Sorption, desorption and mineralisation of the herbicides glyphosate and MCPA in samples from two Danish soil and subsurface profiles

• Published in: Environmental pollution (1987) 2006-05, Vol.141 (1), p.184-194
• Main Authors: Sørensen, Sebastian R., Schultz, Anne, Jacobsen, Ole S., Aamand, Jens
• Format: Article
• Language: English
• Subjects: 2-Methyl-4-chlorophenoxyacetic Acid - analysis; Adsorption; agricultural soils; Agronomy. Soil science and plant productions; Applied sciences; Biodegradation; Biodegradation, Environmental; Biological and medical sciences; Biological and physicochemical properties of pollutants. Interaction in the soil; clay soils; Denmark; desorption; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Monitoring - methods; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Geologic Sediments - analysis; Glycine - analogs & derivatives; Glycine - analysis; Glyphosate; Herbicides - analysis; MCPA (herbicide); mineralization; Minerals; Natural attenuation; Pesticides; polluted soils; Pollution; Pollution, environment geology; sandy soils; Soil - analysis; Soil and sediments pollution; Soil and water pollution; Soil Pollutants - analysis; soil pollution; Soil science; sorption; spatial distribution
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2005.07.023

The vertical distribution of the sorption, desorption and mineralisation of glyphosate and MCPA was examined in samples from two contrasting soil and subsurface profiles, obtained from a sandy agricultural site and a non-agricultural clay rich site. The highest mineralisation of [ 14C-methylen]glyphosate, with 9.3–14.7% degraded to 14CO 2 within 3 months was found in the deepest sample from the clay site. In the deeper parts of the sandy profile high sorption and low desorption of glyphosate coincided with no or minor mineralisation indicating a limited glyphosate bioavailability. MCPA was readily mineralised except in the deepest samples from both sites. The highest MCPA mineralisation was detected just below the surface layers with 72% or 44% degraded to 14CO 2 at the sandy or the clay sites, respectively. MCPA sorped to a minor extent in all samples and no indications of sorption-controlled mineralisation was revealed. None of the herbicides were mineralised under anoxic conditions. Natural attenuation potential of the herbicides glyphosate and MCPA was assessed in soil and subsurface profiles.