Sustainable farming systems with enhanced crop yields can be achieved through the use of cropping systems with plant cover. This strategy promotes physical, chemical and biological soil fertility processes. Experiments on cropping systems with plant cover were set up to assess the impact of these techniques on soil macrofauna. The cover crops used to produce this vital biomass were oat (Avena sativa) and a legume, i.e. greater bird's food trefoil (Lotus uliginosus). Systems with plant cover associated with a maize crop were found to significantly restore soil macrofauna populations. (Resume d'auteur)