Potato yield projections under climate change in Canada

Potato (Solanum tuberosum L.) is an important staple crop in Canada. Past studies have forecasted future yield decreases under climate change, which could have major consequences for the economy of some regions. However, limitations in those studies suggest that further investigations are needed. In this study, we simulated the effect of 15 climate change scenarios (classified from low to moderate and high) on potato potential (no N and water stresses) and rainfed (no N stress) yields at 59 locations across Canada representing current and future potential production regions using three crop models (Decision Support System for Agrotechnology Transfer [DSSAT], DeNitrification and DeComposition [DNDC], and Simulateur mulTI-disciplinaire pour les Cultures Standard [STICS]). Simulation trends were generally consistent across all three crop models and suggested (1) an increase in potential and rainfed yields in the future (up to 4.4 t ha⁻¹ dry matter in 2051–2080 compared with 1991–2020) in the northern regions where production is currently limited, if not impossible, due to a too short growing season; (2) a slight-to-moderate increase in potential and rainfed yields in the near future (2021–2050) for the remaining regions with greater increases for drier regions (0.7–3.1 t ha⁻¹) than in wetter regions (0.5–1.4 t ha⁻¹); and (3) stable or lower yields (up to −2.7 t ha⁻¹) in the distant future (2051–2080), for most regions except the northern ones, due to excessively high temperatures, especially in the moderate and high-climate change scenarios. This study gave the first extensive projections of future potato yield in Canada, including northern locations where production may become possible.