Western Australian research seeking to unlock substantial grain yield increases from crops grown on sandy soil has been detailed at a premier international conference in Perth.
Western Australian research seeking to unlock substantial grain yield increases from crops grown on sandy soil has been detailed at a premier international conference in Perth.
Speaking at the Global Conference on Sandy Soils 2025, Department of Primary Industries and Regional Development (DPIRD) principal research scientist Gaus Azam said soil re-engineering presented a new frontier in crop yield potential from challenging soils.
"Multiple subsoil constraints and unpredictable climatic events are common in the Western Australian grain belt, restricting the water-limited yield potential of grain crops," Dr Azam said.
"Soil profile re-engineering involves redesigning the physical, chemical and biological properties of the soil profile, providing the crop with an unconstrained soil environment with increased soil water holding capacity.
"Our previous research suggests that soil profile re-engineering could potentially double grain yield and water use efficiency in the short term, particularly in favourable seasons.
"However, key questions remain such as will these improvements be sustained in the long term and if so, can this approach be scaled for widespread adoption by growers."
To address these questions, DPIRD researchers investigated two experiments over four seasons at Bolgart on deep sand and Meenaar on sandy duplex soils.
The research is being undertaken through the Soil Water and Nutrition (SWAN) strategic research collaboration between DPIRD and the Grains Research and Development Corporation (GRDC).
"The results from the long-term experiments showed that certain soil re-engineering treatments at least doubled grain yield and water use efficiency on deep sand compared to the control, while the most effective treatment achieved the estimated water limited yield potential on both sand and sandy duplex soils," Dr Azam said.
"Overall, yield increased by 66 per cent following the removal of subsoil acidity and compaction to a depth of 80 cm.
"On deep sand, the deep incorporation of clay and organic matter significantly enhanced grain yield and water-use efficiency, whereas this effect was not observed on sandy duplex soils.
"Conversely, the deep placement of additional inorganic nutrients provided significant benefits on sandy duplex soils but not on deep sand.
"Our findings indicate that these improvements in soil properties persisted for four seasons so far and are expected to last even longer."
Dr Azam said researchers also successfully implemented several grower-scale experiments using a combination of farming and road-building implements, eliminating the need for labour-intensive approaches previously used in blue-sky experiments.
"Initial results suggest that subsoil acidity and compaction were immediately mitigated, while soil water-holding capacity improved significantly," he said.
"Our research demonstrates the potential for developing more resilient sandy soils and achieving greater yields consistently at the farm scale."
The 2025 Global Conference on Sandy Soils runs from 21 - 24 July in Perth.
