What is Yield Prophet?
Yield Prophet® is an on-line crop production model designed to present grain growers and consultants with real-time information about their crops, providing integrated production risk advice and monitoring decision support relevant to farm management. Operated as a web interface for the Agricultural Production Systems Simulator (APSIM), Yield Prophet generates crop simulations and reports to assist in decision making. By matching crop inputs with potential yield in a given season, Yield Prophet subscribers may avoid over- or under- investing in their crop.
The simulations provide a framework for growers and advisors to:
- Forecast yield
- Manage climate and soil water risk
- Make informed decisions about nitrogen and irrigation applications
- Match inputs with the yield potential of their crop
- Assess the effect of changed sowing dates or varieties
- Assess the possible effects of climate change
How much does it cost?
There are three costs associated with subscribing to Yield Prophet®: a subscription fee, soil sampling expenses and soil analysis charges. The total cost of subscription usually ranges between $300 and $400/paddock (ex GST). A breakdown of these costs is shown below:
- Yield Prophet subscription: $155/paddock (ex GST)
- Soil sampling: Depends on your contractor; approximately $100/paddock (ex GST)
- Soil analysis: Depends on the analysis that your paddock requires and the soil testing laboratory used. For more information on soil analysis costs, please consult the Soil Analysis Guide. Usually between $54.55 and $212.50/paddock (ex GST)
What you get:
- 1 x log-in for grower
- 1 x log-in for grower’s consultant (if requested)
- Help-line access for growers and consultants
- Access to Yield Prophet workshops and training sessions for growers and consultants
How do I sign up?
Information you will need:
- Your contact details (including a working e-mail address)
- Paddock names and locations
- Consultant’s name and e-mail address
- Soil test results for each paddock being used in Yield Prophet (Prices do not include soil sampling and analysis for initial soil conditions). Information on the requirements and costs of initial soil data are available here.
- If you have subscribed to Yield Prophet previously, your Yield Prophet log-in details. If you do not have your login details please contact Tim McClelland.
Click here to subscribe to Yield Prophet®
See it for yourself
You can visit the Yield Prophet website (www.yieldprophet.com.au) to view previously generated reports for the BCG trial site and access help files with more information about operating Yield Prophet and how to interpret reports. Simply respond to Username and Password by typing in ‘Visitor’.
How does it work?
Simulation Inputs
The crop simulations are created by combining the essential components of growing a crop including
- A soil test sampled prior to planting;
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- A soil classification selected from the Yield Prophet
library of 500 soils selected as representative of the
production area - Historical and active climate data taken from the
nearest Bureau of Meteorology (BOM) weather station - Paddock specific rainfall data recorded by the user
(optional) - Individual crop details
- Fertiliser and irrigation applications during the
growing season.
Soil Test Sampling
In late summer and autumn, subscribers sample the soil in their Yield Prophet paddocks down to the maximum rooting depth of their crop at different intervals (eg 0-10, 10-40, 40-70, 70-100cm). These samples are analysed for water content, organic carbon, nitrate and chloride concentration, electrical conductivity and pH. This information is entered into the Yield Prophet web interface and is then used by the grower/consultant and the Yield Prophet team to select a suitable soil classification. Information on the requirements and costs of initial soil data are available here.
Soil Classification
An appropriately measured soil classification is essential for Yield Prophet to accurately simulate crop growth and yield.
The Plant Available Water Capacity (PAWC) and bulk density of a specific soil type are used to determine how much of the measured water and nitrogen is available to the crop for growth during the season. PAWC is determined by a soil’s ‘Drained UpperLlimit’ (DUL, or field capacity) and its ‘Crop Lower Limit’ (CLL, similar to permanent wilting point).
Yield Prophet has a catalogue of soil classifications for many of the major cropping soil types found throughout Australia. More information about the catalogue of soils can be found here. Many subscribers have soil types for which there is no available measured classification data. In these circumstances, a soil classification is estimated based on soil type and previous rainfall and crop yields, and any information available from existing soil surveys. An estimated classification is less likely to produce accurate results in comparison with a measured classification and it is recommended that potential subscribers to Yield Prophet consider characterising their soil if no appropriate data exists.
If you are interested in having your soils characterised or would like more information please feel free to contact Tim McClelland. Alternatively, if you would like to understand more about soil classification process, please click here for a methodology.
Climate Data
Yield Prophet uses the last 100 years of climate data (maximum and minimum temperature, radiation, evaporation and vapour pressure) taken from the subscriber-nominated BOM weather station to simulate crop growth and make predictions about crop yield. The climate information is sourced directly over the web from the SILO Patched Point Dataset (PPD). This is a catalogue of climate information for 4600 weather stations across Australia. If you wish to know more about the SILO PPD please click here.
Rainfall Data
During the season, Yield Prophet subscribers may enter rainfall for each paddock into the web interface. Alternatively, they can opt to utilise the seasonal rainfall data recorded at their nominated BOM station.
Crop Details
Yield Prophet requires subscribers to enter individual crop details into the website for inclusion in the simulations. Specific details required are the type and amount of starting stubble, sowing date, crop type, cultivar and sowing density.
Fertiliser and Irrigation Applications
During the season, subscribers update paddock management details (cultivations and nitrogen fertiliser and irrigation applications) as they occur.
Crop Growth Simulation
When a report is requested, the paddock-specific information is emailed from the Yield Prophet database to a computer cluster where the simulation is processed. Using climate data for the current season, Yield Prophet simulates the soil water and nitrogen processes in the paddock from the soil sampling date together with the crop growth from the user-nominated sowing date, up to the present. Yield Prophet calculates the amount of water and nitrogen available to the crop and the water and nitrogen demands of the crop. This is used to determine whether the crop is suffering stress from lack of either of these resources and any resultant reduction in growth and yield potential.
Using historic climate data, Yield Prophet then simulates crop growth and resource availability from the day on which the report was generated to the end of the season.
This process is repeated 100 times (once for each year of climate data) providing 100 separate yield outcomes (Figure 1). These yields are then plotted as a probability curve (Figure 2), providing growers with an estimate of the probabilities of obtaining a range of yields. This output is then adapted to the requested report type and emailed to the database where it can be viewed by the subscriber. Report generation takes from five to fifteen minutes.

Figure 1 (above): Visual representation of the Yield Prophet simulation process
Figure 2 (below): is the main output of Yield Prophet which is a core component of all the reports generated in Yield Prophet. Figure 2 is showing that this crop has:
- A yield potential of 3t/ha given the best season finish on record with available nitrogen.
- A yield potential of 4t/ha given the best season finish on record with unlimited nitrogen.
- A yield potential of 1t/ha given the worst season finish on record
- A 50% chance of achieving a yield of at least 2.2t/ha with available nitrogen
- A 50% chance of achieving a yield of at least 2.6t/ha with unlimited nitrogen
- An 80% chance of benefitting from the application of nitrogen (i.e. the nitrogen limited curve separates from the nitrogen unlimited curve at the 80% line).

Figure 2 (above): A yield probability curve, the principal output of yield prophet.
Scenario predictions
The likely impact of different sowing dates, varieties and irrigation and nitrogen applications can be determined by simulating different ‘scenarios’. Yield Prophet generates a probability curve for each scenario, and subscribers use this to determine the probability of achieving a yield response from the addition of water or nitrogen (Figure 3 and Figure 4), or from different sowing dates and varieties (Figure 5). Yield Prophet can also calculate a nitrogen gross margin based on the predicted grain quality and price (Figure 6).

Figure 3 (above): Yield probability curves for three different nitrogen top-dressing scenarios generated for a dryland wheat crop. Scenario 1 (pink line) is the yield probability adding no further nitrogen, Scenario 2 (blue line) is the yield probability with 20 kg/ha of nitrogen top-dressed and Scenario 3 is the yield probability with 40 kg/ha of nitrogen top-dressed. There is an 80% chance of achieving a yield response with top-dressing, and about a 30% chance of achieving a 1 t/ha yield response from 40 kg/ha of nitrogen.
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Figure 4 (above): Yield probability curves for three different nitrogen and irrigation scenarios generated for an irrigated wheat crop. Scenario 1 (pink line) is the yield probability adding no further water or nitrogen, Scenario 2 (blue line) is the yield probability with an additional 50 kg/ha of nitrogen top-dressed, Scenario 3 is the yield probability with 50 kg/ha of nitrogen top-dressed and two additional 25 mm irrigations.

Figure 5 (above): Yield probability curves for three different sowing date scenarios (sowing dates are shown above the graph) generated for a wheat crop at Birchip.

Figure 6: Nitrogen profit curves for the same nitrogen application scenarios shown in Figure 3. Each line is calculated as the return from grain (determined by yield and protein minus cost of fertiliser and spreading) for Scenario 1 (solid pink line 0kg/ha of nitrogen) Scenario 2 (solid blue line, 20 kg/ha of nitrogen) and Senario 3 (solid red line, 40 kg/ha of nitrogen). This shows the difference in return between applying nitrogen of specified amounts, and not applying nitrogen. In this case, the cost of fertiliser is assumed to be $2.00 per kg of nitrogen, cost of spreading $10 per ha and the wheat price (AH) $350/t, with a $2.50 per 0.5% protein bonus.
Yield Prophet Services
Yield Prophet is a sophisticated tool with a significant number of applications and services that can support your farm business in the production and marketing of grain.
Paddock Subscriptions
Yield Prophet should be incorporated into every farm as it provides in-crop decisions support and generates information that contributes to producers matching crop inputs with production potential.
By registering a number of paddocks across the farm with different soil types, climatic conditions and crop types, a representative sample of crop conditions should be generated.
Yield Prophet Workshops and Help Line
Individuals and businesses who subscribe to Yield Prophet are entitled to the necessary assistance to ensure easy operation of the web interface and interpretation of Yield Prophet reports.
A help line is available to assist subscribers with any problems or queries that arise in the day-to-day operation or interpretation of Yield Prophet.
Subscribers are also entitled to request a workshop in which a member of the Yield Prophet team will provide training in the operation of the web interface and an introductory session on the interpretation of Yield Prophet reports and outputs.
Yield Prophet Reports
A number of report types are available to users of Yield Prophet to assist with management decisions in and out of the growing season. In season reports are the:
- Crop Report:The Crop Report is the principal report used by Yield Prophet subscribers. It contains twenty separate outputs relating to the individual crop and produces a snap shot in time with:
- a potential yield range for grain and hay production;
- the quantity of available water and nitrogen water resources;
- the incidence of nitrogen and water stress;
- estimated and forecast phenological progress of the crop;
- the probability and incidence of water logging, frost and heat shock; and
- climate forecasts and the effect on yield.
This report is used throughout the growing season as an in-crop decision support tool for decisions related to nitrogen management, irrigation management, hay cutting, frost risk assessment, marketing, insurance etc
To see an example of a Crop Report please click here.
- Nitrogen Comparison Report: The Nitrogen Comparison Report allows subscribers to compare the effects on yield of changes in the quantity or timing of applied nitrogen in different scenarios.
To see an example of a Nitrogen Comparison Report please click here.
- Nitrogen Profit Report: The Nitrogen Profit Report, using basic gross margin inputs, allows subscribers to compare the profitability of the management decisions applied in the Nitrogen Comparison Report.
To see an example of a Nitrogen Profit Report please click here.
- Irrigation Comparison Report:The Irrigation Comparison Report allows subscribers to compare the effects on yield of changes in the quantity or timing of water and nitrogen applied by simulating different scenarios.
- Irrigation Profit Report:The Irrigation Profit Report, using basic gross margin inputs, allows subscribers to compare the profitability of the management decisions applied in the Irrigation Comparison Report.
Out of season reports are:
- Sowing by Variety Report: The Sowing by Variety Report allows subscribers to simulate different scenarios and compare yield probability distributions of crop cultivars or sowing dates. By comparing the effects on yield, growers can assess the impacts on likely crop yield of different sowing dates and cultivars prior to the growing season.
Yield Prophet produces a probability curve for each scenario allowing subscribers to compare the yield effects. This report is generally used by subscribers prior to the growing season as a basis for planting decisions by assessing the impacts of different sowing dates and cultivars on likely crop yield.
To see an example of a Sowing by Variety Report please click here.
- Sowing Opportunity Report:The Sowing Opportunity Reportallowing subscribers to generate reports that show the effect of sowing date on potential yield, and frost and heat shock risk which is relative to their specific paddock, climatic conditions and chosen variety. The report shows the 100 year average nitrogen unlimited yields for crops planted from the 1stof April to the 30thof June and associated frost and heat shock probabilities.
To see an example of a Sowing Opportunity Report please click here.
- Fallow Monitoring Report:The Fallow Monitoring Report allows subscribers to determine the soil moisture and nitrogen levels at the time of the report. This report is generally used after crops have been harvested and feeds into the Stubble Management Report.
To see an example of a Fallow Monitoring Report please click here.
- Stubble Management Report: The Stubble Management Report allows subscribers to compare the effect of different tillage and grazing decisions on soil nitrogen and moisture content. This report is usually used out of the growing season, between harvest and sowing, as a basis for tillage and grazing decisions.
To see an example of a Stubble Management Report please click here.
- Climate Change Report: The Climate Change Report allows subscribers to observe the potential effects of climate change on crop yields in the year 2030. Yield Prophet produces a yield probability curve for historic climatic conditions and two climate change scenarios developed by the CSIRO for comparison.
To see an example of a Climate Change Report please click here.
- Climate Adaptation Report: The Climate Adaptation report allows subscribers to compare their crop potential using their current practice versus an adapted practice under two different climate change scenarios, ‘best case’, and ‘worst case’. Subscribers are able to review the yield potential with their current practice under these two scenarios and then “experiment” with alternative crop cultivars, plant densities, sowing window, nitrogen and irrigation applications, and stubble and tillage management to adjust to the potential changes in climate. This report allows users to form and test strategies to respond to climate change before the effects are fully realised.
To see an example of a Climate Adaptation Report please click here.
For further information...
Please contact:
Tim McClelland
Yield Prophet Coordinator
p: 03 54 922 787
f: 03 54 922 753
m: 0400 090 659
e: yieldprophet@bcg.org.au

