Comparing standardised precipitation and barley yield across Quebec

Climate change and variability continue to affect crop production across the world in general and in Quebec in particular. Therefore, it is important to better understand this climate-yield nexus. Unfortunately, in Quebec, there are currently no studies that analyse both precipitation and barley yield. This study aims at filling this research gap by comparing standardised precipitation (SPI) against barley yield gaps across Quebec for three peripheral and three southern/central regions of Quebec. The study uses growing season precipitation data from Ouranos and barley yield data from Institut de la Statistique du Québec. This work deploys the use of standardised index (SPI) index and a machine learning yield gap algorithm (actual barley yield minus projected barley yield) to provide a provincial portrait of the relationships between SPI and barley yield. The results show that the peripheral regions record below zero SPIs (Abitibi-Temiscamingue - 0.48, Saguenay-Lac-Saint-Jean - 0.14 and Outaouais - 0.10) and more yield gap years, while the southern/central regions record positive SPIs (Estrie 1.17, Centre du Quebec 0.86 and Monteregie: 0.33) and fewer years with yield gaps. This shows that there is a south-north gradient in the variations of SPI and yield gaps. The SPI and yield patterns can be explained by prolonged winters further north of Quebec and recently winters with insufficient snow cover which triggers rapid snow melt and thus shortening the growing season for barley. Policy actions around drought-resistant varieties within a co-creation context and more research that explores daily and monthly liquid precipitation totals during the growing season of the crop need to be explored. There is also a need to better understand the economic costs and benefits of the associated yield gaps as well as the impacts of temperature.