Forward this email | View in web browser
Soil Moisture Monitoring
16 February 2021
2021 Issue 1
In this edition:

The soil moisture monitoring project, with the use of underground probes, provides real time soil water content data to Victoria’s farmers.

Monitoring sites have been set up in cropping regions throughout the state by Agriculture Victoria.

The sites record soil water content at one source point from 30 centimetres down to one metre as a reference point for a paddock.

Sites monitored include: Werrimul, Ouyen, Speed, Kerang, Birchip, Normanville, Lah, Bangerang, Taylors Lake, Coonooer Bridge, Raywood, Elmore, Youanmite, Hamilton, Lake Bolac, Tatyoon, and Sale.
Locations of Agriculture Victoria soil moisture monitoring sites

To access information provided in the graphs, log onto the new Agriculture Victoria soil moisture monitoring dashboard.

No login or passwords required, and speedos automatically updated.

January rainfall % of mean for Victoria. Rainfall ranges are above 100 per cent in the wimmera and North East hills.

Figure 1: January rainfall per cent of mean for Victoria

The blue shaded areas are districts that received 200 per cent or greater mean rainfall for January and after the dry period prior, the SMM sites in these areas had good moisture infiltration.  Generally, most of the rain influencing the mean values fell in the last week of January, so larger volumes in a short period of time had more impact than small events spaced apart.

Victoria rainfall deciles for January

Figure 2: January rainfall deciles for Victoria

Rainfall deciles for January are mostly average to above average but the district between Swan Hill and Ouyen is below average. If there is no further rain in the next fortnight in this district, large parts of the Mallee will have decile 2-3 summer rainfall and soil moisture values will be similar to the harvest period.  Areas of decile 10 will have "banked varying amounts of deep soil moisture" for this year’s winter crop program which is explained in this report.

Month rainfall totals for February (month to date 9 February). Rainfall was concentrated to North East Victoria and East Gippsland with rainfall on 5 February.

Figure 3. February rainfall totals for Victoria (as at 19 February, 2021)

Rainfall was concentrated to North East Victoria and East Gippsland with rainfall on 5 February and significant infiltration observed with >50 millimetres of rain. Sites with >25 millimetres following above average January rain also had moisture move down through the wet top horizon and deeper into the soil profile.

AWRA soil moisture map of Victoria from 9 February. A drop pin location at minyip has this area modelled at above 50 per cent moisture.

Figure 4: AWRA modelled soil moisture

The AWRA model is a good indicator of recent rainfall and soil moisture conditions. A dropped pin location has been selected for the district of Minyip that had a positive response to the 29 January rain.

For more information go to Bureau of Meterology website landscape page  then select more information under the section - root zone soil moisture.

Speedo assessments

Soil moisture measurements collected by the Agriculture Victoria monitoring network show a wide range of conditions after recent patchy thunderstorm activity on three distinct days in the past two weeks.  Some regions have received two significant storm events with others just one, resulting in some great infiltration for areas experiencing multiple storms.

The Mallee has generally missed these storms and most monitoring sites are at similar moisture levels to harvest time last year.  If there is no rain for the remainder of the month, a large area of the Mallee will be below average rainfall for summer.  The long data set of monitoring shows that even average rainfall for summer rainfall will not build up soil moisture reserves.

The exception in the Mallee was observed at Werrimull where areas in the Millewa received 50 millimetres on 2 January and on sandy soil this water moved deep into the profile.  This event appears isolated but also in a district that has soils with low water holding capacity and not all this water will be available by sowing time.  It shows the value of having automatic rain gauges to pick up storms that are not widespread so farms can be treated as per rainfall received.

Hay paddocks have more moisture down deep compared to the cereal crops from last year.  The soft spring finish and rain in October that met crop water demands during grain fill, resulted in some of the deep moisture reserves being conserved.
Some areas of North Central and North East Victoria are in a good moisture position, as are lower parts of the Wimmera and the South West but there are some areas in these regions that have missed the storms and are still dry. 

Note - Some soil moisture monitoring speedos below have been temperature adjusted to better reflect the current moisture conditions.

Soil moisture speedos at 9 February 2021
Speedo soil moisture graphs
Werrimull soil moisture (30-100cm)
Werrimull Speedo, moisture currently 90%
Werrimull individual soil moisture traces showing the positive responses to the 2 January rain.

Repairs to the Werrimull rain gauge were activated in time to record the early January rainfall, with more than 45 millimetres recorded.  The profile was about 50 per cent full after an oaten hay crop permitted infiltration of water down to one metre.  This is a fine sandy soil site, positioned on a mid-slope and the lowest water holding capacity of the Agriculture Victoria network. Refer to Soil Moisure Monitor on ExtensionAus for more information on site details.

Ouyen soil moisture (30-100cm)
Ouyen soil moisture is currently 30 per cent.

The Ouyen site has slightly more moisture than this time last year but this is due to the vetch crop cut for hay on 3 September. Moisture increases in summer have been limited.

Speed soil moisture (30-100cm)
Speed speedo showing 70%

There have only been small, well-spaced rain events at the Speed monitoring site so there has been no moisture improvements this summer.  Current soil moisture levels (which are temperature compensated) are high due to no moisture use in spring with early terminated vetch.  Other cereal crops nearby would have a lower moisture status.

Normanville soil moisture (30-100cm)
Normanville speedo moisture currently 40%

Oaten hay at the Normanville site used the shallow to medium depth moisture last year but the deeper moisture still exists. This is a common occurrence with hay as the season is shorter and no moisture was used in October. There have been no moisture improvements over summer at this site.

Birchip soil moisture (30-100cm)
Birchip speedos moisture currently 32%
Individual sensor trace soil moisture graph showing moisture use coming from 60-70cm in October.

Last year the wheat crop ceased using water 11 November, with the root zone at 60 - 70 centimetres the most active prior to that date.  Some traces of moisture were still available right down through the profile.  Since then there has been no moisture increases but it still appears there are blockages with the rain gauge.

Brim soil moisture (30-100cm)
Brim speedo moisture currently 30%
Sheep Hills soil moisture (30-100cm)
Sheep Hills speedo 53 per cent

The temperature compensated speedo graph shows similar moisture values compared to last year but with a vetch hay background from last year.  Cereal crops in the district would likely be drier, particularly if January storms were < 50 millimetres.  Sites south of Sheep Hills, eg Minyip have received rainfall of >75 millimetres and these sites have had positive moisture increases (figure 4).

Taylors Lake soil moisture (30-100cm)
Taylors Lake speedo soil moisture currently 32%

The temperature compensated speedo graph shows some small soil moisture increases on the grey self-mulching soil.

North Central
Coonooer Bridge soil moisture (30-100cm)
Coonooer Bridge soil moisture speedo at 75%.

The Coonooer Bridge site has had the largest moisture increases at 30 - 50 centimetres but there are traces of moisture deeper than this from three distinct rain events in January.

Elmore soil moisture (30-100cm)
Elmore speedo current soil moisture 21%
Summed soil moisture graph from Elmore showing moisture improvement from 29 January.

This clay loam soil with a range of 30 - 45 per cent silt generally takes significant summer rain events to allow deep infiltration as the soil seals up.  Rain on 29 January had some positive impacts with soil moisture improvements.

Examples from the soil water app showing very similar conditions (modelled) to the ag vic smm probe data. Range of 20 per cent.

Report generated from the Soilwater app (smart device app that models soil moisture conditions) with the local soil type. The Agriculture Victoria soil moisture probe is 21 per cent and the model is 20 per cent, showing similarity, particularly with minor moisture increases after the 29 January rain event.

Raywood soil moisture (30-100cm)
Raywood speedos current soil moisture 100%

The Agriculture Victoria SMM site at Raywood has had a 30 per cent moisture improvement in the past month and with a canola paddock history that left moisture deep in the profile after the crop had some impacts from being too wet last year.  Moisture has infiltrated down to 60 centimetres and has connected up to the residual moisture.

Additional smm data from Raywood has this site at 80 per cent.

This is a monitoring site as part of the North Central Catchment Management Authority - Regen Ag program at Raywood and shows the influence of the recent 75 millimetres of rain that has infiltrated down to 50 centimetres with a wheat history from 2020.

Two more monitoring points in the Raywood district showing sites are 80 per cent moisture.

Soil moisture data from the Raywood Regen Ag program with a paired site in the district of Neilborough growing wheat and barley last year.  Greater than 75 millimetres of rain 29 January shows moisture movement down to 60 centimetres and connecting to residual moisture left over from last years crops.  Ideal mineralisation opportunities exist with weed control. Thank you to the Regen Ag group for data and displaying the benefits that a network spread through a district can provide.  These sites are also shown on the SMM dashboard.

North East
Youanmite soil moisture (30-100cm)
Youanmite speedo moisture currently 81%
Youanmite individual sensor soil moisture graph has had soil moisture improvements on 5 February.

Youanmite stacked individual soil moisture graph – 2021 view

Thirty millimetres of rain at the end of January was absorbed and moisture failed to reach 30 centimetres.  Follow up rain on 5 February moved through the topsoil and penetrated down to 70 centimetres and has connected up to residual moisture left over from the canola crop last year.

Tungamah soil moisture graph also has soil moisture improvements from 5 February rain.

Tungamah stacked individual soil moisture graph – 2021 view (source Riverine Plains)

Similar to the Ag Vic soil moisture monitoring site, rain in January wet the top horizon but had limited infiltration.  Rain on 5 February has moved moisture down to 60 centimetres and there are traces of moisture at 80 centimetres, while the >100 centimetre sensors have returned back to existing values indicating it was preferential flow.

See the Weather Plus website for more information. 

Gippsland cropping
Gippsland (Giffard) soil moisture (30-100cm)
Gippsland speedo moisture currently 48 per cent

The Giffard West site has improved 35 per cent during January with rain events at the start and end of the month totalling 70 millimetres.

South West
Lake Bolac SMM (30-100cm)
Lk Bolac (pasture) soil moisture levels at 20 per cent

Lake Bolac has had moisture infiltration down to 50 centimetres with 29 January rain but it is still quite dry as other rain events have spaced apart. This was one monitoring site growing canola last year that depleted most of the soil moisture.

Hamilton soil moisture (30-100cm)

Hamilton is offline until repairs to rain gauge and communication system can be performed..

Yalla-Y-Poora soil moisture (30-100cm)

Yalla-Y-Poora is offline until repairs to soil moisture probe can be performed.


Privacy | Email:


If you would like to subscribe to the Soil Moisture Monitoring newsletter or find out more information, visit the Agriculture Victoria website

This newsletter is distributed by the Department of Jobs, Precincts and Regions.