N2O emission factors for cattle urine: effect of patch characteristics and environmental drivers

Abstract Urine patches from grazing cattle are hotspots of nitrous oxide (N 2 O) emissions. The default IPCC emission factor for urine (EF ) is 0.77% wet climates and 0.32% dry climates. However, literature reports a considerable range EF values characteristics used in experimental studies, revealing contrary results on the effects patch seasonal pattern. Therefore, we examined N O emissions corresponding relation to (urine concentration, volume, area, composition) environmental drivers (precipitation, water filled pore space, soil temperature). Ten artificial application experiments were performed July 2020 June 2022 pasture located Eastern Switzerland. volume composition showed no significant value (p > 0.05). varied, however, strongly over time (0.17–2.05%). A large part variation could be predicted either by cumulative precipitation 20 days after using second order polynomial model (Adj. R = 0.60) or average WFPS 30 linear 0.45). derived was simulate weekly last years showing differences between seasons year. resulting overall 0.67%. More field studies needed across sites/regions differing climate properties implement country-specific 3 Switzerland improve quantification at national scales.