Assessing soil water storage

WHY THIS PROJECT IS NEEDED

Water infiltration into soils after rain and the ability of soils to store water can be affected by soil constraints, such as soil acidity and sodicity.

This project aims to improve the understanding of crop access to water and resources by measuring a range of attributes in a soil with constraints in northeast Victoria.

In short: This project is helping to understand soil water storage in soils affected by constraints such as acidity and sodicity, and the soil-water dynamics between crop types.

Project focus

Through the installation of field sensors, the project will quantify changes in soil water attributes (infiltration, storage, drainage, and crop interaction), due to the diagnosis and management of soil constraints at an existing Soil CRC project site at Burramine, Victoria.

This will allow the development of tools that support soil management for increased access to soil water. It will also provide a better understanding of the competition for water and resources that occurs between mixed species cover crops, and the impact on soil water availability for the subsequent crop. 

Project outcomes

Results from the Burramine trial have been published in Research for the Riverine Plains, 2025. The article describes the investigation into whether summer cover-cropping increased plant available water capacity over a fallow, and how soil water attributes were affected. 

Key messages from the trial were that:

• Soil water content (how much water is in the soil) and matric potential (how tightly water is held by soil) was measured four-hourly at Burramine between March 2023 and December 2024 under summer fallow and summer cover crop treatments, followed by winter crops. 
• Plant available water capacity (PAWC) in the sub-soil was found to be 30 mm greater under the cover crop treatment than under the control.
• Higher PAWC in the cover crop treatment was attributed to a greater number of soil pores at the top of the B horizon. While the cause is unknown, it may be due to more roots at depth and/or greater sub-soil drying over summer, creating cracks.
• There was no difference in PAWC between the cover crop and control plots in the topsoil. 
• While promising, these results are from one trial on one soil and more work is needed to determine the cause and if the effect occurs at other sites and soils. 

There's more to the story. Learn more by reading the full article: Soil water storage: Increased access and tools for assessment