The Management module processes user inputs describing crop management. This includes plantings, irrigations, fertilizer applications, tillage events, addition of organic material (residues or manure) and harvests. The module thus is key in processing information associated with what are considered “treatments” in field experiments. The module includes provisions for rule-based automatic management such as to control planting dates when a given date and soil temperature threshold are attained.
There are currently seven types of field operations that are modeled in CSM.
- Planting Event
- Irrigation application
- Fertilizer application
- Tillage event
- Organic matter application
- Chemical application
- Harvest event
Planting can be based on either field records or on a set of rules for triggering automatic planting.
Field records include information such as date, plant density at sowing and emergence, planting method, row spacing, planting depth, and the weight of material planted. Transplanting material requires additional information about the transplant weight and nursery environment.
Automatic planting allows a planting window to be specified. When soil moisture and temperature conditions are within the specified ranges, and within the specified planting window, a planting event is triggered using the details specified in the field records section of FileX.
Irrigation can be based on either field records or on a set of rules for triggering automatic irrigation.
- Field records
- Automatic irrigation
For more details on specifying irrigation in DSSAT-CSM, see here.
Fertilizer applications are specified as field records either by “year + day of year” format or as days after planting. Fertilizer materials are specified as a code, which triggers a lookup of fertilizer properties from a table.
See here for information about tillage in DSSAT-CSM.
Organic matter application
Organic matter applications are specified based on field records in either “year + day of year” format or as days after planting. Residue material codes are listed in the Details.CDE file in the DSSAT root directory. Physical and chemical properties of these various materials are listed in RESCH***.SDA in the StandardData folder, where the “***” refers to the DSSAT major release version number, e.g., “047” for DSSAT v4.7.
DSSAT-CSM accommodates chemical applications, including date of application, type of chemical, application method, and amount applied. Currently the model only responds to application of ethylene or ethephon (growth regulators) to force flowering in the pineapple model. All other chemical application information listed in an experiment file is considered to be documentation of the field experiment only and will not have an effect on the model processes. Codes for chemical applications are listed in the Details.CDE file in the DSSAT root directory.
Harvest events for annual crops can be specified on a particular date or days after planting based on field records. Automatic harvesting can be specified when the crop reaches simulated maturity date.
The perennial forage model allows “mow” events to be specified in an external file, allowing multiple harvests in a simulation.