pH dependence of Glyphosate adsorption on soil horizons

Resumen

Pesticides bring many
problems to the environment and to human health. The first rationale
for their use is increased food production. Glyphosate
N-(phosphonomethyl)glycine (PMG) is a non-selective, post emergent,
and broad spectrum herbicide, very well known for its extensive
application in agriculture worldwide. PMG adsorption experiments
were carried out in three horizons of a Typic Haplustoll soil from
the Province of Santiago del Estero, Argentina. Adsorption isotherms
were fitted using Freundlich and Langmuir models. The affinity
constants (KF and KL), the adsorption intensity (1/n) and the
maximum surface coverage (Γmax) were obtained. The results show the
dependence of the parameters KL and Γmax with pH and also with the
different horizons and particle size.