Respectively, Hydrologist and Environmental Careers Organization Associate, U.S. Geological Survey, 840 Market Street, Lemoyne, Pennsylvania 17043.
FACTORS AFFECTING HERBICIDE YIELDS IN THE CHESAPEAKE BAY WATERSHED, JUNE 19941
Version of Record online: 8 JUN 2007
JAWRA Journal of the American Water Resources Association
Volume 32, Issue 5, pages 965–984, October 1996
How to Cite
Hainly, R. A. and Kahn, J. M. (1996), FACTORS AFFECTING HERBICIDE YIELDS IN THE CHESAPEAKE BAY WATERSHED, JUNE 1994. JAWRA Journal of the American Water Resources Association, 32: 965–984. doi: 10.1111/j.1752-1688.1996.tb04066.x
Paper No. 95169 of the Water Resources Bulletin. Discussions are open until April 1, 1997.
- Issue online: 8 JUN 2007
- Version of Record online: 8 JUN 2007
- nonpoint source pollution;
- water quality;
- pollution load;
- land use
ABSTRACT: Median concentrations and instantaneous yields of alachlor, metolachlor, atrazine, cyanazine, and simazine were generally highest at sites in the Lower Susquehanna River Basin and in agricultural subbasins. Instantaneous herbicide yields are related to land use, hydrogeologic setting, streamflow yield, and agricultural row cropping practices. The significance of these relations may be affected by the interdependence of the factors. The percentage of basin area planted in corn is the most influential factor in the prediction of herbicide yield. Instantaneous yields of all five herbicides measured in June 1994 related poorly to averaged 1990–94 herbicide use. Annually averaged herbicide-use data are too general to use as a predictor for short-term herbicide yields. An evaluation of factors affecting herbicide yields could be refined with more-current land use and land cover information and a more accurate estimate of the percentage of basin area planted in corn. Factors related to herbicide yields can be used to predict herbicide yields in other basins within the Chesapeake Bay watershed and to develop an estimate of herbicide loads to Chesapeake Bay.