Why are grain-legumes rarely present in cropping systems despite their environmental and nutritional benefits? Analyzing lock-in in the French agrifood system

International audience; Grain-legume plants fix atmospheric nitrogen in the soil and thus do not need nitrogen fertilizers. Therefore, grain- legumes can potentially decrease global warming, as nitrogen fertilization is responsible for half of all agricultural greenhouse gas emissions. Moreover, grain-legumes have many functional and nutritional properties both as feed and food. Despite the fact that the European Union has granted considerable subsidies to promote grain-legume cultivation, their production continues to fall and there has been no satisfactory explanation as to why. This study provides an answer by showing that a situation of technological lock-in has resulted from the co-evolution of crop systems, based on an agrochemical paradigm, public policies, and market dynamics that promote cereals. This process began with the historical choice by European and French public institutions to relegate grain-legumes to feed in direct competition with imported soybeans. Moreover, interrelated factors, such as breeding selection, public subsidies, and food systems, have favored increasing returns to adoption for cereals to the detriment of grain-legumes. Finally, the evolutionary economics approach used here identified several actions that must be implemented together, such as agricultural cost-accounting methods, nitrogen management, institutional innovations, and market out lets to promote grain-legumes and move towards more sustainable agriculture.