Stubble incorporation as an adaptation option for mitigating climate change impacts on water use and crop yield of four winter crops in eastern Australia (2739)
Crop residues returned to soils can improve soil quality and productivity through favourable effects on soil properties. We used APSIM to explore the possibility of implementing stubble incorporation farming practices for mitigating impacts of climate change on water use and crop yield of 4 winter-crops in eastern-Australia. Simulations of crop development, growth and production of wheat, barley, canola and chickpea under various stubble management practices were driven by current climate and statistically downscaled climate data from 28 CMIP5 GCMs (RCP4.5 and RCP8.5) for the period 1900-2100. Soil water balance, water-use and water-use-efficiency (WUE) were analysed to scope their relations to the effects of stubble incorporation and impacts of climate change for developing adaptive strategies for mitigating negative impacts of climate change. The results showed that increasing future temperature has the effect of shortening crop growth duration. Together with projected future rainfall decreases, the effect on yield could be decreases by 10-15% for wheat and barley, 3-5% for canola and 2% for chickpea under future climate change in eastern Australia. However, 100% stubble incorporation could change the crop yield from a decrease to an increase of 3-6 % for wheat and barley. Further analysis showed that greater crop transpiration was the major advantage seen under stubble incorporation. Water use efficiency in wheat and barley was also increased significantly under stubble incorporation due to reduced soil evaporation and surface runoff. Therefore, stubble incorporation can be an effective adaptation option for mitigating impacts of climate change on winter crops through improving WUE