A Sustainable Solution for the Corn BeltBy New York Times Op-Ed Contributing Writer Mark Bittman
November 18, 2014
It’s hard to imagine maintaining the current food system without Iowa. Yet that state — symbolic of both the unparalleled richness of our continent’s agricultural potential and the mess we’ve made of it — has undergone a transformation almost as profound as the land on which cities have been built. A state that was once 85 percent prairie is now 85 percent cultivated, most of that in row crops of corn and soybeans. And that isn’t sustainable, no matter how you define that divisive word.
It’s easy enough to argue that one of the most productive agricultural regions in the world could be better used than to cover it with just two crops — the two crops that contribute most to the sad state of our dietary affairs, and that are used primarily for animal food, junk food and thermodynamically questionable biofuels. Anything that further entrenches that system — propped up by generous public support — should be questioned. On the other hand, if there are ways to make that core of industrial agriculture less destructive of land and water, that is at least moving in the right direction.
For now, many Midwestern farmers believe they are maximizing income by growing row crops in what is best called industrial fashion. (Many prefer the word “conventional,” but as common as it is we do not want chemical farming to be the convention.) This near monoculture, for the most part, fails to replenish soil, poisons water, increases flooding and erosion, spills carbon, robs indigenous species of habitat and uses fossil fuel resources at unnecessarily high rates. Despite this, for the last several years the economic pressure has been on farmers to plant more and more, even in marginally productive areas, land that requires more work and greater applications of chemicals for fewer benefits.
Incredibly, there is a scientifically informed, direct and effective planting tactic that can mitigate much of this. Called STRIPS, for (ready?) “science-based trials of rowcrops integrated with prairie strips,” it means just that: Take around 10 percent of your farmland (in most cases, the least productive part), and replant it with a mix of indigenous prairie plants. Then sit back and watch the results, which are, according to researchers and even some farmers, spectacular.
Lisa Schulte Moore, a researcher at Iowa State University, has been working on the principles behind STRIPS for more than 10 years. (In 2003, she worked with Matt Liebman and Matt Helmers, two other pioneers in making contemporary American agriculture more sensible; I wrote about Liebman’s work a couple of years ago.) “It’s well-known that perennials provide a broader sweep of ecological function than annuals,” she told me last week, “so our hypothesis was that if you put a little bit of perennials — a little bit of prairie — in the right place, you get these disproportionate benefits. That is, without taking much land out of production, you get a lot of environmental benefit.”
The research has produced impressive numbers: If you convert 10 percent of a field of row crops to prairie, soil loss can be reduced by up to 95 percent, nutrient loss by 80 to 90 percent, and water runoff by 44 percent. Biodiversity nearly quadruples, and some of those species are pollinators, predators of pests, or both. And, unlike some ecological management techniques, the process is not expensive.
In general, reports Moore, seven years into this process, “Though science is messy, it’s amazing how clear our results are.”
By the end of the year, there will be 17 commercial farms integrating prairie strips in Iowa and Missouri — a mere 1,000 acres or so (the corn/soy belt is about 170 million acres this year), although the program is increasing rapidly. And because it’s difficult to find fault with it, the approach has the potential to unite farmers and environmentalists in a way that few other things do.
In recent years, many Iowa farmers have believed that if they weren’t 100 percent “in” corn, they weren’t doing a good job. Because of the pressure to plant, many of them have expanded their cultivated areas beyond where it makes sense, creating erosion and runoff problems. Iowa is among the major contributors to the Gulf of Mexico’s “dead zone,” a direct result of fertilizer runoff into the Mississippi water system, and half of Iowa’s topsoil has been lost.
Some common solutions to these problems — like terracing, or simply patching areas where runoff is extreme — are expensive and/or temporary. But the STRIPS experiment seems to demonstrate that being 90 percent “in” results in unheard of environmental benefits with little or no sacrifice to the bottom line. And, says Watkins, “I’ve felt for years that environmentalists and farmers should be friends, and we are starting to see that in Iowa.”
Prairie strips are both cheap and permanent, and they come with little opportunity cost. There does not seem to be an argument against them, other than that they make an imperfect — or even destructive — system less so. But while we’re figuring out a better way to do things on a big scale in the Midwest, this is a sensible interim step.