Biotic resource loss beyond food waste: Agriculture leaks worst

- Use efficiency relates biotic resources to the Earth system and food security.
- Relating biotic products to resource use quantifies efficiency and losses.
- The biotic residue ratio reveals the resource use efficiency beyond edibility.
- The highest efficiency improvements achieved by omitting animal production.
- Agrifood efficiency requires loss avoidance and circular biotic resource use.

Enhancing the efficiency of biotic resource use by avoiding losses and boosting circular economy is one key in agrifood systems to ensuring food security and the functioning of the Earth system. The aims of this study were to first identify the greatest prospects for improving the biotic resource use efficiency and, second, to design methods to assess this efficiency. We assessed biotic resource use efficiencies (outputs/inputs) and biotic residue ratios (residues/inputs) in terms of dry matter, energy (LHVd), nitrogen and phosphorus for two Finnish case regions. We identified the greatest biotic resource use inefficiency as occurring in animal production, followed by crop production. The resource use efficiency in animal production is unavoidably low, but in crop production, the utilization of recycled nutrients, i.e., animal and green manures, and the rejection of the use of spare mineral fertiliser can enhance efficiency. In addition, the agrifood system efficiency was 3.4-21% higher according to the circular use of biotic resources compared to the exclusion of these. The losses from the agrifood system represent 52-76% of the current biotic inputs of the studied elements in crop production, which highlights the importance of efficient resource use in terms of food security. We conclude that substituting the external resources in favour of the circular use of biotic resources as well as the avoidance of losses are the keys to enhancing the system's efficiency. The determination of the biotic resource use efficiency and biotic residue ratio applying the introduced generic assessments serves boosting of circular economy.