Niagara Gazette — "It's time for governments at all levels to put the lake on a diet by setting targets and achieving real reductions," said Lana Pollack, chairwoman of the commission's U.S. section.
The reduction targets should be met by 2022, the report said.
Overall levels have not risen since the mid-1990s, according to the report, based on two years of study by more than 60 scientists with universities, private firms and government agencies. But a type called dissolved reactive phosphorus, or DRP, has more than doubled — and it's the variety "most easily used by the algae for growth," said Don Scavia, director of the University of Michigan's Graham Sustainability Institute.
DRP chemical fertilizers are popular for producing corn used as animal feed on large industrial farms, Scavia said. Manure also can undergo a process that generates DRP. In the past couple of decades, farmers increasingly have applied both in fall and winter, when the material sometimes has remained atop frozen ground or snow instead of soaking in. Farmers also have done less tilling.
Such changes prevented fertilizers from being worked into the soil, making them more apt to wash into streams and eventually the lake during the spring melt, Scavia said. As the climate has warmed, more intense rainstorms have boosted phosphorus flushing.
The report urges states in the Lake Erie watershed, including Michigan, New York, Ohio, Pennsylvania and Indiana — as well as the Canadian province of Ontario — to ban spreading farm fertilizers on frozen or snow-covered ground.
Farm groups acknowledge a role in the problem but favor voluntary best-management practices to cut down on runoff, such as making sure fertilizer comes in contact with the soil, said Larry Antosch, environmental policy director with the Ohio Farm Bureau. Regulations don't allow enough flexibility, he said.