Measurement and modelling of glyphosate fate compared with that of herbicides replaced as a result of the introduction of glyphosate‐resistant oilseed rape

Abstract

Because of the detection of AMPA in the deep soil layer, the replacement of both trifluralin and metazachlor with glyphosate might not contribute to decreasing environmental contamination by herbicides. PRZM may be used to evaluate and to compare other weed control strategies for herbicide-resistant as well as non-resistant crops.

Sources of aminomethylphosphonic acid (AMPA) in urban and rural catchments in Ontario, Canada: Glyphosate or phosphonates in wastewater?

“…The highest glyphosate concentrations apparently represent extreme loadings shortly after herbicide application, generally higher than concentrations reached by its degradate AMPA. Furthermore, these data are consistent with earlier interpretations that AMPA is more persistent than glyphosate and reported by Kjaer et al (2005) and Mamy et al (2008) [see interpretation below re source of AMPA]. This can explain why AMPA is found in the majority of samples, often at higher concentrations than glyphosate (e.g.…”

Analysis of glyphosate and aminomethylphosphonic acid in water, plant materials and soil

“…The most commonly used extractants for soil have been aqueous bases (0.1–1.0 M KOH or NaOH; 0.25 M NH 4 0H/0.01 M KHPO 4 ; 1.0–2.0 M of NH 4 OH) water (Table ) . Other extractants include: 10% phosphoric acid, 0.1M KH 2 PO 4 , and sodium borate buffers .…”

“…As with water and plant material analyses, FMOC‐Cl has been the most commonly used derivatizing agent in soil analyses, although indocyanine fluorescent dyes, o ‐phthalaldehyde, TFAA/TFE, HFB/TFAA, 1,2‐naphthoquinone‐4‐sulfonate, ninhydrin and ammonium sulphamate have also been used (Table ). Soil analyses had the fewest methods not requiring derivatization and all had MS detection, LC‐ICP‐MS, LC‐MS/MS and CE‐MS …”

“…For separation by HPLC, C18, C8, Aminex, –NH 2 , cation exchange and polymethacrylate resin columns have been used. HP‐5 columns, or the equivalent, have been used for GC separation.…”

Comparison of three pesticide fate models with respect to the leaching of two herbicides under field conditions in an irrigated maize cropping system

“…Therefore, numerous models have been developed for a priori assessment of the transfer of pesticides from the soil surface to groundwater after their application to an agricultural field. These pesticide fate models are extensive, economic and efficient tools to predict the fate of pesticide in addition to field and laboratory data (Herbst et al, 2005;Mamy et al, 2008). Their ability to take into account most of the major processes involved in the environmental fate of pesticides (sorption, degradation, leaching, volatilization, plant uptake and wash-off, erosion and runoff) in varying degrees of complexity makes them to be also used for pesticide registration purposes (FOCUS, 2000;Regulation EC No 1107/2009, 2009).…”