Glyphosate, AMPA, and metsulfuron-methyl retention in the main horizons of a Typic Argiudoll

Abstract

Retention is one of the processes controlling the behavior and fate of pesticides in soil. The objective of this work was to evaluate the adsorption and desorption of glyphosate, AMPA, and metsulfuron-methyl in the main horizons of a Typic Argiudoll destined for agricultural use. For this purpose, the batch equilibrium method was used at a range of concentrations for each compound. Desorption was performed in three consecutive steps after the adsorption experiment. The results obtained showed strong adsorption of glyphosate and AMPA in the three horizons, following the trend B > A > C, with weak desorption. Metsulfuron-methyl, on the other hand, showed weak adsorption in the three horizons, following the trend A > B > C, with relevant desorption. Our results allow us to identify metsulfuron-methyl as the compound that poses the greatest environmental risk in terms of the potential contamination of other areas and groundwater. However, despite their strong adsorption and weak desorption, glyphosate and AMPA also represent potential contaminants of other environmental matrices.

Keywords:

• Adsorption
• desorption
• Freundlich model
• soil profile
• pesticides

Acknowledgments

Eliana Gonzalo Mayoral holds a scholarship from CONICET (Consejo Nacional de Investigaciones Científicas y Técnicas). This publication is part of her doctoral thesis in Agricultural Sciences at the Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata. The authors would like to thank A.D. Schneider and D.R. Saldanha at LMMM UFSM (Laboratório de Magnetismo e Materiais Magnéticos da Universidade Federal de Santa Maria) for the support during X-ray diffraction experiments, and G.L. Schaefer, A. Mosca, N. Gulle, L. Alonso and L. Moro for their help. We also thank the Asociación de Universidades Grupo Montevideo (AUGM) for the mobility grant assigned to the first author to carry out a stay in UFSM Brazil and allow the production of some of the data used in this work, and INTA (Instituto Nacional de Tecnología Agorpecuaria) for providing the necessary infrastructure to carry out these experiments.

Availability of data

The data that support the findings of this study are available from the corresponding author, [E.G.M.], upon reasonable request.

Declaration of interest statement

The authors report there are no competing interests to declare.

Additional information

Funding

Funding for this study was provided by PN Suelo 1134044 (INTA) and PICT 2014-1462 (FONCyT- Fondo para la Investigación Científica y Tecnológica).