Climate change impacts and adaptation strategies in spring barley production in the Czech Republic

The crop model CERES-Barley was used to assess the impacts of increased concentration of atmospheric CO2 on growth and development of the most important spring cereal in Central and Western Europe, i.e., spring barley, and to examine possible adaptation strategies. Three experimental regions were selected to compare the climate change impacts in various climatic and pedological conditions. The analysis was based on multi-year crop model simulations run with daily weather series obtained by a stochastic weather generator and included two yield levels: stressed yields and potential yields. Four climate change scenarios based on global climate models and representing 2 x CO2 climate were applied. Results: (i) The crop model is suitable for use in the given environment, e. g., the coefficient of determination between the simulated and experimental yields equals 0.88. (ii) The indirect effect related to changed weather conditions is mostly negative. Its magnitude ranges from - 19% to + 5% for the four scenarios applied at the three regions. (iii) The magnitude of the direct effect of doubled CO2 on the stressed yields for the three test sites is 35 - 55% in the present climate and 25 - 65% in the 2 x CO2 climates. (iv) The stressed yields would increase in 2 x CO2 conditions by 13 - 52% when both direct and indirect effects were considered. (v) The impacts of doubled CO2 on potential yields are more uniform throughout the localities in comparison with the stressed yields. The magnitude of the indirect and direct effects ranges from - 1 to - 9% and from + 31 to + 33%, respectively. Superposition of both effects results in 19 - 30% increase of the potential yields. (vi) Application of the earlier planting date ( up to 60 days) would result in 15 - 22% increase of the yields in 2 x CO2 conditions. (vii) Use of a cultivar with longer vegetation duration would bring 1.5% yield increase per one extra day of the vegetation season. (viii) The initial water content in the soil water profile proved to be one of the key elements determining the spring barley yield. It causes the yields to increase by 54 - 101 kg. ha(-1) per 1% increase of the available soil water content on the sowing day.