The Challenge of Saline Soils
Saline soils pose a significant challenge to farmers, reducing crop yields and making land unproductive. However, innovative techniques can transform these lands back into productive farmland. David Schmidt’s farm in Waikerie, South Australia, provides a compelling example of how sand mulch can rejuvenate saline soils and boost agricultural productivity.
The Case Study
David Schmidt, along with his brother Anthony and father Glynn, manages a 10,000-hectare farm with a variety of soil types, including deep sands and red loams. Over the years, patches of dry saline land have appeared, ranging from small scalds to large areas unable to support plant growth. These saline patches were particularly problematic on the flats of red clay or grey ashier soils.
In 2015, David decided to tackle this issue head-on. He hired a contractor to apply approximately 10 cm of sand mulch over a severely affected area. This simple yet effective method provided a non-saline layer for crops to establish, creating a significant turnaround for the land.
Results and Benefits
The impact of sand mulch was immediate and dramatic. By 2020, the treated area supported a successful wheat crop of 2.4 t/ha, a stark contrast to the adjacent untreated area which yielded only 0.1 t/ha. The sand mulch not only improved crop yield but also significantly reduced soil salinity levels.
Key Benefits of Sand Mulch:
- Creates a Non-Toxic Germination Layer: The sand provides a safe environment for seeds to germinate.
- Soil Cover: New plant growth limits the rise of saline water during dry periods.
- Moisture Management: Growing plants use moisture in the root zone, preventing it from rising and leaving salts on the surface.
- Reduced Moisture Wicking: Coarse sand particles minimise moisture movement to the surface, unlike clayey soils.
The treated soil maintained low salinity levels for at least nine years, showing no signs of salinity returning.
Ongoing Efforts and Future Plans
David continues to rehabilitate dry saline patches as resources allow. Early intervention is key, treating areas as soon as salinity is detected. The family uses a laser bucket to spread sand more efficiently, despite the labour intensive nature of the process.
David Schmidt’s case study highlights the effectiveness of sand mulch in restoring saline soils to full productivity. This innovative approach not only improves crop yields but also ensures long-term soil health. Farmers facing similar challenges can learn from David’s experience and consider sand mulch as a viable solution for saline soil remediation.
David Schmidt’s innovative approach serves as a testament to the resilience of farmers and the potential for transforming saline soils. For more information and to read the full case study, click here
For a detailed account of this case study, visit our website and explore how sand mulch can transform your farmland.
This case study was developed as part of the “Building resilience to drought with landscape scale remediation of saline land” project through funding from the Australian Government’s Future Drought Fund.
