VULNERABILITY OF AGRONOMIC SYSTEMS IN BULGARIA

In recent years the problem of climate and its variations under the in fluence of natural processes and factors of anthropogenetic origin has come to the forefront of scientific and practical problems on a world -wide scale. Climate change vulnerability assessments of agronomic sys tems in Bulgaria have been initiated. In this paper preliminary result s of this study are presented. Different climate change scenarios were defined. Global circulation model (GCM) scenarios and incremental sce narios for Bulgaria were created and applied. The influence of climate change on potential crop growing season above a base of 5 degrees and 10 degrees C in Bulgaria was investigated. Increases in temperature c an be expected to lengthen the potential growing season, resulting in a shift of thermal limits of agriculture in Bulgaria. The Decision Sup port System for Agrotechnology Transfer (DSSAT) Version 2.1 was used t o assess the influence of climate change on grain yield of maize and w inter wheat. Maize and winter wheat yields decreased with increasing t emperatures and decreasing precipitation.