Can farmers do more to cut emissions?

The average canola yield on the Prairies increased to 34.1 bushels per acre in 2010-13 from less than 25 bu. per acre in 2000-03.

Meanwhile, greenhouse gas emissions from agricultural soil from applying nitrogen in Canada increased to 32 megatonnes of carbon dioxide equivalents in 2012 from 29 megatonnes in 2000.

This means canola yields increased 40 percent while nitrous oxide emissions from agricultural soil increased only 10 percent.

That may be a great success story, but a University of Manitoba soil scientist says Canada’s agricultural industry can do more. Growers can increase crop yields while lowering emissions.

“I’m convinced we need to reduce total greenhouse gas emissions in agriculture,” said Mario Tenuta, Canada research chair in applied soil ecology, who has been studying greenhouse gases from soil for years.

Tenuta’s comments are timely because Prime Minister Justin Trudeau unveiled a plan in early October to put a price on carbon, starting at $10 per tonne in 2018 and rising to $50 per tonne by 2022.

Lowering greenhouse gas emissions from farming would be a philosophical shift because for the last decade or longer the industry has focused on reducing emissions intensity.

“The story in Canada’s agriculture is that emissions have remained relatively constant (while) production has increased very significantly — livestock products and grain,” said Brian McConkey, an Agriculture Canada scientist in Swift Current, Sask.

“We’re doing really well in terms of getting more product out there per (unit) of greenhouse gas emissions.”

Tenuta said that approach has limitations.

“Agriculture in Canada makes up about 10 percent of emissions,” he said.

“And that’s just the production of food. That doesn’t include the manufacture of fertilizer and pesticides. It doesn’t include transportation fuels and doesn’t include processing emissions.”

He said producers can definitely increase yields and cut emissions from cropland.

“We have research that can show we can reduce those emissions greatly, without affecting yield, and in some cases improve yields,” he said.

“(For nitrous oxide), I know we can reduce the emissions by 30 percent, something like that.”

Critics have said a price on carbon and lower emissions from agriculture will make Canadian farmers less competitive.

In an effort to improve the competitiveness of canola, the Canola Council of Canada has set a yield goal of 52 bu. per acre by 2025. Tenuta said it’s possible to achieve that yield and lower emissions.

“Yes. I think we can do both.”

The question is how.

Tenuta said a great place to start is the 4R nutrient stewardship program, which stands for:

  • right rate of fertilizer, to match crop needs
  • right time, so nutrients are available when plants need them
  • right place, so nutrients are kept where crops use them
  • right source, so that type of fertilizer is matched to crop needs.

The fertilizer trade and agronomists have touted 4R in Canada for a while, but Tenuta said adoption has been slow.

“At the moment, we’re not really going hard with the 4R (approach) … and in some cases we’re going backwards.”

Improvements in plant genetics and nitrogen use efficiency will also be critical because applying less nitrogen will reduce nitrous oxide losses.

“Modern hybrids or varieties are way more efficient at taking nitrogen and producing yield,” Tenuta said.

Paul Thoroughgood, chair of the Soil Conservation Council of Canada and a Ducks Unlimited agronomist, said a shift in thinking about crop yield is another possible solution.

Instead of applying fertilizer to maximize yield, producers should apply fertilizer to maximize profits.

“Sometimes wringing that last five to 10 bushels out of a crop, while it may look good on the scale tickets … it isn’t economical at the end of the day.”

Thoroughgood agreed with Tenuta’s argument that the agricultural industry needs to do its part to cut emissions but said increasing production and lowering emissions intensity has been very effective.

“We’ve seen … less emissions per unit of production, which I think is a great first step, and we need to be careful not to throw away that success.”

Tenuta is convinced it’s technically possible to lower emissions and increase yield, but getting farmers on board may be a challenge.

He admitted this is about a change in behaviour, and change is hard. Nonetheless, today’s growers are more receptive to the topic of carbon and climate change.

“When I’m talking with growers now, I see a big difference from 10 years ago,” he said.

“When I used to talk about greenhouse gases, they would just roll their eyes.”

Tenuta intends to spend more time talking to growers about climate change this fall and winter. He plans to meet with commodity groups and farm organizations, across Canada to discuss lowering emissions from agriculture.

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