Wisconsin project works with farmers to reduce phosphorus runoff, hopefully reducing Great Lakes algae blooms

A four-year pilot project near Green Bay, Wisconsin, is trying to see if farmers can reduce phosphorus runoff while still remaining profitable. It's an important question because phosphorus, an ingredient in  fertilizers, triggers algae blooms in lakes, rivers and oceans that sicken people, kill animals, and hurt tourism.

"The Silver Creek Pilot Project began downstream, at the treatment plant handling the city of Green Bay’s wastewater. The state of Wisconsin told the Metropolitan Sewerage District — known as NEW Water — that it must cut back drastically on the phosphorus in the effluent it discharges into the bay," Stephanie Hemphill reports for Ensia, a non-profit climate news organization. "A 2012 state plan requires industries in the watershed to cut their phosphorus by about half. That plan also calculated that farms in the watershed contributed almost half of the nearly 275 tons (250 metric tons) of phosphorus entering the bay each year."

The treatment plan would normally have responded to the state's new mandate by spending $100 million in added filtering, but that wouldn't have addressed the overall problem, said Erin Houghton, NEW Water's watershed specialist. Instead, the district decided to work with other stakeholders to help farmers reduce their phosphorus runoff, Hemphill reports. 

Popular methods of reducing phosphorus runoff include using cover crops, low-till or no-till farming, using lands that are prone to erosion for rotational grazing instead of row crops, and planting buffer zones of grass or perennials along streams. "The problem is, all these methods work differently depending on soil conditions, crop type, climate and weather. There are many variables, and few controlled studies, so researchers have been unable to pinpoint with confidence how well they work," Hemphill reports. The project aims to get solid data on which methods work best in which kinds of conditions.

NEW Water is mostly paying for the project with a $1.67 million grant from the Environmental Protection Agency's Great Lakes Restoration Initiative. The Oneida Nation is a major partner in the project, since the creek lies within its land and it owns more than half of the land involved in the project, which it leases to many non-Oneida farmers, Hemphill reports. Other partners include: the U.S. Fish and Wildlife Service, the U.S. Department of Agriculture's Natural Resources Conservation Service, the U.S. Geological Survey, the University of Wisconsin Green Bay, the Brown County and Outagamie County Land and Water Conservation Departments, The Nature Conservancy, Ducks Unlimited, Wisconsin Department of Natural Resources, and some private agronomists.