Earthworms interactively affected the influence of seed dressings on collembola activity, whereas collembola increased earthworm surface activity but reduced soil basal respiration.

Results: Seed dressings (particularly fungicides) increased collembola surface activity, increased the number of protozoa and reduced plant decomposition rate but did not affect earthworm activity.

Earthworms and Collembola increased biomass of seeds, shoots and roots of wheat.

Earthworms, Collembola and litter distribution affected plant growth, N acquisition and aphid development in an interactive way.

Signatures of delta(13)C proved density responses of Collembola taxa to be related to the added mulch materials.

Increased plant growth by earthworms and Collembola was mainly due to increased transfer of N from soil (rather than litter) into plants.