Cover plant-based cropping systems have gained considerable attention over the last few years because of the recognized benefits of increasing the diversity of agrosystems to sustain services other than those pertaining to production. While agronomical tools and methods to assess these services in multispecies plant communities barely exist, trait-based approaches, originally developed in the field of comparative functional ecology, provide an appropriated framework to study the effects of plant diversity on agrosystems. The aim of this article is to discuss how a trait-based approach can be used to assess the services delivered in cover plant-based cropping system. We focus on semiperennial cropping systems based on cover plants, exemplified by the banana cropping systems. These systems are described in a first section to identify the services targeted. A second section, based on a literature survey, analyzes the processes associated with each service and identifies related effect traits of cover plants. A shortlist of markers to be used to assess agrosystem processes is proposed and hypothesis on trade-offs and synergies among services are formulated. In a third section, issues related to the scaling-up from plant traits to the services delivered by plant agricultural communities are discussed. Such an approach, originated in the field of ecology, appears highly promising to tackle agronomic issues and its application to agrosystems constitutes a challenging test of their genericity. It raises specific questions and stresses the need for new methodological developments, which could be part of a research agenda at the interface between the two disciplines.