European agriculture faces increasing pressure to maintain crop production while reducing external inputs, recycling organic residues, and adapting to more frequent drought, heat, and disease stress. Soil improvers made from food-processing residues, including products derived from olive pomace, grape pomace, beer bagasse, digestate, composted plant residues, or biochar-containing blends, may help address these challenges by returning carbon and nutrients to soils while supporting crop stress tolerance. This thesis will investigate whether selected residue-derived soil improvers can enhance crop performance under controlled stress conditions, including drought, heat, combined drought–heat stress, and soil-borne disease pressure.
The project will also explore whether these soil improvers create short-term plant–soil feedbacks that influence the performance of a subsequent crop grown in the same soil. By linking circular resource use with crop stress responses, disease outcomes, and soil legacy effects, the thesis will evaluate whether food-residue-derived soil improvers function only as nutrient inputs or also contribute to broader agroecosystem resilience. The results will support FiBL's research on circular soil fertility, organic crop protection, and climate adaptation in sustainable farming systems
Controlled pot experiments; plant pathology; statistical analysis (R)
Pascal Herren & William Thompson
1. September 2026
De Long, J.R., Heinen, R., Heinze, J. et al. Plant-soil feedback: incorporating untested influential drivers and reconciling terminology. Plant Soil 485, 7–43 (2023). https://doi.org/10.1007/s11104-023-05908-9
