Table 3.

Combined analysis of variance over years (2012 and 2013) for soil microbial biomass and enzyme activities affected by tillage and fertilization systems.

Source of Variation	DF	Soil organic carbon	MBC	Acid phosphatase	Alkaline phosphatase	Dehydrogenase	Urease
Year (Y)	1	ns	ns	ns	ns	ns	ns
R/Year	4	ns	ns	ns	ns	ns	ns
Tillage systems (T)	2	ns	**	**	**	**	**
T*Y	2	ns	ns	ns	ns	ns	ns
Error a	8	–	–	–	–	–	–
Fertilization methods (F)	7	ns	**	**	**	**	**
F*Y	7	ns	ns	ns	ns	ns	ns
F*T	14	ns	*	ns	ns	ns	**
F**Y	14	ns	ns	ns	ns	ns	ns
Error b	84	–	–	–	–	–	–

ns, non-significant; ^* and ^**, significant at 1 and 5% probability levels, respectively.