Effect of Microccocus luteus inoculation dose in the absence (C) or presence (E) of earthworms (Aporrectodea caliginosa) on Arabidopsis thaliana (a) shoot (C: r2 = 0.12; E: r2 = 0.64), (b) root (C: r2 = 0.21; E: r2 = 0.38) and (c) total (C: r2 = 0.15; E: r2 = 0.68) biomass production.