Study Finds That Boosting Soil's Sponge-Like Qualities Would Help Farmers, Communities Combat Floods and Droughts

Farming practices that keep soil covered year-round can reduce the damage caused by both floods and droughts, according to a new study released by the Union of Concerned Scientists (UCS). "Turning Soils Into Sponges: How Farmers Can Fight Floods and Droughts" shows that that widespread adoption of these practices in a state like Iowa could reduce storm runoff by 15 percent and make as much as 11 percent more water available to crops on average through the end of the century, even as weather patterns become more severe.

"Many people think of soil as 'just dirt'--but it's actually an incredible resource that can make communities and farmers less vulnerable to droughts and flooding as weather becomes hotter and rains come in heavier downpours," said agronomist Andrea Basche, a Kendall fellow at UCS and the report's author. "When soil is healthy, it can soak up water like a sponge, preventing runoff into nearby communities while also holding onto it for plants to use later when there is less rain. When soil isn't healthy, it acts more like concrete.

Basche reviewed more than 150 field experiments from six continents and found that in 70 percent of them specific conservation and agroecology practices--no-till farming, cover crops, perennials, agroforestry, crop rotations and managed grazing--increased soil's ability to soak up water. Basche then used a hydrology model to see how adoption of these practices across a region would impact drought and flood impacts. The report focused on Iowa, which is representative of Midwestern agriculture and weather patterns, and found that:

• Converting approximately one-third of Iowa's cropped acres--the state's least-profitable and most-erodible acres--to perennial crops or to corn or soybeans grown with a winter cover crop would result in significant water savings.
• During the devastating droughts in Iowa in 1988 and 2012--each of which caused more than $30 billion in damages--adoption of these practices would have made as much as 16 percent more water available for use by crops.
• Had these practices been in place during the massive floods of the last three decades runoff would have been reduced by up to one-fifth and flood frequency cut by the same amount.
• Had these practices been in place between 1981 and 2015, spongier soils in Iowa would have retained 400 trillion more gallons of water during that time. This is equal to nine years' worth of irrigation water withdrawn across the entire United States at current rates.

Taxpayers must often foot the bill for weather damage on farms and in communities. For example, UCS found that between 2011 and 2016, flood- and drought-related claims to the taxpayer-subsidized federal crop insurance program resulted in $38.5 billion in payouts to farmers, approximately two-thirds of the total paid by the program. A recent Office of Management and Budget report concluded that climate change could double the payouts of crop insurance, costing an additional $4 to $9 billion dollars annually by 2080.

Farmers, water utilities and policymakers have expressed a growing interest in improving soil quality. Several states--including California, Maryland, Massachusetts and Hawaii--have begun to invest in soil initiatives.

"Floods not only cause preventable damage--they create long-lasting trauma and heartache," said Rob Hogg, an Iowa state senator whose district was one of the hardest hit during the 2008 floods, which caused the Cedar Rapids River to rise 19 feet over flood stage. "Policymakers at all levels of government should be looking for ways to decrease the impacts of extreme weather. Building soil health is a critical component of flood risk management and being able to reduce runoff by 15 percent would be enormously helpful during flood peak when every inch matters."

At the federal level, existing farm conservation programs help farmers shift away from soil-damaging monocultures of annual crops. But these small programs are no match for crop insurance and other subsidies that reinforce the status quo.

"I can't think of anything riskier than growing millions of acres of just corn and soy, but farm payments, crop insurance and the market are set up in in a way that reward doing just that," said Jon Bakehouse, a fifth-generation farmer who grows primarily corn and soy in Southwest Iowa, but whose family used to grow wheat and raise cattle and pasture on a more diversified farm that integrated livestock with crops. "Policies that help farmers build healthier soils won't end the problem of weather disasters, but they can buffer farmers and communities and save everyone money in the long run."

With the reauthorization of the federal farm bill due in 2018, Congress and the U.S. Department of Agriculture (USDA) have an opportunity to invest in healthy soil and resilient farms. Policymakers should expand financial support for farmers through the USDA's Conservation Stewardship Program and its Regional Conservation Partnership Program (RCPP); provide incentives in the federal crop insurance program for risk reduction through soil management; and invest in research to optimize the benefits of good soil management practices, according to UCS.

"Healthy, spongier soils are a win-win for farmers and water utilities and benefit rural and urban communities alike," said Tariq Baloch, Cedar Rapids water utility plant manager and participant in the Middle Cedar Partnership Project, which receives funding from RCPP and brings together landowners, utilities and farmers to reduce nutrient runoff into drinking water sources. "Investing in soil health means investing in soil productivity and reduced soil loss. Doing so will improve source water quality, reduce runoff that contributes to flooding and, ultimately, enhance the sustainability and prosperity of our communities."