ARS | Publication request: HERBICIDE BIODEGRADATION AND SORPTION IMPACTS ON WATER QUALITY AT FIELD AND WATERSHED SCALES

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: February 6, 1997
Publication Date: N/A

Technical Abstract: Herbicide entry into surface and ground water is the result of hydrologic flow patterns, sorption interactions with soil, and residence time in soils and subsurface sediments. Variations in sorption and biodegradation processes at the field and watershed scales are important in delineating the principal routes of contaminant entry and limiting herbicide movement at the different MSEA sites. The biodegradation of atrazine at different MSEA site surface soils was related to soil depth, population of atrazine-degrading microorganisms and sorption. Variations in field-scale topography and sorption affects leaching and movement into tile drainage water and deep groundwater. The low rate of atrazine biodegradation in subsurface till sediments may explain the greater frequency of detection of this herbicide compared to other herbicides. In other alluvial sediments, biodegradation may be sufficient to reduce the concentration of herbicides in groundwater.