By Seth Shulman
For corn and soybean farmers in Iowa and other midwestern states, the status quo presents a problem: despite record harvests in 2016, US farm incomes have dropped to some of their lowest levels in more than a decade. What’s more, the current farming system that predominates throughout Iowa and much of the Midwest—rotating between fields of corn and soybean every two years with heavy fertilizer use and plowing (or “tilling”) bare fields between crops—is taking a toll on vital soil and water resources. Farm fields are eroding at unsustainable rates, and nitrogen pollution from agriculture costs the nation an estimated $157 billion per year in human health and environmental damages.
There’s a better way.
A new UCS analysis models what would happen if Iowa farmers adopted an extended, no-till crop rotation system. The findings? Farmers could adopt the system on as much as 40 percent of the state’s farmland, generating a winning combination of benefits: higher yields, less erosion, and dramatically less fertilizer use with its associated costs, water pollution, and global warming emissions. Read the full report.
Innovative Crop Rotation
The UCS analysis builds on a long-term study conducted since 2003 by researchers at Iowa State University that shows moving from today’s dominant two-crop rotation system to a more diverse rotation involving three or four crops (such as adding oats and a cover crop of red clover, which acts as a “green” manure) can increase crop yields and maintain similar per-acre profits. Average corn yields were 2 to 4 percent higher and average soybean yields 10 to 17 percent higher compared with the two-crop system and, especially given the reduced fertilizer costs, the diverse rotations were just as profitable as rotating between corn and soy alone.
UCS analyzed the economic and environmental potential of expanding diverse crop rotation systems, paired with no-till methods, and found that Iowa’s farmers could scale them up to 20 to 40 percent of the state’s farmland—some 5 million to 11 million acres. Doing so could:
- reduce soil erosion by 88 percent compared with tilled corn-soy; and
- save taxpayers between $241 million and $505 million annually in cleanup costs and reductions in global warming emissions.
As Kranti Mulik, the UCS report’s lead analyst explains, “There are barriers to adoption that need to be overcome, but this looks like a win-win-win scenario for midwestern farmers: producing higher yields, maintaining profits, while protecting the soil, cutting pollution-causing fertilizer and pesticide use, and reducing global warming emissions.”