Table 3.

Soil physicochemical properties under different nitrogen (N) addition level.

Factors	CK	N50	N100	N150
Soil water (%)	7.68 ± 0.63a	7.69 ± 0.43a	7.98 ± 0.15a	7.67 ± 0.19a
Organic carbon (g/kg)	9.20 ± 0.54 a	9.43 ± 0.25 a	8.61 ± 0.03 b	8.56 ± 0.16 b
Total nitrogen (g/kg)	0.78 ± 0.01d	0.84 ± 0.01c	0.88 ± 0.01b	0.96 ± 0.02a
Total phosphorus (g/kg)	0.83 ± 0.01 a	0.83 ± 0.01 a	0.82 ± 0.01 a	0.82 ± 0.01 a
Available phosphorus (mg/kg)	4.28 ± 0.12 a	4.07 ± 0.14 a	3.97 ± 0.08 ab	3.73 ± 0.25 b
pH	8.45 ± 0.02a	8.32 ± 0.02b	8.27 ± 0.01b	8.18 ± 0.01c

Data are mean ± SE. Different letters after peer data indicate significant differences between treatments (P < 0.05).

CK No nitrogen fertilizer added, N50 Nitrogen addition amount 50 kg/ha², N100 Nitrogen addition amount 100 kg/ha², N150 Nitrogen addition amount 150 kg/ha².