by Felicity Harrop Soil CRC Adoption Manager
Sandy soils cover vast areas of Australia’s agricultural land, the Australian Soil Classification has an entire classification for them (Arenosols), yet their naturally low nutrient and water-holding capacity, susceptibility to water repellence, and tendency toward compaction can significantly limit crop performance. Multiple CRC projects have been addressing the interacting constraints common in sandy soils across Western Australia, South Australia and Victoria. These investigations have highlighted that improving sandy soils is not just about boosting short-term yields; but building long-term resilience and protecting soil as a critical farm asset.
Leading soil scientists Dr Richard Bell (Emeritus Professor, Murdoch University) and Dr Amanda Schapel (PIRSA) joined Soil CRC PhD students Stephen Lang (Adelaide University) and Dr Tania Monir (previously of Murdoch University) to share the latest findings in the Soil CRC webinar: Unlock the Potential of Sandy Soils. The webinar highlighted practical, research-backed strategies to improve the productivity and resilience of sandy soils. A key theme was the importance of increasing the soil’s “reactive surface area” using amendments such as clay, organic matter and biochar to improve nutrient retention, water availability and long-term soil health. The presenters showed how combining these amendments strategically can produce more durable gains than single interventions alone.
The webinar examined “hard setting” sandy soils—where dense layers restrict root growth—and discussed emerging solutions including deep tillage and organic amendments to improve rooting depth and water access. A meta-analysis revealed that amendment effectiveness depends heavily on sand depth, with organic amendments like compost most beneficial on the deepest sands. The productivity sweet spot for subsoil clay sits at 6–15% clay concentration, and effects can persist for up to 15 years.
Successful management depends on tailoring interventions to local soil type, rainfall patterns and production goals. Practical on-farm strategies can assist growers to make smarter decisions to enhance profitability while safeguarding soil resources for future generations. Western Australian field trials showed subsoil claying delivered a 50% yield increase over 15 years at Esperance, though yields still fell short of water-limited potential. Emerging research on carbon stabilisation found that combining organic and inorganic amendments (e.g., compost with hydrotalcite) enhances long-term carbon protection in sandy soils.
The next steps to bring these findings from research plots to broad-acre adoption include multi-season field validation, optimised amendment formulations, and scalability assessments.