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Crop Parameters Overview

MONICA distinguishes between species-level and cultivar-level crop parameters. These parameters are linked in the simulation setup through the crop.json file.

Example: crop.json

The crop.json file specifies which parameter files are used for each crop in a simulation.

"WW": {
  "cropParams": {
    "species": ["include-from-file", "../monica-parameters/crops/wheat.json"],
    "cultivar": ["include-from-file", "../monica-parameters/crops/wheat/winter-wheat.json"]
  },
  "residueParams": ["include-from-file", "../monica-parameters/crop-residues/wheat.json"]
}

In this example:

  • "WW" is the crop code for winter wheat.
  • "species points to the species-level parameter file.
  • "cultivar points to the cultivar-level parameter file.
  • "residueParams points to the crop residue parameter file.

During simulation, MONICA merges the parameters from the species and cultivar JSON files to form the complete crop definition.

How MONICA uses these parameters

When a workstep in the crop rotation references a crop, for example:

{ "date": "1991-09-22", "type": "Sowing", "crop": ["ref", "crops", "WW"] }

MONICA performs the following steps:

  1. Loads the species-level parameters from wheat.json
  2. Loads the cultivar-level parameters from winter-wheat.json
  3. Merges them to form the complete winter wheat parameter set
  4. Applies residue parameters after harvest as defined in crop-residues/wheat.json

Available crop parameter files

The current list of available species and cultivar parameter files can be found in the MONICA parameters repository.

The crop parameters are organized in two levels within the crops directory.

  • Species-level files are the JSON files directly inside the crops directory (e.g., crops/wheat.json)
  • Cultivar-level files are located inside subfolders named after the crop species (e.g., crops/wheat/winter-wheat.json)