In recent weeks two separate New York Times columnists have suggested that America’s farmers should go back to traditional integrated crop and livestock systems with much longer crop rotations. Food writer Mark Bittman called this “A Simple Fix for Farming,” and Rural Life columnist Verlyn Klinkenborg said this traditional approach indicated farmers in the past “knew more” than farmers today.
The evidence presented by both these New Yorkers was a study conducted on 22 acres of land owned by Iowa State University between 2003 and 2011, comparing the performance of three different cropping rotations: 1) corn/soybeans; 2) corn/soybeans/oats; and 3) corn/soybeans/oats/alfalfa, integrated with livestock. The study showed “better yields” for both corn and soy in the longer rotations, with reductions in the use of nitrogen fertilizer and herbicides.
Bittman did acknowledge this study had been turned down for publication by two premier journals—Science, and Proceedings of the National Academy of Sciences—before finally appearing in a less well established on-line journal. We can only guess the technical reasons for the turn-downs, but the most misleading aspect of the study is the claim of “better yields” for corn and soy. Maybe yields per acre were higher but, in the four-crop rotation only half as much land was being planted to corn and soy, so total production was far less. The simple fix offered by this study seems to be “just produce less food.”
The New York Times promotion of this artificial study misleads readers in another respect, as well—through the accompanying suggestion that today’s cropping systems depend more than in the past on excessive chemical use. In fact, for the past three decades production has increased on America’s farms while chemical use has declined. Since 1982 in the United States, total farm output has increased by 40%, while total fertilizer use per year has actually declined. Total herbicide and insecticide applications have declined, as well. Innovations such as no-till, GPS and crops that self-protect against insects have allowed U.S. farms to grow more with less.
Even for a big crop like corn over the last 15 years the share of planted acres with excess nitrogen applied (above 25% of the crop’s needs) has fallen by 20%. Since 1980 total corn production has doubled, while land use per bushel has declined by 30%, and energy use per bushel has declined by 43%. The calculations come from USDA studies of actual commercial farms, not university-based experiments.
The New York Times wants its readers to believe sustainable farming will require going back to the past, always combining crops with livestock and using more land to produce lower-value crops. Farmers have moved away from this model not because they “know less” than farmers in the past, but because this earlier model produced much less food overall while taking up more land and using much more labor. The way we farmed 30 years ago also demanded far more water, energy and chemicals for each bushel of production. Turning back the clock sounds good to food writers in Manhattan, New York, but in better informed parts of the country (closer to Manhattan, Kansas) American agriculture prefers moving forward.