State soil moisture monitoring - 2015
Dale Boyd1
Department of Economic Development, Jobs, Transport and Resources (DEDJTR)
Peer review: Graeme Anderson, Dale Grey (DEDJTR)
Background
Crop potential and cropping inputs are increasingly being subject to greater instability
and uncertainty due to seasonal variability. There are increasing examples of soil
moisture probes installed in dryland cropping system in Victoria with interest from both
service providers and farmers. This technology is being used to gain a greater
understanding of seasonal conditions through a repeatable measurement in the soil rather than estimates based
on rainfall.
Why was the project done?
The Department of Economic Development, Jobs, Transport and Resources (DEDJTR) network of soil moisture
probes, provided an overview of the soil moisture status around the state in 2015 and this was used to compare
conditions to previous seasons. DEDJTR used the traditional forms of communication (email, forums, field days
and farmer meetings). Twitter was also used quickly to circulate information around the industry using a visual
display of changing conditions using a speedometer. The monthly summaries were aimed to be informative and
also be a learning tool for anyone investing in the technology in the future to be able to interpret their own data.
The DEDJTR network data is also displayed live via website, so in-between monthly summaries are also an option.
Locations of DEDJTR soil moisture probe locations
1 2015 Jan
Mar
May
July
Sept
Nov
Jan 2016
Total soil moisture graph from Werrimull 2015. Rain in January and April significantly increased soil moisture with
sensors detecting soil moisture changes at 100cm during April.
Key messages
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Northern Mallee started the 2015 growing season with soil moisture to depth after conserving water from
two significant rain events in January and April.
Other parts of the state failed to accumulate soil moisture to depth which exposed large areas to the spring
finish.
Previous soil moisture data shows periods to build moisture are Summer/Autumn and winter. In Spring,
crop water requirements generally exceed rainfall so soil moisture reserves are drawn down, particularly
rapidly in low decile springs.
In 2015, crop inputs on monitored paddocks were reduced with the low potential yields projected. Rapid
soil moisture depletion could be tracked through September and projected crop lower limit was expected
around flowering time (critical growth stage).
Decisions to salvage crops for hay instead of grain were made on the basis of soil moisture conditions,
crop dry matter and spring forecast conditions.
The crop at Werrimull was taken to grain with moisture available through grain-fill but Wimmera and Central
Victorian crops had higher crop salvaging percentages compared to usual. Soil moisture probes proved
useful as one of the tools for this decision making.
For monthly summaries/access to live soil moisture data, contact Dale [email protected]
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