Evaluating the quality of marine composts by using humification and spectroscopy: A summary of workshop presentations and learning outcomes from the MARIGREEN_TECB project

This report summarizes the presentations and activities made during a workshop organized under the auspices of the project MARIGREEN_TECB (Training, Exchange, and Capacity Building), which was funded by the third supplementary call of the ERA-NET Cofund on Blue Bioeconomy (BlueBio) program (grant number 346849) . MARIGREEN_TECB was an extension of MARIGREEN (sustainable exploitation of MARINE resources to promote GREEN plant production in Europe), a project funded by the first supplementary call of the ERA-NET BlueBio program (EU Horizon 2020 grant agreement 817992). MARIGREEN's aim is to valorise poorly utilized residual materials from the blue sector by treating them with suitable technologies such as extraction, composting and biochar impregnation after extraction, and using them in organic agriculture. The project works with available residual material from fishing, the brown algae industry, the mussel industry and organic aquaculture. The main objective of MARIGREEN_TECB was to improve the understanding of humification during composting of marine raw materials and how to improve the quality of "blue" compost and to gain expertise in FT-IR analysis and spectrum interpretation for humic substances. MARIGREEN_TECB was a collaboration between NORSØK and USAMV in Bucharest. The workshop was organized by the Research Center for Studies of Food Quality and Agricultural Products at USAMV's campus in Bucharest and was held from 23 to 26 October 2023. The topics for the workshop were chosen because they are directly relevant to the MARIGREEN main project and several of the work packages. However, they also have global relevance. While the focus was on marine-based compost, the methods covered during the workshop are relevant to all types of composts, organic-based fertilizers and soil conditioners. Methods to improve compost quality and improve humification can be applied to compost made with all raw materials. The same applies to evaluation of compost quality by more traditional methods and by FT-IR spectroscopy.