Author(s)

Louis Kouadio¹, Nathaniel Newlands², Andries Potgieter³, Greg McLean⁴, Harvey Hill⁵

¹International Centre for Applied Climate Sciences, University of Southern Queensland, Toowoomba, Australia.
²Science and Technology (S & T), Environmental Health, Agriculture and Agri-Food Canada (AAFC), Lethbridge Research Centre, Lethbridge, Canada.
³Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Toowoomba, Australia.
⁴Queensland Department of Agriculture and Fisheries, Toowoomba, Australia.
⁵National Agroclimate Information Service, S & T-AAFC, Saskatoon, Canada.

Assessing the impacts of climate variability on agricultural productivity at regional, national or global scale is essential for defining adaptation and mitigation strategies. We explore in this study the potential changes in spring wheat yields at Swift Current and Melfort, Canada, for different sowing windows under projected climate scenarios (i.e., the representative concentration pathways, RCP4.5 and RCP8.5). First, the APSIM model was calibrated and evaluated at the study sites using data from long term experimental field plots. Then, the impacts of change in sowing dates on final yield were assessed over the 2030-2099 period with a 1990-2009 baseline period of observed yield data, assuming that other crop management practices remained unchanged. Results showed that the performance of APSIM was quite satisfactory with an index of agreement of 0.80, R2 of 0.54, and mean absolute error (MAE) and root mean square error (RMSE) of 529 kg/ha and 1023 kg/ha, respectively (MAE = 476 kg/ha and RMSE = 684 kg/ha in calibration phase). Under the projected climate conditions, a general trend in yield loss was observed regardless of the sowing window, with a range from  -24% to -94% depending on the site and the RCP, and noticeable losses during the 2060s and beyond (increasing CO2 effects being excluded). Smallest yield losses obtained through earlier possible sowing date (i.e., mid-April) under the projected future climate suggested that this option might be explored for mitigating possible adverse impacts of climate variability. Our findings could therefore serve as a basis for using APSIM as a decision support tool for adaptation/mitigation options under potential climate variability within Western Canada.

Climate Variability, APSIM, Crop Modelling, Spring Wheat

Kouadio, L. , Newlands, N. , Potgieter, A. , McLean, G. and Hill, H. (2015) Exploring the Potential Impacts of Climate Variability on Spring Wheat Yield with the APSIM Decision Support Tool. Agricultural Sciences, 6, 686-698. doi: 10.4236/as.2015.67066.