TABLE 2.

Differences of N accumulation and NHI under different treatments.

Cultivars	Nitrogen rate	Jointing stage (kg ha–1)		Silking stage (kg ha–1)		Maturity stage (kg ha–1)		N harvest index
		2019	2020	2019	2020	2019	2020	2019	2020
	N 0	18.58 f	23.11 g	66.22 f	55.01 f	104.17 d	100.51 d	0.50 d	0.58 bc
	N 120	31.38 d	34.86 e	101.19 d	87.46 d	162.73 b	136.58 c	0.51 cd	0.57 cd
ZH 311	N 240	38.90 a	44.28 a	147.54 a	117.82 a	205.02 a	180.39 a	0.50 d	0.55 de
	N 360	36.23 b	37.46 d	128.49 b	114.10 a	194.91 a	175.04 a	0.49 d	0.54 e
	Mean	31.27 A	34.93 A	110.86 A	93.60 A	166.71 A	148.13 A	0.50 B	0.56 B
	N 0	15.17 g	19.34 h	52.77 g	41.50 g	80.20 e	74.32 e	0.56 a	0.62 a
	N 120	27.73 e	33.53 f	85.08 e	67.96 e	113.46 d	98.88 d	0.51 bcd	0.60 ab
XY 508	N 240	31.62 d	40.11 b	108.02 d	93.52 c	148.42 c	137.37 c	0.52 bc	0.58 bc
	N 360	33.92 c	38.83 c	119.90 c	102.55 b	167.00 b	165.16 b	0.53 b	0.60 ab
	Mean	27.11 B	32.95 B	91.44 B	76.38 B	127.27 B	118.93 B	0.53 A	0.60 A
F value	Years (Y)	282.36**		231.03**		80.15**		285.74**
	Cultivar (C)	117.90**		296.67**		520.98**		85.01**
	Nitrogen (N)	973.72**		793.65**		693.20**		9.74**
	Y × C	15.01**		1.08ns		11.59**		0.43ns
	Y × N	8.11**		4.44*		5.50**		1.69ns
	C × N	15.02**		20.35**		23.84**		4.92**
	Y × C × N	2.49ns		4.28*		2.11ns		1.82ns

Values followed by different lowercase letters are significantly different with p < 0.05; within cultivars, values with different uppercase letters are significantly different with p < 0.05 according to the least significant difference test. **p < 0.01; *p < 0.05; ^nsNot significant. The bold values are the mean value of one cultivar in different N treatments.