Performance-based criteria for safe and circular digestate use in agriculture.

ABSTRACT: Anaerobic digestion converts organic waste into renewable energy (biogas) and recyclable nutrients (digestate), generating over one billion tons of digestate annually. While this represents a major resource, its safe reuse remains a bottleneck for nutrient circularity, particularly for closing global nitrogen loops. We analyzed digestates from 23 full-scale digesters in Sweden, Norway, and Denmark across whole, liquid, and solid fractions using germination index (GI) assays and chemical profiling. Three parameters predicted phytotoxicity: total ammonia nitrogen (TAN ≥ 1,122 mg N L^- 1), potassium (K ≥ 39.6 × 10³ mg kg^- 1), and boron (B ≥ 22.5 mg kg^- 1). When all thresholds were exceeded, germination indices dropped below 50% in every case. Based o

SUBMITTER: Anacleto TM 

PROVIDER: S-EPMC12834953 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature