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Exposure to sulfosulfuron in agricultural drainage ditches: field monitoring and scenario‐based modelling
Author(s) -
Brown Colin D,
Dubus Igor G,
Fogg Paul,
Spirlet Marie,
Gustin Christophe
Publication year - 2004
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.876
Subject(s) - ditch , environmental science , pesticide , drainage , hydrology (agriculture) , dilution , calibration , macro , outfall , environmental engineering , ecology , geology , geotechnical engineering , computer science , programming language , statistics , physics , mathematics , biology , thermodynamics
Field monitoring and scenario‐based modelling were used to assess exposure of small ditches in the UK to the herbicide sulfosulfuron following transport via field drains. A site in central England on a high pH, clay soil was treated with sulfosulfuron, and concentrations were monitored in the single drain outfall and in the receiving ditch 1 km downstream. Drainflow in the nine months following application totalled 283 mm. Pesticide lost in the first 12.5 mm of flow was 99% of the total loading to drains (0.5% of applied). Significant dilution was observed in the receiving ditch and quantifiable residues were only detected in one sample (0.06 µg litre −1 ). The MACRO model was evaluated against the field data with minimal calibration. The parameterisation over‐estimated the importance of macropore flow at the site. As a consequence, the maximum concentration in drainflow (2.3 µg litre −1 ) and the total loading to drains (0.76 g) were over‐estimated by factors of 2.4 and 5, respectively. MACRO was then used to simulate long‐term fate of the herbicide for each of 20 environmental scenarios. Resulting estimates for concentrations of sulfosulfuron in a receiving ditch were weighted according to the prevalence of each scenario to produce a probability distribution of daily exposure. Copyright © 2004 Society of Chemical Industry