On Aug. 22, the Ottawa Soil and Water Conservation District held the “Lake Erie Ag Tour 2011.” With all the headlines about algal blooms on Ohio lakes the past two years, and farmers getting much of the blame, the goal of the tour was to get farmers on Lake Erie and let them see things firsthand.
About 40 farmers, local homeowners and government officials participated. They traveled on Ohio State University research vessels to sample the lakes water, then to Gilbralter Island, home of OSU’s Stone Laboratory and Ohio Sea Grant Program, to analyze their samples.
“I want to know what we have to do for our farms to push less phosphorus into the lake,” said Dave Fastinger, an Ottawa County hog producer who participated in the tour. “I like fishing in Lake Erie as much as anyone, so I came to hear the latest ideas of what we can do.”
Fastinger has had a manure management plan for his farm since 1977 so there is no runoff into waterways. A valve was put into his field tile system, so when irrigating manure onto fields, the valve can be shut to prevent runoff. He uses no-till on all of his crop fields, and no fertilizer is added to areas receiving manure, so nutrient levels do not exceed what is needed for crop growth.
So while he has done a lot already, Fastinger was anxious to take part in the tour to get new ideas and learn the extent of the algal bloom issue in Lake Erie.
“Just to watch all the collecting of data was interesting,” he said.
A recent U.S. Geological Survey report found that sewage-treatment plants in Detroit, Toledo and other lakeside communities put nearly the same amount of phosphorus into Lake Erie as the fertilizers and manure that rains wash off farm fields. That’s a surprise for some Ohio-based scientists who have estimated that farm fields can provide as much as 60% of the phosphorus in Lake Erie.
Dale Robertson, a Geological Survey research hydrologist, said in a Columbus Dispatch article that his computer modeling shows government-ordered cleanups at sewage plants in the 1980s didn’t cut enough phosphorus.
Blue-green algae problems date from the 1970s but vanished from Lake Erie in the 1980s after sewage-treatment-plant upgrades. Farmers also took steps to cut the amount of phosphorus-laden soil that rains wash into nearby streams.
But algae started making a comeback in 1995.
Data from Heidelberg University’s National Center for Water Quality Research show heavy concentrations of farm-field phosphorus flowing down the Maumee and Sandusky rivers and into Lake Erie. Robertson’s results list the Maumee as the leading phosphorus supplier and estimates that 82.6% came from farms.
The Detroit River is the No. 2 source, with nearly 75% coming from sewage-treatment plants. The Detroit River estimate is low, he said, because it doesn’t include phosphorus from the Canadian side.
Overall, according to the USGS report, 42.1% of Lake Erie’s total phosphorus load comes from sewage, and 43.6% comes from farms. The rest comes from decaying plant matter in forests and wetlands and from lawn fertilizers washed into storm sewers.
But while the cause of the algae growth in the lake may be up for some debate, the extent of the problem is not in question. This year, the toxic algae that spreads across the western basin of Lake Erie each summer is the worst recorded since researchers started tracking the problem in 2002.
“Essentially, we’re returning to the conditions we had in the 1960s and 1970s when Lake Erie was the poster child for pollution problems in this country,” said Jeff Reutter, director of the Ohio Sea Grant and Stone Laboratory at Ohio State University, who addressed the tour group after lunch. “The only way to solve this problem is to reduce the amount of phosphorus we’re putting into the lake. Clearly we can’t continue the direction we’re going.”
But society also demands cheap, abundant food, so the challenge for agriculture is how to keep the nutrients on the fields and out of the waterways, Reutter said. Some of his suggestions include:
• Incorporating phosphorus into the soil when it is applied, which can reduce runoff by up to 50%.
• Not applying more phosphorus than is needed agronomically for crops to grow.
• Not applying manure onto frozen ground during the winter.
• Reducing fall applications of fertilizer.