Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/30/2001
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: The Iowa MSEA program sponsored multidisciplinary research at plot, field and watershed scales. Water monitoring studies targeting herbicide and nitrate transport were conducted in different hydrogeologic settings. In central and northeast Iowa, herbicides were transported from fields in runoff and in subsurface drainage water. Herbicides, principally atrazine, leached to groundwater, but concentrations generally remain below the MCL. Relative losses of different herbicides are related to their persistence patterns in soil and soil permeability. In contrast to herbicides, nitrate concentrations in stream water often exceed the MCL and losses are controlled by subsurface drainage. Nitrate losses are affected by fertilization patterns, mineralization of soil N, and timing of spring rainfall. The MSEA program established broader knowledge about the routes of contaminant entry into surface waters, contaminant sources and effects of selected practices. The influence of this MSEA on present research and agricultural practices will be discussed.