A Debate Over Roundup (Glyphosate)

In the April issue of Horticulture, Frank Hyman reports that "soil microorganisms quickly break down glyphosate (aka Roundup) into non-threatening phosphorus and amino acids." I was a bit skeptical of the article because I'd always heard that Roundup is an extremely toxic herbicide.

Then just last week, I received the following information from fellow Oakland resident, Kelly Harvey, that indirectly challenges the article.

"Roundup's effects aren't limited to the visible above-ground plant kill; it also is a powerful killer of soil microflora. Beyond that, a resulting impact on animal and human health may await us. The Obama administration has recently approved planting 2 new Roundup Ready® crops in the US. A brief article with links to 5 short video interview clips discussing Roundup's effects by Dr. Don Huber, Purdue University Professor Emeritus of plant pathology, are found here.

Quote from Dr. Huber's video interview:

The April 2011 issue of Horticulture
featured an article that championed
the use of glyphosate (aka Roundup).

"A growing body of scientific evidence has shown that the overuse of Roundup and Glyphosate has created severe micronutrient deficiencies in the soil and plants causing an epidemic of diseases, such as Goss's Wilt on Roundup Ready® corn and Sudden Death Syndrome in Roundup Ready® soybeans."

Quote from the beginning of Dr. Huber's paper "AG Chemical and Crop Nutrient Interactions - Current Update":

AG CHEMICAL AND CROP NUTRIENT INTERACTIONS – CURRENT UPDATE

Don M. Huber, Emeritus Professor, Purdue University

ABSTRACT: Micronutrients are regulators, inhibitors and activators of physiological processes, and plants provide a primary dietary source of these elements for animals and people. Micronutrient deficiency symptoms are often indistinct (“hidden hunger”) and commonly ascribed to other causes such as drought, extreme temperatures, soil pH, etc. The sporadic nature of distinct visual symptoms, except under severe deficiency conditions, has resulted in a reluctance of many producers to remediate micronutrient deficiency. Lost yield, reduced quality, and increased disease are the unfortunate consequences of untreated micronutrient deficiency. The shift to less tillage, herbicide resistant crops and extensive application of glyphosate has significantly changed nutrient availability and plant efficiency for a number of essential plant nutrients. Some of these changes are through direct toxicity of glyphosate while others are more indirect through changes in soil organisms important for nutrient access, availability, or plant uptake.

Quote from page 2:

"Recognizing that glyphosate is a strong chelator to immobilize essential plant micronutrients provides an understanding for the various non-herbicidal and herbicidal effects of glyphosate. Glyphosate is a phloem-mobile, systemic chemical in plants that accumulates in meristematic tissues (root, shoot tip, reproductive, legume nodules) and is released into the rhizosphere through root exudation (from RR as well as non-RR plants) or mineralization of treated plant residues. Degradation of glyphosate in most soils is slow or non-existent since it is not „biodegradable‟ and is primarily by microbial co-metabolism when it does occur. Although glyphosate can be rapidly immobilized in soil (also spray tank mixtures, and plants) through chelation with various cat-ions (Ca, Mg, Cu, Fe, Mn, Ni, Zn), it is not readily degraded and can accumulate for years (in both soils and perennial plants)."

"Understand that the corporations that are pushing this on our agricultural system have only one motive, profit," Harvey wrote in a subsequent email after I pointed out the Horticulture article. "Monsanto has plenty of money to buy editorial articles that will try to undercut the science and calm people into inaction. The results are becoming catastrophic."