Table 4.

Balance of N as affected by different doses of fertilizer N in the rice-maize system. Mean values followed by at least one lowercase letter are not significantly different at p < 0.05 by Tukey's HSD test.

Treatments	Straw/stover yield		Straw/stover N content		Grain N uptake		Straw/stover N uptake		Total plant uptake of N	Soil total N stock (0–45 cm)		Fertilizer N	Soil N balance
	Rice	Maize	Rice	Maize	Rice	Maize	Rice	Maize		Initial	Final
	t ha−1		%		kg ha−1
N0	4.92ns	3.73c	0.65c	0.61ns	36.6d	26.1d	55.6b	34.9c	153.2c	5186	5124b	0	−62.0ab
N40	5.82	4.64c	0.66c	0.49	45.4cd	38.2cd	68.9ab	45.7c	198.3c	5186	5112b	80	−154.1bc
N80	6.42	6.13bc	0.78b	0.48	63.2ab	58.7c	84.6ab	70.7bc	277.2b	5186	4689c	160	−656.2d
N120	5.85	7.80ab	0.80b	0.63	53.7bc	84.1b	75.4ab	92.5ab	305.6b	5186	4680c	240	−745.4d
N160	6.21	9.33a	0.88b	0.58	63.6ab	112.7a	81.8ab	118.8a	376.9a	5186	5025b	320	−480.5d
N200	6.66	6.69abc	0.85b	0.46	62.0ab	88.0ab	95.1a	89.6ab	334.8ab	5186	5157b	400	−429.1cd
N240	6.21	6.48abc	1.03a	0.58	67.7a	85.7b	92.7a	89.1ab	335.1ab	5186	5889a	480	223.1a
Mean	6.01	6.40	0.80	0.55	56.0	70.5	79.2	77.3	283.0	–	5097	–	–

#The number after N indicates kg of fertilizer N applied per ha.