Glyphosate

 Wikipedia-Glyphosate
    I don't pretend to be an expert on Glyphosate but I try to keep up on current revelations, --and factors promoting them.  After attending a few agricultural meetings this fall several statements were thrown around about glyphosate that prompted me to look further into the subject.  Wikipedia, I find to be a fantastic source of information on about everything.  They have a lot of material on Glyphosate (click on link above).  If printed out there would be thirty five pages in 12pt type.  It shows 216 different reference sources.  The material is broken out into ten major categories: General statement, Discovery, Chemistry, Mode of Action, Uses, Formulations, Environmental Fate, Toxicity, Effects of Use, and Legal Status.  If that isn't enough reading you can further educate yourself by reading the thousands of pages contained in the 216 source documents.
Here are a few things I found worth remembering about glyphosate:
     ---First synthesized in 1950 by Swiss chemist Henry Martin.
     ---1964 Stauffer Chemical patented it as a "chelator"as it binds and remove minerals such as Ca,Mg,Mn, Cu, and Zn.  We need to keep this in mind as a potential factor related to plant nutrition  and effectiveness of the chemical itself.
     ---In 1970 Monsanto became involved, and discovered many derivatives were potential water-softening agents, and a couple had weak herbicidal activity.
     ---Monsanto's John E. Franz, working with these few derivatives, developed glyphosate as we know it, bringing it to market in 1974.
     ---A broad-spectrum systemic herbicide that is an organophosphorus compound, used to inhibit the plant enzyme, --5-enolpyruvylshikimate-3phosphate synthase.
     ---Works through the shikimate pathway.  This pathway does not exist in the mammal/humane genome, but is in plants and some other life forms.
     ---Has relatively small effect on some clover species and morning glory.
     ---Is an acid molecule so it is formulated as a salt for packaging and handling.  Different companies use different salt formulations.  Monsanto uses isopropylamine salt of glyphosate.  It should be kept in mind that different salt formulations of glyphosate, along with the adjuvants that become part of the compound applied may give different results/effectiveness .
     --- Glyphosate adsorbs strongly to soil particles, and it's residues are expected to generally be immobile in soil.  Glyphosate found in water was probably carried there on soil particles.
     --- Glyphosate is readily degraded by soil microbes, but not as readily by water or sunlight; although the stated pathway for the degradation of glyphosate is through hydrolysis. (citation #35 is a good general read for a more complete explanation)
     ---Some of the aminomethylphosphonic acid found in water bodies may be from the degradation of detergents rather than glyphosate.  They degrade in a similar manner.
     ---Anaerobic conditions release phosphorous and can also release glyphosate from sediments as well.
     ---Half life of the glyphosate molecule ranges from 2-197 days depending on soils and climate.  Colder the clime the longer it seems to take to degrade below detection level.
     ---2003 Monsanto patented glyphosate as an anti parasitic.  Glyphosate combined with other agents are used as prevention and therapy of pathogenic infections such as malaria.
     ---Health. Literature reviews have reports of human consumption of the glyphosate concentrate (not diluted) running from no adverse effect to being fatal, --depending on the person and amount consumed being among the factors.  Charges of various health issues run the gamut.  Research tends to support the concept of glyphosate being safe, --but there are caveats to that.
     Glyphosate is more than a simple herbicide.  Being a potential chelator, anti parasitic, and a herbicide raises all kinds of questions in peoples minds.  I have a better understanding of how a small grain of truth can lead people to link glyphosate with every imaginable bad thing experienced by humans.
     When glyphosate herbicide was introduced back in 1974, it cost ~$100/gal and was reported to be the discovery of the century.  After 44 years I think it is living up to that report pretty well.  Will it make 100 years? --anyones guess!  It's demise, if glyphosate does go away, will be because of its popularity.  The Roundup Ready crops are a double edge sword for the farming community.  First, they are encouraging the use of glyphosate.  This rapidly expanding market is causing alarm.  Secondly, research for new chemistry has ground to a halt do to glyphosate being so effective, versatile and inexpensive.
     I don't expect glyphosate to go away anytime soon; however, I do think that more regulation will come into play, and it's effectiveness will become less as time passes. 
     More than once I have been asked how we will continue no-tilling if glyphosate is pulled from the agricultural market.  I personally don't see that being a problem.  In the short term, there is alternative chemistry to replace glyphosate.  They will be more expensive, much harsher on the environment and less safe to use, but currently not under the public microscope.  Hopefully it will give us-Kye time to figure out how to incorporated biologicals and cover crops into our cropping system that will reduce reliance on synthetic chemicals and fertilizers.  I am of the opinion that we have to remove chem fallow from our cropping system to make this all work. Vacant ground increases weed pressure.  Our current chemical fallow has to become either green fallow or be replaced with a cash crop.