Behavior of the Non-Selective Herbicide Glyphosate in Agricultural Soil

Abstract

Glyphosate [N-phosphonomethyl]glycine is a systematic, non-selective, organophosphorus herbicide used worldwide in agriculture and industrial zones. Following its application, residues of glyphosate can threaten soil or aquatic organisms in adjacent water. In this study, we followed the degradation, stabilization, remobilization and leaching of 14 C-glyphosate in three agricultural soils in laboratory incubations and in lysimeters under field conditions. Glyphosate degradation was relatively rapid with a half-life of 14.5 days in the silt clay loam soil incubated at 20°C. Glyphosate's degradation product, Aminomethylphosphonic Acid (AMPA), represented more than 85% of residues after 80 days of laboratory incubation. Leaching of glyphosate in lysimeters of three different investigated soils under outdoor conditions was very slow, less than 1% of the initial applied amount has been detected in the leachates after 100 days of experimentation. Glyphosate rapidly formed non-extractable residues after treatment. In summary, glyphosate was removed from soil very rapidly and its leaching seems to be very slow regardless the type of treated soil. On the other hand, the contamination risk of groundwater with its metabolite AMPA at long term is probably due to the release of the non-extractable residues.

Distribution of glyphosate and aminomethylphosphonic acid (AMPA) in agricultural topsoils of the European Union

“…Here GlyBH are usually applied one (cereals and oilseeds) to three times a year (orchard crops and vines), at recommended rates between 0.72 and 2.88 kg glyphosate ha −1 per treatment, and at a maximum annual application rate of 4.32 kg glyphosate ha −1 (EFSA, 2013(EFSA, , 2015. Numerous laboratory and field studies have been performed to investigate glyphosate and/or AMPA behavior in more detail, especially their transport to the aquatic environment (Al-Rajab and Hakami, 2014;Borggaard and Gimsing, 2008;Daouk et al, 2013;Laitinen et al, 2006Laitinen et al, , 2009 indicating some recognition and concern that these substances can move towards surface waters. At the same time, glyphosate and AMPA are only sporadically detected in deep groundwater systems and at low concentrations (Battaglin et al, 2014;Horth, 2012;Poiger et al, 2017) indicating that the leaching of these compounds is generally unlikely and probably negligible.…”

An integrated approach for evaluation of groundwater quality in Korba district, Chhattisgarh using Geomatic techniques

“…Water pollution simultaneously affects the water quality and threats the economic development and social prosperity of human health (AI-Rajab and Hakami, 2014). On earth, water is available as surface water and groundwater.…”

Groundwater Quality Assessment in Jazan Region, Saudi Arabia

“…On the other hand, groundwater quality is dominant to use it as drinking water or in domestic uses and irrigations; its quality depends on different factors such as recharged water quality, rainfall, geochemical processes, and human activities 5 . Water pollution affects simultaneously the water quality and threats the economic development and social prosperity by affecting the human health 6,7 . Physico-chemical properties of groundwater are being the key tool to estimate the water quality and its suitability for drinking, irrigation, or domestic uses 8,9 .…”