Responses of Ammonia-Oxidising Bacterial Communities to Nitrogen, Lime, and Plant Species in Upland Grassland Soil

Table 1

Soil, plant, and microbial characteristics for grassland microcosms. Nitrogen/Lime treatments, 𝑛=12; plant treatments, 𝑛=16. Different letters indicate values that are significantly different. SED, standard error of the difference. Significance levels: **𝑃<.01; ***𝑃<.001. Parts of this table have been previously presented in the work by Kennedy et al. [6].

	pH	Root Biomass	Shoot Biomass	Microbial Activity	Nitrogen	Phosphorus	Potassium
		(mg per plant)	(mg per plant)	(mg TPF g^-1 soil)	(%)	(mg P kg^-1)	(mg K kg^-1)
Nitrogen/Lime treatments
No treatment (plant only)	4.23b	1.90a	1.94a	49.2b	0.62a	8.54a	140.7b
Lime	4.92d	1.64a	3.68c	158.0d	0.55a	11.88c	156.3d
NH4NO3	3.78a	3.81d	2.83b	8.7a	0.62a	9.84b	143.7c
Lime + NH4NO3	4.55c	2.72c	4.66d	109.9c	0.60a	12.67d	128.2a
SED	0.09	0.41	0.39	7.05	0.04	0.15	2.20
Plant species
Unplanted soil	4.50b	N/A	N/A	101.9b	0.61b	7.88a	131.2b
A. capillaris	4.13a	0.79a	0.84a	38.3a	0.48a	11.96b	174.2c
L. perenne	4.48b	4.25b	5.73b	104.2b	0.70c	12.36c	121.4a
𝑃-value	**	***	***	***	***	***	***
SED	0.09	0.49	0.48	11.47	0.04	0.13	2.85