Table 6.

Nitrogen balance in the soil depth of 0–60 cm with different N control measures.

Crop	Treatments	Nitrogen total input (kg ha-1)a						Nitrogen total output (kg ha-1)b
		Fertilizer N	Soil residual N pre-planting	Pre-wheat straw Nc	Deposition Nd	Mineralized N at plantinge	Total N input	Crop uptake	Soil residual N post- harvest	Apparent N lossf
Wheat	CK	0	16.4	77.2	12.8	115	221.4	199	22.4	0
	FN	285	16.4	77.2	12.8	115	506.4	247	67.3	192.1
	RN	225	16.4	77.2	12.8	115	446.4	255	42.0	149.4
	CRF	225	16.4	77.2	12.8	115	446.4	265	44.1	137.3
	CRF80%	180	16.4	77.2	12.8	115	401.4	257	34.9	109.5
	RN80%+DCD	180	16.4	77.2	12.8	115	401.4	267	35.2	99.2
	RN80%+NC	180	16.4	77.2	12.8	115	401.4	264	32.8	104.6
Maize	CK	0	22.4	27.9	15.0	126.1	191.4	183	8.4	0
	FN	392	67.3	40.3	15.0	126.1	640.7	235	150.0	255.7
	RN	300	42.0	41.8	15.0	126.1	524.9	244	138.2	142.7
	CRF	300	44.1	45.5	15.0	126.1	530.7	239	150.6	141.1
	CRF80%	240	34.9	57.9	15.0	126.1	473.9	241	115.0	117.9
	RN80%+DCD	240	35.2	46.3	15.0	126.1	462.6	249	112.1	101.5
	RN80%+NC	240	32.8	36.0	15.0	126.1	449.9	243	107.2	99.7

^aNitrogen balance status from pre-planting and post-harvest of wheat and maize are calculated. Nitrogen total input is composed of N fertilizer, soil N pre-planting, pre-crop straw return N, N deposition from dry and wet atmosphere and mineralized N at planting. ^bNitrogen total output comprises N uptake of crop, soil N post-harvest and apparent N loss. ^cIn wheat season, the pre-maize straw N is from the maize result of FN in this paper. ^dAtmospheric N deposition is derived from Liu et al. (2010). ^eMineralized N (kg/ha) = N crop uptake in CK + Soil residual N post-harvest in CK - Soil residual N pre-planting - N deposition from atmosphere - Pre-crop straw return N. ^fApparent N loss (kg/ha) = Total N input - N uptake of crop - Soil residual N post-harvest. Treatments of CK, FN, RN, CRF, CRF80%, RN80%+DCD and RN80%+NC represent the corresponding treatments as described in Table 1.