Considering the already observed trends of increasing air temperatures, changes in precipitation regimes, and extension of the growing season, as well as predictions that climate conditions in Serbia will deteriorate and the risks to farming will increase, the objective of this research is to assess the vulnerability of agriculture in Serbia to climate change, based on farmers? perceptions. A team of experts in all areas of agriculture and soil and water management compiled a questionnaire for a semi-open online survey. The snowball sampling approach was followed, relying on personal contacts and social media. In total, 141 farmers responded to the questionnaire. The data were evaluated using descriptive statistics. The differences by region, activity and topography were tested by ANOVA and Student?s t-test. The feedback was used to assess the damages sustained by farmers due to climate change and reduced revenues in their respective areas of agricultural activity. Certain positive effects of climate change were also identified. A need for training in climate change impact mitigation is noted. The collected data were analyzed by descriptive statistics. The surveyed farmers believe that the most important effects of climate change were periods of extreme high temperature, droughts, late spring frost, and hail. Climate change seems to be reducing yields, facilitating the appearance of new diseases and pests, and causing a lower tolerance to existing diseases and pests. Farmers expressed considerable interest in climate change impact adaptation and mitigation training.

In order to calculate water deficit of agricultural crops, it is necessary to have an insight into the evapotranspiration process. As for evaluation of reference evapotranspiration, the Penman-Monteith (FAO56-PM) method, suggested by The International Commission on Irrigation and Drainage (ICID) and Food and Agriculture Organization of the United Nations (FAO), requires several climate parameters, which are often unavailable. Thus, in this paper, the methods for computing ETo, which use limited weather data, were tested and then compared to FAO56-PM. The selected methods were those most often used as the replacement for FAO56-PM: Hargreaves, adjusted Hargreaves, Copais, Turc, Priestley-Taylor, Makkink and Hamon. ETo was calculated at the daily and average monthly levels, for the 2010-2013 period, using data from the following meteorological stations: Nis, Belgrade, Novi Sad, Loznica, Valjevo, Zlatibor, Cuprija and Kikinda. Special importance was given to the vegetation period during the dry season due to the application of irrigation. The comparison of methods was based on statistical analysis, using parameters: MXE, MAE, RMSD, ARMSD, WRMSD, b and R2. The highest rate of matching FAO-PM at the average monthly level, as well as during the 2012 growing season, was shown by Copais, Turc and Priestley-Taylor methods, thus these methods may be recommended as the replacement for FAOPM under climate conditions of Serbia. In case only temperature data are available, the results of this research justify the use of the adjusted Hargreaves equation to calculate ETo for the vegetation period.

Due to the air temperature increase, longer growing seasons and erratic rainfalls in the last two decades, natural grasslands like meadows or pastures grow in unfavourable climatic conditions that disable the regeneration. The aim of this work is to assess the impact of climate changes on the water requirement of grasslands in Serbia. The results of ensembles of nine regional climate models from the EURO-CORDEX database were used to analyse future climatic conditions. As the most probable value, the median of scores obtained for each ensemble member was considered. The period of 1986-2005 was used as the reference. The time slices in future periods are: 2016-2035 (the near future), 2046-2065 (the mid-century) and 2081-2100 (the end of the century). Analyses were conducted for two scenarios of GHG emissions: RCP4.5 and RCP8.5. Permanent grasslands will be more prone to drought risks in the future. Water shortage could be expected at the end of May when the water stored in the soil will be depleted by the duration of drought until September heavy rains. According to both scenarios, an increment of water requirement of 7% could be expected in the near future. The RCP4.5 scenario projects an increase in the water requirement in the range of 10.7-24.2% from the mid to the end of the century. The less favourable but more realistic RCP8.5 scenario projects a water need increment in the range from 4% to 14 % in the mid-century and 28.4-41.9% toward the end of the century. Recent research indicates that drought resistance will be developed through natural diversity and the spread of species resistant to high temperatures and water scarcity.