Journal of Radioanalytical and Nuclear Chemistry

, Volume 249, Issue 2, pp 385–390

Competitive sorption between glyphosate and inorganic phosphate on clay minerals and low organic matter soils

  • H. H. HillJr.

DOI: 10.1023/A:1013222704311

Cite this article as:
Hill, H.H. Journal of Radioanalytical and Nuclear Chemistry (2001) 249: 385. doi:10.1023/A:1013222704311


Inorganic phosphate may influence the adsorption of glyphosate to soilsurface sites. It has been postulated that glyphosate sorption is dominatedby the phosphoric acid moiety, therefore, inorganic phosphate could competewith glyphosate for surface sorption sites. We examine sorption of glyphosatein low organic carbon systems where clay minerals dominate the available adsorptionsites using 32P-labeled phosphate and 14C-labeled glyphosateto track sorption. We found glyphosate sorption strongly dependent on phosphateadditions. Isotherms were generally of the L type, which is consistent witha limited number of surface sites. Most sorption on whole soils could be accountedfor by sorption observed on model clays of the same mineral type as foundin the soils.

Copyright information

© Kluwer Academic Publishers/Akadémiai Kiadó 2001

Authors and Affiliations

  • H. H. HillJr.
    • 1
  1. 1.Center for Multiphase Environmental ResearchWashington State UniversityPullmanUSA