Previous studies on the productive value of biodiversity emphasized that crop diversity increases crop yields. Here, we focus on the productivity of crop diversity and permanent grasslands for crops and milk. Using a GMM approach, we estimate detailed production functions using a sample of 3960 mixed farms from the FADN between 2002 and 2013. We highlight that permanent grasslands enhance crop production. We confirm that crop diversity increases crop and milk yields. Permanent grasslands and crop diversity are however substitute inputs. We also find that both of these biodiversity productive capacities influence variable input productivities. These results suggest the potential adaptations of farmers’ choices to environmental measures.