Table 4.

UK scale emissions of N₂O from the application of AN, CAN and urea fertilisers for the year 2017 are estimated using the agricultural inventory EFs (developed under the UK agricultural emission factor, e.g. Brown et al. 2019) and the EFs calculated by applying the Bayesian method to 623 events in this study.

UK 2017		Agricultural Inventory		Bayesian Method
Fertiliser	Application	Mean EF	Emission	Mean EF	95% C.I.	Emission	95% C.I.
	(kt N)	%	(kt N)	%	%	(kt N)	(kt N)
All
AN	460.1	1.15	5.29	1.09	(0.97–1.22)	5.02	(4.49–5.61)
CAN	46.9	1.6	0.75	0.98	(0.74–1.30)	0.46	(0.35–0.61)
Urea	159.9	0.66	1.06	0.58	(0.48–0.72)	0.93	(0.76–1.14)
Arable
AN	325.6	0.99	3.22	0.60	(0.50–0.72)	1.96	(1.63–2.35)
CAN	10.5	1.1	0.12	0.49	(0.29–0.88)	0.05	(0.03–0.09)
Urea	131.6	0.66	0.87	0.74	(0.38–1.38)	0.97	(0.51–1.82)
Grass
AN	134.5	1.54	2.07	1.34	(1.18–1.52)	1.80	(1.58–2.04)
CAN	36.1	1.7	0.61	1.11	(0.81–1.51)	0.40	(0.29–0.55)
Urea	28.2	0.62	0.17	0.58	(0.47–0.72)	0.16	(0.13–0.20)