How to make corn more sustainable? Grow less of it.

I wrote a story about the future of crop science that's printed in the June issue of Popular Science. When I was doing the research, the big question I wanted to ask was this: "How can we take the most important agricultural crops and make them more sustainable and adapted to climate change?"

I suppose there are a lot of ways to define "most important", but I went with the crops that feed the most people. Wheat, rice, and corn account for more than 50% of all the calories consumed on Earth. So those are the plants I looked at. And that's where I ran into a surprise. Scientists had some really interesting, concrete suggestions for how to prepare wheat and rice for a changing world. But with corn, they took a different tack. Basically, the scientists said the best thing to do with corn was use less corn.

Large yields and high calorie content have made corn the most popular and most heavily subsidized crop in America. That’s an increasingly urgent problem. In 2010, corn production consumed nine million tons of fertilizer and led to greenhouse-gas emissions equivalent to 42 million tons of CO2—and corn isn’t even something we can easily eat. “The digestibility of unprocessed corn to humans isn’t very high,” says Jerry Hatfield, a plant physiologist with the USDA. “We have to put it through processing of some sort, whether that happens in a factory or an animal.” Set those problems aside, and a deal-breaker remains: modern corn is more sensitive to heat than any other major crop, and attempts to create drought- and heat-resistant corn through genetic modification are still unproven. A recent study found that a 3.6°F increase in global temperatures could make corn prices twice as volatile.

All of which is why many experts advocate replacing corn with a portfolio of hardier, more nutritious and more efficient food sources. Wheat production generates less than half the fossil-fuel emissions of corn and returns 63 percent more protein. Other crops actually give back to the land. Chickpeas and peanuts contain twice as much protein as corn, and they increase the nutrient content of soil.

Read about the other suggestions for adapting major food crops to climate change.

Image via WATTAgNet


  1. Plus, feeding corn to cows is really bad for them.  They can’t digest it easily, so we have to feed them lots of antibiotics to keep them healthy.

    If you really want to understand the evils of corn, read the first section of The Omnivore’s Dilemma.  You will come away with it with a much deeper understanding of the way corn fits into America’s food system, and the ways in which that is profoundly broken.

  2. I vote for chickpeas (garbanzo). They are great food and can be used is so many ways (they make a great flour).

    1.  Ugh, I beg to differ (on the “make great flour” part).  My wife is intolerant to wheat so we’ve tried all the various substitutes, and garbanzo flour is without a doubt the most taste invasive one… that is, it isn’t easily masked by other ingredients.   I love me some falafel and hummus, but when you are trying to make cookies, pasta or bread that is definitely NOT the taste you’re going for.

      Rice flour is where it’s at.

    1. That’s the interesting thing. From a global perspective, we have to think in terms of, ‘how do we generate as many nutritionally balanced calories as possible, with as few resources as possible’ (over simplifying). It’s only in the Western world, and even then only in recent history, that we’ve had to start putting so many resources into eating somewhat more inefficiently so not to over-fatten ourselves.  

  3. “corn isn’t even something we can easily eat”

    I keep hearing people say that, and I understand that it’s meant to indict the corn-industrial-complex, cow feedlots, HFCS, etc.  But… the average Mexican eats 120 kg of tortillas in a year.  Rural Americans used to eat cornbread for multiple meals per day. Are tortillas, tamales, cornbread and pozole somehow worse or ‘less natural’ than wheat bread?

    1. I believe the modern version of the corn plant, the kind being grown in huge numbers, is quite different from the natural corn plant Mexicans have been eating for centuries (at least until NAFTA came along and fucked it all up.) Come to think of it, diabetes and obesity have been on the rise in Mexico over the last decade, just around the same time that globalization hit them. Hmm….

      1. Not quite. Yes, before human involvement, teosinte (the ancestor of modern corn) was quite different. But even the Aztecs had corn more or less like the modern variety — Native Americans were quite good at selective crop breeding.

      2. Yeah, Jonathan Badger is correct here. This has nothing to do with GM foods or “modern” corn and everything to do with corn’s nutritional value for the amount of work you have to put into making it nutritional. Even in traditional foodways. See the link I added above. 

    2. The point isn’t that it’s “unnatural”, but note that even the Mexicans aren’t eating just plain unprocessed corn on the cob as a staple — there’s a lot of processing that goes into making corn something easily digestible by a human — which is why most corn is used as animal feed.

      1. See, now you’re doing it!  ‘a lot of processing’ in what sense?  Corn bread is made from plain, ground up whole-grain corn.  Arguably less processing than we subject wheat or rice to, considerably less than required by e.g. cassava.

        Nixtamalization is probably equivalent in complexity to polishing rice or producing white flour, although I might point out that nixtamalizing technology predates large-scale rice or wheat refining by a couple of thousand years, so it’s not exactly a space-age practice.

        1. Grinding up grain into flour is of course processing it. That’s why machines for grinding up food are called “food processors”. Processing food to make it more useful/digestible has been going on for a very long time and isn’t necessarily an evil or unhealthy thing. 

          1. Sure, but that’s a lot less processing than what we do to corn these days.   Corn often gets processed into streams of chemicals that are only sort of related to corn, and then reassembled into new foodlike products.

        2. It doesn’t have anything to do with whether the processing is modern or not. More processing is more processing, and that takes energy, resources, money, ect. If you want to feed a lot of people cheaply, you’re better off with food sources that provide the most nutritional value for the least amount of necessary processing. Corn isn’t one of those things. 

          And that imbalance just gets worse with the fertilizer/pesticide inputs necessary to produce the yields of modern corn farming. 

          Sorry for the confusion.

    3. Right, no one claimed it was worse or ‘less natural’, just that it was resource intensive to grow and process.  From what I understand, cassava, major carbohydrate staple in the traffics, is actually poisonous in its unprocessed form, so needing to process food doesn’t necessarily conflict with it being a staple.

    4. It’s not any healthier for them. It’s just what there is. It’s better than starvation — which, given that the current out-of-control corn subsidies in the US came out of the Dust Bowl/Great Depression era, the last time we had widespread starvation in the US, is why we eat it, too. Corn is practically the only large-grain domesticable annual that’s native to this hemisphere. (This is, as Diamond documented in Guns, Germs, and Steel one of the two main reasons that civilization lagged so far behind in this hemisphere: crippling shortage of domesticable plants and even more severe shortage of domesticable animals.)

      Western hemisphere native cultures maximize the nutritional value of corn by processing the heck out of it, too; that European and African immigrants to this hemisphere didn’t know how to do that was what lead to the pellagra epidemic of the late 19th, early 20th century.

    5. Let’s see if I can clarify…  here’s a list of the world’s largest foodcrops:

      corn is #2.  But, to find something on that list that is ‘easier to eat’ than corn, we have to go all the way to #5, potatoes.  The next thing on the list that doesn’t require elaborate processing is #10, sweet potatoes.

      So… I’m not saying that corn should be the massive global crop that it is.  All I’m saying is… it’s food!  Saying that it isn’t food doesn’t help your case against corn unless you are also making a case against essentially all of the world’s non-perishable crops.

    6. What they’re talking about here isn’t “natural” or “unnatural”, but how much processing it takes before we can get nourishment out of the food. Corn takes a lot compared to chickpeas. You can’t just eat boiled corn kernels and have that be a healthy diet. In fact, it took a major advancement in food processing to allow ancient central and south americans to use corn as a primary food source:

      That’s not necessarily a bad thing. It’s just that “take chickpeas and boil” is easier and cheaper. 

      And the chickpeas still have more protein. 

      1.  You can’t just eat boiled corn kernels and have that be a healthy diet.,

        Healthy or not, fresh corn is delicious.  I get as much of it as I can during the summer, along with fresh tomatoes.

        1. Please keep in mind that that the sweet corn you eat off the cob in the summer is a completely different corn variety than the corn that is grown for feed, HFCS, ethanol. I guarantee that if you go into a random field of corn in Iowa and try to eat an ear of it, you will be disgusted.

  4. Hey Maggie, don’t forget the other big, obvious reason growing less corn would be good for this planet- having such a huge imbalance in what we grow creates a monoculture system that hurts, rather than helps. In other words, just like any Wall Street exec will tell you to have a diverse portfolio with a wide variety of investments, so does nature, by having complementary plants grow together to create a healthy biodiversity all over. Turning our midwest into a giant corn field has created a ridiculous imbalance in too many ways to mention here. Switching to chick peas, or any other crop, in similar numbers would not solve the real problem. Farming a variety of crops, as well as raising animals near those crops (in other words, reverting back to how we used to farm) is a much more sustainable solution.

    Good luck convincing our government of that.

  5. Presidents and congressmen have been trying to divert farm subsidies away from corn and towards plants that contain actual nutrition since the Ford administration. Every time they do, the big corn-processing companies flood the airwaves with ads accusing them of trying to bankrupt family farmers, and voters revolt. It’s a horse-crap argument; family farmers could relatively easily convert their corn farms to wheat farms, or some other annual. No, cutting corn subsidies would screw the heck out of the companies that own the expensive, high-polluting, industrial-food-producing processing plants that specialize in corn production. And they’re rich enough to buy all the politicians they need. They’ve spent the last 40 years proving beyond all shadow of a doubt that they will use every penny of their vast wealth to prevent politicians from obsoleting their hardware investments.

    Since that means that this is a problem that is no longer addressable through the political process, since no matter who you vote for you’re going to get corn subsidies and poor people will only be able to afford corn by-products, all there is that the rest of us can do is refuse to eat the stuff, and hope that it dents their profits to the point where they can no longer out-fund-raise anti-corn politicians. I don’t think even that is likely to work, but I don’t see anything more plausible to try.

    1. … since no matter who you vote for you’re going to get corn subsidies and poor people will only be able to afford corn by-products, all there is that the rest of us can do is refuse to eat the stuff, …

      I don’t dispute your frustration, but isn’t wheat still cheaper than cornmeal, even with the subsidies? Though I guess that’s a moot point, as probably few poor people in this century are buying raw ingredients and living on wheat/corn porridge and simple breads. By which I mean raw calorie cost is only one factor in price of food available for purchase.

      I do cook with flour, and was impressed once when I did the calculation. Less then 80 cents for 2000 calories worth of wheat flour. And this in North-Eastern New Jersey, one of the highest cost-of-living places is the US. Grains — any grains — by western standards are ridiculously cheap.

    2. Very true, and so yet again we have good intentions (“help farmers grow food”) turn bad, and we end up spending tax dollars we don’t have to make a commodity cheaper and more prevalent, when it would be better to let it get more expensive and thus reduce its use. *Sigh*

  6. Another consideration that should be added here is that of water resources.  Many areas, like Kansas or Eastern Colorado, that have switched from wheat to corn have also added circle irrigators, tapping into finite and depleting water sources such as the Ogalala Aquifer.

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