Legumes offer a wide array of services to be promoted in production systems and supply chains: production of protein-rich raw materials with interesting nutritional properties for both food and feed; beneficial preceding crop effects through the restitution of biologically fixed N and the time/space diversification of cropping systems. However the high variability of performances hinders anticipating and exploiting such services through adapted cropping system management. Today, stakeholders are lacking local references for diverse legume species and insertion modes (sole crops, intercrops for cash crops as well as cover crops). Hence approaches to insert more legumes in territories need to be assisted by identifying 1) the actor’s expectations, 2) services obtained by farmers in real farm context, 3) the main variability factors and levers to optimally exploit services, and by sharing results with actors. In 3 french territories (Pays de la Loire-PDL, Burgundy-B and Midi-Pyrénées-MP) observatories have been set up in partnership with cooperatives. Several species and insertion modes selected by local actors have been studied: spring/winter lupin as sole crop or intercropped with triticale (PDL); alfalfa and spring pea (B), soybean, and lentil as sole crop or intercropped with wheat (MP). A 2-year followup of the legume crop and the next crop has been performed in 2015-16 and was repeated on other plots in 2016-17. The variability of productivity (grain and protein yield) and grain protein content was high but differed according to species. Moreover there is a high variability in the yields and N acquisition of the following crops in relation to the performances of the legume and its N acquisition and allocation (N2 fixation, nitrogen harvest index, nitrogen in residues). The conditions and levers required to achieve both high yield productivity of legumes and high N preceding effect are discussed.