Impact of Soil Characteristics and Weed Management Practices on Glyphosate and AMPA Persistence in Field Crops Soils from the St. Lawrence Lowlands (Quebec, Canada)

The use of glyphosate-based herbicides (GBHs) in industrial agriculture has intensified the past decades, causing a growing concern about occurrence and spatial distribution glyphosate its principal metabolite, aminomethylphosphonic acid (AMPA), environment. In 2014, AMPA content was measured 45 soils from St. Lawrence Lowlands (Quebec, Canada) before seeding at harvest soybean field crops using various weed management practices with or without GBH applications. At same time, recent history agricultural soil conditions compiled for sampled sites. results study show that 91% samples contained detectable amount either AMPA, maximum values 0.47 mg·kg−1 1.16 respectively. Surprisingly, amounts were fields not treated GBHs whereas traces both detected organic crops, highlighting potential spreading and/or persistence compounds Glyphosate significantly higher clay rich exchangeable cations, such as Mg2+, K+ Ca2+, which can contribute to retention via complexation processes.