A better use of crop genetic diversity is recognized as an essential leverage for agroecology, as it promotes various ecosystem services, in a context of increasing environmental stochasticity caused by global change. Increasing within field diversity through the use of cultivar mixtures is a timely option, as testified by past major “success stories”, and recent bibliographic reviews. Yet, cultivar mixtures are still poorly developed worldwide, even if their use is in strong progression for wheat crop in France.