Hidden cost in productivity: Why fertilizer emissions accounting needs an overhaul

As Canadian farmers produce more per acre to feed a growing global population, fertilizer use has jumped 108% over the past two decades. That has come with an environmental impact: synthetic fertilizers now account for a quarter of the agriculture sector’s emissions in Canada.¹ But the current emissions accounting system is flawed as it primarily focuses on the quantity used. What’s missing in the equation is farmer stewardship of fertilizer use to optimize placement, source and timing that help lower emissions.

In an effort to optimize fertilizer use, the number of Canadian farmers with a nutrient stewardship plan has more than tripled over the past five years.²

Rising adoption rates are a sign of climate action. But it’s also an economic decision, especially as geopolitics continue to disrupt fertilizer supplies and raise prices. Nitrogen fertilizers have faced the brunt of supply chain shocks from geopolitical conflicts over the past five years as key producers include the Middle East and Russia. Nitrogen is also the primary driver of GHG emissions from fertilizer use. When nitrogen is not fully consumed by crops to grow, nitrogen can be emitted into the atmosphere as nitrous oxide (N₂O) emissions, a GHG that is 273 times more potent than carbon dioxide over a 100-year time scale. When farmers adopt nutrient stewardship practices, GHG reductions can be substantial. An Ontario study, for example, found that when nitrogen fertilizer rates are optimized, and technology and practices that improve the source, timing and placement of fertilizer are adopted, N₂O emissions can fall by up to 57%.

To capture in the accounting the full suite of practices, Canada, and other agriculture producing countries, including Australia, Denmark, New Zealand, Brazil and the U.S., are developing research and industry networks to collaboratively advance N₂O measurement and monitoring systems.  

These research-driven networks have multiple lab-to-market applications, including those focused on:

• Improving the understanding of how farmers’ practices impact N₂O emissions, supporting investment decisions by farmers, industry and governments in nutrient stewardship

• Building a suite of indicators that allow for more accurate tracking against GHG emission targets at the farm, regional and national scale

• Refining the measuring, monitoring, reporting and verification (MMRV) protocols for carbon offsets and sustainability programs, improving the accounting of farmers’ climate actions to better connect them to market-based incentives and provide greater assurance to carbon credit buyers

Canada: A driving force in innovation of measurement and monitoring practices

Canada’s response to fertilizer-related N₂O emissions has increasingly focused on improving measurement, coordination, and on-farm nitrogen management. A central initiative is the Canadian Nitrous Oxide Network (CanN2ONet), a collaborative research network involving universities, government agencies, farmer groups, and industry partners. The network was established shortly after Canada’s national target for reducing fertilizer-related N₂O emissions by 30% by 2030 was announced in 2020—a policy with notable industry push back that has since faded in sector discourse.

CanN2ONet operates a series of long-term monitoring sites across Alberta, Saskatchewan, Manitoba, and Ontario. These sites use micrometeorological techniques to continuously measure N₂O emissions from agricultural fields under different climates, soil conditions, and management systems. The network also addresses a long-standing challenge in agricultural climate policy: accurately measuring emissions at field scale. Traditional national GHG inventories often rely on generalized assumptions that do not fully capture local soil and weather conditions.

Denmark: An ambitious vision for meeting GHG targets

Denmark’s SmartField initiative represents one of Europe’s most advanced efforts to reduce agricultural N₂O through data-driven and field-scale innovation. Led by the Danish Technological Institute and funded by the Novo Nordisk Foundation, SmartField aims to cut N₂O emissions from Danish agriculture by as much as 30% by 2030 without reducing yields or increasing other forms of nitrogen pollution. 

Canada and Denmark-based researchers are advising one another as both CanN2ONet and SmartField focus on building a national testing and validation platform for emission-reduction technologies and farming practices. The SmartField project combines stationary “supersites,” mobile measurement systems, advanced sensors, and modelling tools to monitor how fertilizers behave in real farming conditions. These facilities generate detailed datasets on nitrogen cycling, soil biology, crop performance, and greenhouse gas emissions. 

One of the initiative’s features is the integration of science, policy, and implementation. SmartField brings together universities, government agencies, agricultural organizations, and private-sector stakeholders to accelerate the adoption of low-emission farming practices.

New Zealand: Balancing rural economic growth and GHG trajectories

Agriculture accounts for roughly half of the country’s GHG emissions. Cattle manure from livestock and fertilization of grasslands for animal feed are the main culprits of N₂O emissions. The agricultural sector is also the largest contributor to export revenue, accounting for 70% of merchandise exports, with agricultural production alone contributing 5% to the country’s GDP.

New Zealand’s approach to managing its large agriculture environmental and economic footprint has evolved over the past five years with an initially strong prioritization on GHG reductions aligned with legislated net-zero targets. Through industry engagement, the focus has shifted towards innovation and scaling practices and technologies that present win-wins in productivity and emissions reduction. A government-led, centralized approach to advancing N₂O emissions accounting has been driven by the country’s Ag Emissions Centre and rolls into New Zealand’s broader ambitions to mitigate GHG emissions from agriculture.