Farming systems in developed countries have highly specialized to reach economies of scale. In addition to their low economic resilience, specialized agricultural systems face more and more agronomic problems such as yield stagnancy or pest and pathogen resistance. Crop diversification is a lever to overcome these problems and to reduce chemical inputs. But the adoption of diversification crops remains low and heterogeneous, due to both monetary and non-monetary determinants. Unobservable determinants such as the perception of crop characteristics might explain this heterogeneity. The paper proposes an evaluation of farmers’ preferences for these characteristics with a choice modelling conducted among 71 specialized grain farmers of south-western France. A random parameter logit model interacting crop attributes with farms’ individual characteristics show that, in addition to monetary attributes, crop traits such as the level of nitrogen restitution and the positive effect of the diversification crop on pest management influence adoption. It shows an even stronger impact of these agronomic attributes when soil and agronomic conditions are constraining. Moreover, demand for crop diversification is influenced by the performance of the farm’s main crop and by the type of marketing contract adopted, which suggests cross effects with risk management strategies.