October 31, 2008
AMES, Iowa — A cooperative effort to reduce the loss of nitrate and phosphorus from Iowa farm fields has earned national recognition. Iowa State University researchers play a key, supporting role in the ongoing effort to reduce hypoxia in the Gulf of Mexico.
A partnership between the Iowa Department of Agriculture and Land Stewardship (IDALS), the Iowa office of U.S. Department of Agriculture's Farm Service Agency (FSA) and the Iowa Farm Bureau Federation received a Gulf Guardian Award Oct. 29 in New Orleans. The honor was in recognition of the partnership's efforts to reduce nitrate carried through local waterways from Iowa to the Gulf of Mexico.
The Environmental Protection Agency's (EPA) Gulf of Mexico Program initiated the Gulf Guardian awards in 2000 to recognize businesses, community groups, individuals and agencies taking positive steps to keep the Gulf healthy and productive. Three awards are given annually in seven categories. The Iowa groups received third place in the partnership category.
In announcing the award, the EPA said Iowa farmers, landowners and conservation agencies have a three-part strategy to address Gulf hypoxia. This strategy includes research to develop technologies for wetland and drainage systems to reduce nutrient transport from cropped lands, construction of nitrogen-removal wetlands through the Iowa Conservation Reserve Enhancement Program (CREP) and development of pilot demonstrations.
Rick Robinson, environmental policy advisor for the Iowa Farm Bureau, said Iowa State has played a critical role in this effort. "It just couldn't have happened without Iowa State's involvement. This is evidence that science can effectively help drive our natural resource policy decisions," he said.
Iowa State University researchers have been involved since passage of the Iowa Groundwater Protection Act in 1987, which placed a tax on the sale of agricultural chemicals to fund water protection efforts. Jim Baker and Stewart Melvin in the agricultural and biosystems engineering department received funding to study the impact of drainage wells on nutrient losses from cropland.
It became clear the problem will not be solved with just in-field nitrogen management. Bill Crumpton, now an associate professor in the ecology, evolution and organismal biology department, joined Baker and Melvin on the IDALS project team. He set up a research project to study the potential for wetlands to remove nitrate from farm field subsurface drainage.
In 2000, Crumpton, Baker and Melvin began to work with Dean Lemke, chief of the IDALS Water Resources Bureau, to develop the CREP. Tom Isenhart, now an associate professor in the natural resource ecology and management department, had been a graduate student of Crumpton's, working on wetlands and water quality. Later, he served as the CREP coordinator for the first three years of the program. Shawn Richmond, another former graduate student of Crumpton's, is the current CREP coordinator.
At a news conference following the Gulf Guardian award presentation, Lemke said the underlying technology for using wetlands to filter water from cropland was developed at Iowa State. Currently 72 sites are either in the planning and construction phase or already complete. "These wetlands are highly targeted to areas where they will do the most good," Lemke said. "Currently there are just 715 acres in the wetland pool treating 86,000 acres of watershed."
Baker and Melvin have retired from Iowa State but continue as emeritus professors and are involved in the CREP as IDALS consultants. Crumpton also continues to work with the CREP. His monitoring has shown, on average, 40 to 70 percent reductions in nitrate after tile drainage is intercepted and channeled into wetlands.
"A unique aspect of the Iowa CREP is that nitrate reduction is not simply assumed based on wetland acres enrolled, but rather is calculated based on the measured performance of CREP wetlands," Crumpton said. "A representative subset of wetlands is monitored and we have developed models that allow us to predict the performance of all of them."
A relatively new player is Matt Helmers, assistant professor and extension agricultural engineer, who joined Iowa State's agricultural and biosystems engineering department five years ago. Under the ongoing contract with IDALS, Helmers studies the impact of in-field nutrient management strategies and educates landowners and stakeholder groups about the positive aspects of wetlands restorations.
"I think it's really a great concept," Helmers said. "There are multiple benefits with these restorations. We're providing water quality benefits, increasing landscape diversity, providing some wildlife habitat and adding aesthetic value."
Under CREP, financial incentives are provided to private landowners to develop and restore wetlands that intercept tile drainage from agricultural watersheds. Landowners receive annual land payments for up to 15 years and reimbursement for costs of wetland and buffer establishment. Easements to maintain the wetlands and buffers are required for a minimum of 30 years with permanent easements also offered.