Summary of the Article on Crop Phenology in CLM5-BGC-Crop:

Phenology in CLM5-BGC

- CLM5-BGC includes phenology algorithms for evergreen, seasonally deciduous, and stress deciduous vegetation.
- CLM5-BGC-crop uses the AgroIBIS crop phenology algorithm, which consists of three distinct phases.

Planting
- Crops must meet temperature and growing degree-day (GDD) requirements between the minimum and maximum planting dates.
- At planting, each crop seed pool is assigned 3 gC/m^2 from its grain product pool, which is transferred to the leaves upon emergence.
- The model updates the average GDD necessary for the crop to reach vegetative and physiological maturity (GDD_mat) based on AgroIBIS rules.

Leaf Emergence
- Leaves may emerge when the GDD of soil temperature to 0.05 m depth reaches 1-5% of GDD_mat.
- Leaf onset occurs at the start of phase 2, and leaf area index generally increases throughout this phase.

Grain Fill
- Phase 3 (grain fill) begins when the GDD of 2-m air temperature reaches 40-65% of GDD_mat, or when the maximum leaf area index is reached.
- In phase 3, the leaf area index begins to decline due to a background litterfall rate.

Harvest
- Harvest occurs when the GDD of 2-m air temperature reaches 100% of GDD_mat or the number of days past planting reaches a crop-specific maximum.

The article includes a detailed table of crop-specific phenology and morphology parameters used in the model.