Fate of the organophosphate herbicide glyphosate in arable soils and its relationship to soil phosphorus status

Summary

Glyphosate is one of the world's most widely used herbicides. This study was undertaken to unravel the factors affecting its movement, sorption, persistence and leachability in different Finnish soils to create a sound basis for risk assessment.
Field experiments indicated rather long persistence of glyphosate in Finnsih soils low in soil test P.
The key soil factors promoting the persistence and reducing the leaching of glyphosate and its metabolite aminomethylphosphonic acid appeared to be low P status and high Al and Fe oxide contents in soil, leading to low degree of P saturation and to reduced biodegradability as result of strong sorption.