Alternative combinations of tillage practices and crop rotations can foster earthworm density and bioturbation

Earthworms, which contribute to important soil functions, suffer from intensive agriculture. Their response depends among other things on the earthworm ecological group (anecic, endogeic, epigeic) and the combination of the applied farming practices. To advice on methodological adaptations that enhance earthworm-mediated soil functions, effects of different practices on earthworms need to be studied in concert. We investigated the effects of tillage intensity (conventional, reduced, no tillage) and crop rotation diversity (simple = wheat, barley; diverse = wheat, peas, oil seed rape) on earthworm density and community composition in a Swedish long-term experiment. Furthermore, we calculated annual earthworm bioturbation to quantify the effects of farming practices on earthworm functions. Total earthworm densities did not vary between the different tillage intensities, but were on average 58% higher in the diverse than in the simple crop rotation. The pattern was mainly due to the respon...