Extreme Dry Years in the 21st Century at the Level of the Agricultural Areas of Muntenia, Romania

Abstract The global climatic changes consisting of the increased in the average air temperature and changes in the rainfall regime have led in the last decades to the extension of the agricultural areas affected by the drought phenomenon, both worldwide and in Romania. During the last half century, the drought and the phenomena associated with it, namely aridization and desertification, are a major problem for mankind. The limiting factor affecting field crops on the largest surface is the drought, the extent and intensity of this type of risk causing annual reduction of agricultural production by at least 30-50%. Drought represents the natural phenomenon determined by the amounts of precipitations below the normal values. The absence of rainfall is due to the predominance of the anti-cyclonic type. The most frequent phenomena occur in the extra-Carpathian agricultural regions of southern and south-eastern Romania Muntenia is located in the drought-sensitive area, where the influx of continental anti-cyclones is higher. Although this phenomena is possible in all seasons and in all agricultural areas, it doesn’t occur simultaneously and doesn’t have the same intensity. In the 21st century, the agricultural years 2001-2002, 2002-2003, 2006-2007, 2011-2012 and 2014-2015 are included in the list of the most recent years in terms of rainfall quantities, the heat units recorded in the warm season, as well as the soil moisture reserve available to winter wheat and maize plants during maximum water consumption. The objective of this paper is to highlight the correlation between the pluviometric regime analyzed during periods of maximum consumption of water from winter wheat and maize crops, the phenomenon of "heat" and the soil moisture reserve. The analysis of these specific indices helped us characterize the mentioned agricultural years, in the context of analysing the phenomenon of pedological drought with an impact in agriculture in Muntenia Region. An important element in the development of agricultural management strategies is to improve scientific knowledge and capacities to better manage climate variability by examining climate data and risks and opportunities analysis. The decrease in production of winter wheat and maize wheat crops occurs in extreme dry agricultural years due to the shortening of the vegetation season as a result of the increase in air temperature and water stress during the period of accumulation of the dry matter in the grain (the filling phase grain) caused by the reduction of precipitation amounts. Drought periods are increasingly common in Romania and are a major problem for agriculture with high impact on the agricultural production.