Table 4. Effects of irrigation and nitrogen application on EAAI and PDCAAS in wheat grain in 2012/2013, 2013/2014 and 2014/2015, and interactions between irrigation and nitrogen application; summary of F significance from analysis of variance of the effects of main factors and interactions.

Treatment	EAAI (%)			PDCAAS (%)
	2012/2013	2013/2014	2014/2015	2012/2013	2013/2014	2014/2015
I0	58.70b	57.71	57.18b	51.99	53.00c	53.46b
I1	61.81a	57.98	57.72b	54.47	56.55a	54.18b
I2	60.21ab	57.12	61.58a	53.40	54.69b	56.54a
F-test	**	ns	**	ns	**	**
N0	61.01	64.29a	62.17a	55.74a	60.77a	61.15a
N180	58.54	54.76b	57.31b	51.98b	51.97b	52.64b
N240	61.34	56.18b	57.89b	53.51ab	53.24b	52.59b
N300	60.07	55.20b	57.94b	51.92b	53.01b	52.53b
F-test	ns	**	**	*	**	**
I0×N0	59.16	65.47a	58.47	53.30	62.57a	58.20a
I0×N180	58.34	46.82c	56.33	51.57	43.89c	51.06b
I0×N240	59.25	59.28b	57.01	51.78	51.13b	52.31b
I0×N300	58.04	59.28b	56.92	51.32	54.43b	52.27b
F-test	ns	**	ns	ns	**	**
I1×N0	61.60	65.81a	61.03a	54.76	61.75a	60.93a
I1×N180	59.45	59.11b	56.64b	54.63	56.82b	53.37b
I1×N240	63.65	59.11b	56.93b	55.20	59.54b	51.65bc
I1×N300	62.53	47.89c	56.27b	53.28	48.08c	50.77c
F-test	ns	**	**	ns	**	**
I2×N0	62.28	61.58a	67.00a	59.16a	57.98a	64.32a
I2×N180	57.81	58.33b	58.97b	49.74b	55.21a	53.48b
I2×N240	61.11	50.14c	59.74b	53.56b	49.05b	53.80b
I2×N300	59.63	58.43b	60.62b	51.15b	56.53a	54.54b
F-test	ns	**	**	*	**	**
Grand mean	60.24	57.60	58.83	53.29	54.75	54.73
I×N (F-test)	ns	**	**	ns	**	**
CV (%)	7.78	5.279349	2.06	15.06	5.80612382	2.43

Note: EAAI: essential amino acid index; PDCAAS: protein digestibility-corrected amino acid score; ns, not significant at P < 0.05;

* Significant at P < 0.05;

** Significant at P < 0.01; Data in the same column with different letters indicate a significant difference at P < 0.05.