That's a key research finding of NSW rice grower and 2017 Nuffield Scholar Mark Groat, who with support from AgriFutures Australia travelled across the United States, South America, China and India drawing comparisons and insights for rice production back in Australia.

Mr Groat's report outlines that with lower water allocations and higher water prices posing major challenges for the rice industry, increasing water use efficiency both in terms of production per megalitre and return per megalitre must be a critical focus.

"It's about gaining a greater return for the water used, whether that's in terms of yield, quality, consumer demand, or company reputation," Mr Groat said.

Exploring the role of genetic enhancement of rice, the report looks at the successes of both short-season rice varieties and a system of stubble management implemented in North-West India.

"Shortening the season by developing 110-day rice varieties (instead of the conventional 140-day variety) enables planting to be delayed by a month, avoiding extreme heat during the mid-May to June period," he said.

"The added benefit of bringing planting closer to monsoonal rains of late June allows water use to be decreased by 35 percent without compromising yield.

"Winter crop rotation and stubble management has also dramatically increased WUE while enhancing soil characteristics in the region.

"As is the case in Australia, looking at the system as a whole, rather than the individual crop, is key."

Mr Groat's report features a series of comparative case studies from international rice growing regions with similar geographic and climatic traits as Australia, such as the USA's Mississippi Delta, Uruguay, North-East China and North-West India.

"We are world leaders in terms of rice yield per hectare, but I wanted to better understand how we compare to the rest of the world in terms of our water use efficiency," he said.

"In the Mississippi Delta, the majority of water is pumped from the Mississippi River Valley alluvial aquifer with no regulation on extraction, and no charge for water," he said.

"This has led to largely inefficient water usage and aquifer depletion by between 0.15 and 0.45 metres per year. "Efforts in the region to address aquifer overdraft are aimed at irrigation efficiency, however uptake has been very low."

A number of case study comparisons reveal Australia to be a leader in efficient and sustainable rice production, but the report concludes that the free market system of water in southern rice growing regions means rice is just another crop competing for a finite resource.

"Benchmarking of Australian data shows an identifiable yield gap of two tonnes per hectare between the average and top 20 percent of growers," Mr Groat said.

"Identifying and addressing causes of this gap, decreasing evaporation and increasing marketability are key components to increasing water use efficiency in terms of dollars per megalitre."

Ultimately, the report recommends the industry re-focus on benchmarking, extension and research into in-situ stubble management. "This is an extremely challenging time for the Australian rice industry, but it's also a time of immense opportunity," he said.

"The combination of technology, irrigation design, crop protection products and rice genetics has opened the door to maximising water use efficiency like never before. "If as an industry we can focus on effective in-situ stubble management, identify and prioritise extension services on yield gaps, re-evaluate our research priorities and better tell our story, then we will be better placed to seize the opportunities before us."