Glyphosate and phosphorus competing in soil
Phosphate is playing a particularly important role in
determining the availability of glyphosate to organisms
in soils because of shared adsorption mechanisms
and sites for phosphorus and glyphosate in soils [21,25].
Although depending on soil characteristics and other
environmental conditions, phosphorus can outcompete
glyphosate for soil sorption sites. For example, soil pH
is the most important single factor for glyphosate sorption,
which is negatively correlated with acidity [3], whereas
phosphorus adsorption in soil is not strongly determinedby soil pH [1,21]. Furthermore, different microbial species
have different mechanisms of glyphosate degradation
(either via AMPA or sarcosine), and ample presence of
glyphosate and the presence or absence of phosphorus in
the environment causes selection pressure for microbial
flora [26,27]. This complexity of the degradation and adsorption
calls for a deeper understanding of soil chemistry
and emphasizes the importance of long-term studies on
accumulation and translocation of glyphosate and its main
metabolites.