Potential impacts of climate change on maize production and the introduction of soybean in Ireland

The impact of climate change on agriculture can be assessed by evaluating changes in yield using simulation models. Maize was investigated because it was until recently a semi-marginal crop that is now regarded as a good source of high energy forage in Ireland. Soybean was investigated because it is not currently suitable for commercial production in Ireland but is used as a protein supplement by livestock producers. With climate change soybean may become a viable forage crop. The aim of this work was to evaluate the impact of climate change on maize and soybean yield in Ireland using crop simulation models and climate scenario data to assess potential changes between baseline and future scenarios, and to assess some of the implications of these changes. The models used for this work are part of the Decision Support System for Agrotechnology Transfer (DSSAT). Simulation results for the baseline climate were compared with available data and indicated that the models were acceptable for use in Irish conditions. The soil descriptions were based on a simplification of the General Soil Map of Ireland into seven classes. Simulations were undertaken for a 10 km x 10 km grid over Ireland for grid cells representing < 150 m altitude and with mineral soil (not allocated as peat or urban/water), for 30 replicate years in each cell, for each of three scenarios (baseline, 2055, 2075). It was concluded that maize could become a major crop in Ireland but may suffer water stress in summer, and that soybean may become a specialist, marginal crop.