ORIGINAL ABSTRACT

Transgenic glyphosate-resistant crops (GRCs) have been commercialized and grown extensively in the Western Hemisphere and, to a lesser extent, elsewhere. GRCs have generally become dominant in those countries where they have been approved for growing. Potential effects of glyphosate on soil and water are minimal, compared the effects of the herbicides that are replaced when GRCs are adopted. Perhaps the most important indirect effect is that GRCs crops promote the adoption of reduced- or no-tillage agriculture, resulting in a significant reduction in soil erosion and water contamination. Glyphosate and its degradation product, aminomethylphosphonate (AMPA), residues are not usually detected in high levels in ground or surface water in areas where glyphosate is used extensively. Furthermore, both glyphosate and AMPA are considered to be much more toxicologically and environmentally benign than most of the herbicides replaced by glyphosate.