van der Weerden, TJCox, NLuo, JiafaDi, HongPodolyan, AndriyPhillips, RLSaggar, Sde Klein, CAMEttema, PRys, G2017-09-082016-02-172016-04-152016-02-06van der Weerden et al. (2016). Refining the New Zealand nitrous oxide emission factor for urea fertiliser and farm dairy effluent. Agriculture, Ecosystems and Environment, 222, 133-137. doi:10.1016/j.agee.2016.02.0070167-8809DX4XE (isidoc)https://hdl.handle.net/10182/8553Applications of urea fertiliser and farm dairy effluent (FDE) to New Zealand pastures are the second and third largest sources of nitrous oxide (N₂O) emissions, after emissions from excreta deposited during grazing (urine and dung). New Zealand currently employs emission factors (EF₁) (percentage of N applied which is emitted as N₂O) of 0.48% and 1% for urea fertiliser and FDE, respectively, for calculating its national N₂O inventory. The country specific emission factors for urine and dung are 1% and 0.25% respectively. Because FDE has a higher organic nitrogen (N) content than urea, and because it is a diluted mixture of urine and dung, the mean FDE EF1 is expected to be less than 1%. With a recent increase in research trials measuring EF₁ for FDE and urea, the objective of this study was to refine New Zealand-specific EF₁ values for these N sources. We analysed urea fertiliser and FDE N₂O emission data from 45 EF₁ field trials conducted in New Zealand. This meta-analysis yielded a combined (urea and FDE) EF₁ mean of 0.46% (95% confidence interval of 0.07% and 0.90%), with EF1 means for urea and FDE of 0.59% and 0.25%, respectively. There was no statistical difference between urea fertiliser and FDE EF₁ values. However, we recommend separate country-specific EF1 means of 0.6 and 0.3% for urea fertiliser and FDE, respectively, for New Zealand's agricultural soils N₂O emissions inventory due to the different origin and characteristics of these N sources.pp.133-137Undetermineden© Elsevier B.V. All rights reserved.nitrous oxideemission factorurea fertiliserfarm dairy effluentmeta-analysisJournal Article10.1016/j.agee.2016.02.0071873-2305ANZSRC::30 Agricultural, veterinary and food sciencesANZSRC::41 Environmental sciencesANZSRC::44 Human society