ENERGY AND IRRIGATION IN SOUTH EASTERN US AGRICULTURE UNDER CLIMATE-CHANGE

The effects of three scenarios of climate change under effectively dou bled carbon dioxide have been studied for yield effects; this paper sh ows the possible effects on energy efficiency and irrigation water dem and under these conditions. Forty years of daily weather data for twen ty-seven south eastern U.S. weather stations have been assembled into the IBSNAT format (International Benchmark Sites Network for Agrotechn ology Transfer) for running crop simulation models under Decision Supp ort System for Agrotechnology Transfer (DSSAT). Three general circulat ion models provide monthly parameters to adjust the historical data to form new data sets representing weather for equivalent doubled carbon dioxide conditions, predicted to occur around the year 2040. Dynamic process models of soybean, peanut and maize, with daily time steps, re sulted in maturity dates, yields and water use for irrigated and non-i rrigated crops for historical weather conditions used as a benchmark a nd for climate change scenarios. We analysed the differences in energy inputs and outputs under irrigated and rain-fed conditions for histor ical data and for the climate change scenarios. Data for two locations , near Pensacola, Florida and Columbia, South Carolina are given here. In general, climate change scenarios resulted in a greater demand for irrigation water and a lower energy efficiency of production.