Storing grains and foodstuffs in local, healthy, resilient, low-carbon conditions, and without using fossil fuels, is a major challenge not only for food security and sovereignty, but also for the famous "One Health" concept. Yet very few scientific and technical references are available on this topic. In the south of France, organic cereal producers, archaeologists who are experts in underground medieval silos, cereal pathologists, geneticists and agronomists of cultivated diversity, biochemists, millers and bakers, an underprivileged local authority, cereal craftsmen and an artist have decided to work together on this project and to IMAGINE (co-design innovative storage ideas as alternatives to current techniques), EXPERIMENT (co-build underground silos to store harvests at farmers' and craftsmen's sites, evaluate the effect of storage conditions on the sanitary and technological quality of grains and flours) and SWARM from Occitanie to other territories. Relying on ancestral techniques to respond to the urgent needs of the present and the challenges of the future is at the heart of this project, which aims to bring on board a collective of players with very diverse outlooks, skills and disciplines, and to deploy animation and communication methods to facilitate the emergence of a collective intelligence with operational societal spin-offs in the short term.

Grain storage in underground silos was probably practiced from the early Neolithic until very recently in some communities around the world. For thousands of years, the underground silo should have been an essential development for the life and survival of populations, with an undeniable economic stake. The underground silo and the practices associated with its construction and use are now a threatened or disappeared tangible and intangible heritage. Historical, archaeological and ethnographic data do not clearly shed light on the practices of underground silage through the ages. The latest archaeological excavations of the large silage areas make it possible to count the pits, to characterize their shape and volume, to reflect on the chronology and organization of a grouped silage area, but not to know the peasant’s know-how and the quality of food preservation in the underground silos. The peasant communities have had durably solved the various problems linked to this type of grain storage: attacks by pests, humidity, heating of the grains, whereas modern agriculture uses ventilated, cooled and chemically protected silos that consume energy. In the multidisciplinary project SilAchaeoBio, we develop an experimental archaeology approach by recreating 13 pits in two sites and practicing short- and long-term grain storage in these airtight pits equipped with recorders of the internal climatic conditions. Different technical options are tested and grain quality is assessed by acquiring biological data using modern analysis methods. The data collected provides information on the lifespan of a silo and the duration of underground storage guaranteeing germination properties, the food quality and food safety of stored grains. The lessons from experimental archaeology lead to a new emphasis on archaeological, historical, agronomical documentary analyses to produce new interpretations for the economic history of peasant communities in North Mediterranean in the Middle Ages. The knowledge produced in this study can be used in other geographical situations and for other periods. Such preservation of grains without recourse to an energy source for cooling and ventilation and without the use of pesticides, echoes the expectations of 21th century people for changes in systems of agricultural production towards localization, environmental protection and the preservation of human health. It can inspire development of present-day technologies. In summary, SilAchoBio establishes a dialogue between scientific methods and professional practices related to cereal farming, using both old data and current knowledge. It is anchored in a local context (Roussillon) to re-find peasant knowledge and to understand the role of these silos in the economic and cultural organization of ancestral societies in the Mediterranean basin and beyond. This multidisciplinary project will make it possible to progress in archaeological and historical knowledge and could also give rise to technical solutions applicable to sustainable agriculture in the 21st century.