Description of the Business As Usual (BAU):
Crop residues and pruning biomass are left to decompose or are openly burned, returning CO2 to the atmosphere within months to a few years. Soil organic carbon remains stable or declines due to tillage, limited organic inputs, and fertilizer-driven mineralization. Soil organic carbon (SOC) typically remains stable or declines under intensive management, with reduced soil structure, fertility, and microbial activity. Nutrient leaching and erosion risks remain high. In this scenario, soils act mainly as carbon sources rather than sinks.
Description of the system change:
Biochar is a stable, carbon-rich material obtained by pyrolyzing organic biomass (crop residues, pruning wood, manure, etc.) under limited oxygen. When incorporated into agricultural soils,
it functions as a carbon dioxide removal (CDR) technology by permanently storing atmospheric carbon originally fixed by plants through photosynthesis.
In croplands and perennial systems, biochar is incorporated into the root zone (via soil mixing, banding, or co-application with compost or fertilizers). It enhances soil structure, nutrient retention, microbial activity, and water-use efficiency. Meta- analyses summarized in Schmidt et al. (2021) show that biochar:
• Increases crop yields by 13–16%, particularly in acidic or low-fertility soils.
• Boosts root biomass (+32%), microbial biomass (+25– 36%), and soil organic carbon (+39–52%).
• Enhances water use efficiency (+19–20%) and soil porosity while lowering bulk density (−8–9%).
Biochar is especially effective in acidic or sandy soils with low fertility where it improves cation exchange capacity, pH buffering, and water retention. When combined with fertilizers, the yield
benefits extend also to temperate regions with loamy soils (e.g., cereal rotations).
The practice shifts conventional agriculture from rapid carbon cycling (residue decomposition or burning) to permanent carbon storage and improved soil function. It strengthens ecosystem
resilience, supports nutrient recycling, and contributes to multiple EU environmental objectives, including climate change mitigation and adaptation.