Simulating agricultural production with APSIM

  • 29 January 2012 | Updated 16 January 2012

Publishing History

Page 3 of 3

What is APSIM?

APSIM (the Agricultural Production Systems Simulator) is a farming systems computer model that simulates the effects of environmental variables and management decisions on production (crops, pasture, trees, livestock), profits and the environmental variables (e.g. soil erosion).

It can be used to analyse risk and explore alternative management options such as crop choice, planting date and fertiliser rate, using local climate data and paddock-specific soil data. When used interactively with farmers, it can also take into account the social and/or economic values or goals that influence an individual farmer's management decisions.

An important feature of APSIM is its ability to integrate sub-models from different research domains or even different disciplines. This allows research from one domain or discipline to benefit another domain or discipline. It also allows researchers to compare sub-models on a common platform

In Australia, APSIM is used by researchers and advisers in government agencies and universities

In Australia, APSIM is used by researchers and advisers in government agencies and universities. Although not designed for use by farmers, it is the engine that drives many decision-making tools that farmers use, such as Yield Prophet®.

For a given production scenario, APSIM can estimate profitability, economic risk, yield, animal production and effects on the environment.

Given characteristics of the plant species and varieties, livestock species, breeds and age classes, soil water and fertility and management, it can simulate, day by day:

  • plant growth (crops, pasture, trees, weeds)
  • animal liveweight gain, reproduction,wool production
  • soil processes (water balance, solutes, nitrogen, phosphorus, carbon, pH)
  • surface residue dynamics (e.g. rate of stubble decomposition) and erosion
  • dryland or irrigated systems
  • a range of management options (e.g. different sowing dates)
  • crop rotations, fallowing and combinations of these
  • pests and diseases
  • short- or long-term effects.

APSIM's modules

APSIM's plant, stock, environment and management modules support a diverse range of crops, pastures and trees, soil processes, nitrogen and phosphorus transformations, soil pH, erosion and a full range of management controls.

The plant/animal and environment modules simulate biological and physical processes in farming systems. APSIM supports more than 30 crops (such as wheat, sorghum, sugarcane, barley, grapevine, oats, cotton and rice), pastures (such as Rhodes grass), stock (cattle and sheep), tree species (such as Eucalyptus and Pinus radiata), weeds, parasites and rodents.

Environment modules handle variables such as climate and weather, soil characteristics (e.g. water balance, nutrients, pH, temperature), crop residue, and erosion. 

Management modules allow management rules for a given scenario to be specified, including variables related to sowing, harvesting, fallowing, tillage, irrigation, fertiliser use, grazing management, stocking rate, and crop mix.

How is APSIM used?

APSIM can be applied in multiple domains such as:

  • climate variability and change – to evaluate management options
  • agronomic practice – to support decision making for improved production and environmental benefits
  • assessing land-use options – to quantify the trade-offs of alternative systems (eg. carbon farming)
  • gene-to-phenotype modelling and breeding – to support crop breeding efforts.

It has been used in Australia and around the world in a broad range of applications, including:

  • supporting on-farm decision making
  • designing farming systems for production or resource-management objectives
  • assessing the value of seasonal climate forecasting
  • analysing supply-chain issues in agribusiness
  • developing waste-management guidelines
  • assessing risk for government policymaking
  • guiding research and education
  • guiding crop breeding strategies.