NitrogenARM (Nitrogen Agricultural Risk Management) helps calculate the optimum nitrogen fertiliser application for cereal crops, for a range of potential yield outcomes and season types.
- Who this tool is for
- Questions this tool answers
- What this tool does
- Support available
- Where to get it
Read about our selection process for including tools on Climate Kelpie
Wheat and sorghum producers and advisors at selected sites in Queensland and northern New South Wales.
What is the required rate of nitrogen fertiliser for maximum gross margin, for given stored soil moisture and nitrogen level, grain prices, total variable costs and potential rainfall projections?
NitrogenARM 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 required nitrogen fertiliser application rate based on the difference between the demand and supply of nitrogen for wheat and sorghum crops:
- Demand is calculated from desired crop yields using CropARM (formerly known as WhopperCropper).
- Supply is calculated from soil test analysis results, then entered directly into the calculator.
- Yield response to total available nitrogen is calculated for four season types.
- Maximum gross margin can be achieved by varying the total nitrogen supply.
- Nitrogen fertiliser rate required for maximum gross margin is shown.
You enter the following data into NitrogenARM:
- agronomic setup (crop maturity, planting date and density, row configuration)
- stored soil water
- soil nitrogen test results
- expected planting time
- expected season type (e.g. poor, average)
The calculator uses data from CropARM (formerly known as WhopperCropper) to calculate the yield response.
NitrogenARM estimates, for 4 season types:
- nitrogen fertiliser rate required to maximise the gross margin
- gross margin
- difference in gross margin for 2 different nitrogen levels (including applied nitrogen fertiliser)
- nitrogen mineralisation from soil sampling to planting
- grain yield response to nitrogen supply
- crop demand for nitrogen
- soil supply of nitrogen
The inputs and results are displayed on a single screen. The results are shown as both graphs and tables. Figure 1 is an example.
NitrogenARM can be used for wheat and sorghum. It uses weather data from regional sites; you cannot enter your own on-farm rainfall data, so it is more applicable at the regional, than paddock, scale.
Because it is based on existing climate data, as our climate changes the tool is likely to become less reliable.
NitrogenARM was formally called the Nitrogen Fertiliser Calculator.
It was part of the ‘Smart N Decisions’ package for central and southern Queensland. The package included a best-practice reference manual (The Nitrogen Book), a user guide and the calculator.
NitrogenARM was developed by Howard Cox and Alastair Doherty from Department of Agriculture, Fisheries and Forestry (Queensland).
The Nitrogen Book was compiled by Howard Cox and Wayne Strong from the Department of Agriculture, Fisheries and Forestry (Queensland) 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 these projects.
Support is provided by Howard Cox, Department of Agriculture, Fisheries and Forestry (Queensland).
Phone: 07 4688 1381 or 0418 708 278
You can use NitrogenARM online. There is no download.
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