INTERACTION OF THE HERBICIDE GLYPHOSATE WITH COPPER IN HUMIC COMPLEXES

Glyphosate is a herbicide which is considered to be inactived in soil by bonding to clays and organic matter, possibly through metal bridges . In this paper it has been shown that copper in inner-sphere complexe s with humic Substances is complexed by the herbicide. After hydrolysi s of the humic acid fraction with water followed dy 6M HCl, the glypho sate was unable to react with copper in the humic-copper complex to fo rm a glyphosate complex probably because the copper is more strongly b ound on sites previously occupied by iron. Copyright (C) 1996 Elsevier Science Ltd