Hatfield dishes the dirt (ok, soil) on excess nitrogen in waters

Excess nitrogen in surface waters is not only about fertilizer management, it's also about water management, says Dr. Jerry Hatfield, director of the National Laboratory for Agriculture and the Environment in Ames, IA. Hatfield spoke to a large turnout including many area farmers at the Hawk Creek Watershed Project annual meeting Feb. 28 in Renville. Research accumulating since the 1930s shows that changes in cropping systems away from hay and small grain to intensively-row cropped corn, soybeans, and sugar beets has "changed the whole dynamics" of agriculture and the environment, Hatfield says. (Photo by Tom Cherveny, West Central Tribune-Willmar)

"The loss of nitrogen is basically the loss of money. We need land use changes across the U.S. We need small grains, hay and cover crops." Improving soil organic matter is key. "A lot of things change when we change the soil." It's the foundation of practices that control water in the fields and downstream, he says. "We're losing 1,000 lbs. of carbon per acre per year. That's not sustainable. We need more vegetation and less tillage." Changing as little as 10 percent of the cropped acres in targeted areas would have a significant impact, he says, and simply to reduce the amount of nitrogen fertilizer without better water and crop management is not realistic. All the data and tools can be found online in the Agricultural Conservation Planning Framework. According to the MPCA Nutrient Reduction Strategy, in Minnesota 11.2 million acres would benefit by following U of M recommended fertilizer rates, watch placement and timing of application, and use N inhibitors. The Dept. of Agriculture's proposed nitrogen rule, would regulate fertilizer management for nitrogen in groundwater-sensitive areas. (See article below: "Gov. Dayton proposes groundwater protection measure to reduce elevated nitrate levels in drinking water.")

Other speakers at the annual meeting included Dale Setterholm, Minnesota Geological Survey on groundwater; Forrest Peterson, MPCA, on Hawk Creek headwaters-Willmar chain of lakes; and Wendy Caldwell, Monarch Joint Venture, on monarch butterflies. Watershed project coordinator Heidi Rauenhorst and field technician Dean Dambroten gave updates on grants and implementation projects.