© 2024 Kansas City Public Radio
NPR in Kansas City
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations

Planting Perennial Grasses On Cropland Could Reduce Gulf’s ‘Dead Zone’

Miscanthus, shown growing in Iowa, is a perennial grass that could help keep nutrients out of waterways.
Rick Fredericksen
/
Iowa Public Radio

A new study supports planting perennial grasses on current cropland as a way to reduce nutrient loss from farm fields.

Researchers used models to calculate how much the flow of nitrogen into the Mississippi River, which has contributed to a dead zone the size of Connecticut, could be reduced if certain amounts of farmland grew switchgrass or miscanthusinstead of their current crops.

Iowa State University agronomist Andy Vanloocke says the results show that the grasses can help—but are not a silver bullet.

  “Perennial biofuels are an effective land use management,” he said, “when it comes to trying to improve water quality. But they are not the only way to go.”

Switchgrass or miscanthus could be used as feedstock for cellulosic ethanol, but currently there is little commercial market for them. In Iowa, some miscanthus is used for energy production, Vanloocke said.

The new study expands upon existing research, Vanloocke said, by looking at the entire Mississippi River basin. Converting some amount of cropland to perennial grasses could improve water quality across the region. But, Vanloocke said the grasses also could prevent water from flowing downstream.

So the study considered streamflow as well as nutrient movement.

“We would like to see a scenario where streamflow is status quo, where it stays as close to where it has been as possible,” Vanloocke said, to prevent creating new problems. “But where that water is flowing has as little nitrogen in it as possible.”

He says the grasses offer the most gain for areas that currently have the highest nutrient runoff, such as places with high rainfall.  

The paper appears in the journal Global Change Biology Bioenergy.

Amy Mayer is a reporter based in Ames. She covers agriculture and is part of the Harvest Public Media collaboration. Amy worked as an independent producer for many years and also previously had stints as weekend news host and reporter at WFCR in Amherst, Massachusetts and as a reporter and host/producer of a weekly call-in health show at KUAC in Fairbanks, Alaska. Amy’s work has earned awards from SPJ, the Alaska Press Club and the Massachusetts/Rhode Island AP. Her stories have aired on NPR news programs such as Morning Edition, All Things Considered and Weekend Edition and on Only A Game, Marketplace and Living on Earth. She produced the 2011 documentary Peace Corps Voices, which aired in over 160 communities across the country and has written for The New York Times, Boston Globe, Real Simple and other print outlets. Amy served on the board of directors of the Association of Independents in Radio from 2008-2015.
KCUR serves the Kansas City region with breaking news and award-winning podcasts.
Your donation helps keep nonprofit journalism free and available for everyone.