Table 4.

Correlations between the community structure AOA and AOB, soil chemical parameters (pH, ${\text{N - NH}}_4^{+}{\text{, N - NO}}_3^{-},$ OM %, clay content % and water content %) and NEA (Relate Analysis) obtained with Primer-E (BEST test), for all sampling times per soil and per soil type.

	NEA* (μgN h−1 gdw−1)	pH (CaCl2)	${\text{N - NH}}_4^{+}$ (mg−1 kg)	${\text{N - NO}}_3^{-}$ (mg−1 kg)	OM (%)	Humidity (%)
AOA STRUCTURE ACROSS SOILS (I)
Buinen	NS	NS	NS	0.49***	NS	NS
Valthermond	NS	0.48**	0.22**	0.12*	NS	0.19**
Droevendaal	0.19*	0.59***	0.16*	0.36***	0.24**	NS
Wildekamp	0.73***	0.58***	0.28**	0.44***	NS	NS
Kollumerwaard	NS	NS	0.15*	NS	0.33**	NS
Steenharst	NS	0.58***	NS	0.26**	0.22**	0.16*
Grebbedijk	0.56***	0.28**	0.15*	0.39***	0.15*	NS
Lelystad	NS	0.28**	NS	NS	NS	0.24**
PER SOIL TYPE (III)
Sandy	0.26**	0.39***	0.53***	0.49***	0.43***	0.46***
Clayey	0.07*	NS	0.05*	NS	NS	NS
AOB STRUCTURE ACROSS SOILS (I)
Buinen	0.54***	0.12*	0.36***	0.31***	NS	NS
Valthermond	0.40***	0.37***	NS	NS	0.28***	0.25**
Droevendaal	0.42***	0.46***	0.22**	0.29**	0.29***	NS
Wildekamp	0.57***	0.24**	0.18*	0.19*	NS	NS
Kollumerwaard	NS	0.22*	0.27***	0.19*	0.40***	NS
Steenharst	0.58***	0.44***	NS	0.12*	0.32***	NS
Grebbedijk	NS	NS	0.32**	NS	0.16*	0.15*
Lelystad	NS	0.21**	0.25***	NS	NS	0.18*
PER SOIL TYPE (III)
Sandy	0.26***	NS	0.09***	0.08***	NS	NS
Clayey	0.19***	NS	0.09***	NS	0.08*	NS
NEA ACROSS SOILS (I)
Buinen	0.19*	0.16*	NS	NS	0.19	0.19*
Valthermond	NS	NS	0.26*	NS	0.24*	NS
Droevendaal	0.29**	NS	0.30**	NS	NS	0.29**
Wildekamp	0.19*	NS	NS	NS	NS	0.19*
Kollumerwaard	NS	0.21*	NS	NS	NS	NS
Steenharst	NS	NS	NS	0.37**	NS	NS
Grebbedjik	NS	NS	0.31**	NS	NS	NS
Lelystad	NS	NS	0.20*	NS	NS	NS
PER SOIL TYPE (III)
Sandy	0.48**	S	NS	NS	NS	NS
Clayey	NS	0.05*	NS	NS	NS	NS

NEA, nitrifying enzyme activity; AOA, ammonia oxidizing archaeal; AOB, ammonia oxidizing bacteria; NS, not significant; ***P < 0.001, **P < 0.01; *0.01 < P < 0.05.