The "SOil Functional biodiversity as an Indicator of Agroecosystems management" (SOFIA) project aims at shading more light on environmental issues related to cropped agroecosystems management, climate change and biodiversity conservation. It specifically addresses the impact of agricultural practices on the taxonomic and functional diversity of living communities in the soil, and the effects of those practices on some of the functions the soil sustains: regulation (greenhouse gases emissions, carbon storage), supply (availability of nutrients for crop production) and maintenance of biodiversity (soil fauna and flora). This project brings together eight academic (universities, INRA) and one private (Agrotransfert) partners. It builds a part of its experimental design on the Estrées-Mons site (22 ha, Somme, north of France) managed by INRA and setup in 2010. This site is dedicated to the study of long-term anthropogenic disturbance on biogeochemical cycles and biodiversity (ORE –ACBB) and focuses especially on disturbances brought by cropping. The site is characterized by a series of experimental treatments comprising varying levels of crop rotation (eg. annual, perennial and energy-based crop rotations), mineral inputs (nitrogen) and tillage practices. Hence, these treatments significantly modulate the amount, chemical nature and location of food resources for soil organisms but also their physical habitat. All along the project, the partners will monitor the induced-differentiation of the agroecosystems setup 2010 in terms of agronomic variables (plant biomass production) and soil physical and chemical variables. Concomitantly and by taking into account the significance of ecosystem services supported soil organisms, the project will characterize earthworms, macro-invertebrates, microfauna, bacterial and fungal communities taxonomic and functional diversity as well as its dynamic. Finally, some of the soil functions that are known to be greatly affected by these communities will be quantified: carbon and nitrogen mineralization, decomposition of plant residues, N2O emissions for instance. Laboratory experiments will also be performed and, both field and laboratory, results shall be used to test and improve biotic and abiotic indicators of soil functioning. In the end, the SOFIA project aims at the proposal of indicators that could better guide farmers choice, especially during transitions phases created by the evolution of cropping practices (introduction of energy crops, abandonment of tillage, reduced inputs, etc..). This project will also contribute to the improvement of indicators assessing the environmental impact of farming practices.