The Murray-Darling Basin Authority (MDBA) is helping one of the most water intensive crops in the world to increase production. 

The Australian rice industry has a target to be able to grow 1.5 tonnes of rice per megalitre of water by 2026. 

Rice crops are extremely water-instensvie, requiring an average of 1,670 litres of water per kilogram according to the Water Footprint Network (PDF).

However, with water becoming more expensive and scarcer in dry years, researchers are working with the local industry to find ways to make each megalitre of water stretch further, while saving on labour costs.

The MDBA says its Smart Irrigation Control for Water and Labour Savings in Rice project is combining remote sensing technology and new telecommunication methods to find the ‘sweet spot’ between minimum amount of soil moisture needed before yield is compromised compared to traditional rice-farming methods.

“This is about maximising your water productivity - and use of technology is key,” says researcher Matt Champness, one of the academics undertaking the trials. 

“My research applies infield and remote-sensing technology to the aerobic rice growing system to reduce water use. The results are looking promising.

“The aerobic rice-growing system involves direct drilling the rice into the ground. Instead of keeping the crop ponded for long periods of time, it’s flushed regularly with water. This drastically reduces the amount of water used to produce a crop.

“Traditional drill-sown rice has 3 water flushes – or waterings – per season, to establish it. Then the rice paddy is flooded permanently for a longer period.

“We are trialling aerobic rice in a commercial setting aimed at using less water than traditional rice cultures. 

“It’s much more labour intensive as the farmer needs to manually perform around 30 flushes per paddy per season. Working out exactly when to water to get that ‘sweet spot’ effect is not currently known,” Mr Champness said.

Aerobic rice has been proven across the world to save water. However, it comes at substantial yield risk and is not currently profitable in Australia due to reduced yields and high labour costs.

Mr Champness and colleagues are looking into irrigation triggers for aerobic rice to help give farmers confidence on when to irrigate, with automation enabling irrigation to occur while farmers are conducting other farm duties. 

“Flushing can be controlled using an app on a phone from nearly anywhere, even on holidays,” he says.

“However, depending on mobile or wifi coverage, service isn’t always reliable. 

“I’ve found using low frequency radio signal to communicate between the farmer and their irrigation infrastructure works very well.

“Working with commercial growers and providers of automated irrigation systems to refine the technology for use in commercial settings has proven commercial aerobic rice production is doable

The expert group says trials have been undertaken at De Bortoli Wines in Griffith where they also grow rice as a broadacre crop. 

The main trial investigating various irrigation thresholds has already seen 1.6 tonnes of rice grown per megalitre of water. With some nitrogen treatments, yields have exceeded 2.2 tonnes per megalitre, well above the current industry average of 1 tonne per megalitre.

The Smart Irrigation Control for Water and Labour Savings in Rice project is co-funded by the Australian Government from the Rural Research and Development for-Profit Program, Deakin University and AgriFutures.