Connected To The Land 04-2018-Fall-718-PM96 - Page 10

Inconsistent carbon sequestration in Canadian forests also hurts western growers’ chances of being rewarded for sequestering carbon. and if you believe the century model, it would tell you that there is not much more that can be gained in sequestering carbon,” Bennett said. Tenuta said Canadian officials have shied away from advocating for the inclusion of carbon sequestration in soil at the international level because Canadian forests are not the carbon sink they were once thought to be. He said the Prairie Soil Carbon Balance Project (PSCBP) is an important initiative that will help with the truth on carbon models of prairie soils. Former Prime Minister Brian Mulroney’s Progressive Conservative government and subsequent Liberal governments were forceful at the international level in pushing to get carbon sequestration in soil included in the discussions and agreements on climate change. This was largely because Canadian officials thought there was a massive amount of carbon being taken up in the boreal forest. However, Tenuta said once federal scientists looked closely at the carbon sequestration and emissions rates of Canadian forests over time, they found the amount of carbon being sequestered to be highly variable. Some years there would be huge carbon sequestrations, other years would be neutral and then there were years with a massive release of carbon from forest fires. “Canada immediately shut up on the world scene and said, ‘carbon sequestration, we’re not talking about it,’ ” Tenuta said. “If you talk about it for soils for direct seeding, then other countries are going to make us talk about it for forest.” In 2005, former Prime Minister Stephen Harper’s Conservative government set Canada’s original reduction target, which is to reduce greenhouse gas emissions by 30 percent below 2005 levels by 2030. While using 2005 emissions as the measure for all carbon gains or losses may work for most industries in Canada, it presents a big problem for western grain growers. Much of the soil organic carbon gains enabled by direct seeding happened before 2005 because most western grain growers transitioned to direct seeding before then. The project, which has been running for 20 years, measures soil organic carbon levels in approximately 130 sites around Saskatchewan. The carbon levels at these sites were measured before and five times since the uptake of direct seeding in the province. Bennett said the project shows soil organic carbon has increased in minimum tillage fields far beyond what the century model predicts. “The Prairie Soil Carbon Balance Project to date, which has run 20 years, is showing there is some serious weakness in the Century Model,” Bennett said. “I think the ag sector should pay very close attention to this because what it would do is it would indicate that there is tremendous potential here that is not being recognized.” He said the SSCA is planning a second PSCBP. There are also ongoing studies examining if rotations that include pulses, canola or cover crops are capable of sequestering carbon beyond what the Century Model predicts. Tenuta said it’s also difficult to implement carbon regulations that account for carbon being sequestered into soil because even though recommended agronomic practices increase soil organic carbon, the carbon can quickly be lost. “We can also lose the organic matter if we till the soil or if we changed our rotation,” he said. “So that’s a thing we would have to address as well, in terms of do we have to worry if we have to change the land use and it loses 2011 carbon and you’ve received carbon credits for it in the past?” Western Canadian grain farmers who direct seed and use recommended rotations that include a pulse have among the world’s lowest greenhouse gas footprints when it comes to emissions per bushel of grain produced. However, there is no premium being paid for this efficiency on the bulk of Canadian exports. This is largely because markets where much of Canadian grain end up, often in Asian destinations, are not looking for sustainability measures when sourcing grain. Also, Canada’s global pledge to cut carbon emissions by 30 percent below 2005 levels by 2030 requires overall greenhouse gas emission reductions, which is not necessarily compatible with focusing on efficiency per unit of production. Mario Tenuta of the Soil Ecology Laboratory at the University of Manitoba said focusing only on greenhouse gas per bushel produced is a bad way to frame the issue because Canadian crops are constantly getting larger, so there can still be an increase of N20 emissions from Canadian growers even if the greenhouse gas level per bushel is reduced. “I also think that in some cases the efficiency approach makes us relax a little bit, whereas if we say we are going to reduce the N20 emissions per acre, it means we have to work a lot harder. “We have to do the research, come up with the practices, do the extension, find out the costs, the profitability and the economics of those practices. I think it can be done, we just have to make a real effort to do it,” Tenuta said. W For more information on the SSCA’s Soil Carbon Position Paper, visit http://bit.ly/2EQDJxl This article originally appeared in the January 25, 2018 edition of the Western Producer. This map from Agriculture Canada shows the amount of organic carbon change in Canadian soil over time. See AAFC’s Soil Organic Matter Indicator at http://bit.ly/2rELLYG. “This is a painful, painful thing,” Bennett said. “It’s enshrined in federal policy, and it’s suggesting that any thing to count as a carbon offset has to be additional to what was done in 2005.” Furthering the deck-stacking against western grain growers are the carbon models that the federal government uses — the Century Model — which suggests that soil organic carbon levels out at a steady state after 20 to 30 years of direct seeding. “The challenge is the Century Model is a model that a lot of federal policy is made on, 10 Large Increase (> 90 kg ha/yr) Moderate Increase No Change (25 to 90 kg ha/yr) (-25 to 25 kg ha/yr) Moderate Large Decrease Decrease (< -90 kg ha/yr) (-90 to -25 kg ha/yr) Not Assessed Connected to the Land