Regionalized life cycle inventory and assessment of conventional and potential alternative malting barley production practices in western Canada

Western Canada has a reputation for producing high-quality malting barley due to favourable climatic and soil conditions, on-farm management practices and crop genetics. However, malting barley production has been documented as a significant contributor to the greenhouse gas (GHG) emissions of beer production, with inorganic nitrogen (N) fertilizer consistently identified as a major contributor to life cycle environmental impacts. With Canada announcing its intention to reduce GHG emissions by 45% below 2005 levels by 2030, it is imperative to assess and mitigate the environmental impacts of malting barley production, particularly those associated with inorganic N fertilizer production. To establish baselines of the resource intensity and environmental impacts of Canadian malting barley production, and to inform and track future emission reduction measures, this research conducted a cradle-to-gate ISO 14044-compliant life cycle assessment (LCA) study of malting barley production in western Canada. Primary life cycle inventory (LCI) data were collected directly from 51 farmers via a survey. Production was modelled at the individual farm level and aggregated to regional and varietal averages to identify key drivers of variation in environmental performance. A systematic PRISMA literature review was conducted to investigate the cost, techno-economic feasibility and environmental impact mitigation potential of green ammonia as an alternative to conventional ammonia production for inorganic N fertilizers. A scenario analysis was subsequently performed to evaluate the environmental mitigation potential within the context of Canadian malting barley production. The LCA identified field-level emissions from nitrogen fertilizer application, nitrogen fertilizer production and field-activity fuel use as significant contributors to life cycle environmental impacts and resource intensity. The scenario analysis demonstrated that the transition to green ammonia fertilizer could reduce global warming and fossil resource scarcity impacts for the malting barley product system by 10% and 25%, respectively. However, trade-offs were identified for water, land and energy use, as well as increased toxicity impacts of up to 60%. In the near-term, mitigation efforts should prioritize demand-side strategies to reduce nitrogen fertilizer use on farm. It is recommended to investigate the nitrogen-use efficiency of major malting barley varieties and to breed new nitrogen-efficient varieties.