monitoring Survey and Environmental Modeling

摘要

Dissipation, accumulation, and the potential offsite movement of pendimethalin, a soil-applied herbicide, were determined by conducting a retrospective monitoring survey and environmental modeling. The test area for the monitoring survey had a history of annual pendimethalin applications. Soil, water, and sediment samples were collected and analyzed. Information from laboratory and field dissipation studies was utilized in the environmental modeling to predict potential long-range transport and deposition to soil, water, and sediment. The monitoring survey has shown very low concentrations of pendimethalin in the treated soil. Residues were not detected in the non-agricultural soil, surface water or sediment, which indicates no accumulation of pendimethalin, at levels greater than the limit of detection, as a result of degradation, offsite movement through runoff and/or atmospheric transport and re-deposition. Model simulations estimate that the concentration of pendimethalin in soil, water, and sediment resulted in concentrations below the level of ecological concern.