Keeping the Australian rice industry competitive: transitioning to management practices that increase water productivity

When the Rice Variety Nitrogen and Agronomic Management Project was first funded by the AgriFutures Rice Program in 2015, there was little data supporting the agronomics of growing  different rice varieties and this advice was based on aerial sowing.

Many growers experienced economic setbacks due to the lack of access to relevant agronomic information on new varieties, prompting AgriFutures Rice Program and NSW Department of Primary Industries (NSW DPI) to invest in research and development (R&D) aimed at filling the rice agronomy research gap.

“The overall aim realistically was to maximise the water productivity of rice growing,” said Brian Dunn, NSW DPI Research Agronomist.

“We’ve looked at a number of facets – one is improving the management of the varieties so the timing of their sowing, the nitrogen rates and timing of nitrogen so you’re maximising yield. We also considered the way the crop is grown. For example, if it was aerial sown, drill sown or drill sown with delayed permanent water.”

Six years later, the industry now has robust, data driven recommendations for eleven rice varieties, and a better understanding of how the different sowing methods can impact growers’ profitability.

Extensive research fine tunes growing practices

61 experiments were conducted across the rice growing regions of southern New South Wales from 2015 – 2021, in the Murray and Murrumbidgee Valleys, including sites at the Yanco Agricultural Institute, Leeton Field Station and Rice Research Australia (RRAPL).

A minimum of six experiments were conducted each season, with three in each valley.

As a result, the project has delivered agronomic and nitrogen management guidelines for all current rice varieties, and for all sowing methods and water management practices – to support the production of high yielding, low-risk rice crops.

Bunnaloo rice grower Antony Vagg was among the group of growers involved in on-farm trials. Antony found that the results and resources developed through the project have assisted him to refine sowing times and scheduling for nitrogen applications.

“Rice is actually relatively easy to grow. But it’s not that easy to grow a really good rice crop,” said Antony.

“There’s been a little bit of guesswork for growers, what’s worked and what hasn’t. Whereas now, as a result of R&D, we have a good, detailed guide to grow a successful rice crop. If you follow these steps, you’ve got a very good opportunity to produce a quality crop.”

Antony believes the outcomes of this project can only benefit the industry’s sustainability in the future. “Going forward, the information and resources from NSWDPI’s research will provide growers with more confidence in being able to achieve consistently high yielding targets, which stands rice quite competitively against other crops.”

Benefits of transitioning to drill sowing and delayed permanent water (DPW)

The most significant outcome of these trials is the ability to increase water productivity via on-farm management practices, which is critical for the future of the rice industry as it competes against other irrigation crops in a challenging water market.

The study recommended rice growers move away from traditional aerial sowing and dry broadcast methods, towards drill sowing and delayed permanent water (DPW) as the default growing practice – particularly as the industry seeks to achieve its target of producing 1.5 tonnes of grain per megalitre of water. The research team found that changing from aerial to drill sowing results in water productivity increases of 0.1t/ML, with DPW providing an additional saving of 0.15t/ML. This translates to an extra 4,000 hectares of rice grown on a 50,000 hectare crop, using the same amount of water as an aerial sown crop.

Already there’s been a swing towards this method, thanks in part to the release of updated information for rice variety guides during the life of the project.

“There’s around 30% more drill sowing in the last season than there was when we started the project in 2015. And there are also a number of growers – particularly in a season when water’s a bit short – that are utilising delayed permanent water which we’ve found has the same yield potential as the other growing methods, but saves a considerable amount of water,” said Brian.

Where irrigation layouts allow, Brian encourages more growers to consider taking up this method but believes it will take further time to change the mindset within the industry.

“It might take another five or 10 years before another 20 or 30% of growers really adopt it. But as farmers look over the fence and see that it does work, it’s sustainable, and they can achieve consistent high yields with water savings, I think it will become the main sowing and irrigation method for rice growing.”

Growing more with even less in the future

The report’s key recommendations include growers and agronomists continuing to have access to agronomic management packages for new rice varieties as they are released and further education in relation to drill sowing and DPW.

The NSW DPI is now seeking to further its work as part of a new agronomy project over the next three years, which will incorporate remote sensing research.

“The next step forward in improving water productivity is reducing variability within the field and using remote sensing to identify where variability will be during the season. This will provide an opportunity to even up the crop across the field and maximise grain yield on every hectare, which is the next step forward in improving productivity,” said Brian.

Rice growers and agronomists are encouraged to review the detailed research findings of the report and the project recommendations.

Related resources

Rice variety nitrogen and agronomic management

Final report summary: Rice variety nitrogen and agronomic management

Rice growing guide

Rice crop protection guide

Fact sheet: Rice variety guide 2021-22