The glyphosate molecule grabs vital nutrients and doesn’t let them go. This process is called chelation and was actually the original property for which glyphosate was patented in 1964. It was only 10 years later that it was patented as an herbicide. When applied to crops, it deprives them of vital minerals necessary for healthy plant function ~ especially for resisting serious soil borne diseases. The importance of minerals for protecting against disease is well established. In fact, mineral availability was the single most important measurement used by several famous plant breeders to identify disease-resistant varieties.
Glyphosate annihilates beneficial soil organisms, such as Pseudomonas and Bacillus bacteria that live around the roots. Since they facilitate the uptake of plant nutrients and suppress disease-causing organisms, their untimely deaths means the plant gets even weaker and the pathogens even stronger.
The herbicide can interfere with photosynthesis, reduce water use efficiency, lower lignin damage and shorten root systems, cause plants to release important sugars, and change soil pH ~ all of which can negatively affect crop health.
Glyphosate itself is slightly toxic to plants. It also breaks down slowly in soil to form another chemical called AMPA (aminomethylphosphonic acid) which is also toxic. But even the combined toxic effects of glyphosate and AMPA are not sufficient on their own to kill plants. It has been demonstrated numerous times since 1984.
When glyphosate is applied in sterile soil, the plant may be slightly stunted, but it isn’t killed (see photo).
The actual plant assassins, according to Purdue weed scientists and others, are severe disease-causing organisms present in almost all soils. Glyphosate dramatically promotes these, which in turn overrun the weakened crops with deadly infections.
Glyphosate can also accumulate for 6-8 years inside perennial plants like alfalfa, which get sprayed over and over.
Glyphosate residues in the soil that become bound and immobilized can be reactivated by the application of phosphate fertilizers or through other methods. Potato growers in the West and Midwest, for example, have experienced severe losses from glyphosate that has been reactivated.
Glyphosate can find its way onto farmland accidentally, through drifting spray, in contaminated water, and even through chicken manure!