This paper introduces a Web-based tool that has been developed to facilitate learning object annotation in agricultural learning repositories with IEEE LOM-compliant metadata. More specifically, it presents how an application profile of the IEEE LOM standard has been developed for the description of learning objects on organic agriculture and agroecology. Then, it describes the design and prototype development of the Organic. Edunet repository tool: a Web-based for annotating learning objects on organic agriculture and agroecology, organizing them in using a portfolio-like user interface in a learning repository, and then federating this repository with a network of agricultural learning repositories.