Near-Term Nitrous Oxide Reduction Options
Systematic review of fertilizer strategies identifies practical options to cut emissions, with implications for Canada’s 2030 reduction targets.
Increasing pressure to expand output while maintaining or decreasing input and land use has placed farmers in a difficult position. The increase in fertilizer use to support growing yields and soil deficiencies in Canada lead to a significant spike in nitrous oxide emissions over the past 18 years. In 2020, the federal government of Canada introduced the first emission reduction target specific to the agricultural sector, aiming for a 30 percent reduction of inorganic fertilizer-based emissions by 2030.
Agriculture and Agri-Foods Canada released a discussion paper in 2022, supplementing the federal government’s target with practical strategies and recommendations for farmers to adopt with associated changes and trade-offs, in order to reach the target. This systemic review of meta-analytical studies based explores the potential impact of 4R stewardship adoption and other mitigation strategies, including biochar, irrigation, and the use of legumes in crop rotation, on N2O emissions in Western Canada. Results were mixed, likely due to the interrelationships between environmental and soil factors in the nitrogen and hydrological cycles.
Overall, enhanced efficiency fertilizers were identified as the most advantageous and applicable practices, with less applicable practices like biochar and micro irrigation also reducing N2O emissions. In order to improve N2O emission measurements and reflect the adoption of all mitigation strategies, Canada’s N2O accounting methodology should be updated before the 2030 target deadline.