Abstract. Nitrogen fertilizer applied to soil is the primary source of the greenhouse gas (GHG) nitrous oxide (N 2 O). The assessment of N 2 O emissions, or net fluxes of the GHG methane (CH 4 ), are lacking for upland, arid agricultural ecosystems worldwide. In California, where rates of application for nitrogen (N) can exceed 300 kg per hectare for N-intensive fruit and nut crops (.2 million acres), liquid N fertilizers applied through microirrigation systems (fertigation) represent the predominant method of N fertilization. Little information is available for how these concentrated and spatially discrete N solution applications influence N 2 O emissions and net CH 4 fluxes (the sum of methanogenic and methanotrophic activity). In this study we examined soil N 2 O-N emissions and net CH 4 fluxes for drip and stationary microsprinklers, two of the most widely used fertigation emitters, in an almond orchard where 235.5 kg N/ha were applied during the season of measurement (2009)(2010). We accomplished this by modeling the spatial patterns of N 2 O and CH 4 at the scale of meters and centimeters using simple mathematical approaches. For two applications of 33.6 kg/ha and three applications of 56.1 kg/ha targeted to the phenologic stages with highest tree N demand, the spatial patterns of N 2 O fluxes were similar to the emitter water distribution pattern and independent of temperature and fertilizer N form applied. Net CH 4 fluxes were extremely low and there was no discernible spatial pattern, but areas kept dry (driveways between tree rows) generally consumed CH 4 while it was produced in the microirrigation wet-up area. The N 2 O-N emissions for fertigation events at the scale of days, and over a season, were significantly higher from the drip irrigated orchard (1.6 6 0.7 kg N 2 O-N ha À1 yr À1) than a microsprinkler irrigated orchard (0.6 6 0.3 kg N 2 O-N ha À1 yr À1 ). N 2 O emissions and net CH 4 fluxes were only significantly correlated with soil water filled pore space and not with mineral-N. The correlation was much better for N 2 O emissions. Our results greatly improve our ability to scale N 2 O production to the orchard level, and provide growers with a tool for lowering almond orchard carbon and nitrogen footprints.