Impact of climate change on grass growth at two sites in Ireland

The MoSt grass growth model was used in conjunction with the group 6 WRF EC-Earth forecast model to predict the change in grass growth between 1986-2000 and 2031-2060. The future weather projection period is composed of two different emission scenarios, a low-medium emission and a high emission. Grass growth and N leaching predictions were obtained using the weather projection for two locations in Ireland (Moorepark (south) and Ballyhaise (north)) and for two soil types: heavy soil or free draining soil. Overall, the simulations show that, in the future, grass growth will start slightly earlier in the year but will reduce during the summer period. This reduction is more pronounced in the high emission scenario than in a low-medium emission scenario and is highly dependent on soil type. It is complicated to draw definitive conclusions from this work due uncertainty associated with simulation of future weather; however, it does highlight the increase in variation between years which will lead to a more complex grazing management due to fewer ‘standard’ years.