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Diuron in Surface Runoff and Tile Drainage from Two Grass‐Seed Fields
Author(s) -
Rupp David E.,
Peachey R. Edward,
Warren Kristina L.,
Selker John S.
Publication year - 2006
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2005.0093
Subject(s) - surface runoff , tile drainage , hydrology (agriculture) , environmental science , growing season , surface water , drainage , sowing , dry season , tile , agronomy , soil water , ecology , environmental engineering , soil science , biology , geography , geology , geotechnical engineering , archaeology
ABSTRACT The typical method of cool‐season grass‐seed production in Mediterranean climates briefly exposes surface waters to potentially high concentrations of the herbicide diuron [3‐(3,4‐dichlorophenyl)‐1,1‐dimethyl urea] during the initial season of growth. To better understand the process, and the degree, of diuron transport from agricultural fields, two grass‐seed fields in the Willamette Valley of Oregon were monitored for diuron loss in surface runoff and tile drainage during the first wet season after planting. Initial diuron concentrations in surface runoff were high (>1000 μg L −1 in one field and >100 μg L −1 in the other), though they decreased by two orders of magnitude by the end of the season. Concentrations in the tile drains were as much as 1000 times lower than in the surface runoff during the first few weeks of runoff events, and they remained lower than surface water concentrations throughout the season. Total losses in surface runoff were between 1.3 and 3% of the amount applied—much higher than losses via the tile drains. It is also shown by means of a simple first‐order decay model that, when little information is available, it may be best to describe diuron depletion in runoff water as a function of cumulative rainfall during the wet season.