Changes

Glyphosate can reach the soil by washing off the foliage of plants, via spray drift, by exudation from the roots of treated plants, or by the decomposition of treated plants. However, "risks of glyphosate toxicity to non-target organisms in soils are generally considered as marginal,since glyphosate is almost instantaneously inactivated by adsorption to clay minerals and cationic binding sites of the soil matrix (Piccoloetal.,1992;Dong-Meietal.,2004), while glyphosate in the soil solution is prone to rapid microbial degradation (Giesy et al., 2000)."<ref>Tsehaye Tesfamariam, S. Bott, I. Cakmak, V. Römheld, G. Neumann, "[http://stopogm.net/webfm_send/53 Glyphosate in the rhizosphere – role of waiting times and different glyphosate binding forms in soils for phytoxicity to non-target plants]," ''European Journal of Agronomy (2009), 31:126-132.</ref><ref>John P. Giesy, Stuard Dobson, and Keith R. Solomon, 2000, "[http://www.colby.edu/biology/BI402B/Giesy%20et%20al%202000.pdf Ecotoxicological Risk Assessment for Roundup Herbicide]," Rev Environ Contam Toxicol 167:35-120.</ref> In other words, glyphosate residues in the soil are not considered hazardous as it either breaks down quickly or binds to minerals that make it no longer a threat to plants. Glyphosate that biodegrades usually breaks down into carbon dioxide and ammonium (NH4+).<ref>John P. Giesy, Stuard Dobson, and Keith R. Solomon, 2000, "[http://www.colby.edu/biology/BI402B/Giesy%20et%20al%202000.pdf Ecotoxicological Risk Assessment for Roundup Herbicide]," Rev Environ Contam Toxicol 167:35-120.</ref> In an analysis of 47 studies, 50% of glyphosate broke down in the soil in time periods ranging from 1.2 days to 197.3 days. The arithmetic mean amount of time was 32 days and the geometric mean was 17 days.<ref>John P. Giesy, Stuard Dobson, and Keith R. Solomon, 2000, "[http://www.colby.edu/biology/BI402B/Giesy%20et%20al%202000.pdf Ecotoxicological Risk Assessment for Roundup Herbicide]," Rev Environ Contam Toxicol 167:35-120.</ref>

=== Glyphosate in Water ===