Legumes have a key role to play in agriculture transition towards greater sustainability, due to their ability to provide ecosystem services. However, choosing the right grain legumes to provide specific ecosystem services remains difficult because references are lacking for a diversity of species. Guinet et al. characterized and distinguished ten-grain legumes according to their ability to deliver contrasted nitrogen-related ecosystem services. Their study provides a rationale for choosing legumes species according to intended objectives and for adjusting N management in cropping systems.