Abstract: Climate projections indicate that rising temperatures will affect summer crops in the southern Iberian Peninsula. The aim of this study was to obtain projections of the impacts of rising temperatures, and of higher frequency of extreme events on irrigated maize, and to evaluate some adaptation strategies. The study was conducted at several locations in Andalusia using the CERES-Maize crop model, previously calibrated/validated with local experimental datasets. The simulated climate consisted of projections from regional climate models from the ENSEMBLES project; these were corrected for daily temperature and precipitation with regard to the E-OBS observational dataset. These bias-corrected projections were used with the CERES-Maize model to generate future impacts. Crop model results showed a decrease in maize yield by the end of the 21st century from 6 to 20%, a decrease of up to 25% in irrigation water requirements, and an increase in irrigation water productivity of up to 22%, due to earlier maturity dates and stomatal closure caused by CO2 increase. When adaptation strategies combining earlier sowing dates and cultivar changes were considered, impacts were compensated, and maize yield increased up to 14%, compared with the baseline period (1981-2010), with similar reductions in crop irrigation water requirements. Effects of extreme maximum temperatures rose to 40% at the end of the 21st century, compared with the baseline. Adaptation resulted in an overall reduction in extreme T-max damages in all locations, with the exception of Granada, where losses were limited to 8%.

Abstract: Adaptation can reduce climate change risks to crop production and is best analyzed at local scales considering regional specificities. Uncertainty inherent in modelling adaptation options is due to climate projections, downscaling and imperfections of crop models. The challenge of making effective adaptation decisions requires powerful approaches for exploiting the potential of genotype by environment by management interactions, and for generating projections informed with uncertainty.Here we present a methodology that constructs impact response surfaces (IRSs) from an ensemble of crop models and applies these to explore the adaptation potential of rainfed winter wheat at Lleida (NE Spain) in a water-limited environment. The simulation experiment includes: 1) a systematic sensitivity analysis to changes to baseline temperature and precipitation (1981-2010) through a delta change approach that accounts for seasonal differences, 2) three levels of CO2 representing present-day and future conditions until 2050 (A1B scenario), and 3) soil profiles representative for the variable conditions around Lleida. The adaptation simulations represent adjusted management practices about sowing, supplementary irrigation, and the thermal and vernalisation requirements of cultivars used.A pre-selection of the adaptation options was done iteratively, in ranges supported by literature review of crop adaptation in the Mediterranean (e.g. shifts from current sowing date between -30 and +45 days). This procedure allowed to identify a limited number of effective and feasible adaptations to be evaluated combining IRSs and probabilistic projections of climate change. No Label