Canadian agriculture can do little to combat greenhouse gases on worldwide scale, but it can take some steps
Canada’s agriculture industry cannot save the planet.
About 8.5 to 10 percent of Canada’s greenhouse gas emissions come from farming, depending on the method of counting, and agriculture produces 60 million tonnes in carbon dioxide equivalents, based on federal government data.
In comparison, China produces about nine billion tonnes annually. If Canadian farmers reduced their carbon footprint by 25 percent, 15 million tonnes, that’s equivalent to China cutting its carbon by 0.0166 percent.
Still, Canadian farmers can do their part and there are real benefits to taking action, such as better relations with skeptical consumers, said an Agriculture Canada scientist.
“(It) goes into this area of social licence and customer demands,” said Roland Kroebel, an Ag Canada scientist in Lethbridge who studies farming and greenhouse gas emissions.
Over the last two decades, Kroebel and his Ag Canada colleagues have been working on a computer model, called Holos, so farmers can evaluate GHG emissions from their farm.
“Holos helps producers green their agriculture operations by monitoring and adjusting farming practices to lessen greenhouse gases,” states information on an Agriculture Canada website about Holos.
The greenhouse gases from agriculture come from two main sources: methane from livestock and nitrous oxide from fertilizer and manure.
Of the two, the public pays the most attention to belching and farting cows, possibly because media reports constantly blame cattle for climate change.
In October, for instance, there were dozens of stories on a United Kingdom Committee on Climate Change report. The document recommended that sheep and cow numbers should be reduced 20 to 50 percent to cut GHG emissions and restore pastures to natural forests.
Canadian producers can push back on such negative reports by using Holos and taking steps to cut emissions on their farm, Kroebel said.
“You can play around with it and find out what works for you, on your farm,” he said.
“Then you’ll have an argument to say: look, these guys from AAFC say this is a better practice.”
Holos software is available on the Agriculture Canada website. It’s free and producers can use it to test out management practices on their farms.
“Examples of these adjustments include changing livestock feed, reducing tillage or including perennial forages in rotation,” AAFC says on its website. “Once information is entered into the program, Holos estimates carbon dioxide, nitrous oxide and methane emissions.”
When it comes to cattle and methane, high-quality feed is an easy way to reduce emissions and increase animal rate of gain.
“You’re passing grain through the rumen. The slower this goes, the more enteric methane you have,” Kroebel said. “The higher quality you have the higher productivity you have.”
Research suggests that Canada’s cattle sector has already made strides, when it comes to beef cattle and GHG emissions.
A University of Manitoba study released in 2016, found that the industry emitted 15 percent fewer greenhouse gases in 2011, per kilogram of beef, than it did in 1981 because of improvements in feed efficiency.
“Every day an animal is alive he or she is burping out methane,” said Kristen Tapley, a cattle producer from Langruth, Man., back in 2016. “If we can speed up that process, of getting the calf off the cow and through the feedlot, our carbon footprint goes down.”
When it comes to fertilizer and NO2 emissions, Holos may be a bit behind the times.
The most recent version of Holos doesn’t account for enhanced efficiency fertilizers.
Such fertilizers, now widely used in Canada, can reduce nutrient losses to the atmosphere and water bodies, while increasing nutrient availability for the plant or crop.
“These fertilizers can either slow the release of nutrients for uptake, or alter the conversion of nutrients to other forms that may be less susceptible to losses,” The Fertilizer Institute says on its website.
Kroebel said Holos can’t account for different types of fertilizers and how their use could impact GHG emissions.
However, one of his Ag Canada colleagues is looking at the relevant data on enhanced efficiency fertilizers and that could be part of the next version of Holos.
Kroebel also hopes to include carbon sequestration in the new Holos, because producers want information on how to get more carbon into the soil.
Zero tillage and crop rotations that include forages, for example, can increase the percentage of organic matter and the amount of carbon stored in the soil. The new Holos will allow producers to test out various scenarios, to see how a particular practice affects carbon sequestration.
Where do Greenhouse gases come from?
In 2016, agricultural practices generated 59.6 tonnes of greenhouse gas (GHG) emissions in Canada — that’s eight percent of all emissions.
It’s transportation that contributes the most to GHG in Canada (28 percent), followed by electrical/heat generation (14 percent.)
Cattle may be frequently blamed as a primary cause of global warming, but Canadian studies show that cattle, which belch methane when they digest feed through enteric fermentation, are responsible for just 3.6 percent of the nation’s GHG emissions.
In fact, agricultural soil produced nearly the same amount of GHG.
In 2016, livestock (mostly cattle) emitted 24.7 tonnes of greenhouse gases while agricultural soils emitted about 24 tonnes, mostly through the release of nitrous oxide, a potent greenhouse gas.
Soils release nitrous oxide through denitrification, a process where bacteria convert nitrates to nitrogen gases that are lost to the atmosphere.
Denitrification is more prevalent when soils are warm and saturated.