for using fertilizer efficiently
New research by the International Institute for Sustainable Development has confirmed what Keystone Agricultural Producers president Doug Chorney already knew about how farmers manage fertilizer in this province.
After comparing how much synthetic fertilizer Manitoba farmers use in every municipality across agro-Manitoba against the nutrients removed by crops, researchers found farmers here are highly efficient compared to other jurisdictions.
In fact, in some areas and in some years, they are actually applying less than is removed by their crops, which is leaving a net deficit of phosphorus in their soils.
“What it points out is that Manitoba (farmers are) actually very efficient users of fertilizers in total compared to other jurisdictions in the world and they are getting better,” said Hank Venema, director of IISD’s Water Innovation Centre.
Chorney said the study, a draft of which was released at a Winnipeg conference on water management last week, came as no surprise. But it was encouraging all the same.
“It proves that producers are efficiently managing synthetic fertilizer use and I think that confirms what many of us know,” he said. “But it’s nice to have some evidence of that.”
Chorney said crop farmers have been accused of over-applying fertilizer, which contributes to increased run-off and nutrient contamination in Lake Winnipeg. “I think we can make the case that synthetic fertilizer is used pretty efficiently.”
But still too much
But while the way farmers manage their inputs isn’t a major contributor to nutrient overloads in the water systems, how they manage their land might be playing a bigger role than previously thought.
“Despite this overall high efficiency and improving efficiency and running into net deficits in recent years, we don’t see that in the ecological watershed response. We see a still increasing nutrient loading to Lake Winnipeg,” Venema said.
Venema said the IISD research reinforces the findings of Ducks Unlimited research in the Broughton’s Creek watershed. It concluded water quality monitoring doesn’t properly measure the dynamics of rainfall run-off events.
“The other implication is that the phosphorus that’s in the system from decades past is still being mobilized and is still loading up Lake Winnipeg,” he said. “So despite the fact that we are efficient and getting more efficient, there is still a lot out there because of the size of the land mass and loadings from decades past (that) we think are getting mobilized under flooding events, and high rainfall events.”
DU researchers also found that increased drainage is not only increasing the flow of water, it is mobilizing the nutrients it previously stored on the landscape.
“It is what is called ‘Legacy P,’” Venema said. “There is so much in the system from decades past — some natural, some synthetic — that the only way to remove this from the system is by interception.”
Venema said the research is reinforcing the need to curb and perhaps restore wetlands “to intercept those nutrients because they are old nutrients that are coming off the landscape and there are very few other ways to get at them and stop them.”
He said the study also points to a need for methods that remove nutrients from the system permanently, rather than simply storing them, such as with biomass harvesting.
“There is a logic to managing our distributed storage systems to permanently remove those nutrients and reapply them where they are needed,” Venema said.
Manitoba Conservation Minister Gord Mackintosh told the day-long conference, called Keeping Water on the Land, the province will be announcing a new surface water strategy along with a new drainage policy within weeks.
“We are looking at that as a key shift in how the landscape of Manitoba must look,” Macintosh said.
While crediting the leadership the agricultural community has shown towards nutrient management, Macintosh said one of the province’s goals will be to curb ongoing and alarming loss of wetlands.
“How do we continue to enhance our agricultural productivity while not continuing to drain as we have in the past?” he said, noting the province has been working with KAP, Ducks Unlimited and the Manitoba Conservation Districts Association to overhaul drainage licensing.
Macintosh said surface water management will work towards using “seasonal wetlands” to temporarily store water. Drainage regulations will shift away from “culvert cops” that delay minor drainage maintenance such as culvert replacements towards a risk-based system that results in no net loss of wetlands.
He hinted that enforcement will be beefed up to curb illegal drainage. “In concert with the risk-based approach we are looking as well at the consequences that are currently there and what might speak more effectively,” he said.
As well, Macintosh said the federal and provincial governments are drafting an environmental goods and services initiative, under which farmers receive incentives and compensation for maintaining wetlands under the Growing Forward 2 program.
Macintosh told the conference that if Manitoba has any hope of achieving co-operation between the jurisdictions contributing towards the nutrient overloads in Lake Winnipeg, it must be seen as a leader in water management.