Fig. 3. Frequency of detection and median concentration of selected herbicides and herbicide metabolites in streams draining till and windblown loess-derived soils of the upper U.S. Midwest, August 1997.
Fig. 3. Frequency of detection and median concentration of selected herbicides and herbicide metabolites in streams draining till and windblown loess-derived soils of the upper U.S. Midwest, August 1997.