The increase in agricultural input prices challenges the viability of outermost island farms. The need to reduce dependency and to mobilize local resources in a circular way is rising. From 2017 to 2020, an R&D project was carried out on Reunion Island to implement a territorial approach to biomass in agriculture based on a circular economy. One of the five case studies undertaken with stakeholders dealt with a scenario of on-farm composting manure with green waste. As an extension of this case study, the CONVER (Co-CONception d’un scénario de Valorisation des biomasses dans une démarche d’Economie circulaire, à la Réunion) project (2019-2023) was conceptualized to implement the on-farm scenario. Therefore, we set up on-farm experiments with five farmers to test and demonstrate the feasibility of composting green waste with poultry and pig manure. Then we assessed the agronomic value of the compost produced on meadows and in market gardening.