Farmers may worry when global warming critics blame crops and cows.
But researchers in the University of Manitoba’s animal and soil science departments are trying to grab those greenhouse gas emissions and put them back into the soil and animals’ guts.
After all, greenhouse gas emissions are inputs that are being thrown away.
“Loss of nitrogen is not just a nitrous oxide problem but also a loss of fertility from the fertilizer we put on,” said soil scientist Brian Amiro. “Loss of carbon is a loss to the soil because we’re trying to build up soil organic matter to have healthier soils.”
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Animal scientist and greenhouse gas reduction expert Ermias Kebreab agreed.
“If we can improve the efficiency and reduce the loss from the animal, we’re improving the efficiency of production.”
Researchers hope to not only find small, incremental solutions to the problem but also whole-farm, system-wide changes that could improve farm economics and the environment.
The university’s National Centre for Livestock and the Environment is focusing a lot of energy on studying greenhouse gas emissions.
The first big push came from federal government interest under former Liberal governments. Now the main influence is the Manitoba government, which sees agriculture as a significant player in efforts to reduce greenhouse gas.
All cows and crops produce greenhouse gas, but in most provinces agriculture comprises only a small part of the total.
In Manitoba, however, agriculture is the second-largest producer of greenhouse gas, after transportation. And with the economic slowdown, agriculture could become the primary source.
“Agriculture is really looked upon as a means to reduce greenhouse gas emissions,” said Mario Tenuta, head of the university’s soil science department. “It could make significant contributions potentially to a total reduction in emissions from the province.”
However, agricultural researchers know gains will be made only if they pay off for farmers.
“We’re looking at direct gains for the producers,” Amiro said.
“Even if it wasn’t a GHG problem, nitrogen and carbon loss and leakage is something you don’t want to happen.”
Researchers are looking at changing feed rations, crop rotations and the mechanical handling of manure and fertilizer.
Tenuta said these kinds of a la carte changes could bring 10 to 15 percent improvements in crop production.
“It would make a difference,” he said.
“But to get something really serious, like a 50 to 60 percent reduction, we’d probably need to push the envelope on how we do things, and change how we do things fundamentally.”
The biggest greenhouse gas emissions from farmland come during spring and fall, when no crops are on the land and when most fertilizing is done.
Farmland produces few emissions when crops are growing because carbon is taken out of the atmosphere and returned to the soil.
As a result, researchers are trying to find ways to keep the soil covered with growing crops.
One way would be to develop perennial grain crops, which would not require annual seeding and would protect the soil, much the way forage crops do. It would also reduce the number of field operations farmers would have to undertake.
“It’s one of those holy grails,” Amiro said.
“We’ve got to believe that it’s going to happen one day and it’s really going to change how we do things on the Prairies. Especially spring on the Prairies.”
Kebreab said varying the amounts of forages and grains in livestock rations, or adding fats to the diet, can substantially reduce methane emissions.
However, overall reductions from the farm would need to consider emissions from manure, feedgrain production, animal production and transportation.
Sometimes factors altered in one part of a production system to reduce greenhouse gas could increase it along the chain.
“When you put it into a whole system, we don’t know what the relation is,” Kebreab said.
“Everything is interrelated. We need to look at the whole system to find the net greenhouse gas effect.”
