BLOOMINGTON, Ind. — It’s a form of whiplash that’s more than just a pain in the neck, and it’s having a growing impact on farmers, along with drinking water supplies.

  

A recent study by Indiana University scientists revealed that “weather whiplash,” defined as wide swings between droughts and floods, is becoming more common and result from global warming.

 

The impact on pocketbooks is not just for farmers, but also consumers and municipalities from having to build expensive plants to remove higher nitrate levels from drinking water supplies.

 

More of the nitrates in fertilizer applied to fields get flushed into ditches and streams when periods of rainfall become more extreme and can find their way into the drinking supply. Levels can then exceed federal requirements.

 

For example, a $4 million nitrate removal plant costing $7,000 a day to operate was built in Des Moines, Iowa, because of skyrocketing nitrate levels in the Des Moines and Raccoon rivers.

 

“If these trends continue, we will see more towns spending money on nitrate removal, with the ultimate cost passed on to the consumer,” said Adam Ward, an IU hydrologist and co-author of the study.

 

According to the researchers, the nitrate removal facility has had to operate anywhere from 25 to more than 150 days a year and the utility sued several farming counties upstream to recover its cost. Another consequence is more algae developing in lakes and other bodies of water that could lead to higher fish kill, from oxygen depletion.

 

During prolonged drought, heavier crop damage and higher prices for food result, of course, but fertilizer applied to soil in the spring doesn’t get absorbed by the plants and when the dry conditions suddenly become excessively wet, the nutrients get washed away in heavier amounts.

 

“Farmers are by and large smart and rational, but they can’t control the weather,” Ward said. “They’re working hard to ensure high crop yields while enduring longer droughts followed by excessive rainfall. The result, unfortunately, is harm to the environment.”

 

The researchers conducted the study because of interest in the 2012-13 drought/flood cycle that led to a nitrogen spike in surface waters feeding into rivers in the Midwest. The team used data from the U.S. Geological Survey and National Oceanic and Atmospheric Administration to investigate nitrogen pollution associated with weather whiplash over the past 40 years across the agricultural

Midwest.

 

The data were also used to forecast water quality futures in the face of changing climate and weather patterns. Members of the research team also included Terry Loecke and Amy Burgin of the University of Kansas, Diego Riveros-Iregui of the University of North Carolina, Steven Thomas of the University of Nebraska-Lincoln, Caroline Davis of the University of Iowa and Martin St. Clair of Coe College.

 

The study follows a report by the Risky  Business Project (http://riskybusiness. org) that predicted heavy losses in agriculture from weather and climate changes because of global warming in the decades to come. Crop losses of 18- 24 percent each year from extreme heat were predicted in Missouri, Illinois and Indiana over the next 5-25 years if farmers don’t adapt significantly.

 

Yields for corn and wheat could be as much as 11-69 percent across the Midwest by 2100 without reductions in greenhouse gas emissions blamed for warming the planet.

 

Jerry Hatfield, an agricultural climatologist with USDA, said farmers can do things such as add organic matter to their fields to help soil retain water for longer durations to give crops a better chance at surviving extended drought.

 

Putting crop residue on the soil at tilling also helps to slow evaporation, he said. “Climate resilience first has to start with how do we build the soil as having the capacity to absorb and store water?” he added.

 

Advances are constantly being sought to provide even more drought-resistant crops.

 

In terms of erosion, another tool is planting cover crops to guard against soil washing away from more torrential rain events, Hatfield said.