Quantifying nitrous oxide (N 2 O) emissions from grazed pastures can be problematic due to the presence of hotspots and hot moments of N 2 O from animal excreta and synthetic fertilisers. In this study, we quantified field scale N 2 O emissions from a temperate grassland under a rotational grazing management using eddy covariance (EC) and static chamber techniques. Measurements of N 2 O by static chambers were made for four out of nine grazing events for a control, calcium ammonium nitrate (CAN), synthetic urine (SU) + CAN and dung + CAN treatments. Static chamber N 2 O flux measurements were upscaled to the field scale (F CH FIELD) using site specific emission factors (EF) for CAN, SU+CAN and dung + CAN. Mean N 2 O EFs were greatest from the CAN treatment while dung + CAN and SU + CAN emitted similar N 2 O-N emissions. Cumulative N 2 O-N emissions over the study period measured by F CH FIELD measurements were lower than gap-filled EC measurements. Emission factors of N 2 O from grazing calculated by F CH FIELD and gap-filled were 0.72% and 0.96%, respectively. N 2 O-N emissions were derived mainly from animal excreta (dung and urine) contributing 50% while N 2 O-N losses from CAN and background accounted for 36% and 14%, respectively. The study highlights the advantage of using both the EC and static chamber techniques in tandem to better quantify both total N 2 O-N losses from grazed pastures while also constraining the contribution of individual N sources. The EC technique was most accurate in quantifying N 2 O emissions, showing a range of uncertainty that was seven times lower relative to that attributed to static chamber measurements, due to the small chamber sample size per treatment and highly variable N 2 O flux measurements over space and time. • N 2 O emissions were measured using EC and static chambers (SC) from a grazed pasture. • The magnitude of mean N 2 O-N EFs measured by SC were CAN > dung + CAN > SU + CAN. • EFs of CAN, dung + CAN and SU + CAN were used to upscale SC N 2 O fluxes (F CH FIELD). • N 2 O-N EFs by EC and F CH FIELD were 0.72% and 0.96%, > IPCC default value 0.6%. • EC showed lower uncertainties in cumulative N 2 O emissions compared to F CH FIELD. [ABSTRACT FROM AUTHOR]