Agriculture in Romania is sensitive to climate variability, especially in the extreme weather events. The maize is one of the most important field crop of Romania's agriculture (more than 40 % from the total arable land), essential for the economy of the country. The maize yield presents fluctuation from one year to another, due to the current weather conditions. Consequently, the yield forecasts in the present climatic conditions are of major importance in view to establish the correct management practices as well as adaptation options that would reduce the adverse effects. The precise information in advance on crop production are most useful, representing a vital component in transition to market economy.
The aim of the present paper is to quantify the impacts of climate variability on maize grain yield and the main components of water balance (evapotranspiration, water use efficiency) in one of the most vulnerable zone of Romania (the south region). In addition, the paper evaluates shifts in the crop productivity when faced with different management practices in order to maximize the grain yield in the case of extreme weather events. For the purposes of this study, a weather data generator was used to create the climatic data sequences for 30 year-period (the interval 1961-1990). CERES-Maize simulation model linked with seasonal analysis program included in a Decision Support System for Agrotehnology Transfer (DSSAT v3.0) was selected as tools for the impact assessments. Both biophysical and economic analyses were used to obtain information on the adaptation measures to negative effects of climatic extremes.
Results of crop simulations under climate variability indicate that the maize crop is affected by the water availability, especially in the floral initiation-tasseling and silking-grain filling phases. The largest water shortage associated with high temperature occur during these phenological phases resulting in significant yield losses. The economic risk analysis gives as dominant strategy for unfavorable years: irrigated maize crop and increase fertilizer levels applied in the vegetation season.