to algae blooms, pervasive problems
DETROIT (AP) -- Farmers are making significant cutbacks in erosion of soil and nutrients into the Great Lakes, where runoff is suspected of being a leading contributor to rampant growth of algae that damages water quality, a new U.S. Department of Agriculture report said.
The study estimated that because of changes in cultivation practices, the amount of sediments washing into rivers and streams that feed the lakes is 50 percent less than it would have been otherwise. Nitrogen and phosphorus runoff is about one-third lower than it would have been without the improvements.
The report, released this week, was based on computer modeling and surveys of involved farmers on the U.S. side of the lakes, from New York to Minnesota.
The government "appreciates the actions of every farmer who is stepping up to implement conservation practices, protect vital farmlands and strengthen local economies," Agriculture Secretary Tom Vilsack said. "At the same time, we also see opportunities for even further progress."
Farm runoff is of growing concern in the region, with a resurgence of algae in all the Great Lakes except Lake Superior. The situation is worst in Lake Erie, the warmest and shallowest, where scientists say algae covered more of the surface this summer than it has in a half-century.
Plant nutrients such as phosphorus and nitrogen are believed at least partly responsible, although a report issued this week by the International Joint Commission, a U.S.-Canadian agency, said scientific evidence is unclear about the causes of the algae comeback.
The study by the Agriculture Department's Natural Resources Conservation Service did not look into the algae problem or other Great Lakes water quality issues, said Doug Lawrence, deputy chief of soil survey and resource assessment. It focused on how well farmers have done at curbing erosion within the Great Lakes basin, which includes parts of eight states: Michigan, Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania and New York. About one-fourth of the region consists of cultivated farmland.
It also did not measure reductions over a specific period of time. Instead, researchers developed computer simulations that compared conditions when the farmers were surveyed -- from 2003 to 2006 -- with how they would have been without erosion control measures. Despite the time lag between the survey period and the release of the report, Lawrence said farm practices that produced the improvements have continued and perhaps increased.
The study was the third of 14 planned for major watersheds around the nation. Others that have been completed focused on the upper Mississippi River and Chesapeake Bay.
Congress set erosion control standards in 1985 for farmers to meet over a 10-year period. Many changes since then involve reducing or eliminating cropland tillage while using less fertilizer or applying it in ways that prevent it from washing away.
"It's pretty clear that we've got the tools to address the problem," Lawrence said. "These are all well-known practices."
Andy Buchsbaum, director of the National Wildlife Federation's Great Lakes office in Ann Arbor, said federal programs encouraging different cultivation techniques are helping cut erosion. But the worsening algae problem demonstrates that "the success is not reflected in the water," he said.
"Lake Erie's got the worst toxic algae blooms in its history, we're seeing those algae blooms in other places and those are primarily caused by the very nutrients that these programs are reducing," he said during a conference of Great Lakes advocates in Detroit.
The report also did not measure a particular form of dissolved phosphorus that is most responsible for the algae blooms, he said.
Congress is scheduled to reauthorize farm support programs next year. Conference participants said they would seek more money for programs that encourage farmers to fight erosion, such as placing plant barriers between streams and cultivated fields.
"We need to make sure that conservation produces a good economic return for our landowners," said Gildo Tori, Great Lakes policy director for Ducks Unlimited, which works on wetland and waterfowl preservation.