Table 3.

Water use efficiency (WUE) of winter wheat (kg ha⁻¹ mm⁻¹) under ambient (aCO₂) and elevated carbon dioxide (eCO₂) at a high rainfall site near Pullman, at a low rainfall site near Lind and at an irrigated site near Moses Lake, WA.

	aCO2 (µmol mol−1)	eCO2 (µmol mol−1)
	400	500	600	700	800	900	1000
Pullman WA
APSIM	12.29 ± 0.31	13.94 ± 0.27	15.52 ± 0.31	16.95 ± 0.36	18.18 ± 0.37	19.07 ± 0.39	19.56 ± 0.40
CropSyst	12.01 ± 0.30	13.94 ± 0.27	15.52 ± 0.31	16.95 ± 0.35	18.18 ± 0.38	19.07 ± 0.40	19.56 ± 0.41
DSSAT	12.00 ± 0.32	13.06 ± 0.35	14.09 ± 0.39	15.00 ± 0.37	15.80 ± 0.38	16.51 ± 0.39	17.06 ± 0.41
EPIC	11.87 ± 0.29	13.06 ± 0.33	13.97 ± 0.37	14.69 ± 0.33	15.25 ± 0.36	15.68 ± 0.39	16.03 ± 0.42
STICS	13.71 ± 0.33	16.10 ± 0.40	17.92 ± 0.38	19.33 ± 0.35	20.47 ± 0.39	21.32 ± 0.39	21.92 ± 0.43
Lind WA
APSIM	9.67 ± 0.35	11.39 ± 0.43	12.86 ± 0.43	14.48 ± 0.43	15.68 ± 0.45	16.38 ± 0.46	17.06 ± 0.47
CropSyst	11.74 ± 0.37	13.71 ± 0.42	15.53 ± 0.45	17.30 ± 0.48	18.94 ± 0.49	20.23 ± 0.51	20.90 ± 0.52
DSSAT	10.92 ± 0.33	12.35 ± 0.39	13.80 ± 0.41	15.19 ± 0.42	16.45 ± 0.43	17.64 ± 0.45	18.69 ± 0.47
EPIC	13.05 ± 0.36	15.49 ± 0.44	17.89 ± 0.47	20.40 ± 0.50	22.61 ± 0.52	24.58 ± 0.55	25.46 ± 0.59
STICS	9.79 ± 0.32	11.95 ± 0.43	14.38 ± 0.43	16.60 ± 0.45	17.43 ± 0.46	17.83 ± 0.43	18.10 ± 0.47
Moses Lake, WA
APSIM	13.09 ± 0.35	14.35 ± 0.40	15.18 ± 0.41	15.35 ± 0.42	15.52 ± 0.43	15.69 ± 0.44	15.72 ± 0.45
CropSyst	17.60 ± 0.37	19.04 ± 0.41	19.85 ± 0.43	20.36 ± 0.44	20.69 ± 0.45	20.94 ± 0.47	21.11 ± 0.48
DSSAT	13.87 ± 0.35	15.21 ± 0.39	16.48 ± 0.41	17.57 ± 0.43	18.51 ± 0.44	19.32 ± 0.45	19.95 ± 0.43
EPIC	13.33 ± 0.36	14.77 ± 0.41	15.37 ± 0.43	15.85 ± 0.44	16.46 ± 0.45	17.16 ± 0.46	16.87 ± 0.48
STICS	12.26 ± 0.37	13.32 ± 0.42	14.22 ± 0.43	15.03 ± 0.45	15.78 ± 0.47	16.28 ± 0.42	16.56 ± 0.45

(Note: Standard errors (SE) of mean of the simulated data are represented as ±).