The Soil Water Repellence Project
Exploring management options for ameliorating non-wetting soils in the West Midlands region.
Exploring key aspects of soil amelioration on variable soil types through diagnosing paddock scale soil constraints, identifying the most appropriate amelioration method(s) for the constraints and determining the economic advantage (ROI for the paddock) behind these methods.
Commencement: 2024 | Completion: 2026
Funding body(s): Grain Research and Development Corporation (GRDC)
Project Lead Organisation: The West Midlands Group
Background
Farmers across the Geraldton and Kwinana West Port Zones are faced with the significant, ongoing challenge of managing soil water repellence. The regions sandy soils are low in clay content and as a result, have a low surface area. Waxy substances that originate from plant organic matter when they decompose are left in the soil to coat the sand particles and over time, this process causes the soil to have reduced infiltration of rainfall. This leads to patchy crop emergence and lowers grain yield while also causing issues with weed management and fertiliser use efficiency.
Across the region farmers have successfully implemented a range of once-off soil amelioration strategies for the deep sandy soils where there are few physical obstructions to the use of deep tillage equipment like mouldboard ploughs, rotary spaders, and deep rippers. This has led to an increase in grain yield and increased profitability which has been consistent for every year following soil amelioration (Planfarm 2024). While this approach has been successful on the deep sandy soils in the region, farmers have not been confident in tackling some of the other soil types in the region.
A feature of soils in the region is the presence of multiple soil types in one paddock, from rock to gravel to coloured and white sand. Each soil type has its challenges in applying the same soil amelioration practices as the deep sands, and return on investment following the deployment of soil amelioration practices. There is not a ‘one size fits all’ approach in paddocks where there are many soil types, and so farmers require the skills to identify the soil constraints in their paddock, understand which practice is likely to be effective in each soil type, and gain confidence to apply this knowledge and implement the practices across their farm.
WMG have been working in the area of soil amelioration for nearly 15 years, having first starting helping farmers address soil water repellency in the region after 2009. Partnering with DPIRD to deliver a range of trials that explored the first phase of soil amelioration which was new and exciting. The second phase of our research and demonstration activities was focused on reducing the environmental risks of soil amelioration through a later timing of practices (winter amelioration).
Our current focus in soil amelioration is on developing the next generation of strategies that build on the first generation of soil amelioration to improve long-term soil health. This is primarily in the field of stacking soil amendments and amelioration strategies, identifying soil amelioration options for paddocks with variable soil types, and in tackling the issue of re-emergence and/or prevention of re-emergence of soil water repellence in the region.
Over the next three years, WMG will establish a network of Participatory Action Research (PAR) groups and demonstration sites across the Geraldton and Kwinana West port zones. Each year, 1-2 sites will be established with local PAR groups that build on the learnings from previous year to develop the farmer knowledge base on successful soil amelioration strategies.
The PAR groups will explore the three key aspects of soil amelioration on variable soil types: how to diagnose paddock scale soil constraints, identify the most appropriate amelioration method(s) and highest ROI for the paddock, and gain confidence/experience in applying these practices through peer learning and knowledge sharing. Over the course of the project, each PAR group will visit demonstration sites and leading farmers who have made significant progress in understanding and addressing paddock-scale variability and how this affects the implementation of soil amelioration practices.
Project Objectives
The outcome of this project will be that by 2026, 30% of the growers in the Geraldton and Kwinana West Port Zone will have increased knowledge of management techniques to overcome non-wetting issues.
Trial sites will be established in 2024 and will continue into 2025, with a partial economic analysis to be completed at the end of 2024, and a full economic analysis conducted at the conclusion of the project to evaluate the range of practices employed and their efficacy.
Latest Updates
- Soil Amelioration & Groundcover Post-Harvest: Implications for Farmers
Post-harvest groundcover matters—especially in fragile soils. Learn how soil amelioration improved biomass, reduced weed pressure, and protected soil in a 2024 Dandaragan trial, offering practical insights for managing erosion, moisture retention, and resilience between harvest and seeding.
- Understanding Soil Water Repellence: Causes, Risks and Management Options
Water repellence is a major constraint in sandy soils—but strategic amelioration can help. Learn what causes repellence, how it affects crop performance, and which management options can improve infiltration, reduce erosion, and support long-term soil function.
- Evaluating the Economics of Soil Amelioration Strategies for Non-Wetting Soils
How can different soil amelioration methods improve crop yields and farm profitability? See our economic analysis of the 2024 season results from the Dandaragan Soil Water Repellence trial site to find out more.
- How can amelioration affect crop uptake of nutrients in gravel soils?
Explore how soil amelioration methods like deep ripping and inversion tillage impact nutrient uptake in gravel soils with results and analysis from the Dandaragan Soil Water Repellence Project trial site.
- Capturing the benefit of increased plant growth following amelioration
How can we get the most out of increased plant biomass in the first year of soil amelioration? Read on to explore insights for grain-and-graze, hay production and other mixed farming systems.
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Want to get involved?
Get in touch with our Project Officer, Kate Parker.
projects@wmgroup.org.au
0459 353 840
Post-harvest groundcover matters—especially in fragile soils. Learn how soil amelioration improved biomass, reduced weed pressure, and protected soil in a 2024 Dandaragan trial, offering practical insights for managing erosion, moisture retention, and resilience between harvest and seeding.
Water repellence is a major constraint in sandy soils—but strategic amelioration can help. Learn what causes repellence, how it affects crop performance, and which management options can improve infiltration, reduce erosion, and support long-term soil function.
How can different soil amelioration methods improve crop yields and farm profitability? See our economic analysis of the 2024 season results from the Dandaragan Soil Water Repellence trial site to find out more.
Explore how soil amelioration methods like deep ripping and inversion tillage impact nutrient uptake in gravel soils with results and analysis from the Dandaragan Soil Water Repellence Project trial site.
How can we get the most out of increased plant biomass in the first year of soil amelioration? Read on to explore insights for grain-and-graze, hay production and other mixed farming systems.