Ratio of non-growing season to growing season N₂O emissions in Canadian croplands: an update to national inventory methodology

National inventory reporting of agricultural nitrous oxide (N 2 O) emissions in Canada is based primarily on measurements obtained using static chambers. In regions with cold winters and an accumulated snowpack (including Canada), these tend to focus the growing season (typically May–October). However, research has shown that continue throughout non-growing (NGS) account for a significant proportion annual emissions. Canadian Inventory NGS currently are assumed be adequately captured western Canada, while they accounted eastern by multiplying correction factor 1.4, value was derived limited number measurements. Here we use recent studies validate this factor. We collected data from available measured soil N O systems entire year determined occurred during NGS. The varied widely, ranging −4% 119% mean 35.5%, compared previous estimate 30%. Due high variability, few differences were observed between means associated climatic, soil, management variables. To correct soils, suggest current converting total changed 1.4 1.55 used all soils rather than just Canada.