An evaluation of climate change effects on agricultural systems: the case of Trasimeno Lake

Climate change is a current matter that is viewed as controversial by the general public, within scientific communities and by governments. Among the production sectors, agriculture is the most significantly influenced by the effect of climate change. This study is aimed at understanding and measuring the changes that occur in agricultural systems due to climate, and at determining how climate change can affect both agricultural productivity and the environmental impacts of agricultural systems, by focusing a case study on the Trasimeno Lake (region of Umbria, Italy). The analysis was performed using the CropSyst software package. CropSyst is a multi-year, multicrop, daily time step crop growth simulation model with the possibility of connection with GIS (Geographic Information System) software. The specific typology of climate change that was simulated was the doubling of the amount of CO2 in the atmosphere during a time interval of 100 years (from year 2000 to 2100), according to the hypothesis of the CCM3 model (Govindasamy et al., 2003). The results of our simulation have shown an increase of plant productivity (connected with yield and biomass production) and an invariable situation concerning the indicators of stress by nitrogen, water and temperature. With reference to the environmental situation, our results have shown a general increase of nitrogen lisciviation, as a consequence of the increase of mineralisation, with potential effects on the soil fertility loss, and a decrease of runoff and deep percolation. The erosion indicator did not vary in a significant way. Our CropSyst - GIS system developed for this study has been useful both for the evaluation of the existing data, and for the simulation of future data.