Water-Quality Sleuths
by Natalie Knudsen

Corn Growers Commit to Nitrogen Research

Nutrient runoff from farm fields is being blamed for the "dead zone" in the Gulf of Mexico. But there isn't any solid data on how to improve water quality without jeopardizing farm profits. About 70 southwestern Minnesota corn growers will help change that. As participants in The Center for Agricultural Partnerships' Midwestern Water Quality Project, they'll gather data on the effects of reduced nitrogen rates on corn yields. They laid the groundwork last fall by applying nitrogen at 60, 90, 120, 150 and 180 lbs/acre in 50-acre test plots.

They'll gather yield and other data from the 3,500 acres over the next three years. But the information will actually pertain to more than 105,000 acres in southern Minnesota. And project leaders hope to identify the most efficient and cost-effective use of nitrogen based on variables including soil type, tillage and other factors - information that can be applied to corn acres across the Midwest.

Farmers are willing to do their part to reduce nutrient runoff and improve water quality, says Larry Elworth, executive director of the Center for Agricultural Partnerships (CAP), headquartered in Asheville, NC. But they need proven information on nitrogen use and yield response before they risk an entire year's crop with reduced rates.

That's why it's important for farmers to be involved in the research, says Elworth.

"Farmers need to participate, see and believe the results," he says.

Participating farmers are role models for others in their communities, adds Maggie Jones, owner of Blue Earth Agronomics and senior consultant for CAP.

"They're the innovative ones, willing to accept change and try new things," she says.

For Pat Duncanson, Mapleton, MN, the decision to join the project was easy.

"We've always been environmentally conscious farmers and this well-designed project looks at a range of nitrogen rates on real farms," he says.  "The days of wholesale nitrogen application are over and we need to take a real look at the effective rates of nitrogen under various conditions. " The farmers will get plenty of help from CAP and other groups.

"CAP's role is to sit down with Minnesota corn growers and identify the problems they face: water quality, threat of government regulation, concerns about rivers and groundwater, and profitability," stresses Elworth. "Then we work to pull together the partnership of private companies, government entities, universities and public and private organizations that can make the program work. And last - but certainly not least - provide the funding and resources to make it all happen."

One partner - the University of Minnesota's Precision Ag Center - contributes aerial remote sensing expertise as well as water-quality monitoring and modeling programs.

"This type of cooperation and data sharing ensures that we don't have to reinvent the wheel every step of the way," says Jones. "The data we collect can be run through its models built on thousands of samples and provide us with immediate, valid numbers."

The knowledge gathered will be disseminated by groups like the Minnesota Corn Growers Association (MCGA) and the National Alliance of Independent Crop Consultants.

"Corn farmers working together to conduct statistically valid, on-farm research is an innovative concept, and one that will carry a lot of weight with other farmers," notes Jenny Eldredge, MCGA's communications manager.

"Farmers are looking for profitable ways to manage nitrogen," says CAP's Elworth. "Participation in the program documents vital information from the community and serves as protection for farmers." In 2001 and 2002, the project will be limited to the Minnesota River Valley, says Jones. Hopefully, it'll be duplicated in other Midwestern states by the third year, Maggie Jones says.

Can Less Nitrogen Make Water Well?

A study on the effects of varying nitrogen levels on corn yields has been under way in the St. Peter, MN, watershed since 1997.

The St. Peter Wellhead Project was started because of concerns about nitrate levels in the city's water supply.

"The nitrate levels in two of our shallow wells are approaching the 10 ppm level," says Pete Moulton, St. Peter's water and wastewater superintendent. "This is an early indicator that there is a surface influence in our agricultural area that we need to evaluate. Presently, we are blending water from these two shallow wells with
water from deeper wells so that the nitrate level is at a safe consumption level."

Replicated nitrogen rates ranging from 0 to 150 lbs/acre are applied at six farm sites in the watershed.

"Replicated studies help us look at the interaction between the rate of nitrogen applied and the resulting yield," notes Maggie Jones, owner of Blue Earth Agronomics and senior consultant with the Center for Agricultural Partnerships.

Results from the project won't clean up the water in the two wells tomorrow, but will offer some statistical data on nitrogen use and corn production.

"The St. Peter Wellhead Project looks at the actual worth of nitrogen application," says Moulton. "At what point do lower rates of nitrogen result in lower yields? Where does profitability fit into that picture? Can slightly lower yields result in similar or greater profits? Those are the questions farmers need answers to."

The Minnesota Pollution Control Agency, University of Minnesota Extension Service, Blue Earth Agronomics and several other agencies and groups are involved in the project.