Adaptation to climate change of wheat growing in South Australia: Analysis of management and breeding strategies

Evaluation of adaptive management options is very crucial for successfully dealing with negative climate change impacts. Research objectives of this study were (1) to determine the proper N application rate for current practice, (2) to select a range of synthetic wheat (Triticum aestivum L.) cultivars to expand the existing wheat cultivar pool for adaptation purpose, (3) to quantify the potential impacts of climate change on wheat grain yield and (4) to evaluate the effectiveness of three common management options such as early sowing, changing N application rate and use of different wheat cultivars derived from (2) and given in the APSIM-Wheat model package in dealing with the projected negative impacts for Keith, South Australia. The APSIM-Wheat model was used to achieve these objectives. It was found that 75 kg ha-1 N application at sowing for current situation is appropriate for the study location. This provided a non-limiting N supply condition for climate change impact and adaptation evaluation. Negative impacts of climate change on wheat grain yield were projected under both high (-15%) and low (-10%) plant available water capacity conditions. Neither changes in N application level alone nor in wheat cultivar alone nor their interactive effects could offset the negative climate change impact. It was found that early sowing is an effective adaptation strategy when initial soil water was reset at 25 mm at sowing but this may be difficult to realise given that a drier environment was projected, which will limit the opportunity for early sowing.