FertiliserType

The FertiliserType model defines the composition of a specific fertiliser product. It specifies the types and proportions of up to six solutes that are released when fertiliser is applied, allowing users to simulate the nutrient dynamics of complex fertiliser formulations.

Overview

FertiliserType is a submodel of the Fertiliser model. It provides a detailed configuration of the fertiliser’s composition by defining up to six solutes, each with a specified name and mass fraction. Additionally, it includes a threshold fraction to determine when the remainder of the fertiliser is released. This model allows researchers and users to represent a wide variety of fertiliser types used in agricultural systems and tailor nutrient release behavior to specific scenarios. Pre-defined fertiliser types are stored in a resource file named Fertiliser.json.

Model Structure

This section describes how this model is positioned within the APSIM framework. It outlines the broader structural and computational components that define its role and interactions in the simulation system.

This model inherits structural and functional behaviour from the following core APSIM components:

Connections to Other Components

This section describes how the model interacts with other components in the APSIM Next Generation framework.
These connections allow the model to exchange information—such as environmental conditions, developmental stage, or physiological responses—with other parts of the simulation system. For a general overview of how model components are connected in APSIM, see the Connections Overview.

Component Model Connection Type Description
Fertiliser Fertiliser Parent Parent model that manages fertiliser applications using this type.

Model Variables

This section lists the key variables that describe or control the behaviour of this component. Some variables can be adjusted by the user to modify how the model behaves (configurable), while others are calculated internally and can be viewed as model outputs (reportable). For a general explanation of variable types and how they are used within the APSIM Next Generation framework, see the Model Variables Overview.

Configurable and Reportable Properties

Property Type Description
Description string A description of the fertiliser type
FractionWhenRemainderReleased double Threshold for full fertiliser release (default: 0.995)
Solute1Name string Name of the first solute component
Solute1Fraction double Fraction of the fertiliser that is solute 1
Solute2Name string Name of the second solute component
Solute2Fraction double Fraction of the fertiliser that is solute 2
Solute3Name string Name of the third solute component
Solute3Fraction double Fraction of the fertiliser that is solute 3
Solute4Name string Name of the fourth solute component
Solute4Fraction double Fraction of the fertiliser that is solute 4
Solute5Name string Name of the fifth solute component
Solute5Fraction double Fraction of the fertiliser that is solute 5
Solute6Name string Name of the sixth solute component
Solute6Fraction double Fraction of the fertiliser that is solute 6

Read-Only Reportable Properties

No read-only properties are available for this function.

Processes and Algorithms

FertiliserType acts as a container for the fertiliser composition. When a fertiliser is applied in a simulation, the associated solutes are released into the soil according to the specified fractions. The FractionWhenRemainderReleased controls when the final residual portion of fertiliser is applied, which is useful for simulating slow-release or staged-release fertilisers.

Each solute is released in proportion to its defined fraction. Solute names must match those defined in the soil or nutrient models of the simulation. The sum of all solute fractions does not need to equal 1.0, as fertiliser products may contain inert materials.

Pre-defined Fertiliser Types

APSIM NG includes a comprehensive library of commonly used fertiliser types. Below is a summary of fertiliser types pre-defined in the system:

Name Description Release Solute1Name Solute1Fraction Solute2Name Solute2Fraction Solute3Name Solute3Fraction
CalciteCA Ca as finely ground Agricultural Lime 1 Ca 1.00
CalciteFine finely ground Agricultural Lime 1 Ca 0.40
Dolomite finely ground dolomite 1 Ca 0.22
NO3N N as nitrate 1 NO3 1.00
NH4N N as ammonium 1 NH4 1.00
NH4NO3N ammonium nitrate 1 NO3 0.50 NH4 0.50
DAP di-ammonium phosphate 1 NH4 0.18
MAP mono-ammonium phosphate 1 NH4 0.11
UAN_N N as Urea-AmmoniumNitrate 1 NO3 0.25 NH4 0.25 Urea 0.5
UreaN N as urea 1 Urea 1.00
UreaNO3 N as urea 1 NO3 0.50 Urea 0.50
UreaGranular Urea fertiliser 1 Urea 0.46
NH4SO4N ammonium sulphate 1 NH4 1.00
RockP Rock phosphorus 1 RockP 0.80 LabileP 0.20
BandedP Banded phosphorus 1 BandedP 1.00
BroadcastP Broadcast phosphorus 1 LabileP 1.00

User Interface

FertiliserType can be added as a child of a Fertiliser node in the model tree. Right-click the parent Fertiliser node, select “Add Model…”, and search for FertiliserType in the Filter Box.

Practical Example

No practical example is available for this function.

See Also