By Mark Bittman
IT’S becoming clear that we can grow all the food we need, and profitably, with far fewer chemicals. And I’m not talking about imposing some utopian vision of small organic farms on the world. Conventional agriculture can shed much of its chemical use — if it wants to.
This was hammered home once again in what may be the most important agricultural study this year, although it has been largely ignored by the media, two of the leading science journals and even one of the study’s sponsors, the often hapless Department of Agriculture.
The study was done on land owned by Iowa State University called the Marsden Farm. On 22 acres of it, beginning in 2003, researchers set up three plots: one replicated the typical Midwestern cycle of planting corn one year and then soybeans the next, along with its routine mix of chemicals. On another, they planted a three-year cycle that included oats; the third plot added a four-year cycle and alfalfa. The longer rotations also integrated the raising of livestock, whose manure was used as fertilizer.
The results were stunning: The longer rotations produced better yields of both corn and soy, reduced the need for nitrogen fertilizer and herbicides by up to 88 percent, reduced the amounts of toxins in groundwater 200-fold and didn’t reduce profits by a single cent.
In short, there was only upside — and no downside at all — associated with the longer rotations. There was an increase in labor costs, but remember that profits were stable. So this is a matter of paying people for their knowledge and smart work instead of paying chemical companies for poisons. And it’s a high-stakes game; according to the Environmental Protection Agency, about five billion pounds of pesticidesare used each year in the United States.
No one expects Iowacorn and soybean farmers to turn this thing around tomorrow, but one might at least hope that the U.S.D.A.would trumpet the outcome. The agency declined to comment when I asked about it. One can guess that perhaps no one at the higher levels even knows about it, or that they’re afraid to tell Monsantoabout agency-supported research that demonstrates a decreased need for chemicals. (A conspiracy theorist might note that the journals Science and Proceedings of the National Academy of Sciences both turned down the study. It was finally published in PLOS One; I first read about it on the Union of Concerned Scientists Web site.)
Debates about how we grow food are usually presented in a simplistic, black-and-white way, conventional versus organic. (The spectrum that includes conventional on one end and organic on the other is not unlike the one that opposes the standard American diet with veganism.) In farming, you have loads of chemicals and disastrous environmental impact against an orthodox, even dogmatic method that is difficult to carry out on a large scale.
But seeing organic as the only alternative to industrial agriculture, or veganism as the only alternative to supersize me, is a bit like saying that the only alternative to the ravages of capitalism is Stalinism; there are other ways. And positioning organic as the only alternative allows its opponents to point to its flaws and say, “See? We have to remain with conventional.”
The Marsden Farm study points to a third path. And though critics of this path can be predictably counted on to say it’s moving backward, the increased yields, markedly decreased input of chemicals, reduced energy costs and stable profits tell another story, one of serious progress.
Nor was this a rinky-dink study: the background and scientific rigor of the authors — who represent the U.S.D.A.’s Agricultural Research Service as well as two of the country’s leading agricultural universities — are unimpeachable. When I asked Adam Davis, an author of the study who works for the U.S.D.A., to summarize the findings, he said, “These were simple changes patterned after those used by North American farmers for generations. What we found was that if you don’t hold the natural forces back they are going to work for you.”
THIS means that not only is weed suppression a direct result of systematic and increased crop rotation along with mulching, cultivation and other nonchemical techniques, but that by not poisoning the fields, we make it possible for insects, rodents and other critters to do their part and eat weeds and their seeds. In addition, by growing forage crops for cattle or other ruminants you can raise healthy animals that not only contribute to the health of the fields but provide fertilizer. (The same manure that’s a benefit in a system like this is a pollutant in large-scale, confined animal-rearing operations, where thousands of animals make manure disposal an extreme challenge.)
Perhaps most difficult to quantify is that this kind of farming — more thoughtful and less reflexive — requires more walking of the fields, more observations, more applications of fertilizer and chemicals if, when and where they’re needed, rather than on an all-inclusive schedule. “You substitute producer knowledge for blindly using inputs,” Davis says.
So: combine crop rotation, the re-integration of animals into crop production and intelligent farming, and you can use chemicals (to paraphrase the report’s abstract) to fine-tune rather than drive the system, with no loss in performance and in fact the gain of animal products.
Why wouldn’t a farmer go this route? One answer is that first he or she has to hear about it. Another, says Matt Liebman, one of the authors of the study and an agronomy professor at Iowa State, is that, “There’s no cost assigned to environmental externalities” — the environmental damage done by industrial farming, analogous to the health damage done by the “cheap” standard American diet — “and the profitability of doing things with lots of chemical input isn’t questioned.”
This study not only questions those assumptions, it demonstrates that the chemicals contributing to “environmental externalities” can be drastically reduced at no sacrifice, except to that of the bottom line of chemical companies. That direction is in the interest of most of us — or at least those whose well-being doesn’t rely on that bottom line.
Sadly, it seems there isn’t a government agency up to the task of encouraging things to move that way, even in the face of convincing evidence.