Journal or Publishing Institution: Journal of Environmental Science (China)
Date of Publication: 09/01/2010
Study: http://www.ncbi.nlm.nih.gov/pubmed/21174968
Author(s): Al-Rajab, A.J., and Schiavon, M.
Article Type: Peer Reviewed Study
Abstract:
Glyphosate (N-phosphonomethyl glycine) is the most used herbicide worldwide. The degradation of 14C-labeled glyphosate was studied under controlled laboratory conditions in three different agricultural soils: a silt clay loam, a clay loam and a sandy loam soil. The kinetic and intensity of glyphosate degradation varied considerably over time within the same soil and among different types of soil. Our results demonstrated that the mineralization rate of glyphosate was high at the beginning of incubation and then decreased with time until the end of the experiment. The same kinetic was observed for the water extractable residues. The degradation of glyphosate was rapid in the soil with low adsorption capacity (clay loam soil) with a short half-life of 4 days. However, the persistence of glyphosate in high adsorption capacity, soils increased, with half-live of 19 days for silt clay loam soil and 14.5 days for sandy loam soil. HPLC analyses showed that the main metabolite of glyphosate, aminomethylphosphonic acid (AMPA) was detected after three days of incubation in the extracts of all three soils. Our results suggested that the possibility of contamination of groundwater by glyphosate was high on a long-term period in soils with high adsorption capacity and low degrading activities and/or acid similar to sandy loam soil. This risk might be faster but less sustainable in soil with low adsorption capacity and high degrading activity like the clay loam soil. However, the release of non-extractable residues may increase the risk of contamination of groundwater regardless of the type of soil.
Keywords: glyphosate, N-phosphonomethyl glycine, contamination, groundwater, soil, AMPA, aminomethylphosphonic acid, mineralization, degradation, pesticides, herbicides, residues
Citation:
Al-Rajab, A.J. and Schiavon, M., 2010. Degradation of 14C-glyphosate and aminomethylphosphonic acid (AMPA) in three agricultural soils. Journal of Environmental Sciences, 22(9), pp.1374-1380.
Category:
- Environmental effects
- Pesticide use
Record ID: 39
