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Smoking Guns And Testy Waters

We almost expected to hear the hoofbeats of a white horse in the background as Manitoba Premier Greg Selinger rode to Lake Winnipeg’s rescue last week.

Armed with a new report by Saskatchewan biologist Peter Leavitt that says changing agricultural practices, specifically increased hog production in Manitoba, are to blame for at least half of the phosphorus overloading in Lake Winnipeg, Sheriff Selinger was full of tough talk about saving the lake from a slow, choking death due to toxic algae.

OK. It’s an election year. Politicians are prone to bluster. We get that.

But aside from the possibility that Leavitt’s somewhat illogical conclusions won’t hold up to scientific scrutiny, (more on that later), leadership is about building bridges, not finding scapegoats and deepening the divisions that already exist between communities.

Manitoba’s hog producers have put more effort and resources into understanding how they interact with the environment than any other sector. They deserve credit for that – not a stick in their eye.

When the smoke had lifted, it became clear Selinger was shooting blanks when it comes to reducing the hog industry effect on Lake Winnipeg – quite possibly because there isn’t that much effect to reduce.

Push away the pointing fingers and what is the government doing to the hog industry that it hasn’t already done?

It’s legislating a ban on winter manure spreading. Large operations haven’t done that for years and regulations due to take effect in 2013 remove that option for small operators. Enshrining it in legislation matters not one iota to the lake.

It is banning any hog industry expansion that does not use “advanced environmental practices.” When asked, Selinger was at a loss to describe precisely what was meant by that somewhat nebulous terminology.

There is already a total ban on expansion on the eastern side of the province. Livestock operations must already file manure management plans before they can be approved. It’s highly doubtful anyone proposing antiquated or harmful practices would be allowed to proceed.

Leavitt’s report is based on sampling lake sediments to determine nutrient increases over time. His research team then correlated those findings against climatic data and land-use changes in search of an explanation for a sudden surge in nutrient overloading in recent decades.

Their conclusion? “Water quality degradation during the 20th century is explained best by changes in livestock and crop production. Climate change had much less direct effect.”

The study team then looked at the fivefold increase in the hog industry since the 1990s and said “aha.”

Well, the hog industry did increase, and in the early days of that expansion, manure management practices did leave something to be desired. That said however, hog manure is not widely spread on the Manitoba landscape.

The 2007 Clean Environment Commission report into the environmental sustainability of the hog industry found that the sector produces 5,000 to 7,000 tonnes of phosphorus annually. At the time, hog manure was applied to 2.5 per cent of Manitoban’s cropland. Even in the areas where it is applied at rates higher than crop-removal rates, it’s hard to fathom how that can be the smoking gun responsible for polluting the lake.

The Leavitt study also makes note of increased intensification of crop production.

We wonder whether the research team considered another significant shift in land management practices during that same time period – such as the widespread adoption of conservation tillage and zero tillage.

University of Manitoba researchers studying the water quality effects of land management practices discovered that while zero tillage reduced the amount of nitrogen lost in run-off water by 68 per cent, the amount of phosphorus in run-off water increased by 12 per cent and the concentrations of P in that run-off water rose by 42 per cent.

This is not to suggest farmers should pull the old mouldboard plows out of the bush – only that this transition took place across a much broader land base and would be a more plausible explanation for increased phosphorus loading than hog barns. Less tillage is also associated with increased soil fertility.

Perhaps farmers can get by with buying less phosphorus, period. Who pays for that research? Certainly not the fertilizer companies.

Which brings us to the one positive thing for agriculture we can pull out of last week’s press conference – official acknowledgement that farmers provide ecological services.

Using the same cause-and-effect analysis that drew the Leavitt team to its conclusions, we surmise that this means the provincial government is ready to fund both research and direct incentives to help farmers fulfil that role. [email protected]

About the author

Vice-President of Content

Laura Rance

Laura Rance is vice-president of content for Glacier FarmMedia. She can be reached at [email protected]



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