CropARM (Crop Agricultural Risk Management) is a computer program that simulates the effects of your resources (e.g. soil and water) and farm management inputs (e.g. crop type and fertiliser) on yield by using crop modelling and climate forecasting capabilities.

Read about our selection process for including tools on Climate Kelpie


Who this tool is for

Growers and advisors involved in producing:

  • wheat, chickpea, sorghum, mungbean, cotton and sunflower in northern Australia
  • wheat and canola in southern and western Australia

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Questions this tool answers

At farm-scale to locality/shire scale:
•how much nitrogen do my cereal crops need and what yields am I likely to get this season?
•given farm inputs and forecasts based on the Southern Oscillation Index [link to Queensland – weather and climate drivers page], what yields and gross margins am I likely to get this season?

What range of crop yields could I achieve this season based on:

  • how much water my soils can hold?
  • how much moisture is stored in my soils?
  • how much nitrogen is already in my soils?
  • how much nitrogen fertiliser I add to the crop?
  • how densely I sowed the crop?
  • how I configured the crop rows?
  • how the Southern Oscillation Index is looking?

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What this tool does

CropARM is a computer program designed to let you explore the range of potential yields for the coming season with different choices for crop management options, based on rainfall records for the past 100 years.

You can compare the effects, and therefore the risk, of many different crop management combinations and inputs on the range of potential yields.

CropARM gives you graphs that show the difference in yield potential for each management choice, including crop physiology outcomes such as time of flowering.

The program uses APSIM and 100 years of historical climate records.

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You can enter:

  • crop type
  • maturity length
  • sowing density
  • soil water-holding capacity
  • stored soil water at sowing
  • sowing date
  • soil nitrogen content
  • nitrogen fertility rate
  • Southern Oscillation Index phase

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CropARM calculates 50 different outputs, including:

  • yield
  • biomass at flowering and harvest
  • water-use efficiency
  • range of potential rainfall received from planting to critical crop stages such as flowering
  • days to flowering
  • days to boll initiation
  • days to squares initiation
  • leaf area index
  • effect of temperatures at critical stages; for example: number of days of temperatures that may cause frost damage, or average minimum/maximum temperatures during critical crop stages

You can choose to see the results as graphs over time or different types of probability graphs.

Figures 1 and 2 are examples.

Figure 1. Annual variability of grain yields



Figure 2. What is the potential yield response to nitrogen fertiliser? Note the excellent response to applied N to 50kgN/ha, then no response.

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CropARM is restricted to a number of crops, and uses standard varieties.

It works best at the locality/district scale; local town weather data is used.

Accuracy will diminish as our climate changes, because the outputs are based on historical climate data.

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CropARM was formerly called WhopperCropper. CropARM was developed by the APSIM (formerly the Agricultural Production Systems Research Unit) and has drawn on the skills of many research and extension officers.

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Support available

Support is provided by Howard Cox, Department of Agriculture, Fisheries and Forestry (Queensland).


Phone: 07 4688 1381 or 0418 708 278

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Where to get it

You can use CropARM online. There is no download.

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            [pathwaypage] => 1
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            [topic] => Explore potential yield of different management options
            [cost] => Free
            [summary_commodity] => Grains, cotton
            [summary_region] => All
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JRegistry Object ( [data:protected] => stdClass Object ( [pathwaypage] => 1 [pathwaytype] => 1 [scale] => [topic] => Explore potential yield of different management options [member] => [cost] => Free [summary_commodity] => Grains, cotton [summary_region] => All [tabledisplayscale] => 0 [tabledisplaycost] => 0 [tabledisplaytopic] => 0 [tabledisplaymember] => 0 [tablesubpagetitle] => Page ) )

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