Project SOLO: co-creating research and innovation roadmaps to restore European soils

Healthy soils are fundamental for life on Earth, providing essential ecosystem services such as food production, climate regulation, and disease control. Yet, over 60% of soils in Europe is degraded. In response, the Soil Strategy of the European Union aims to restore all soils in Europe by 2050. Achieving this aim requires more than scientific understanding of soil processes and novel technologies, since soils are embedded in complex societal systems. For instance, agricultural soils are part of food supply chains that influence how farmers can manage their soils. Improving soil health therefore also requires understanding the societal processes that affect soil health, and what knowledge or innovation can help steering these processes towards sustainability. To assess the latter, input from societal soil stakeholders is essential.

Project SOLO addresses this challenge by developing transdisciplinary roadmaps for future European soil research. These roadmaps identify what knowledge or innovation is needed to restore all soils in Europe towards a healthy state. Nine thematic roadmaps, covering issues such as soil biodiversity and erosion, are co-created by diverse groups of scientists and societal stakeholders. These roadmaps are updated annually, and open for review. The context-dependence of what we want from soils and what is possible is captured by four regional nodes that develop local research agendas in contrasting European settings. Further regional inputs are collected during annual outreach events across 12 different countries. An overarching roadmap synthesizes the thematic and regional roadmaps into a holistic research agenda that informs future EU funding calls.

This synthesis was led by soil scientists and enriched by the contributions of social scientists who were essential in developing a bottom-up methodology for quantitative synthesis and for interpreting the results. The overarching roadmap reveals the synergies and trade-offs when addressing knowledge gaps across different soil health themes and European regions. These insights resulted in four promising strategies for developing the knowledge needed to improve European soil health most effectively.

This presentation will highlight the 2025 overarching roadmap, its key findings, and the inter-and transdisciplinary approaches that enabled its development. The SOLO roadmaps support structuring the policy agenda for future soil research and innovation that is needed for Europe’s transition toward sustainable soil use.