David Phelan1, Greg Holz1, David Parsons1, and Caroline Mohammed1
1Tasmanian Institute of Agriculture, University of Tasmania, PO Box 54, Hobart. Tasmania. email@example.com
Projected changes to the Tasmanian climate will have profound impacts on agricultural enterprises at farm, industry and regional scales. This will lead to substantial changes in farm management, choice of crops and land use. Projections of climate variables from the Climate Futures for Tasmania (CFT) project were used to assess the impacts of a changing climate on six different crop enterprises at two locations within north-central Tasmania (Meander Valley and Southern Midlands). Six fine resolution (0.1° grid) dynamically downscaled climate model outputs allow for impacts, to be differentiated between the two sites over the period 1971 to 2065. The mean annual temperature under the A2 emission scenario across both regions is projected to rise by 1.8 to 2.1°C from the baseline (1971–2000) to 2050 (2036 – 2065). Mean annual rainfall is projected to increase slightly at both Meander Valley and the Southern Midlands by 2% and 3% respectively. Agricultural opportunities for the two sites were assessed for three crops under irrigation; wheat, barley and perennial ryegrass. Yield and production impacts were simulated using the projected CFT data and the biophysical models of APSIM and DairyMod. Mean annual pasture yields are projected to increase from the baseline to 2050 largely due to an increase in spring pasture growth. Wheat yields are projected to increase by 6% and barley yields are projected to decrease by 2% by 2050. This study suggests that increased temperatures and elevated atmospheric CO2 concentrations are projected to impact positively on irrigated cropping and pasture yields, where water availability is not a limiting factor.