The GENERIC CERES 3.00 maize model, which has been integrated into a decision-support system for agrotechnology transfer (DSSAT), was adapted to the soil and climatic conditions in Bulgaria using meteorological agrometeorological and biological data from 1980 to 1993 at irrigated and rainfed experimental crop variety stations across the country. A simulation approach, based on the DSSAT and GENERIC CERES 3.00 maize model, was used to determine the appropriate amounts and dates of irrigation and the choice of most efficient strategy of irrigation in Bulgaria. The strategic analysis, which was carried out by the DSSAT Seasonal Analysis program, was done in respect to the value of harvest yield of maize and net return. The studied method could be used by individual farmers, governmental or private organizations to determine an irrigation strategy for particular soil and climatic conditions in Bulgaria.