Effect of fertilizer regime, sample time and the interaction between them on the relative abundance (%) of abundant bacterial classes (subgroups) £ (relative abundance >1%).

Values are means ± standard deviation (n = 6 or n = 18).NS: no significant (P>0.05).Means followed by the same letter for a given factor are not significantly different (PActinobaceria, Gemmatimonadetes, Nitrospira were not included in this analysis as they had only one class.Fertilizer regimes as described in Table 1.