Nitrogen Fertiliser Calculator
The Nitrogen Fertiliser Calculator determines the optimum nitrogen fertiliser application for cereal crops, for a range of potential yield outcomes.
- Who this tool is for
- Questions this tool answers
- What this tool does
- Inputs
- Outputs
- Reliability
- History
- Support available
- Where to get it
- Cost
Read about our selection process for including tools on Climate Kelpie
Who this tool is for
Wheat and sorghum farmers in Queensland and selected sites in northern New South Wales.
Questions this tool answers
What is the likely wheat or sorghum yield response to nitrogen, for a given starting soil moisture and regional rainfall projections?
What this tool does
The Nitrogen Fertiliser Calculator is part of the ‘Smart N Decisions’ package for central and southern Queensland, which also includes a best-practice reference manual (The Nitrogen Book) and a user guide.
The calculator determines the optimum nitrogen fertiliser application rate based on the difference of the demand and supply of nitrogen for cereal crops:
- Demand is calculated from desired crop yields using WhopperCropper.
- Supply is calculated from soil test analysis results or entered directly into the calculator.
- Yield is calculated for four season types.
- Nitrogen fertiliser rate can be adjusted to compare the effects on gross margin.
Inputs
You enter the following data into the Nitrogen Fertiliser Calculator:
- soil nitrogen test results
- expected planting time
- stored soil water
- expected season type (e.g. poor, average)
The calculator uses WhopperCropper to calculate nitrogen budgets.
Outputs
The Nitrogen Fertiliser Calculator estimates:
- nitrogen mineralisation from soil sampling to planting
- crop demand for nitrogen
- soil supply of nitrogen
- nitrogen fertiliser rate required
The calculator also estimates the losses you will incur if the season turns out differently than expected.
The inputs and results are displayed on a single screen. Figure 1 is an example.
Reliability
The Nitrogen Fertiliser Calculator can be used for a limited range of commodities, and is applicable more at regional than paddock scale.
Because it is based on existing climate data, as our climate changes the tool is likely to become less reliable
History
The Nitrogen Fertiliser Calculator was developed by Howard Cox with programming by Alastair Doherty from Queensland Primary Industries and Fisheries.
The Nitrogen Book was compiled by Howard Cox and Wayne Strong from Queensland Primary Industries and Fisheries in association with the Central Queensland Sustainable Farming Systems Project and South Queensland Farming Systems Project. The Grains Research and Development Corporation assisted with funding of these projects.
Support available
Support is provided by Howard Cox, Queensland Primary Industries and Fisheries.
Email: howard.cox@dpi.qld.gov.au
Phone: 07 4688 1381 or 0418 708 278
Where to get it
Queensland Primary Industries and Fisheries - Business Information Centre
Phone: 13 25 23
Cost
Free