Soil science digs deep on emissions

Some phrases sound good…until they don’t: “Good grief!”; “smart bomb”; “sweet sorrow”. In the same vein, “greenhouse” seems positive, but pair it with “gases” and you have a problem. As the leading cause of climate change, greenhouse gases (GHGs) are a major concern. In 2021, the Canadian government released its 2030 Emissions Reduction Plan, aimed at lowering emissions in various sectors by 40 per cent below 2005 levels by 2030, and achieving net-zero emissions by 2050. Since fertilizers result in the release of nitrous oxide, a powerful GHG, the plan includes a 30 per cent reduction in fertilizer emissions by 2030. As researchers work to help agriculture do its part for the cause, while preserving grower profits, projects like “Nitrification Inhibition on GHG Emissions, Soil Health and Barley Performance" are a key piece of the puzzle.

“By necessity, agriculture in Canada uses huge amounts of urea [a fertilizer rich in nitrogen that can aid crops with high nitrogen needs],” said Dr. Linda Gorim. Gorim is an assistant professor, Department of Agricultural, Food and Nutritional Sciences at the University of Alberta, and WGRF (Western Grains Research Foundation) chair in Cropping Systems.

“We know we have to reduce emissions, and one option for doing so is enhanced efficiency Nitrogen fertilizer (EENF).”

These fertilizers aim to reduce the loss of Nitrogen to the environment while boosting nutrient availability for crops. They do so by either slowing the release of nutrients for uptake or delaying the conversion of ammonium to nitrates that are prone to losses. Though EENFs are not new, they have been gaining more attention lately in the wake of the 2030 Emissions Reduction Plan.

Up for adoption

“Unfortunately, there has yet to be wide adoption of EENFs, as they have not been shown to increase yields enough to offset the additional cost incurred from their purchase. Generally, 40 per cent to 60 per cent of applied urea is taken up by the crop, depending on the production system and management practices. As an industry, we need to increase that uptake and reduce the amount of urea lost to the environment through GHGs or leaching.”

Leaching involves the removal of water-soluble nutrients from the soil via runoff or drainage. It represents an environmental issue for agriculture as chemical-heavy fertilizers are swept away and wind up in bodies of water.

“One way to minimize leaching is for growers to apply EENFs, either mixing them with urea or buying already coated urea products from companies.”

On average, EENFs cost about $0.10 per acre more than regular urea, but if scientists can enhance their efficiency, these products may hold more appeal for farmers.

Keeping their balance

“In light of the 2030 Emissions Reduction Plan, the government is asking growers to be custodians of the environment, a role they take very seriously. Farmers care about the land, yet they also have to feed an ever-growing population. That is a real challenge, so we launched this project to see if reducing the amount of EENF applied in the field would compensate for the extra expense and make sense economically.”

EENFs work by stopping the bacteria that breaks down urea into nitrates, which are then converted to nitrous oxide, a leading GHG. Researchers posit that by slowing this process, they can keep more urea in the vicinity of the plant, thereby increasing its efficiency, lowering the amount of EENF needed – to account for its extra cost – and reducing waste and environmental impact.

“As part of the study, we will conduct an agronomic analysis of barley crops in the presence of reduced EENF application rates to see if farmers break even or perhaps actually save money with this approach. We will also determine how much GHG is produced when using EENFs and their effects on the soil microbiome.”

The trials cover both feed barley (AB Cattelac, a 6-row variety) and malting barley (AAC Synergy, a two-row variety). Since no studies have been carried out on the Prairies with barley to date, researchers chose two lines with contrasting genetics to gain a full picture of the crop’s response to EENF. Testing is slated for three sites including the University of Alberta, University of Saskatchewan and a volunteering farmer’s field in Manitoba.

“Based on our findings, barley growers can crunch the numbers to make an informed decision about EENFs and whether they make economic sense for their operation. Also, barley commissions will have the data we gather on GHG emissions for reporting to the federal government on how much we may reduce emissions from barley production when we apply EENFs using the 4R approach [right fertilizer source at the right rate, right time and in the right place]. This will dovetail nicely with agriculture’s efforts to support the 2030 Emissions Reduction Plan.”

No Dutch treat

According to Gorim, the need for science-based solutions to GHG emissions is underlined by the situation in the Netherlands, where mass protests erupted recently. This was in response to the government’s pledge to cut nitrogen emissions by 50 per cent by 2030, a move it acknowledged could force some farmers out of business.

“We don’t want to see that sort of thing in Canada. Our producers are already dealing with droughts, floods and high input costs, so we need to reduce their stress by offering solutions based on prairie- specific data.”

Of course, providing those solutions comes at a cost, and Gorim is quick to credit funders for footing the bill.

“I am so grateful for the support from the WGRF and the Canadian Barley Research Coalition [a collaboration between the Saskatchewan Barley Development Commission, Alberta Grains and the Manitoba Crop Alliance]. In addition to funding, they both offered a lot of guidance as I prepared the research proposal. I was a bit green around the edges at that point, so their input was a huge help. I also want to thank producers, as they are integral to all of our research projects.”

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