• Introduction
• Weather and soil moisture monitoring observations
• Speedo assessments - change in overall soil moisture at a particular site.
• Speedo soil moisture graphs
  • Mallee
  • Wimmera
  • North Central
  • Northeast
  • Gippsland cropping
  • Southwest

The soil moisture monitoring (SMM) 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 (cm) down to 1 metre as a reference point for a paddock.

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

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

Figure 1: Out of season rainfall deciles for Victoria (November - end of April)

The Victorian rainfall decile map for out of season rainfall in winter cropping regions show large areas of decile 8 - 9 and patches of decile 10 rainfall. Despite the recent dry conditions, deep moisture deposited in summer will still be in the profile. In some regions of the Wimmera and Mallee, this moisture is not connected, nor have crops emerged. Areas of decile 10 will likely have better deep soil moisture conditions. Areas in the average rainfall regions will be drier with limited deep moisture.

Figure 2. April rainfall deciles and rainfall totals

Average rainfall conditions in most of the cropping districts, but this was from rainfall in early April, and the dry topsoil had mixed responses with germination of weeds. 

Early to mid-April provided opportunity for sowing small areas of long season wheat and canola. Areas with >50mm provided conditions for a successful autumn break.

Figure 3. Current month to date May rainfall totals and rainfall percentages for Victoria

Melbourne north to Echuca received the biggest totals on May 10 and crop emergence is underway in these districts. West of the state received little to no rain and has been very dry for 6 weeks, making it challenging to get newly sown crops to emerge. Deep soil moisture levels have remained stable despite the dry conditions.

Soil moisture measurements displayed on the Agriculture Victoria dashboard, the monitoring of cropping sites in the northern part of the state shows solid deep soil moisture profiles with decile 8-10 rainfall conditions since harvest. There is evidence of drying profiles in sites where volunteer crop and summer weeds (red dots) which would have provided grazing opportunities.
The perennial pasture selected sites (image right) would have had pastures using moisture through summer, and limited rain in the autumn thus far has left those profiles much drier.

Note - use extensionaus.com.au/soilmoisturemonitoring to activate your preferred reference monitoring location soil moisture percentage. 

All sites soil moisture percentages 24 May including annual winter crop and non-cropped paddocks and perennial pastures.

Pastures have continued to deplete soil moisture during the past 6 weeks and are <25%. The drop-down selection bar on bottom left-hand side of the map provides the option to either select crop or grazing sites.

Wet deep soil moisture conditions but dry on top and moisture not connected. No measurement from 0-30cm and the region requires rain to allow crop emergence.

Wet deep soil moisture conditions but dry on top and moisture not connected. No measurement from 0-30cm and the region requires rain to allow crop emergence.

Wet deep soil moisture conditions and district has benefited from 15 - 25mm on 10 May to allow germination of dry sown crops.

Deep soil moisture conditons are good and vaidated on 16 May - see link. Top soil had marginal moisture conditions.

Wet deep soil moisture conditions but dry on top and moisture not connected. No measurement from 0-30cm and the region requires rain to allow crop emergence.

This paddock was grazed over summer with germination of volunteer canola. Wet deep soil moisture conditions still exist from 70cm but dry above this on top and moisture not connected. No measurement from 0-30cm. Paddocks with summer weed control would have higher soil moisture.

Wet deep soil moisture conditions but dry on top and moisture not connected. No measurement from 0-30cm and the region requires rain to allow crop emergence.

Wet deep soil moisture conditions but dry on top and moisture not connected on the heavy soil types. No measurement from 0-30cm and the region requires rain to allow full crop emergence and provide relief to emerged crop that has been exposed to several frosts.

Wet deep soil moisture conditions and the district has benefited from 20 - 30 mm on 10 May to allow emergence of dry sown crops. Crops sown into good moisture after this rain have germinated and the bottom photo shows the wheat development 6 days after sowing.

Wet deep soil moisture conditions and district has benefited from 20 - 30 mm on 10 May to allow emergence of dry sown crops. Crops sown into good moisture after this rain have germinated. Deep soil moisture conditions are better than this time last year.

Modelled soil moisture at Elmore with the Soilwater app compared to moisture probe data (bottom chart). Using an estimated 30% moisture at mid-November to run the model and determine out of season moisture.  There is good correlation to moisture probe data.  Both information sources have approximated 75 - 85% plant available moisture and conditions are better than this time last year.

Now is the time to be setting up models to assist with estimating soil moisture, that will provide some guidance on yield potential later in the growing season when crop inputs are assessed.

Rain events in late November, Christmas and early January have filled the profile to 100%.  Repairs to the probe have been ongoing to obtain a regular connection to the field sensors.  When connection occurs, it shows that deep moisture is still 100%.

This was confirmed with site validated with soil cores on 2 May - see link.

At this time, 2 May, canola emergence was patchy, but plants were 2 leaf growing in lighter soil areas of the paddock.

Wheat and Clover sown in early April and will be grazed next month.  Deep soil moisture conditions are good, and more rain would be welcome to boost crop and pasture growth prior to winter.

A wet harvest period at the Lake Bolac site allowed moisture to infiltrate down to 70 – 80 cm and there was no recharge below that. Moisture that was laid down during that period has now been used and the profile is approximately 30%. Connection to the probe fails at times so the Intelligraph display is the best option to fill the gaps.

Limited opportunity to build soil moisture in the southwest site at Hamilton over summer and autumn. The region is dry with only small rain events through April and May (month to date).

Red wheat sown in early April at Yalla – Y - Poora, emerged in the second half of April and has benefited from the 10 May rain event. Rain was patchy so like the rest of the state, more rain is required for the region.