Everything in Agriculture is a Trade-Off

The idea of trade-offs is familiar to everyone. None of us have unlimited money, time, or energy. We make decisions every single day about how to spend our money, our time, and our energy. Do I buy the red shirt or the blue shirt? Do I watch the football game or go to the concert? Should I ride my bike to work or hope I can find a good parking place? Do I call a plumber or try and fix the sink myself? Do I want the chili or the pasta? All of these decisions have costs (and hopefully benefits); some financial, some social — and some digestive.

Similarly, farmers face production decisions almost every day. Farming is complex. Just about every decision made on a farm will send ripple effects throughout the entire system; these decisions will influence the cost/benefit ratio of many future decisions. This complexity makes it difficult to make rapid changes, and is a major reason why many farmers tend to be pretty conservative in their farming decisions. Even if a farmer wants to try something new (a new technology, or a new crop, for example), that option may be precluded by decisions that were made last year, or even many years ago.

Weeds are a fact of life for farmers around the world, and weeds influence many of the decisions farmers make, either directly or indirectly. If we simply ignored weeds, we could expect world food production to decline by 20 to 40 percent. Sure, a farmer could decide to do nothing about the weeds. That would be a trade-off; letting the weeds grow will reduce crop yields. It is almost always going to be better to do something to manage weeds than to lose a huge percentage of the crop. But now the farmer must decide what to do to control the weeds. Remove them by hand? Till them? Burn them? Alter the crop planting date to disfavor the weeds? Rotate crops to help keep the weeds from building up over time? Harvest the crop early to avoid weed seed production? Spray a herbicide? Which herbicide? On every farm I know of, farmers don’t just just choose one of these things, but a combination of several to many practices.

Over the last 30 years, one of the most common choices made by farmers around the world has been to include the herbicide glyphosate (commonly known as Roundup) in their weed management program. That choice has placed glyphosate in the news again. A paper from Charles Benbrook declares that nearly 19 billion pounds of glyphosate have been applied worldwide since 1974, and that it has become “the most widely applied pesticide” in history. It is difficult to argue that the increase in glyphosate use since its discovery has been pretty remarkable. And to be honest, such a dramatic increase in any single herbicide is a somewhat troubling trend.

“Farmers should stop using so much glyphosate.”

I tend to agree that farmers should stop using so much glyphosate. It is a reasonable request, at least from a big-picture perspective. Such heavy reliance on any single pesticide is probably not a good thing. But let’s zoom in to the farmer perspective. The image below is from a children’s book about how to make decisions. “Knowing how to make decisions involves understanding the decision making process.” There are reasons that farmers use so much glyphosate, and if we are serious about wanting them to change, we need to understand their decision making process. If farmers stopped using glyphosate, weeds wouldn’t just stop growing, so something else must be done to control them. There will be costs to that decision.

I page from a children's book, explaining the decision making process.

A big decision is easier to make when a person knows what to do. Knowing how to make a big decision involves understanding the decision making process.

Some of the costs of not using glyphosate would be financial. My own research has shown that glyphosate use in conjunction with a glyphosate resistant crop has significantly boosted net economic returns. Removing this option, then, would reduce the economic viability of many farming operations, at least under current farm policy. How would you respond if someone asked you to take a 5 to 20% cut in pay? If we want farmers to make decisions that will negatively impact their own livelihood, then we need to figure out a financial incentive to make that happen. How much are we willing to pay to help farmers reduce their use of this herbicide?

There will be social costs to reducing glyphosate use, too. At least for some crops, farmers would have to miss more of their children’s baseball and softball games because without glyphosate, weed control can become much more complex, labor intensive, and time consuming. The well-being of farmers is a key indicator of agricultural sustainability, and a major tenet of the agroecology movement. One reason many farmers have adopted this herbicide in the first place is because it has bettered their lives. Asking them to reverse those gains shouldn’t be taken lightly.

Data from Carlson et al. (2013).

Glyphosate use in glyphosate-resistant crops has had a dramatic impact on farmers. This figure shows the number of farmers reporting weeds as their worst production issue in the Red River Valley of North Dakota and Minnesota before and after adoption of glyphosate-resistant sugarbeet.


And what about the environmental costs of reducing glyphosate use? One study estimates that using glyphosate herbicide in conjunction with glyphosate-resistant corn and soybean have prevented 41 billion lbs of CO2 from being released into the atmosphere between 1996 to 2013. Adoption of glyphosate-resistant soybean was recently estimated to have increased soil conservation tillage practices by 10, an notill adoption by 20%.These practices help reduce soil erosion, and the many environmental problems associated with soil erosion. Is a reduction in glyphosate worth an increase in erosion and worsening climate change? I acknowledge this trade-off is far too simplistic, as there are ways to mitigate these impacts. But those options have costs also.

Because glyphosate breaks down quickly in the soil, farmers who spray glyphosate can rotate to any other crop the following year (or even in the same year). This makes farm management more flexible, and farmers can respond more easily to market changes. It also allows farmers to more easily diversify their crop rotation, which is one reason glyphosate is commonly used in diversified cropping systems. Conversely, many other herbicides (that would almost certainly increase if glyphosate use ceased) have substantial crop rotation restrictions. For example, spraying atrazine, nicosulfuron, or acetochlor (herbicides commonly used in conventional corn) will prevent planting many crops for 2 cropping seasons because they are so persistent. Soybean herbicide restrictions can be even greater; apraying imazethapyr precludes planting some crops for 40 months after application. If we truly want to encourage crop diversity, then glyphosate use can be a powerful tool in allowing those diverse crop rotations while still managing weeds.

I’m a firm believer that public interest in our food supply is a very good thing. And I also acknowledge that modern agriculture has problems. The public has a right to be engaged in the process of farming, if farming decisions affect public resources. But if we, as a community of food eaters, want large-scale changes in the way our food is grown, yelling and screaming and writing articles and editorials isn’t going to work. If we want to change the way farmers run their business, then we damn-well better engage farmers to find out why they make the decisions they do. We need to understand the trade-offs involved if we are to understand how to best implement the changes we want.


  1. I have asked what people think would happen if glyphosate went away. I think they believe that unicorns come through and eat the weeds or something. Have yet to see any image of what that would really look like to them.

    It would be great to hear from one of these editorial writers if they plan to get out and start hand-weeding for farmers.

    1. I understand glyphosate to be very low toxicity in relation to its high effectivity.
      Do we have the tools we need to keep weed resistance at an acceptable level?

    2. I grow food without chemical weeding and it works. It’s not magic. It takes technique and some work.

  2. Excellent post. When people are opposing glyphosate and ht traits, they are not necessarily solving a problem, they are essentially only advocating eliminating one solution to the problem of weed control. Glyphosate paired with glyphosate tolerant genetics has been a solution to the age-old problem of weed competition that has many advantages economically, environmentally and in other ways to the range of solutions that preceded it.

    You put it in the proper perspective, the issue is not that one method is right and one wrong, good or bad, it is more that each option comes with its own unique set of benefits and risks and that choosing one course of action comes with tradeoffs. I don’t think the ge and glyphosate skeptics have really thought about what the tradeoffs would be in a post glyphosate world. Nor do I believe they have any concept of the ag chemical use that preceded glyphosate and ht genetics.

    I think part of what drives public opinion is the perception that ht genetics were forced upon farmers. The public makes the logical, though simplistic and mostly wrong conclusion (particularly now that glyphosate is public domain), that ht is a diabolical scheme to sell ag chemicals. People do not consider that those same companies that supply the chemicals compatible with ht genetics would also be happy to sell the chemicals that would be applied in the absences of ht genetics. Secondly, the public makes the logical inference that, “you mean, the genetics of this crop allow farmers to apply herbicides while the crop is growing? Oh my god, that means that there is no biological constraint to the amount of herbicides a farmer applies and how often they apply it. If that is the case, the whole point of ht traits must be to allow and even encourage farmers to apply herbicides gratuitously” which leads to the hyperbole that crops are slathered, drenched, etc. in herbicides. It would come as a surprise, I think to most, that herbicide use with ht is no more intense than herbicide use without it.

  3. Great article! I constantly try to explain how complex agricultural decisions are, I struggle to understand the difference in farming methods only 100 kms from our own farm never mind grasping every angle on farms across the globe. Banning any technology would have to be weighed against the impact of using the alternative technology or practice. The first step is to stop and understand why farmers do what they do.

  4. Know the true facts, and then make trade offs with all the knowledge on the table. Glyphosate causes tumors in rats, and probably contributes to the rises in pancreatic and thyroid cancers since the mid-1990s. This is from Monsanto’s own data from their two year rat feeding study ending in 1990, using 240 rats. Those exposed to glyphosate in diet had far more pancreatic and thyroid tumors. These cancers have increased in humans. So if you want to rely on chemical weeding, is it an acceptable trade-off to cause the deaths of a few thousand American people? If so, then fine. If not then we need to change something.

  5. Ah, ole Sage is at it yet again with reposting this 26-year old study that did not show what he says it does at all. It has not been replicated for all this time because the results were shown to have very little effect on rats, and of a different nature entirely. The study addressed adenomas, not cancerous tumors. But why bother with facts, when twisting and misinterpreting data is much more fun? Typical activist BS.
    Glyphosate is far better for farmers and the environment than what they used before genetically engineered crops became available.

    1. I would quote “GE Farmer” upon himself: “Why bother with facts?” Especially when only lies can serve your agenda.

      See, the study did show thyroid c cell carcinomas — 5 in the exposed groups and 0 in the control group. That would be considered “cancerous” by anyone’s definition.

      Secondly, adenomas to develop into carcinomas at some rate so elevated levels from glyphosate exposure would be concerning to anyone who thinks clearly and without bias, as it would elevate the overall cancer rates as well.

      And come to think of it, we do see elevated cancer rates in humans from the time frame of widespread introduction of glyphosate into the food supply, in the two organs that glyphosate shows an effect in the lab rat study — pancreatic and thyroid.

      Is this of concern to many people? Yes, it is.

    2. Why didn’t Monsanto consider this data to be of import enough to replicate or modify the experiment and find out for sure? Perhaps it’s because the 1991 EPA memo “took care” of this inconvenient data and paved the way for the introduction of the planned mega-product (Roundup Ready GMO crops) around 1996. Who can say for sure? Not i, unless i see the memos and notes like we have in regard to PCBs from the 1960s and 1970s, but i can surmise fairly well what’s likely, based on the evidence.

      I know you don’t like me, but please try to be accurate and stick to the facts as you admonish me to do. The optics are pretty bad here. For you, i mean. I’m just a carpenter. Who are you?

  6. Still, wondering, is it a fair tradeoff that thousands of people die from pancreatic and thyroid cancer so that Monsanto can make more profits?

      1. No, of course not, but that’s a false choice, and thousands starve in today’s world as it stands now. Malnutrition is primarily a problem of lack of access to resources, not due to lack of GMO technology. And now, will you answer my question or are you here to hear your own voice?

        1. So if we decide to stop using roundup ready crops drop yeilds by 30 percent…. With a growing world population and limiting resources, causing the price of these commodities to increase… Not only limiting the amount of food produced but the people that can afford that food…I am not saying your cancer claim was no legs, but maybe one and a peg leg, lots of other factors affecting the cancer rates, so I saying if we are saving 100 of thousands a year and we are losing less than one percent of that directly because of roundup.. You do the math!

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