Exploring adaptive capacities in Mediterranean agriculture: Insights from Central Italy's Ombrone catchment

CONTEXT Climate change's profound implications for Mediterranean agriculture underscores the urgency of adaptation strategies. These strategies, whether incentivized or farmer-driven, are pivotal in mitigating crop yield losses and harnessing evolving climatic conditions. While the influence of agronomic adaptations on crop yields is well-explored, the implications for water footprint and water balance components remain largely unexplored. OBJECTIVE With this study, we aim to conduct a comprehensive assessment of the adaptive capacity of agricultural systems in the Ombrone catchment, Tuscany. We estimate the impacts of both climate change and adaptation strategies - also referred to as management changes - on crop yields, water footprint and water balance components by comparing simulations with historical and future climate and with and without adaptation strategies. METHODS A Soil and Water Assessment Tool (SWAT+) agro-hydrological model of the Ombrone catchment is calibrated for crop yields of durum wheat, sunflower and irrigated maize. The impacts of climate change are then assessed by forcing the calibrated model with climate data from five bias-corrected regional climate models under Representative Concentration Pathways (RCPs) 4.5 and 8.5. Subsequently, we simulate six autonomous agronomic adaptation strategies (earlier and later sowing, supplemental irrigation, longer crop cycles, zero tillage and cover crops). We quantify their impacts on crop yield, water footprint and water balance components, such as evaporation, water yield and soil moisture. RESULTS AND CONCLUSIONS Our findings reveal negligible and adverse impacts on crop yields under RCPs 4.5 and 8.5 respectively. Agricultural systems show strong adaptive capabilities under both RCPs, particularly when multiple strategies are combined. The most impactful strategies include earlier sowing and extended cropping cycles. Supplemental irrigation and cover crops are beneficial only with specific combinations of climate models and RCPs. While management changes have limited impact on basin-scale water balance components, they induce an average 27% reduction in water yield at the cropland scale, attributed to practices like zero tillage and cover crops. SIGNIFICANCE Despite the uncertain impacts of climate change, our research reveal that changing the management - hence applying adaptation strategies - will be sufficient to maintain or improve current crop yields. Furthermore, we also underscore the non-negligible influence of management changes related to conservation agriculture on water balance components in agricultural catchments. Future adaptation strategy assessments should encompass comprehensive integration to evaluate broader impacts on water resources.