Crops ready for a different future climate

CSIRO has researched wheat, sorghum and sugarcane varieties better able to cope with anticipated future climate conditions.

In Australia, climate change is expected to have complex effects on crop growth and grain quality, with influences on local and global food security.

Projected increased carbon dioxide (CO2) concentrations, increased temperature and different patterns of rainfall will have potentially marked effects on Australia’s ability to grow food.

With a degree of climate change inevitable, there is a need to start breeding new crop varieties for the anticipated conditions in 20 to 50 years time.

Wheat and sorghum

To maintain Australia’s grain supplies, and also our competitive grain export position, the productivity and quality of Australian grain will need to be sustained or increased in competition with increasing demand for food, feed and fuel.

Wheat is the major grain crop in Western Australia, South Australia, Victoria, New South Wales (NSW) with substantial production in Queensland. Sorghum is grown in Queensland and northern NSW.

Together, wheat and sorghum comprise a A$4.5 billion industry (at farm gate value) and supply Australia’s internal needs for food and feed grain, as well as providing substantial export income.

The largest grain-producing state (Western Australia) is forecast to become drier, while all regions will likely be exposed to high temperature and elevated carbon dioxide.

This three-year project delivered to Australian cereal growers an improvement in the long-term stability of grain yield and quality in the presence of likely climate change effects.

The project team examined existing varieties, traits and production systems and advised on suitable geographical shifts (in conjunction with other farming systems projects).

The project defined breeding program requirements and identified sources of germplasm (‘new parental varieties’) with improved responses to higher temperature, less water and elevated (CO2), and more suitable flowering times in the season.

The research included:

  • identifying current locations and novel times for planting which mimic ‘future climate’ situations so potential varieties can be tested
  • simulation modelling to evaluate the potential geographical shifts for current varieties, especially given variation in flowering time
  • glasshouse and field experiments in wheat and sorghum to examine responses of different varieties to sustained high temperatures and high-temperature shocks, particularly around grain yield and flowering
  • growing wheat at high levels of carbon dioxide and/or temperature using small portable ‘greenhouses’ within standard field experiments in Western Australian and Queensland.

The project was a partnership between CSIRO, Queensland Department of Employment, Economic Development and Innovation and The University of Queensland through funding from the Australian Government’s Climate Change Research Program and the Grains Research and Development Corporation.

Sugarcane

Sugar is worth around A$1.75 billion to the Australian economy1. Most of Australia’s sugarcane is grown in high-rainfall areas along the coastal plains and river valleys on 2100 km of the eastern coastline between Mossman in Far North Queensland and Grafton, NSW.

Sugar is worth around A$1.75 billion to the Australian economy.

Sugarcane grown in Queensland accounts for about 94 per cent of Australia’s raw sugar production, while nearly 5 per cent is produced in Northern New South Wales and the remainder in Western Australia’s Ord River Irrigation Area.

Under future climate scenarios2 the annual mean rainfall for Queensland is projected to decrease by 1 to 14 per cent by the year 2030, and between 2 and 42 per cent by 2070.

Annual mean temperatures are projected to increase by 0.5 to 1.2 oC by 2030 and 1.0 to 3.7 oC by 2070.

The biophysical effects of climate change on sugarcane yield is not certain but preliminary modelling shows that increased temperature will speed up crop development but will also increase water stress and so have both positive and negative effects.

The potential for growing sugarcane in the dry tropics is constrained by limited irrigation as well as rainfall and the current average cost of water stress to the industry is estimated at more than A$200 million a year3.

This project contributes to the sugar industry’s adaption to climate change by providing strategies which maximise the benefits of increasing (CO2) levels, ultimately through more effective varieties.

The Climate ready sugarcane: Traits for adaptation to high CO2 levels research project included:

  • reassessing the impact of climate change on the industry by establishing the physiology of sugarcane growing in elevated CO2.
  • assessing adaptive strategies for the sugarcane plant in terms of improved water use efficiency and photosynthesis
  • assessing the opportunity for selecting for greater response to elevated CO2 in terms of improved water use efficiency and sucrose and biomass production
  • assessing the properties of elevated CO2 for mitigation of increased water stress expected with climate change.

The average cost of water stress to the industry in 2009 was A$230 million and has likely increased. It’s estimated this project will help to improve water-use efficiency by 10 per cent, reducing the water stress loss by at least 5 per cent (A$12 million annually).

The project increased the understanding and ability of the industry to adapt to climate change, and points the way forward for introducing traits for improved response to CO2 in plant improvement programs over the next 20 years.

The project had funding from the Sugar Research and Development Corporation.

Footnotes

  1. Australian Canegrowers
  2. A1F1 climate scenario
  3. Inman-Bamber, NG (2007). Economic impact of water stress on sugar production in Australia. Proceedings of the Australian Society of Sugar Cane Technologists 29, 167-175.