Behaviour of glyphosate and ampa in soils

Although glyphosate is a heavily applied herbicide worldwide, the risk of environmental contamination through transport mechanisms of this substance is still not well documented. This work aimed to develop a new extraction method for an exact determination of glyphosate and AMPA in different soils, to investigate the time dependent behavior of glyphosate and AMPA in soils and to investigate the influence of soil erosion processes on the dissipation of glyphosate and AMPA. The developed method covers matrix effects of the most representative agricultural soil types of Austria but can be applied for glyphosate and AMPA investigations on any kind of mineral soils. The method focuses mainly to the glyphosate adsorption by Fe-oxides and organic matter. Based on results, iron-oxides in general seem to be a key parameter for the glyphosate and AMPA adsorption in soils. The rain simulation experiments could clearly show that even a potentially high erodible soil suffers low damages, if adequate protection practices are applied, and respectively that even a potentially high adsorbing soil suffers strong erosion damages, if its structure is unfavorable at the time of application.