Turning food waste into sustainable soil improvers for better soil health and improved food systems

The goal of the Waste4Soil project is to develop practical technical recycling pathways for transforming food processing residues (FPR) into soil improvers (SI) through a circular, systemic, and multi-stakeholder approach at the regional level, involving all actors in the food chain, thereby closing specific loops (nutrients, organic matter, water). To achieve the project's goal, the involvement of various types of actors throughout the entire project is essential, in order to ensure co-creation at different levels — from collaboration in project planning and presentations to implementation, dissemination of results, and all the way to the demonstration phase. All interested stakeholders in the value chain play an important role in improving management practices, reducing waste quantities, and enhancing FPR processing procedures, with the aim of making them environmentally friendly and socially acceptable soil improvers. The main objective of the Waste4Soil project is to provide ecosystem solutions that encompass collaboration within and beyond the project, with numerous and diverse stakeholders: 1) farmers and their ecosystems, 2) the food industry, 3) waste management companies, 4) fertilizer producers, 5) research and educational institutions, 6) local and regional authorities, 7) citizens and civil society.

The Waste4Soil project contributes to the advancement of science by bringing together 28 partners from nine European countries and Switzerland under the Horizo…The Waste4Soil project contributes to the advancement of science by bringing together 28 partners from nine European countries and Switzerland under the Horizon Europe programme to develop ten new technological and methodological solutions for recycling food processing residues into bio-based soil improvers. Through the establishment of seven Soil Health Living Labs across different European regions, it enables comparative, interdisciplinary, and practice-oriented research on the valorisation of eight distinct streams of food processing residues (meat, fish, dairy, cereals, olive oil, beverages, fruits and vegetables, and processed food), while also developing a standardised evaluation framework that lays the groundwork for new scientific methodologies in the fields of circular bioeconomy, soil health, and sustainable food systems.

For Slovenia, the Waste4Soil project is significant because, through the Slovenia – Istria Living Lab, it directly addresses the challenges brought by climate change and emerging agricultural opportunities, particularly the development of olive growing, which is becoming an increasingly important economic sector. Slovenian partners (the University of Ljubljana, KOTO, the Science and Research Centre Koper, and 3R, with the support of the Slovenian Association for Conservation Agriculture and Marjetica Koper) are developing solutions for processing olive-oil residues and mixed food processing residues, which represent a major environmental challenge in two-phase olive centrifugation due to the high moisture content of the waste biomass. Within the Slovenian context, the project promotes knowledge transfer in the cultivation of microalgae for digestate treatment, the use of biochar, field trials of biostimulants on proso millet and wheat, and strengthens cooperation between the research sector, industry, farmers, and local communities (Istria, Gorišnica, Marezige). In doing so, it contributes to the development of a circular bioeconomy, the improvement of soil health, greater resilience of Slovenian agriculture, and the international integration of Slovenian research and industrial partners into the European Research Area.