Durum Wheat in a Changing Climate: Comparing Conservation and Conventional Practices in a Mediterranean environment

The Mediterranean Basin is recognized as a "climate change hotspot" due to its high exposure and vulnerability to interconnected climatic risks. Agriculture in this region must not only adapt to these challenges but also contribute to mitigation goals, as it is a significant source of greenhouse gas emissions. This study evaluates the impacts of climate change on durum wheat productivity in two sites in southern Sardinian (Italy), representative of Mediterranean cereal farming, and compares conservation tillage practices (reduced tillage and no-tillage) with conventional management. Crop modelling was performed using the CSM-CERES-Wheat model, implemented in the DSSAT software, parameterized with data from two long-term experiments on conservation agriculture. Climate projections from the Euro-Cordex platform under three Representative Concentration Pathways (RCP2.6, RCP4.5, RCP8.5) were considered for future projections. Results indicate significant increases in temperatures across all scenarios, with shortened crop growing cycles and earlier maturation by up to three weeks under the most extreme scenarios. Yield variations ranged from -9% to +20% by the end of the century, influenced by the direct effect of increased atmospheric CO₂ concentration on photosynthesis rate and water use efficiency. Grain yields obtained with conservation tillage practices are comparable with the values obtained with conventional practices, but with several related advantages, including reduced operational costs, time savings, and lower greenhouse gas emissions. These findings highlight the dual role of conservation agriculture as a strategy for climate adaptation and mitigation in Mediterranean cereal systems. However, further research is needed to better address uncertainties related to extreme weather, pests and diseases, and greenhouse gas emissions, to ensure sustainable agricultural productivity in the face of climate change.