Table 2.

Microbial processes and microbial NUE at 15 °C and 60% WHC in soils from three land uses (cropland, grassland, forest) on two bedrocks (silicate, limestone). The effects of bedrock (B), land use (L) and their interaction (B × L) are presented as asterisks: *P < 0.05, **P < 0.01, ***P < 0.001; not significant, n.s. Data presented are means ± 1SE (n = 4).

	Unit	Silicate			Limestone			B	L	B × L
		Cropland	Grassland	Forest	Cropland	Grassland	Forest
Microbial growth	mg N kg−1 d−1	0.67 ± 0.24	3.59 ± 2.29	2.00 ± 1.02	2.66 ± 0.54	3.21 ± 3.06	1.37 ± 0.42	n.s.	n.s.	n.s.
Gross N mineralization	mg N kg−1 d−1	2.32 ± 0.26	2.62 ± 0.14	0.66 ± 0.14	0.53 ± 0.10	2.06 ± 0.27	2.52 ± 0.45	n.s.	***	***
Microbial uptake	mg N kg−1 d−1	2.99 ± 0.64	6.21 ± 2.19	2.65 ± 0.99	3.19 ± 0.68	5.27 ± 2.83	3.89 ± 1.16	n.s.	**	n.s.
Microbial NUE		0.22 ± 0.03	0.54 ± 0.07	0.73 ± 0.07	0.84 ± 0.03	0.53 ± 0.10	0.36 ± 0.04	n.s.	n.s.	***
NH4+ immobilization	mg N kg−1 d−1	2.77 ± 0.27	3.14 ± 0.21	1.51 ± 0.16	0.61 ± 0.15	1.06 ± 0.20	2.38 ± 0.25	***	n.s.	***
Gross nitrification	mg N kg−1 d−1	0.70 ± 0.21	0.96 ± 0.36	0.04 ± 0.02	0.35 ± 0.18	1.83 ± 0.54	1.05 ± 0.30	*	*	**