Herbaceous or Salix miyabeana ‘SX64’ narrow buffer strips as a means to minimize glyphosate and aminomethylphosphonic acid leaching from row crop fields Louise Hénault-Ethier a, ⁎, Marc Lucotte a , Matthieu Moingt a , Serge Paquet a , Sophie Maccario a , Élise Smedbol a , Marcelo Pedrosa Gomes b , Laurent Lepage c , Philippe Juneau b , Michel Labrecque d a Université du Québec à Montréal, GEOTOP & Institut des Sciences de l'environnement, CP 8888, Succ. Centre-Ville, Montréal, Québec H3C 3P8, Canada b Université du Québec à Montréal, Département des Sciences Biologiques, TOXEN – GRIL, Institut des Sciences de l'environnement, CP 8888, Succ. Centre-Ville, Montréal, Québec H3C 3P8, Canada c Université du Québec à Montréal, Institut des Sciences de l'Environnement, CP 8888, Succ. Centre-Ville, Montréal, Québec H3C 3P8, Canada d Université de Montréal, Institut de recherche en biologie végétale, 4101 Sherbrooke Est, Montréal, Québec H1X 2B2, Canada HIGHLIGHTS • Aqueous glyphosate transport across narrow riparian buffer strips (RBS) is lit- tle studied. • RBS efficiency for reducing glyphosate and AMPA leaching to streams is limit- ed. • Spontaneous herbaceous vegetation RBS is as efficient as Salix plantations. • Glyphosate, present in runoff after a year, suggest unexpected persistence. • RBS may favor glyphosate infiltration up to 70 cm depth. GRAPHICAL ABSTRACT abstract article info Article history: Received 7 October 2016 Received in revised form 7 April 2017 Accepted 13 April 2017 Available online 12 May 2017 Editor: D. Barcelo Glyphosate is the most widely used herbicide worldwide and is now frequently detected in surface waters of ag- ricultural regions, notably in Quebec (Canada). Numerous legislations require vegetated riparian buffer strips (RBS) along agricultural streams. Quebec policy requires 3-meter-wide RBS. The present study evaluates the ef- ficiency of narrow herbaceous and low- or high-density (33,333 and 55,556 stumps/ha) willow, Salix miyabeana ‘SX64’, RBS, to minimize leaching of glyphosate and its main degradation product (AMPA) from agricultural fields to streams. Our study compared triplicate treatments of herbaceous and willow-planted RBS located in an organic-rich soil at Boisbriand (BB) and in a mineral soil at Saint-Roch-de-l'Achigan (SR). Runoff water was sam- pled with surface collectors and interstitial water was collected with 35 cm or 70 cm tension lysimeters. Potential efficiency of the RBS is reported as the percent reduction between edge-of-field and edge-of-stream concentra- tions in runoff and interstitial waters. Neither glyphosate nor AMPA in runoff were significantly intercepted by the RBS. After field herbicide spraying, glyphosate measured in SR surface soils (0–20 cm) was on average 210 μg·kg -1 dw (range from undetected to ≤ 317 μg·kg -1 dw). Glyphosate was found to be persistent and its infil- tration towards groundwater may be enhanced by the RBS. Contrary to runoff trends, soil glyphosate was Keywords: Fast-growing willows Glyphosate resistant corn and soy Runoff Interstitial waters Agricultural soils Science of the Total Environment 598 (2017) 1177–1186 Abbreviations: RBS, riparian buffer strips; BB, Boisbriand; SR, Saint-Roch-de-l'Achigan; GR, genetically resistant; AMPA, aminomethyl phosphonic acid; S, soy; M, maize; DOC, dissolved organic carbon; CF, close to the field-edge; CR, close to the stream-edge; GC-ECD, gas chromatograph equipped with an electron capture detector; aq, aqueous; TSS, total suspended solids; P, pesticide. ⁎ Corresponding author at: GEOTOP & Institut des Sciences de l'environnement, Université du Québec à Montréal, CP 8888, Succ. Centre-Ville, Montréal, Québec H3C 3P8, Canada. E-mail addresses: louisehenaultethier@hotmail.com (L. Hénault-Ethier), michel.labrecque@umontreal.ca (M. Labrecque). http://dx.doi.org/10.1016/j.scitotenv.2017.04.104 0048-9697/© 2017 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv