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