Growing more grain with less water: Grains Week 2006

Studies facilitated by the CSIRO and Australia’s Grains Research & Development Corporation (GRDC) are part of the Water for a Healthy Country Flagship and aim to determine the best approach to improve water productivity in drought-affected areas.

CSIRO Land and Water’s Dr Shahbaz Khan says dry conditions, environmental flow demands and world pressure to produce increased crop yields mean that rainfall and river supplies are failing to meet irrigation water requirements in many parts of Australia.

“Irrigated agriculture constitutes 70 per cent of Australia’s consumptive water use, existing resources are already stretched and there will be less water available for irrigated agriculture in future,” Dr Khan says. “The only way to ensure growth in the grains industry is to improve water use efficiency at both farm and catchment scales.”

He says evaluation of the economic and environmental merits of on-farm and off-farm water efficiency options, and ranking them in a multi-scale whole of system context, is the key to achieving real and substantial water savings.

Such options include canal lining; irrigation scheduling; high-tech irrigation technologies; improved cropping patterns; and conversion to crops with higher economic returns.

A recent major study in the NSW Coleambally and Murrumbidgee irrigation areas demonstrated that the systems approach could save more than 300gigalitres, with costs of water saving technologies ranging from A$50million to A$5000million.

Options explored by researchers included reducing the break-even period by leasing water for the environment from farmers, and providing preferential access rights to saved water for farmers who invested in water saving technologies.