Projected impacts of climate change on drought stresses in Australian wheat

Abstract

Wheat is one of the primary staple foods. Due to a rising population and improved living standards, demand for this crop continues to increase. Much of the wheat produced in Australia is grown in water-limited environments. Climate models project increases in both temperature and rainfall variability for this century, raising potential challenges for the Australian wheat industry. Given the lead times involved in adapting wheat production to changed environmental conditions, the provision of timely, realistic assessments of the likely impacts of climate change is of key importance. Such assessments must account for the complex interactions between environmental conditions, crop genotype, and management practices. In this study we used the APSIM-Wheat model to capture these interactions at 60 representative sites across the Australian wheatbelt. The weather data for these sites was used as the basis to construct a range of future climate scenarios from the projections of 33 distinct climate models. While we found significant variations in simulated drought impact across the different climate models, consensus among these models was also identified with strong regional trends. The Western regions of the wheatbelt were projected to experience an increase in drought conditions in the coming decades. In contrast, reduced occurrence of severe drought was predicted for Eastern regions, primarily due to shorter crop cycles and accelerated development arising from increased temperatures. Overall, Australian wheat will continue to be significantly impacted by drought in the coming decades.