Long-Term Glyphosate Use Effect on Wheat

Critics of conventional farming often decry the use of herbicides.  Herbicides that are not organic anyway.  That’s all fine and dandy, but the problem I see with the arguments some people present is they contain no substance.  Take a look at this Facebook post on the Kellogg’s Facebook page that I shared to my blog page to get other’s response on.

After seeing this photo posted by someone on the Kellogg's facebook page I had to share myself and point out what's wrong with it.

After seeing this photo posted by someone on the Kellogg’s facebook page I had to share myself and point out what’s wrong with it.

We use glyphosate on our farm.  Glyphosate is the active ingredient in Roundup.  We grow wheat.  I have never seen our wheat germinate as poorly as the right half of that picture shows.  And not over a wide area like a whole field that has a history of Roundup treatments.  There could be any number of factors that contributed to the appearance of that wheat on the right — poor seed-to-soil contact at planting (important to get nutrients, water, etc to the seed), soil compaction (important to alleviate so the cotyledon & root can move through the soil), drought, pests, or a host of other problems.  But I’m positive glyphosate is not the cause.  I am positive based on lots of first-hand experience and education.

Currently there are no glyphosate-tolerant varieties of wheat on the market.  So not only do farmers from all over grow fine wheat crops on soils where Roundup has been applied, the wheat isn’t even resistant to the herbicide in question! Let me explain how wheat and glyphosate both work on my farm.

Let’s say I want to plant a crop that isn’t glyphosate-tolerant, but I want to use it as a burndown treatment (that’s what we do in spring to get rid of weeds and make the field ready for a crop) to knock out weeds that have grown in a field between cash crops.  How long would I have to wait before I plant my crop?  My answer can be found on the Roundup FAQ page.

Annual Weeds: When applying Roundup WeatherMAX® under good growing conditions, seeding may start 4-6 hours later! For all other Roundup brand agricultural herbicides (or under stressful weather conditions), you must wait a minimum of 24 hours before seeding or working the land.

Perennial Weeds: With all Roundup brand agricultural herbicides we recommend that you wait 72 hours under good growing conditions before seeding or tillage. If it’s cool and cloudy wait an extra day before tillage so the herbicide has sufficient time to translocate to the roots of the weed.

There are significant amounts of research and development that goes into these label directions and although those are from an FAQ, they restate what is on the label. A label that is registered with the EPA and the USDA.

Don’t you think wheat farmers all over the United states would be pretty vocal if such a problem existed, or at least quit planting wheat in fields where glyphosate has been used to control weeds in the past?

A photo from June 2012 of our wheat and corn in adjacent fields.  The wheat has changed color because it's nearly mature and ready for harvest.

A photo from June 2012 of our wheat and corn in adjacent fields.

We plant wheat and corn side-by-side at times, just like the photo above shows we did in 2012. This soil probably receives a glyphosate treatment at least once a year depending on the crop. The wheat has changed color because it’s nearly mature and ready for harvest.

Now I suppose you have no reason to believe what I say anymore than that Facebook photo.  But I do hope I’ve been able to build a level of trust on this page by being honest and trying to show you why we use certain agronomic practices on our land. We have a lot of things to consider, even worry about, as we grow crops but the long-term effects of glyphosate is one I feel very comfortable with.

It would be easy to mislead people who may not know a lot about farming practices. And these well-meaning people could get worked up enough to share it with other people wanting to help a farmer like me out. I just hope they are also willing to listen to someone with first-hand experience too.

What do you think about the photo I shared?  Leave a comment below and let’s discuss!

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  1. Great post Brian…I have mentioned in the past there are Opinions of Intellect (can be swayed by logical argument) and Opinions of Emotion (no opportunity to change).

    This seems to be quite an emotional topic. Presenting a logical argument is the right path and may be frustrating.

    Thanks for growing my food!

  2. It is my understanding that glyphosate is an emergent herbicide, killing only weeds that have already spouted. Are weeds that sprout after you have planted your crop a problem? If so, what do you do about that? Lou

    1. You are correct. Glyphosate is a contact killer that offers no residuals effects on weeds that appear after application. A standard practice on farms like mine would be to come in with a glyphosate and 2,4-D mix pre-plant to knock out weeds that emerged in early spring. Depending on weed pressure we will make one or two more applications of herbicide during the growing season. Getting your cash crop to the canopy stage greatly reduces weed pressure because the crop is now capturing most of the sunlight. Canopy is when the space between rows is filled by the plants as they grow larger.

      Many weeds will germinate all season long, not just in spring. Weed seeds can lay dormant in soil for years at a time.

  3. Good explanation. I wish the normal population would give farmer’s more credit on their decisions. Why would farmers want to produce a crop that isn’t safe? No reason I can think of.
    Same issues with livestock production. Why would a farmer mistreat an animal when you have invested a great deal of time and money to produce a healthy animal? Lots of Emotional Opinions as D. Scott said above.

  4. Not having any information about the two photos of wheat (even if they are from the same season), I would say the photo on the right looks more like cold damage or winter kill, as evidenced by the dessicated appearance of the plants, than emergence or glyphosate damage. The only glyphosate damage I have seen on wheat is stunting and leaf lesions caused by drift when nearby fields were burned down during windy conditions for no-till corn planting in the spring.

  5. Sadly it looks like the Facebook thread is gone. Since it was a re-share on Kellog’s page that is also deleted, it looks like the re-shared post with conversation is deleted too. :( That was a really good conversation too. Some good references in there I wish I could get to.

  6. Brian, This is an awesome post! We grow wheat for rotation behind our cotton every two to three years. We have only seen wheat like the photo on the right when we are in a drought. It is my understanding that Glyphosate actually neutralizes when it hits dust. We have seen this first hand when we try to spray and it has been too long between rains. There will be too much dust on the weeds and they won’t die. Of course, they are already harder to kill during a drought situation anyway. Once the glyphosate has neutralized, I also understand that it literally goes inert. Once something has gone inert, and you go back to 9th grade chemistry, an inert product will never again react with anything. That’s the information we use on our cotton farms and have always had excellent results with glyphosate no matter the situation.

  7. “Don’t you think wheat farmers all over the United states would be pretty vocal if such a problem existed, or at least quit planting wheat in fields where glyphosate has been used to control weeds in the past?” Exacly what I say, thanks Brian,good post.

    1. I think that idea seems to be left out of a lot of conversations. Just the simple fact that a lot of people or doing X doesn’t mean it’s right, but it’s worth taking a deeper look don’t you think? Here’s a post hot off the press where a consumer spent a great deal of time talking to farmers, and one of them was me.


  8. Great post Brian and excellent photos. It not only proves the point it is absolutely beautiful. Thanks.

  9. I think the issue is: what are the long term effects, and under what conditions. Surely all fields look like your photos in the early years, or, as you say, the product would not be used. But then, is there a point, varying in some way in the number of years, where the negative effects become visible. I would expect that such negative affects would at first be seen in only a small number of cases. I see that the article includes 23 references from what look to be peer reviewed sources, and you haven’t addressed that. There is also a logic in their arguments that you have not addressed. They say that Glyphosate “doesn’t usually destroy weeds directly,” but rather is “a broad-spectrum chelator” that “binds with nutrients, depriving plants of the minerals needed to help them defend against disease.” This then suggests a logic in which Glyphosate attacks the ability of plants to absorb nutrients. And does that then apply to, for example, soil microbes, fostering leaching? (I’m glad to find this article, as a farmer mentioned some of this to me, but I hadn’t found online sources.) Dan Huber (in several sources) is on YouTube and seems to focus on farm self interests. He raised these issues in a letter to Vilsack or someone a few years ago. Surely to keep buying the same fertilizer (at higher costs) but then get less bang for the buck would be disastrous for farmers (or to buy more and more to get the same results, etc.).

    So, have all of the readers here read the label to RoundUp, as we’re often told to do? Last time I read it, it was 130 pages of tiny print, in an obnoxious red font, and I certainly agree that it’s very well researched in terms of issues that Monsanto knows about (but do farmers), and legally. So if the research proves true, will Monsanto be liable for farmers who’s soil has lost the ability to hold on to fertilizer (if that’s a key issue, as I’ve heard?). Or has that already been thoroughly dealt with (disclaimed) on the label.

    I think my biggest worry is that the technology is a “megatechnics,” (Lewis Mumford) which, by nature, is authoritarian, a system that has made farmers increasingly dependent upon a powerful industrial-complex. Meanwhile, Monsanto seems to be, by far, (ie. 2009) the greatest spender of political influence money of any corp. in the input-complex. (more than 4 x bigger than the second runner up). For me, that issue comes first, leading then to the issues of the cost of production, as in the issues discussed here.

    1. Hopefully I can address some of your points, Brad.

      My photo is not from the early years. That photo of a healthy wheat crop comes from a field that sees an application of glyphosate at least once per year. Glyphosate is a contact killer, meaning is has no residual herbicidal effect in the soil on plants that have yet to emerge. It’s got to hit green tissue to be effective.

      The chelation issue has to do with the possibility that glyphosate, after being processed by a corn plant especially, may have some effect of binding nutrients in the soil. I think the jury is still out on this topic. From a practical farmer perspective US farms continually grow more grain with less inputs year after year. Not only is that environmentally responsible, but it’s also good for the farmer’s pocketbook.

      Dr. Huber has become a controversial figure since writing that letter. I would say his thoughts are worth noting, but after reading responses from his own colleagues at my alma mater Purdue, and many other scientific sources, I would say his claims are questionable. Biofortified has a great post on this called “Extraordinary Claims Require Extraordinary Evidence.” I wrote a post with my personal thoughts as well when the letter came out. Purdue’s response can be found here.

      Labels for all pesticides are generally very long. Why is this? Well for one thing there are many uses for the same product and that product won’t be used the same way in all situations. A chemical that can be used on more than one crop will have a set of instructions for each crop. There will be instructions for spraying with a pump up sprayer around your house to covering hundreds of acres on a farm. Tank mixes with another herbicide, insecticide, fungicide, or fertilizer or combination thereof would require yet another set of instructions for proper and safe use. Long story short, the reason there isn’t much new chemistry in recent decades is because it takes a great deal of money and time to put the work in to make that label and cover all your bases. You never know what someone might do, so the explanation of proper use is by nature, exhaustive. For example when I worked at a job in town we kept the store looking good from the outside by killing weeds around the building. My co-worker went out one night with a hand sprayer to treat weeds behind the building. Instead of reading the label and putting in a few ounces per gallon of water he put a whole quart of Roundup in a 2 gallon sprayer and filled the rest with diesel fuel. Let me tell you those weeds died. In fact, they turned black by the next day. But that was an excessively expensive mix of stuff, and you certainly couldn’t find it on any label.

    2. Perhaps read and write less, comprehend more. You’re getting your issues all pretzeled up. The use of glyphosate has nothing to do with fertilizers, for instance.

  10. If it wasn’t so serious, it would be almost comical. I would have thought a firm like Kellogg’s would know better than to scaremonger in this way.

    1. It’s not a post by Kellogg’s, but rather a something posted by an individual on their page. That page has seen a lot of similar posts since some people thought they were poorly representing the Kashi brand of cereal as natural. Kashi was never organic to my knowledge, but some thought their ads were misleading.

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