CR 12:161-173 (1999)  -  doi:10.3354/cr012161

ABSTRACT: Vulnerability and adaptation assessments of major agricultural crops under climate change were carried out in Bulgaria through the US Country Studies Program. Several climate change scenarios using General Circulation Model (GCM) outputs were created. Annual temperatures in the country are projected to rise between 2.9 (HCGS model) and 5.8°C (UK89 model) under effective doubling of CO₂. Precipitation is expected to increase during the winter and to decrease during the warm half of the year. Under equilibrium 2 x CO₂, the GCM climate change scenarios project an increase in the agroclimatic potential; however, warming would cause decreases in grain yield of winter wheat Triticum aestivum L. and especially maize Zea mays L. Simulated adaptation measures--such as zoning of crop production in agricultural land areas with elevation below 1000 m, changing planting dates, altering varieties, changing optimum value and dates of fertilizer application, and irrigation--were considered as potential responses that may modify any effects of climate change on crop production in Bulgaria. An action plan in Bulgarian agriculture under climate change was developed in cooperation with the Ministry of Agriculture, Forest and Agrarian Reform. Major points of the plan are a decrease in greenhouse gas emissions (reducing methane emissions produced by biological fermentation in stock breeding and rice cultivation; decreasing methane emissions by effective utilization of manure; improving fertilization using mineral fertilizers; decreasing the carbon emissions containing gasses; and retaining soil carbon) and some adaptation measures.

KEY WORDS: Agriculture · Bulgaria · Climate change · DSSAT · GCMs · Maize · Winter wheat · Yield