Climate change in south-west Australia and north-west China: challenges and opportunities for crop production

Predictions from climate simulation models suggest that by 2050 mean temperatures on the Loess Plateau of China will increase by 2.5 to 3.75°C, while those in the cropping region of south-west Australia will increase by 1.25 to 1.75°C. By 2050, rainfall is not expected to change on the Loess Plateau of China, while in south-west Australia rainfall is predicted to decrease by 20 to 60 mm. The frequency of heat waves and dry spells is predicted to increase in both regions. The implications of rising temperatures are an acceleration of crop phenology and a reduction in crop yields, greater risk of reproductive failure from extreme temperatures, and greater risk of crop failure. The reduction in yield from increased phenological development can be countered by selecting longer-season cultivars and taking advantage of warmer minimum temperatures and reduced frost risk to plant earlier than with current temperatures. Breeding for tolerance of extreme temperatures will be necessary to counter the increased frequency of extreme temperatures, while a greater emphasis on breeding for increased drought resistance and precipitation-use efficiency will lessen the impact of reduced rainfall. Management options likely to be adopted in south-west Australia include the introduction of drought-tolerant perennial fodder species and shifting cropping to higher-rainfall areas. On the Loess Plateau of China, food security is paramount so that an increased area of heat-tolerant and high-yielding maize, mulching with residues and plastic film, better weed and pest control and strategic use of supplemental irrigation to improve rainfall-use efficiency are likely to be adopted.