Drastic measures, such as taking 30,000 acres, or 6,300
farms, out of cash-crop production, are needed to curb algae growth in Lake
Erie, says a study released by the University of Michigan Water Center.
The researchers found that current efforts to keep phosphorus,
which is found in livestock manure and artificial fertilizers, on fields
instead of flowing into the lake are falling drastically short of results needed
to achieve a 40 percent cut in runoff.
That’s the target set in February by the International Joint
Commission which includes Canadian and U.S. authorities.
Excessive levels of the nutrient are the leading cause of
increasingly massive blooms, which in 2014 left more than 400,000 people in
Toledo, Ohio, and southeastern Michigan unable to consume tap water for two
days because the bacterial algae produce a toxin.
Another bloom last year was the largest on record.
Phosphorus also causes a "dead zone" in Lake Erie's central basin
with so little oxygen that fish cannot survive.
Ohio and Michigan rely largely on voluntary compliance, but
too few farmers are participating, the report found.
In Ontario farmers have been regulated by Nutrient
Management Plans which basically limit fertilizer and manure applications to
what that year’s crop will use.
But it’s also clear that Ontario farmers will be expected to
further reduce phosphorous erosion over the next five years. They have been reducing tillage, planting cover crops, stopped spreading manure on frozen ground, set aside vegetative strips along streams and rivers, fenced livestock out of streams and invested in expensive manure storage facilities.
Policy alternatives described as "most promising"
by Jay Martin of Ohio State University, the report's co-author, include
widespread use of the best-management practices and conversion of some
croplands to switchgrass or other grasses.
One called for removing nearly 30,000 acres in the watershed
from production. That's the equivalent of 6,300 farms, as the average farm in
the area consists of 235 acres.
Jeff Reuter, past director of Ohio Sea Grant and a Lake Erie
specialist who wasn't involved with the study, said some cropland is so
overloaded with phosphorus that turning it into grassland or wetlands is the
only way to stop runoff.
