...
For each crop, the user configures a planting decision trigger. The planting decision trigger includes a decision type, plant date, optional harvest date, planted area definition and an under irrigation underirrigation factor.
The decision type defines the method for calculating the planted area for a crop. The planted area can be specified using one of three methods:
...
where:
UFactor is user specified under irrigation underirrigation factor
TargetDepletionRegulated is target soil water depletion (mm)
...
The planting decision reassessment trigger allows the user to reassess the planted area of a crop. The user can configure as many reassessment triggers per crop as desired. Each reassessment trigger includes a decision type, reassessment date, an under irrigation underirrigation factor and an area relationship.
...
If the calculated planted area has reduced, then the crop area will be reduce to the new calculate value. The difference in planted area is returned to fallow. The planted area cannot increase through a reassessment trigger. If the under irrigation underirrigation factor is specified, then a new target depletion is evaluated for the remainder of the crop period.
...
| Parameter | Description | Unit | Default | Typical Range | |
|---|---|---|---|---|---|
| 1 | Decision Type | Allows user to select different methods for specifying the crop area on the planting date. Either a fixed area (which supports functions and data sources) or a lookup table that relates available water on the planting date to the planted area. | Fixed Area | ||
| 2 | Plant Date | Date that the planting decision is made and the crop is planted | Calendar date | 31 May | 1/1-31/12 |
| 3 | Harvest Date | Date crop is harvested. By default this is disabled | Calendar date | n/a | 1/1-31/12 |
| 4 | Under Irrigation Underirrigation Factor | Reduces irrigation application by adjusting changing the target depletion level. When it is zero it is inactive and when it is >0 it replaces the Target Soil Depletion. | % | 0 | 0-50 |
| 5 | Area relationship | Defines the crop area as a function of either available water using a lookup table or from a function or data source | ML vs ha | Fixed area | 3-14 ML/ha |
...