Glyphosate losses by runoff and its relationship with phosphorus fertilization.

REPETTI, MARÍA ROSA; MICHLIG, NICOLÁS; DEMONTE, LUISINA; CISLAGHI, ANDREA; GABIOUD, EMMANUEL; SASAL, MARÍA C.; OSZUST, JOSÉ; WILSON, MARCELO; BELDOMÉNICO, HORACIO

San Francisco

Congreso; 13th IUPAC International Congress of Pesticide Chemistry; 2014

The aim of this study was to evaluate the relationship between the application of glyphosate and phosphate fertilizer regarding their contribution to the contamination of surface water runoff. It was carried out in an Acuic Argiudol soil (Tezanos Pinto series). Four treatments were assessed on three dates of rainfall simulation after the application of fertilizer and herbicide. The soluble phosphorus in runoff water was determined by the colorimetric method of ascorbic acid. For the determination of glyphosate and AMPA a method based on the derivatization with FMOC, solid phase extraction (SPE) clean up and UHPLC-MS/MS was employed. The phosphorus fertilizer application resulted in an increased loss of glyphosate by runoff after one day of application. These results suggests the need for further study to understand the interactions and to determine appropriate moments of applications with the goal of reduce risk of contamination by runoff.