Glyphosate dispersion, degradation, and aquifer contamination in vineyards and wheat fields in the Po Valley, Italy

Daniele la Cecilia; Fiona H M Tang; Nicholas V Coleman; Chris Conoley; R Willem Vervoort; Federico Maggi

doi:10.1016/j.watres.2018.09.008

Glyphosate dispersion, degradation, and aquifer contamination in vineyards and wheat fields in the Po Valley, Italy

Water Res. 2018 Dec 1:146:37-54. doi: 10.1016/j.watres.2018.09.008. Epub 2018 Sep 8.

Authors

Daniele la Cecilia¹, Fiona H M Tang², Nicholas V Coleman³, Chris Conoley⁴, R Willem Vervoort³, Federico Maggi²

Affiliations

¹ Laboratory for Environmental Engineering, School of Civil Engineering, The University of Sydney, Bld. J05, 2006, Sydney, NSW, Australia. Electronic address: daniele.lacecilia@sydney.edu.au.
² Laboratory for Environmental Engineering, School of Civil Engineering, The University of Sydney, Bld. J05, 2006, Sydney, NSW, Australia.
³ School of Life and Environmental Sciences, The University of Sydney, Bld. G08, 2006, Sydney, NSW, Australia.
⁴ Environmental Earth Sciences International Pty Ltd, 82-84, Dickson Ave, Artarmon, NSW, Australia.

PMID: 30223108
DOI: 10.1016/j.watres.2018.09.008

Abstract

Biodegradation of glyphosate (GLP) and its metabolite aminomethylphosphonic acid (AMPA) was numerically assessed for a vineyard and a wheat field in the Po Valley, Italy. Calculation of the Hazard Quotient suggested that GLP and AMPA can pose a risk of aquifer contamination in the top 1.5 m depth within 50 years of GLP use. Numerical results relative to soil GLP and AMPA concentrations, and GLP age, half life, and turnover time show that GLP was equivalently removed through hydrolysis and oxidation, but the latter produced AMPA. Biodegradation processes in the root zone removed more than 90% of applied GLP and more than 23% of the produced AMPA between two consecutive applications. Doubling organic carbon availability enhanced GLP and AMPA biodegradation, especially GLP hydrolysis to sarcosine. This work highlights that GLP and AMPA removal is controlled by soil water dynamics that depend on ecohydrological boundary conditions, and by carbon sources availability to biodegraders.

Keywords: AMPA; Biodegradation; Contaminant ecohydrology; Glyphosate; Michaelis-menten-monod; Pesticide.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Farms
Glycine / analogs & derivatives
Glyphosate
Groundwater*
Herbicides*
Italy
Triticum

Substances

Herbicides
Glycine