In face of agricultural sustainability challenges, agronomical research has focused its efforts on the design of new production systems. In parallel, ethnographic-based studies of small farmers’ practices in developing countries have shown the sustainability of the so-called traditional production systems and put them forward for the ecologisation of agriculture. Nevertheless, a gap remains between the rules used for agroecological design and the local practices of particular farms. Our objectives are then to draw principles for agroecological management from the in- depth study of farming practices in ecologically-based farms (Altieri, 2000). Our strategy was to study small family farms in Misiones (Argentina). Far from single-crop farming, producers cultivate many different species in the same place at the same time, mainly to save labour and space. They also take into account negative and positive biological interactions between crops, mostly related to shade and light. The location of each crop and the interweaving of crops and livestock is decided at a micro-scale of individual plant or animal. Moreover, organising this diversity within a farm revealed itself as a socio-cognitive activity embedded in social networks of producers. These observed practices can be sumed up in three management principles: i) adjustment and observation instead of control, ii) Variable temporal and spatial units within a flexible management iii) Permanent on-farm experimentation and specification of technical options. We discuss our results regarding the genericity of these principles and discuss the research paths to take these agroecological systems as models for the ecologisation of conventional systems.