Agroecosystems in the Mediterranean basin face accelerating degradation from rising temperatures, prolonged droughts, and severe depletion of soil organic matter. Carbon farming strategies aim to counteract these climate stresses by stabilizing carbon within agricultural systems while improving overall land resilience. Biochar represents a unique amendment in this framework because its carbon content resists rapid microbial breakdown, surviving in ground storage over centuries. This synthesis evaluates peer-reviewed evidence to assess how biochar influences climate change mitigation and crop health across Mediterranean agricultural landscapes.

The primary dynamic observed across regional soils is a consistent rise in soil organic carbon stocks, driven by the addition of highly recalcitrant pyrogenic carbon forms. This carbon structure remains durable even under high ambient temperatures and repetitive wet-dry seasonal cycles. Beyond direct carbon additions, biochar helps protect existing native organic matter from breaking down through negative priming mechanisms. The environmental trade-off appears in greenhouse gas dynamics, where nitrous oxide mitigation is exceptionally strong, dropping between thirty and seventy percent when biochar binds nitrate and ammonium ions. However, carbon dioxide emissions remain neutral, and methane release can escalate during warm, saturated soil periods due to localized oxygen-starved microsites forming inside the porous char structure.

Agronomic outcomes depend strongly on existing soil constraints and specific crop types. Biochar delivers maximum benefits when applied to coarse-textured, degraded, or saline soils, where it increases porous volume, enhances aggregate stability, and expands water-holding capacity. Perennial systems display the most persistent advantages; olive orchards and grapevines show sustained improvements in water-use efficiency, stomatal conductance, and photosynthetic performance for years following a single application. Legumes like faba beans, cowpeas, and fenugreek also perform exceptionally well, benefiting from improved rhizosphere conditions and enhanced biological nitrogen fixationNitrogen is a crucial nutrient for plant growth, but plants can’t directly absorb it from the air. Nitrogen fixation is a process where certain bacteria convert atmospheric nitrogen into a form that plants can use. Biochar can provide a home for these nitrogen-fixing bacteria, enhancing More.

Conversely, annual field crops such as durum wheat, maize, and various leafy vegetables show mixed reactions. Under optimal growth conditions or non-limiting environments, biochar yields limited additional growth and can occasionally cause temporary nutrient immobilization. Furthermore, excessive application rates risk reducing soil oxygen flow and impairing sensitive root zones, as observed in nectarine orchards. Establishing a balanced amendment strategy requires targeting stress-prone environments and capping application amounts between ten and thirty metric tons per hectare, ensuring optimized carbon sequestration without triggering unwanted gas emissions or nutrient bottlenecks.

Source: Borgatti, D., Radicetti, E., Mancinelli, R., Coluccia, L., Allam, M., Jamal, A., Abideen, Z., Ahsan, M., & Ben Hassine, M. (2026). Carbon farming strategies for mediterranean agriculture: the role of biochar in climate-smart agroecosystems. Crop Health, 4(19), 1-15.