Carbon farming strategies for mediterranean agriculture: the role of biochar in climate-smart agroecosystems.

Mediterranean agriculture is increasingly constrained by climate change-driven stresses, including rising temperatures, intensified drought, and soil organic matter depletion, all of which threaten crop health and yield stability. Carbon farming has emerged as a strategy to integrate climate mitigation with agricultural resilience, and biochar represents a distinctive tool within this framework due to its capacity for long-term carbon sequestration and soil modification. This review synthesizes peer-reviewed studies published between 1999 and 2025 to assess the role of biochar in Mediterranean agroecosystems, with a specific focus on crop health outcomes. Across Mediterranean systems, biochar consistently increases soil organic carbon stocks through the addition of recalcitrant carbon forms and generally reduces nitrous oxide emissions while carbon dioxide emissions remain neutral. However, methane emissions may increase under warm and moist conditions, highlighting the importance of comprehensive greenhouse gas accounting. Biochar improves crop performance primarily when it alleviates limiting soil constraints, particularly in degraded or coarse-textured soils, under water-limited or saline conditions, and in perennial cropping systems. Long-term benefits are most evident in tree crops and vineyards, and legumes often show positive responses linked to enhanced nutrient availability and rhizosphere functioning. In contrast, cereal and leafy vegetable crops exhibit more variable responses, including neutral or negative effects under non-limiting conditions. Overall, biochar is most effective when applied selectively at moderate rates (approximately 10-30 Mg ha⁻1) and integrated with complementary climate-smart practices. Future research should prioritize long-term, crop-centered assessments and methane mitigation strategies to support context-specific biochar deployment in Mediterranean agriculture.