Both increasing human population and pesticide pollution call for alternative food production. Agronomists are thus currrently designing new cropping practices such as ecological intensification and sustainable intensification. However, the meaning and concrete applications of such practices is not clear so far. Wezel et al. review the definitions, principles and practices of ecological intensification, sustainable intensification and agroecological intensification. The photo shows relay intercropping of wheat and undersown lucerne in south-eastern France, an example of agroecological intensification.