Break crop survey findings presented at 2024 Australian Agronomy conference

Research shared at this year’s Australian Agronomy Conference found that break crops and pastures are essential to water efficiency.

The two-day agronomy conference began on October 21 and was held in Albany.

The Department of Primary Industries and Regional Development presented findings on its six-year survey at the conference, which included more than 3700 field visits to 184 paddocks spanning between 2010-2015.

The survey found that over the long-term break crops and pastures lead to better water efficiency compared to wheat-on-wheat crops.

Researchers also found the increased use of herbicides and fertilisers had partially replaced the traditional use of break crops and pastures to reduce weeds and disease.

DPIRD senior researcher Martin Harries analysed the results for his PhD at the University of Western Australia.

“Wheat water use efficiency after a break crop, like canola or lupins, or pastures produced 12.5 kilograms of grain per hectare per millimetre of water used by the crop,” he said.

“This was marginally higher than wheat grown after one previous wheat crop, which yielded 11.2kg/grain/ha.mm.”

However, Dr Harries found that a bigger difference occurs when more than three wheat crops were grown in succession.

In these cases, water use efficiency dropped significantly to just 8.4kg/ha.mm.

He said these results highlight that over the long-term, wheat crops still require more diverse rotations to use water effectively.

“This highlights the need to continue to investigate farming systems that profitably incorporate breaks and pastures,” he said.

A new project by the DPIRD, co-funded by the Grains Research and Development Corporation, is now under way to look into the incorporation of break crops and pastures on water efficiency.

Three long term rotation trials are being held at Northampton, Merredin, and Lake Grace.

This survey was one of the 160 presentations at the conference across a range of topics, which attracted both interstate and international visitors.