U of A researchers study ways to cut agricultural greenhouse gases
EDMONTON A University of Alberta professor is working to find the best system for grazing cattle as a way to store massive quantities of greenhouse gases in the dirt under Western Canada’s grasslands.
“There are vast amounts of carbon in grasslands soils, and all of that has been accumulated, at least in Alberta, over the last 9,000 years,” Mark Boyce, a professor in the department of biological sciences, said Friday.
“If we continue to manage with permanent grassland cover and reasonably intensive grazing, we should be able to continue to add to the soil.”
He has received a $2-million grant under the federal Agricultural Greenhouse Gases Program to evaluate alternative ways to feed livestock to support plant diversity, protect bird habitat and store carbon on land that can annually take in up to three tonnes of carbon dioxide equivalent per hectare.
One approach that’s popular in the United States is to divide ranches into dozens of paddocks, graze one space for a few days and then let the foliage recover while animals are moved elsewhere, but Boyce isn’t sure how well that will work in Canada’s shorter growing season.
Light, continuous grazing might be a better option. Grasslands need some grazing — historically done by bison — to encourage optimal plant growth, Boyce said.
His team will spend five years studying 60 farms as far east as Manitoba to find what’s best.
“If it’s over-grazed … we can lose carbon from the soil, so the how and when and times grazing is done is important to maximize the sequestration of carbon,” he said, explaining vegetation captures the element from the air and holds it in its roots and rhizomes.
“All the carbon is underground, and it’s safe there. Unless you till it, it will stay there for thousands of years.”
Two of his U of A colleagues are also receiving money under the greenhouse gases program.
Guillermo Hernandez Ramirez was given $1 million to analyze the greenhouse gas intensity of perennial and annual cereal crops, while Scott Chang collected $690,000 to study enrichment planting in shelterbelts and windrows.
Boyce’s work includes examining the amount of carbon in the ground so farmers and ranchers can claim government funding under carbon sequestration programs, and holding meetings to explain their findings.
“I would like to see the revenues that are being generated by the carbon tax invested in ways that enhance agricultural production systems. My interest is in biodiversity and grasslands conservation. We can achieve all those ends with grasslands management,” Boyce said.
All the carbon is underground, and it’s safe there. Unless you till it, it will stay there for thousands of years.