• Introduction
• Recent SMM observations
• Speedo assessments
• 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 at agriculture.vic.gov.au/soilmoisturemonitoring

No login or passwords required, and speedos automatically updated.

Figure 1: May rainfall deciles for Victoria

In May it was wetter than average in  South-West Victoria and West Gippsland, below average for  North-West and parts of  North-East, while Central Victoria was average.

Figure 2. June 1-24 rainfall for Victoria

The Mallee has had less than 25 millimetres for June (month to date) while from Echuca - and across to the east – there’s been more than 25 millimetres keeping the conditions wet.  The far south west  is becoming wet with another 50 millimetres of rain.

The monitoring areas in central Gippsland have also had less than 25 millimetres and further rain is required.

Figure 3: AWRA modelled soil moisture bom.gov.au/water/landscape/

Large areas of the Victorian cropping regions have average modelled soil moisture conditionsconditions, but some parts of the southern Mallee have dried down to be below average. There is a considerable area of North Central and North East Victoria that is above average. Some low-lying areas within those districts maybe susceptible to varying levels of water logging.

Soil moisture measurements on the Agriculture Victoria monitoring network show that in the Mallee, sites are generally similar to this time last year (24 June 2019) while the Wimmera sites are slightly drier after hay and up to 50 per cent drier following high yielding grain crops.

North Central and North East Victoria are still wet after summer rains and well above average April rainfall. These sites are wetter than a year ago and currently conditions in those areas range from excellent to wet, with some low-lying areas waterlogged. High soil moisture could be problematic with further rain and low evaporation in winter.

Increases to soil moisture stagnated during June with generally lower rainfall than normal. Some crops and pastures with high growth from early sowing (particularly vetch/cereal mixes and canola), used soil moisture throughout the month.

In South-West Victoria, the moisture improvements have been moderate during the past three months, but in recent weeks some districts have built up a solid moisture profile with more than 50 millimetres of rain for the month.

Early sown vetch has been using some shallow moisture but despite this, deep moisture reserves are high. Conditions in the district are great.

Ouyen summed soil moisture graph – 12 month view

An early sown vetch crop and moisture has got down to 40 centimetres this season. Expect more consistent soil moisture trend changes from this point onwards, either from rainfall or plant water use.  To-date, it appears the recent decreases have been linked to cooling soil temperatures, which occur every autumn at this site.

New moisture from 2020 has moved down to 50 centimetres providing ideal growing conditions for crops in the district. Residual moisture from 2018 still exists at 80 centimetres and below after the lentil crop last year only used moisture down to 70 centimetres.

Brim summed soil moisture graph – 20 month view

Moisture improvements have been 30 per cent this year coming from a dry base of 7 per cent at harvest time.  Conditions are excellent with moisture down to 40 - 50 centimetres promoting good crop growth.  There is capacity to absorb more water with the next rain in the top horizon and then water can infiltrate down deeper. The percentage moisture to depth chart shows there is large scope to build up moisture reserves below 60 centimetres at this site.

Half of the moisture profile was left after the crop was cut for hay last year.  Total moisture peaked at 75 per cent in autumn.  This seasons moisture has infiltrated down to 60 centimetres and connected up to the residual moisture.  Early sown vetch has been grazed and plants were using more water than received by rain in May.  Moisture use has slowed in response to frosts in June. This site would be typical of paddocks with hay history last year, but data shows grain crop rotations are drier in the district.

The site  at Taylors Lake was grazed in autumn from the germination of volunteer barley which used water and prevented the accumulation of moisture.  Canola has been sown at this site and neighbouring paddocks with summer/autumn weed control would have higher moisture levels.

Elmore summed soil moisture graph – 12 month view

Clay loam soil with a 30 - 45 per cent silt component has consistent levels of soil moisture right down the profile.  This soil type has rapid wet up and draining characteristics. A push rod can easily reach 60 centimetres and SMM data indicates 2020 infiltration down 70 centimetres.

Two reports generated from the soil water app, same rainfall, but modelled with two different soil types found locally.  The Agriculture Victoria soil moisture probe, with assumptions of a near full profile in the unmeasured zone of 0 - 30 centimetres is 76 per cent. General rule is not to rely on one source of information but to utilise other data. Soil type can make large differences to moisture availability.

Youanmite summed soil moisture graph – 12 month view

Soil moisture profile has been full since the start of May.

Individual stacked sensor soil moisture graph – Youanmite 12 month view

All moisture sensors down through the soil profile are now saturated.  District paddocks with high soil moisture could be problematic with further rain and low evaporation in winter.

South of Sale (Giffard) summed soil moisture graph – 12 month view

Phoenix canola sown in early April with grazing opportunities to be utilised in winter before lock up for seed.  The canola used water during June, but good soil moisture levels are located deep in the profile (70 centimetres plus) of this predominately clay based soil that has good water holding capacity.

Summed soil moisture graph – Lake Bolac 12 month view

Deep soil moisture level increases with perennial pasture at the Lake Bolac monitoring site have been minimal.   Autumn rain was converted to pasture production. Cropping sites in the district would be wetter. High moisture down to 50 centimetres provides ideal conditions for plant growth and rain in the past week has moved moisture further down past the wet soil horizons to 60 centimetres.