Environmental fate of glyphosate and aminomethylphosphonic acid in surface waters and soil of agricultural basins.

Virginia C. Aparicio^a,*, Eduardo De Gerónimo^a, Damián Marino^b, Jezabel Primost^b, Pedro Carriquiriborde^b, José L. Costa^a

^aInstituto Nacional de Tecnología Agropecuaria (INTA), Estación Experimental Agropecuaria Balcarce, Route 226 Km 73,5 (7620), Balcarce, Buenos Aires, Argentina.

^bCentro de Investigaciones del Medio Ambiente (CIMA – CONICET), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calle 47 y 115 s/n (1900) La Plata, Buenos Aires, Argentina.

* Virginia Carolina Aparicio: vaparicio@balcarce.inta.gov.ar; Te + 54 2266 43900

Argentinian agricultural production is fundamentally based on a technological package that combines no-till and glyphosate in the cultivation of transgenic crops. Transgenic crops (soybean, maize and cotton) occupy 23 million hectares. This means that glyphosate is the most employed herbicide in the country, where 180 to 200 million liters are applied every year.

The aim of this work is to study the environmental fate of glysophate and its major degradation product, aminomethylphosphonic acid (AMPA), in surface water and soil of agricultural basins. Sixteen agricultural sites and forty-four streams in the agricultural basins were sampled three times during 2012. The samples were analyzed by UPLC-MS/MS ESI(+/-).

In cultivated soils, glyphosate was detected in concentrations between 35 to 1502 µg Kg^-1, while AMPA concentration ranged from 299 to 2256 µg Kg^{-1. In the surface water studied, the presence of glyphosate and AMPA was detected in about 15% and 12% of the samples analyzed, respectively. In suspended particulate matter, glyphosate was found in 67% while AMPA was present in 20% of the samples. In streams sediment Glyphosate and AMPA were also detected in 66% and 88.5% of the samples respectively.}

In the present study, it was demonstrated that Glyphosate and AMPA are present in soils under agricultural activity. It was also found that in stream samples the presence of Glyphosate and AMPA is relatively more frequent in suspended particulate matter and sediment than in water.

Key words: Glyphosate; AMPA; Soil; Surface Water; Sediment.