Nitrous Oxide Emissions in Response to ESN and Urea Application in a No-Till Barley Cropping System

We investigated the effect of environmentally smart nitrogen (ESN) fertilizer on nitrous oxide (N2O) emissions under no-till barley (Hordeum vulgare L.) production over 3 years at three sites in Alberta, Canada. Treatments included two barley cultivars, with ESN and urea applied at 1x and 1.5x the recommended rate, and herbicide at 50% and 100% of registered in-crop rates. Cumulative N2O emissions over the growing season were low (0.11 to 1.32kg nitrogen (N) per hectare or 0.05-0.22gNkg(-1) grain yield), and not affected by barley cultivars or herbicide rates in all nine site-years, nor by fertilizer type or rate in seven out of nine site-years. However, average N2O emissions from ESN were 15% lower (P=0.05) than urea across all site-years. Our results suggest ESN could play a role in reducing N2O emissions, but the reduction will depend on rainfall events and crop N utilization.