Soil Moisture Monitoring in Dryland Cropping Areas
Risk management through soil moisture monitoring project
The risk management through soil moisture monitoring project was a three year project (2011-2014) to assist dryland grain growers to make improved informed decisions. With positive results see (Soil moisture monitoring survey report 2013 and 2014) the monitoring component has gained an extension to its funding through the Grains seasonal risk program with the Rain, Grain and F2A (Food to Asia) project.
This project conducted by DEPI will assist the grain sector to lift production and improve grain quality to meet the Food to Asia demand. Increasing targeted inputs and improving crop management will be accomplished by educating industry to understand soil and water interactions and critical crop growth stages, as well as factoring in forecasted seasonal predictions.
Crop potential and cropping inputs are increasingly being subject to greater instability and uncertainty due to seasonal variability. Grain growers are under pressure to increase production across a range of seasons, and adding to the complexity, is the fact that under a climate variability scenario rainfall may decrease and distribution will change.Growers current cropping systems may not be maximising water use efficiency, if they are using subjective assessments. Few are able to monitor water available to the crop and hence do not supply the crop with the appropriate amount of inputs for maximum yield.
The practice of using soil moisture probes has had limited use in the dryland cropping industry and as such many farmers are unable to utilise this technology.
The Department of Environment and Primary Industries will provide live deep soil moisture data to help dryland croppers, farmers, and advisors/managers validate the technology, as well as conducting training to interpret the data for crop decision making. E-Communication will include – monthly broadcasts of 'The Break', soil moisture products, and piloting new technology formats to expand reach and impact.
Sites and measurements
There are eleven soil moisture monitoring sites across Victoria's cropping zones.
- Mallee - at Speed, Werrimull, Birchip, Ouyen and Normanville
- Wimmera - Brim
- South West - Hamilton and Lake Bolac
- Central – Raywood
- Northern East - Youanmite
- South Gippsland – Sale
These sites are being monitored using "capacitance probes" that take hourly measurements of soil water content through the soil profile.
Sensors on the capacitance probes measure zones every 10cm, from a depth of 30cm down to 1m. A total of 8 measurements from 8 probes are taken at each site, with the data collected sent via the mobile phone network to a server which stores the data to allow
interpretation through graphing software.
Soil moisture probes record absolute soil water content and have built up knowledge of crop upper and lower limits under different soil types and crop types for many of the sites with three plus years of monitoring.
Measuring soil moisture will help provide an indication of:
- Yield potential based on plant available water
- Crop water use
- Sub soil moisture base and reserves
- Rainfall required to refill soil profile
- Water infiltration
- Water logging
- Water use of different crops
Access to this data enables growers and advisors to:
- Measure moisture at one representative point in the paddock for a farm in the region
- Use live soil moisture data that is collected from a representative site for a particular rainfall region and soil type.
- Monitor localised weather (rain, wind and temperature/humidity) and have the ability to down load historically data from an archive list for farm management records
- Increase production and efficiencies
- Help farmers to adapt to climate variability
- Make informed input decisions such as minimising input in low decile years with a low soil moisture base and maximising yield potential in more favourable conditions based on current soil moisture levels and incorporating seasonal forecasts probabilities.
- Determine if measurements obtained through the life of the project could be relevant at whole farm or even district level
Benefits to industry
- Service providers using crop forecasting models will be able to use the live soil moisture data that is collected from a representative soil in a particular rainfall region, therefore providing more accurate advice and increasing production and $$ for growers.
- Annual report
- Monthly Newsletters
- Risk management through soil moisture monitoring – Evaluation report
Contact Dale Boyd for copies
How to access and use the data
For information on how to access the data and navigate around the soil moisture monitoring site please email firstname.lastname@example.org or phone (03) 5482 0439.
Soil moisture data is collected by the sensors placed within the soil moisture probe on a regular frequency (1 hour). This data is plotted on graphs to display soil water content change over time. These trend lines will indicate key information that with interpretation will show water infiltration with rainfall and when the crop is actively using moisture.
There will also be times when there is no change and a flat line may indicate that the soil profile is at field capacity or dry to the crop lower limit. It also may show that plant roots are not active in the site for that period of time. The following graph will assist in explaining what is likely to be occurring:
Below are some examples of options you may choose for your paddocks depending on the soil moisture results obtained. Being able to accurately measure soil moisture when required provides opportunities to aid management decisions at various stages in the production cycle. As more information is collected over a wider range of seasons, confidence levels will increase as comparisons can be used to different years.
Early sow long season varieties, canopy management to maximise yields. Up front N.
Reduce upfront input costs, seed rate, fertiliser, and herbicides. Canopy management for average yields.
Reduce upfront costs, and seed rate. Consider decreasing area sown, target lower risk crops and more productive paddocks.
High confidence in N application, weed and disease management.
Lower confidence level. Reduce rates of N application.
Low confidence level. Reduce costs, consider grazing or hay later in the season.
High confidence. Apply late N, fungicides and pesticides.
Lower confidence. Reduce rates of N.
Low confidence. No N. No forward selling. Consider grazing and hay production
High confidence. Consider forward selling options if favourable. Head counts to determine potential yield.
Lower confidence. Reduce forward selling quantities. Head counts to determine potential yield.
Low confidence. No N. No forward selling, consider grazing and hay production.
Determine potential yields. Adjust insurance estimates.
- Agnote: Choosing the right Soil Moisture Monitoring Device, Note Number: AG1412.
Do not act on information here without independent advice from your local agronomist or agricultural advisor.