New Study Shows Diversified Crop Rotation System Could Be Adopted Widely Across Corn Belt And Increase Corn-Soy Yields While Slashing Soil Erosion and Water Pollution

Farmers Could See Soil Erosion Rates Reduced By Over 90 Percent

Published May 9, 2017

WASHINGTON (May 9, 2017)—A new study released today by the Union of Concerned Scientists (UCS) found that modified three- and four-crop farming systems could be scaled up and adopted widely in Corn Belt states, generating benefits to farmers and taxpayers worth hundreds of millions of dollars.

The analysis, “Rotating Crops, Turning Profits: How Diversified Farming Systems Can Help Farmers While Protecting Soil and Preventing Pollution,” builds on a long-term study at Iowa State University, known as the Marsden Farm study, which demonstrated that adding combinations of alfalfa, cover crops, and small grains such as oats to a typical corn-soy rotation can increase farmers’ yields and maintain profits while reducing herbicide and fertilizer use. The UCS analysis shows that pairing these longer rotations with soil-conserving “no-till” practices and scaling the system up strategically would have dramatic results.

The UCS study documents:

  • Adoption of the no-till 3-year or 4-year rotation system, compared with tilled corn-soy, in the 25 Iowa counties with the most erodible soils would slash erosion by as much as 91 percent.
  • For those counties, the diversified rotation would also keep fertilizers out of lakes and streams. Iowa taxpayers would see water pollution cleanup savings of nearly $200 million annually and net reductions in heat-trapping gases valued at up to $78 million annually.
  • Over time, and with the expansion of markets for oats or other small grains in the rotation, the system could be scaled up to nearly 40 percent of Iowa’s current farmland without driving farmers back to predominantly corn-soy. Although the analysis focused on Iowa, the results can be generalized across the 12-state Corn Belt.

The longer rotation system would benefit farmers, who are increasingly squeezed by today’s dominant Midwest corn-and-soy system. U.S. growers of these crops achieved record-high harvests in 2016, but the prices farmers receive for these crops have plummeted; U.S. farm incomes for this year are expected to drop to their lowest levels since 2002. Diversifying  production would leave farmers less vulnerable to such price shifts, and expanding markets for additional crops would create new business opportunities. In addition, the system improves farmers’ soils, ensuring they can keep farming into the future.

“Diversifying crop rotations is a win-win-win solution for farmer profits, the long-term health of their soil, and clean water for communities,” said Kranti Mulik, author of the report and senior economist at UCS. “If we want to multiply the benefits, though, we need to be able to scale these practices up across the region.”

The diverse rotation system works by keeping soil covered and undisturbed year-round. This minimizes soil erosion and reduces the need for fertilizers and herbicides, which keeps pollutants out of lakes and streams. Every year, nitrogen use in U.S. agriculture causes $157 billion in environmental damage—more than double the value of the entire 2011 US corn harvest—and taxpayers, fishing and recreation industries, and under-resourced water utilities pick up the tab. A recent Gallup poll puts Americans’ concerns about water pollution and drinking water at their highest levels since 2001. As public concern rises, community leaders and farm organizations in the Corn Belt are calling for solutions.

“We literally can’t afford to stand by and do nothing about the massive amount of nutrients entering the source water we use to provide drinking water for our 500,000 customers,” said Bill Stowe, CEO and general manager of the Des Moines Water Works, a regional utility in Iowa. “In 2015 alone, we spent $1.5 million running our nitrate-removal system for a record 177 days in order to provide our customers with safe drinking water; these costs are directly passed on to our ratepayers. Taxpayers also get strapped with massive cleanup costs. We need a different set of farm policies that help farmers and also protect our natural resources.”

The UCS report says federal farm policies can help farmers reap the benefits of diversified cropping system by funding additional research, education and technical assistance.

“Our farmers want to implement diverse crop rotations, but the way that financial markets and incentives work, they can’t profitably grow oats or other crops besides corn or soy,” said Sarah Carlson, director of the Practical Farmers of Iowa’s Midwest Cover Crop Project, an initiative that helps farmers adopt cover crops and works with food companies to change the market for small grain crops. “Financial incentives and more technical assistance, like bringing researchers and farmers together to find ways to adopt these practices on their farms—would go a long way to making these changes a reality.”

Other policy changes that would expand adoption include strengthening up-front financial support for farmers to shift to diverse rotations—through the Conservation Stewardship Program, the Environmental Quality Incentive Program, and additional funding for USDA Farm Service Agency loans—and boosting federal crop insurance coverage for diversified farms, not just traditional commodity-driven monocultures.