Table 1.

The significance of the differences in plant parameters resulting from the interactions among factors A (N, NM, NR and NRM), B (N supplies LN and HN) and C (harvest dates T₁ and T₂)

Source of variance	A	B	C	A × B	A × C	B × C	A × B × C
Degrees of freedom	3	1	1	3	3	3	3
Variables:
Photosynthetic rate (µmol CO2 m−2 s−1)	***	***	***	***	**	**	*
AMF
AC (%)	***	***	***	*	ns	ns	ns
VC (%)	***	***	*	***	*	ns	ns
HC (%)	***	***	***	***	ns	ns	ns
N, P content
Leaf N (mg g−1)	***	***	***	***	***	*	ns
Stem N (mg g−1)	***	***	***	***	***	ns	ns
Root N (mg g−1)	***	***	***	***	**	*	ns
Nodule N (mg g−1)	***	***	***	ns	ns	*	ns
Leaf P (mg g−1)	***	***	***	***	**	**	ns
Stem P (mg g−1)	***	***	***	***	***	***	**
Root P (mg g−1)	***	***	***	***	***	***	**
Nodule P (mg g−1)	***	***	***	ns	ns	**	ns
Biomass of plant part
Leaf area (cm2 plant−1)	***	***	***	***	***	**	*
Leaf d. wt (g plant−1)	***	***	***	**	*	**	ns
Stem d. wt (g plant−1)	***	***	***	ns	*	*	ns
Root d. wt (g plant−1)	***	***	***	*	*	**	ns
Nodule d. wt (g plant−1)	*	***	***	ns	ns	***	ns
Biomass (g plant−1)	***	***	***	***	***	***	ns

Percentage AMF colonization, dry mass, leaf area, elemental N and P concentrations of leaves, stems, roots and nodules were analysed by three-way ANOVA with residual estimation, for main effects and interaction effects.

*, **, *** Effects that are significant at P < 0·05, 0·01 and 0·001, respectively; ns, effects that are not significant at P < 0·05.