nor its average capacity to metabolize different carbon substrates (AWCD) are negatively affected by drought or soil compaction since both values increase significantly from 2010 to 2011. In both years, the abundance of earthworms varied significantly among the treatments (N0 < N300 < PS45) (Table 6). This agrees with previous reports showing that slurry treatments have long-term beneficial effects on earthworms [60], although the NHþ4 eN content may be toxic to earthworms in the shorter term [61].