Phosphorus in Lake Winnipeg While agriculture is often blamed, experts say flooding of farmland has contributed to the problem
Manitoba farmland is covered by a sea of regulations about drainage and manure management but is also plagued by a drought of Manitoba-based research, says an expert in soil science.
“There are misconceptions all around about how phosphorus gets from soil into Lake Winnipeg,” Steve Sheppard said in a panel discussion during the Manitoba Pork Council’s annual meeting.
“A large amount of the research done on the problem of phosphorus leaving soils and going into lakes is from areas where the landscape is not flat.”
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Manitoba hog farmers are struggling with many layers of regulatory control on their operations that dictate many elements of production and management, but those controls are based mostly on out-of-province research that Sheppard said “is not relevant to Manitoba.”
Water issues have gigantic political impact in Manitoba: large-scale flooding has hit the province repeatedly in recent decades, hundreds of millions of dollars have been spent on the Red River floodway that protects Winnipeg, and the ailing quality of Lake Winnipeg’s water has been one of the hottest topics in the province for years.
Algal blooms have become alarming large in recent years.
A continuing blame game has seen urban residents blaming farmers for phosphorus and nitrogen loading of river water that ends up in the lake, while others blame the city of Winnipeg for repeated sewage spills.
Some researchers say the main cause of nutrient loading in river and lake water has been the string of wet years and floods that have caused much water to pour off of farmland.
The hog industry has been targeted by some activists as a particular cause of the lake’s problems, and the provincial government has specifically focused on restricting the hog industry’s ability to spread manure and build new operations as a way to protect Lake Winnipeg’s water quality.
The hog industry argues the focus on it is unfair because it produces a tiny minority of the phosphorus going into the lake and there is little or no evidence that it is a particular cause of the problems.
Hog farmers are restricted in how much manure they can apply to farmland, when they can apply it and how they can apply it.
Voluntary and mandatory measures have been implemented over the years to control the flow of phosphorus from farmland into waterways, but Sheppard said much of it has likely been ineffective.
He said vegetated buffer strips along the sides of fields that border streams and rivers might not work in most of Manitoba because strips filter out phosphorus contained in solid materials carried along by fast-flowing water. In most of flat Manitoba, nutrients are carried in a dissolved form, which aren’t filtered out by the buffer strips.
Water quality experts argue that excessive drainage of farmland and the eradication of wetlands are the chief culprits for Lake Winnipeg’s nutrient loading.
Some have argued that reestablishing wetlands and holding back more spring flood waters in rural areas could be key components in improving the Lake Winnipeg situation.
Others have cautioned that holding back water on farmland allows plant-based phosphorus to break down and be absorbed by the water, which means phosphorus levels would be higher when it eventually drains.
The Manitoba Water Council, a government-supported industry-community-researcher organization, recently held a summit on the concept of retaining more water in rural and farming areas.
It was the official kickoff for formulating a surface water management policy approach that could address the multiple and complex issues that affect farmland, water flow, drainage and lake water quality in the province.
Farm groups become anxious whenever water quality becomes an issue in Manitoba because many expect to see farmers blamed for problems.
With more than half the province living in Winnipeg, and the present provincial government heavily dominated by Winnipeg MLAs, farmers often feel they become easy targets.
While the hog industry was specifically targeted in the Save Lake Winnipeg Act, other farm, business and industry groups rallied to the pork industry’s defence, seeing a “thin edge of the wedge” appearing.
With more than 70 percent of phosphorus used by Manitoba farmers coming from commercial crop fertilizer, and the cattle industry producing far more than the hog industry, any expansion of phosphorus re-strictions could hit a much bigger population of farmers, according to Keystone Agricultural Producers.
The Manitoba Water Council includes groups like KAP and the Association of Manitoba Municipalities, which are broadly based, so many hope that its work will be based on solid, Manitoba-based research rather than on assumptions that might not be correct.
