Crop diversification is often presented as a way to improve the sustainability of agricultural production systems (reduction in the use of inputs and environmental damage resulting from their excessive use - pesticides, fertilizer, water). However, despite these benefits and various incentive programs, crop diversification is gaining little ground in France. The objective of this study is to identify: i) the main obstacles to crop diversification at agro-industrial supply chain and farm levels; ii) the levers that can be employed to encourage these stakeholders to integrate greater crop diversity within their production system. An interdisciplinary analysis framework was used, integrating farming system agronomy, sociotechnical transition approach and new institutional economics. This theoretical framework is centred on the "technological lock-in" theory, derived from the innovation economy, and socio-technical transition theory, which proposes potential "break-out" avenues. This framework is tested on twelve crop diversification cases studies with three in-depth analyses. Our results show that the socio-technical system organized on the basis of dominant crops and the simplification of cropping plans is therefore an obstacle to the development of diversification crops as a result of various closely interlinked processes: (i) genetic progress that is less rapid than for "major crops"; (ii) a lack of crop protection solutions (agrochemicals one but also genetic and agronomic ones); (iii) a shortage of technical references concerning minor crops to explain low yield or quality defects at regional scale; (iv) a competition with "major crops" on the raw material market not only due to price but also accessibility and homogeneity differences (v) the diversity of coordination methods between the different stakeholders in the supply chains Finally, to encourage the development of diversification crops, it would appear to be essential to act simultaneously on three levers supported by public action: (1) Promotion of new market outlets, (2) Coordination of stakeholders and structuration of supply chains and (3) getting R&D, advisory and plant breeding actors involved on a national nd regional level to develop innovative technologies and varieties.