Table 8.

Comparison of model results for the GHG emissions (in kg CO₂ eq kg⁻¹ grain) associated with each of the crops to literature values when nitrous oxide emissions from soil are/are not included.

		Model value	Literature value	Reference
Winter wheat	With soil emissions	0.457	0.804	Williams et al. (2006)a
			0.417	Berry et al. (2010)
	Without soil emissions	0.324	0.399	Kramer et al. (1999)
Winter barley	Without soil emissions	0.463	0.326	Kramer et al. (1999)
Winter oilseed rape	With soil emissions	1.50	1.71	Williams et al. (2006)
Winter field beans	With soil emissions	0.227b

^aSpecifically relates to a bread wheat variety.

^bThis value is calculated when the net farm energy is maximised.