Earlier this year, growers and advisers gathered in Kellerberrin for the GRDC Soil Amelioration Upskilling Workshop, hosted by MADFIG as part of the South West WA Drought and Innovation Hub.
The workshop attracted over 40 attendees, including growers, consultants and advisers, who heard from Wayne Pluske (DPIRD) and Erin Cahill (AgVivo). Combining the latest research with practical farming experience, the presenters shared valuable insights into understanding soil constraints and improving the effectiveness of soil amelioration.
Key takeaways
Looking beyond your own farm
One of the strongest messages from the day was not to assume your soil type is unique. Many soil types occur across different parts of Western Australia, meaning valuable lessons can often be learned from growers farming similar soils elsewhere.
Understanding where comparable soil types occur can open the door to proven management practices and successful amelioration strategies that may not have previously been considered.
Soil mapping and sampling: The foundation of successful amelioration
Effective soil amelioration starts with understanding what’s beneath the surface.
Wayne and Erin highlighted the importance of regularly updating soil mapping and sampling practices, explaining that recommendations have evolved significantly over the past decade.
Some of the key recommendations included:
- Mapping soil zones across the farm.
- Using aerial imagery and yield maps to identify constraints.
- Sampling more frequently and deeper into the soil profile than was common a decade ago.
Accurate soil information helps growers make more targeted decisions, reducing the risk of over- or under-investing in soil amelioration.
Strategic liming for long-term returns
Rather than viewing lime as an annual input, Wayne and Erin encouraged growers to see it as a long-term capital investment.
Key messages included:
- Address soil acidity strategically rather than relying solely on blanket applications.
- Surface soil pH should generally be maintained above 5.8, while subsurface soils should remain above 4.8.
- It can take 5–8 tonnes per hectare of high-quality lime to fully ameliorate an acidic soil profile.
- Improvements in soil tests may take two to three years to become evident.
Real-world trial results demonstrated the potential benefits of combining lime application with deep ripping and spading, with one long-term trial increasing canola yields from 0.33 t/ha to 1.25 t/ha.
Understanding the role of gypsum
Another important takeaway was understanding that lime and gypsum serve different purposes.
While lime is used to neutralise soil acidity, gypsum is used to improve soil structure in dispersive soils and supply soluble calcium. Presenters also discussed simple methods growers can use to assess soil dispersion before investing in treatment.
Mechanical amelioration can accelerate results
Mechanical soil amelioration techniques were another major focus of the workshop.
Rather than waiting many years for soil amendments to naturally move through the profile, growers can significantly speed up the process using practices such as deep ripping, spading, mouldboarding and specialised implements such as the Plozza Plough.
Presenters discussed selecting the right approach for different soil types and highlighted the importance of matching machinery and timing to local conditions to maximise long-term productivity.
Thank you
Thank you to everyone who attended and contributed to the discussions. By combining research with practical farming experience, the workshop provided growers with valuable knowledge to support informed soil management decisions and improve long-term productivity.
MADFIG is also hosting a trial site for the ongoing research for the Soil Re-engineering treatment trial managing subsoil acidity and compaction in the Eastern Wheatbelt. It’s part of the Soil Water and Nutrition (SWAN) Strategic Collaboration Program 1A (Soils Re-engineering). There’s more information about the project here.
Useful resources
The following resources shared during the workshop are available to support growers wanting to learn more about soil amelioration:
