Rice: Aerobic growing method could drop water use by half

A new trial growing method could open previously unprofitable areas of land up to rice production.

Deakin University PhD candidate Matt Champness in an aerobic rice trial crop. Picture: Supplied

An automated aerobic rice trial in its second season in NSW is on its way to producing a “sensational” crop, after achieving average yields with just over half average water consumption in its first year.

Darrell Fiddler, Farm Manager for DeBortoli Wines in Bilbul, near Griffith in southern NSW, said this season’s aerobic trial crop was looking “sensational” as it entered its reproductive phase.

Mr Fiddler, who has 34 hectares of land sown to aerobic rice as part of the trial, and also grows 500ha of rice using drill sown and delayed permanent water growing methods, said the aerobic growing method aimed to ”maximise water efficiency”, which was a key challenge for Australian rice growers.

“(Productivity for rice is) about tonnes per mega litre now, It’s not tonnes per hectare any more,” he said.

“We’ve all got plenty of land, but water is always a limiting factor in farming,” Mr Fiddler said.

The Rice Growers Association has set an industry target of 1.5 tonnes of rice per megalitre of water by 2030, which, if achieved, would be a significant increase on the current industry average of 0.9 tonnes per megalitre.

Aerobic rice is one method the industry hopes could help achieve that target. It involves irrigating a crop if and when required, rather than traditional rice-growing methods which grow rice in permanently ponded water.

De Bortoli Wines farm manager and rice grower Darrell Fiddler. Picture: Supplied.

While aerobic methods have been used on cotton and some other crops for years in Australia, this is the first Australian trial on rice.

Mr Fiddler has been participating in trials to find the most water-efficient methods for growing rice for more than a decade. He said the aerobic rice trial at DeBortoli Wines was “showing promise” when it came to water efficiency.

Deakin University PhD candidate Matt Champness, who has been running the trial as part of a research project, said the aerobic rice crop last year succeeded in bringing in an “average yield” of 8.1 tonnes/ha of the Viand rice variety with a bit over half the average water use.

The trial used 7.95ML of water per hectare, compared to traditional growing methods which use around 12ML of water to achieve a similar result.

“We didn’t do exceptionally well last year, but still well above average,” he said.

“Last year was a very, very cold season. It was the coldest season in 20 years. So yields were down (across the board),” he said.

Rice growers hope aerobic production methods could reduce water consumption. Picture: Supplied

This year he had “tweaked a few things from last season”, he said, and “nitrogen uptake has been a lot higher, the crop has a lot more biomass, and it’s looking, looking dark green and healthy and looking really, really good.”

Early indications showed the aerobic growing method could be a useful tool in grower’s belts, particularly for lighter soil types, he said.

“(Aerobic methods) allow you to grow (rice) in lighter country where water use would be traditionally really high. You can potentially bring the water usage right back down.”

“Particularly around Coleambally, water prices are too high now to grow rice on the 20 – 23 ML soil types, whereas I think aerobic rice, we could drop that water use down by half. And that would make rice profitable again in that area.”