The influence of organic matter on sorption and fate of glyphosate in soil--comparing different soils and humic substances.
Soil organic matter (SOM) is generally believed not to influence the sorption of glyphosate in soil. To get a closer look on the dynamics between glyphosate and SOM, we used three approaches: I. Sorption studies with seven purified soil humic fractions showed that these could sorb glyphosate and that the aromatic content, possibly phenolic groups, seems to aid the sorption. II. Sorption studies with six whole soils and with SOM removed showed that several soil parameters including SOM are responsible for the strong sorption of glyphosate in soils. III. After an 80 day fate experiment, approximately 40% of the added glyphosate was associated with the humic and fulvic acid fractions in the sandy soils, while this was the case for only approximately 10% of the added glyphosate in the clayey soils. Glyphosate sorbed to humic substances in the natural soils seemed to be easier desorbed than glyphosate sorbed to amorphous Fe/Al-oxides.
Albers
Christian N
CN
Dept. of Geochemistry, Geological Survey of Denmark and Greenland, DK-1350 Copenhagen, Denmark. calbers@ruc.dk
Banta
Gary T
GT
Hansen
Poul Erik
PE
Jacobsen
Ole S
OS
D000327:Adsorption; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry; D006540:Herbicides / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D000097797:Glyphosate
D005998:Glycine; D006540:Herbicides; D006812:Humic Substances; D012987:Soil; D012989:Soil Pollutants; D000097797:Glyphosate