• Introduction
• Recent Soil Moisture Monitoring observations (from 22 August)
• Speedo assessments - change in overall soil moisture at a particular site.
• Speedo soil moisture graphs
  • Mallee
  • Wimmera
  • North Central
  • North East
  • Gippsland cropping
  • South West

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.

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

No login or passwords are required, and speedos are automatically updated and will represent the most recent rainfall.

From 22 August

Figure 1: June and July rainfall deciles for Victoria

Average rainfall for most parts of the Wimmera. August is on track for this trend to continue (see figure 2). Below average rainfall for the Mallee, cropping areas of the North East and parts of North Central Victoria.

Figure 2: August rainfall percentages (month to date 22 August) for Victoria

Over two-thirds progressed for the month and the cropping districts around Horsham have received average rainfall, which has been beneficial for soil moisture increases. It has been dry in the Millewa.

Figure 3. August rainfall (month to date, 22 August) for Victoria

A drier start to the month in Northern and North West parts of the state. Early sown crops with less than 10 millimetres are starting to create a moisture deficit in the soil. Mid-winter is early to create a moisture deficit but reflects crop biomass and developing yield potential at the monitoring sites.

Soil moisture measurements collected by Agriculture Victoria have shown that soil moisture profiles have remained stable over the past month, with some Mallee sites drying slightly and Wimmera sites getting wetter. Crops depleting small amounts of moisture will be due to higher water requirements, with larger biomass supporting high yield potentials.

Winter has historically been a time to build soil moisture profiles. High yield potential crops ideally have a full or near full soil moisture profile at the end of winter. 

Mallee site data indicates a range of moderate/high deep soil moisture conditions, and some areas experiencing drying of the topsoil after average to below average rainfall in the past 10 weeks.

The Wimmera is also moderate/high but conditions are wetter in the top horizon after higher rainfall totals from storms during August, and these rain events have had better infiltration. Observing positive moisture improvements at the monitoring sites during this critical month of August is ideal to promote plant growth and high yield potential.

Central Victoria and North East Victoria have high soil moisture conditions. Patchy storms have passed over the regions during August and it seems like each cloud has the possibility of depositing rain and maintaining a full or near full profile as we enter Spring. 

These are positive indicators for high yield potential and crops have had nutrition applied to meet their potential.

The South West region has deep soil moisture levels ranging from moderate to moderate/high, but this is adequate for the high rainfall zones. Seasonal outlook and conditions are excellent for yield potential.

Note - use extensionaus.com.au/soilmoisturemonitoring to monitor the changes to the sites relevant to you in between the next reporting period and following rain events.

Soil temperature at 11.9 degrees, low biomass crop at this stage and reflects the low water use during winter.

Ouyen stacked individual soil moisture graph – 2022 view

Moisture continues to be depleted from the soil at Ouyen with 45 per cent used in the past six weeks. Rainfall has not met the barley crop water demands.

Soil water has been used at many depths as the roots explored the sub-soil but it has predominately come from 40 - 60 centimetres.

The Speed soil moisture monitoring site has a wet profile down to 80 centimetres (some of those zones are still saturated, above 100 per cent moisture). During winter, plant water requirements have been met by rainfall.

Excellent wheat growth and root development at Normanville following vetch hay has set up a high yield potential. Crops with high yield potential can deplete soil water reserves in a dry winter.

For recent changes associated wth 23 August rain, please follow this link.

Early August rainfall that fell on a wet profile permitted soil water infiltration to 30 - 70 centimetres and provided a positive boost to the season. Deep moisture is rated as moderate with excellent conditions above that zone.  Wheat growing at this site will soon start to deplete shallow soil moisture reserves.

Please follow the link to the soil moisture monitoring dashboard to obtain the most recent changes to this change in the Wimmera.

The soil moisture infiltration opportunities this season at the Minyip/Bangerang site can be summarised in three periods during the months of April, June and August. This site also had moisture reserves available at the start of autumn (40 per cent).

There have been some small increases to soil moisture during winter. Last year’s crop of clover was a lower water use compared to faba beans growing this year. Please follow the link to the soil moisture monitoring dashboard to obtain the most recent changes with mid - August rain events in the Wimmera at Taylors Lake.

Conditions are wet at Birchip with this season’s rainfall meeting the crop requirements after the profile was filled last year in the fallow phase. Examination of soil cores in early August identified a strong developing root system to draw upon moisture in Spring.

Note - this paddock is in fallow with no crop growing over winter. Additional moisture has been banked with August rain events.

Moisture has moved down to 100 centimetres this season, but other district sites with crop growing could be drier.

After a dry July where the wheat crop had started to deplete some deep soil moisture reserves, August has been wet. Interpretation of soil moisture data can be challenging, and Elmore commonly has preferential flow down the side of the probe with large rain events.

Waiting a week to analyse the impacts of 40 millimetres of rain now shows that this rain was able to infiltrate down to 50 centimetres, and not the initial spike with all the deep sensors.

Total moisture has improved by 15 per cent from 60 per cent on 10 August.

Modelled soil moisture at Elmore with the soilwater app compared to moisture probe data, indicates similar line trend changes associated with rainfall, and now moisture changes with the developing biomass of the wheat crop.

The two screen shots from the soilwater app model are from 19 July and current conditions.

They reflect the mid profile moisture that was being used by the wheat crop. Conditions are now wet after frequent rain events.

The drier conditions of the past two month have just slightly dried the top horizon. Vetch, which is traditionally a low water user in winter compared to cereals, is growing in this paddock.

The Giffard West site in Gippsland confirmed a solid start to the season with autumn breaking in early April. The soil has remained in a wet state for the past five months.

Soil moisture conditions are ideal at Lake Bolac with a wet top horizon, and gradually building a moisture profile where we have previously observed strong plant uptake during spring.

The Lake Bolac site is coming from the driest base of all the monitoring network last year, and is still dry below 80 centimetres. But there is good moisture above that level for a high rainfall zone, with a good buffer against spring waterlogging with further rainfall.

Please follow the link to the soil moisture monitoring dashboard to obtain the most recent changes with late August rain events.

Rain on 31 May had significant infiltration down to 100 centimetres and was further topped up in early June to create a full profile on the raised beds at Hamilton. There is no crop growing at this site yet as it will be spring-sown with chick peas.