Greening Airports - Iowa Airport to Plant Prairie Grasses to Improve Water Quality

Pamela Porter
Newsletter Issue: 
June 2015

Sign for The Eastern Iowa Airport in Cedar Rapids
photo credit: Travelin’ librarian. FlickR.

CenUSA Bioenergy’s vision of more perennial grasses in the agricultural landscape has a new partner – airports. The Eastern Iowa Airport, located in Cedar Rapids owns more than 2,000 acres of farmland, making it one of Linn County’s largest landowners. In the past, the airport’s land was leased to farmers and planted to corn and soybeans. However nutrients linked to row crop production are chiefly responsible for water pollution and the airport wants to have a more positive and sustainable impact on the environment, while still generating revenue.

“We’re one of the largest farmland owners in the county and nutrient runoff is a big deal, said Heather Wilson, Director of Marketing and Communications for the Eastern Iowa Airport. “We’re located at the top of the Cedar and Iowa River watersheds and we wanted to be good stewards to those that live down river from us.”

Row crops like corn and soybeans are susceptible to water runoff and are “leaky” from a nutrient standpoint. They require annual planting, have wide crop rows, and typically use high rates of fertilizer and tillage. Also, much of the soil in a cornfield has limited cover for more than half the year leaving it susceptible to erosion. Perennial grasses need only minimal tillage when planted and have an extensive root system that builds soil and traps nutrients contributing a conservation role in the agricultural landscape.

This summer the Eastern Iowa Airport managers will be working with scientists at Iowa State University to test the use of perennial grasses on water quality. Five years of research has shown that converting just 10% of row crop fields to perennial prairie grass strips reduced runoff water nitrogen by 84% and phosphorus by 89%. The airport will plant prairie STRIPS (Science-based Trials of Rowcrops Integrated with Prairie Strips) on a 100-acre section of land. The land will be divided into a test field and a control field with measurement tools put in place to test the outflow from both fields. Approximately 10 percent of the test field will be planted with native prairie strips.

The airport will also convert 63.6 acres of low-performing farmland to miscanthus, a high yielding perennial grass and important bioenergy crop. The University of Iowa has a goal of producing 40% of its energy from renewable sources and both the prairie strips and the miscanthus will be harvested and used at the University of Iowa power plant in Iowa City as a source of renewable biofuel. Miscanthus is an excellent conservation crop as its root system holds soil and grows well in poor conditions.

CenUSA’s Project Director, Ken Moore sees the airport project as an opportunity to encourage public agencies to consider leasing their lands for grasses rather than row crops.

“Growing perennials in strategic locations within the landscape is one of the most effective ways of reducing movement of sediment and nutrients to waterways, said Moore. “The Eastern Iowa Airport is demonstrating leadership in using the STRIPS approach. The practice can intercept a remarkable amount of nutrients. I hope other airports who have extensive land holdings will follow suit.”

The City of Cedar Rapids, located down river from the airport will be one of the project benefactors.

“These projects fit well with the overall efforts the City of Cedar Rapids is taking in improving water quality,” Said Ron Corbett, Cedar Rapids Mayor. “The airport projects address our responsibility to those communities further down the Cedar and Iowa Rivers. The state of Iowa has implemented the Iowa Nutrient Reduction Strategy requiring a 45 percent reduction in nitrate and phosphorus coming out of Iowa. We all have to work together to accomplish that goal.”

Bird's eye view of Eastern County Airport
The Eastern County Airport, owned by the City of Cedar Rapids, 
has more than 2,000 acres of farmland making it one of Linn 
County’s largest landowners.