IMPACT OF DIFFERENT CLIMATE CHANGE SCENARIOS ON RAINFED CROPPING SYSTEMS IN CENTRAL ITALY

The rainfed cropping system based on the durum wheat-sunflower rotation is very common in Central Italy, to the point of being the almost exclusive system in some areas. The predominance of the system, and the suboptimal environmental con-ditions in which such system is implemented make it at risk in scenarios of possible worsening of weather patterns as esti-mated by weather change scenarios. The objectives of this paper were: 1) to estimate the impact of climate change on the agronomic performance and long term soil fertility; 2) to explore adaptation strategies and to identify research needs. Three years of field data on current cropping system practices were collected at two microcatchments of the Marche (Central It-aly) to calibrate the cropping systems simulation model CropSyst. Crops yield and soil organic matter dynamics were ana-lyzed in relation to increased air temperature and CO2 concentration, as forecasted by different future climate scenarios. To assess the impact of climatic change on mean crop yields and variability, two fifty-years equilibrium climate datasets were generated from a local 20-years daily temperature and rainfall dataset assuming for each scenario constant climate at different atmospheric CO2 concentration: “baseline ” [CO2] = 350 ppm; 2040 equilibrium [CO2] = 450 ppm. To assess the long term impact of climatic change on soil organic matter content, three 100-years transient climatic scenarios were gen