The latest research pushing crop yield frontiers using soil re-engineering will be delivered at Western Australia's leading annual grains research conference this month.
The latest research pushing crop yield frontiers using soil re-engineering will be delivered at Western Australia's leading annual grains research conference this month.
Department of Primary Industries and Regional Development (DPIRD) principal research scientist Gaus Azam will share practical 'tricks and tips' for re-engineering soils across different environments at the Grains Research and Development Corporation (GRDC) Grains Research Update in Perth.
"Persistent yield gaps in Western Australia's grain systems are driven by interacting subsoil constraints, including acidity, compaction and low water and nutrient holding capacity, which cannot be addressed by surface or single-constraint management alone," Dr Azam said.
"Soil profile re-engineering shows that grain yield and water-use efficiency (WUE) can be substantially increased when these constraints are addressed together and to greater depths, providing a clear benchmark for achievable productivity gains.
"While full soil profile re-engineering is not currently scalable to farm level due to the lack of specialist machinery and high cost of implementation, this research provides a benchmark to guide the development of cost-effective, depth-targeted amelioration practices and next-generation machinery."
The presentation brings together results from five long-term soil profile re-engineering experiments at Kalannie, Northampton, Bolgart, Meenar and Tarin Rock, which represent frontier research, along with four grower-scale trials representing adoptive-scale studies across contrasting soils and rainfall zones in WA.
This research program has been jointly funded by DPIRD and GRDC since 2018, including the recently launched Soil Water and Nutrition partnership between the two organisations, with extended collaboration involving The University of Western Australia and Adelaide University.
"Across all study sites, soil re-engineering increased rooting depth from 20 to 30 centimetres in untreated soils to more than 80cm in re-engineered profiles, improving access to water and nutrients and resulting in substantial gains in yield and WUE," Dr Azam said.
"Across the five long-term sites, cumulative grain yield increased substantially following re-engineering, with two to four-fold gains relative to untreated controls.
"Yield benefits were sustained over multiple and contrasting years, indicating durable improvements, rather than short-term responses.
"Grower-scale re-engineering experiments at North Stirling, Wagin, Grass Valley and Mt Horner showed similarly strong early responses.
"Improved crop establishment, root growth and shoot biomass were visually evident and yield improvements were aligned with results from the long-term experiments, indicating strong potential for sustained benefits at farm-scale."
Dr Azam said effective interventions must target the dominant constraints within each soil profile and address multiple constraints simultaneously.
"Responses differed by soil type, highlighting the need for tailored strategies," he said.
"Investment decisions should be guided by robust soil diagnosis in identifying the key constraints limiting crop performance and suitable strategies for amelioration.
"Incremental approaches that improve amendment placement, soil mixing and depth of intervention, supported by continued innovation in machinery and systems, offer the most practical pathway to translate these experimental gains into WA's farming systems."
The 2026 GRDC Grains Research Update will be held in Perth on 16 and 17 February.
Dr Azam will also speak at regional Grains Research Updates events at Beaumont, Brookton, Kalannie and Mingenew.
