Effect of nitrogen addition on the carbon metabolism of soil microorganisms in a Calamagrostis angustifolia wetland of the Sanjiang Plain, northeastern China

Table 1 Physicochemical properties of wetland soil with different nitrogen addition conditions

Treatment	SMC	pH	NO₃− (mg/kg)	NH₄⁺ (mg/kg)	DOC (mg/kg)	DON (mg/kg)	TN (%)	TOC (%)
CK	0.43 ± 0.06a	4.4 ± 0.18a	23.8 ± 6.34a	21.2 ± 3.45a	3897.9 ± 625.37a	299.7 ± 130.71a	0.57 ± 0.23a	5.34 ± 2.23a
N40	0.48 ± 0.03a	4.3 ± 0.0ab	23.4 ± 0.89a	4.3 ± 0.30b	836.0 ± 135.58b	374.2 ± 17.77a	0.77 ± 0.16a	4.62 ± 0.80a
N80	0.50 ± 0.04a	4.1 ± 0.12b	21.7 ± 1.41a	9.4 ± 2.28b	1575.6 ± 325.29b	444.2 ± 134.93a	0.94 ± 0.29a	5.31 ± 1.44a

Each treatment was performed in triplicate. The data are expressed as the mean ± standard deviation; lowercase letters indicate significant differences (P < 0.05)
CK control, N40 40 kg N ha⁻¹ a⁻¹, N80 80 kg N ha⁻¹ a⁻¹, SMC soil moisture contents, DOC dissolved organic carbon, DON dissolved organic nitrogen, TN total nitrogen, TOC total organic carbon

ISSN: 1869-2044