How to solve not enough growing degree days in simulation to reach maturity？

[Rachael001l]

I have the following problem with rate crop parameters.

AssertionError: not enough growing degree days in simulation (1559.7499999999998) to reach maturity (1700.0)

Does anybody know that I should adjust which parameters?

[tfoster88]

Hi @Rachael001l . This error occurs when there are insufficient gdds between planting and harvest to reach maturity. You have a few options to deal with this depending on your simulation location and crop:
(1) lengthen the potential season by bringing forward planting date or shifting latest harvest date to later in the year
(2) adjust the crop phenology to better match growing season of your location. You will need to do this for all growth stages not just maturity so the split of growth stages remains realistic.
(3) switch to running in calendar day mode - in this case crop development is not a function of temperature and so will reach maturity even if you don't have sufficient gdds

[Rachael001l]

Thank you very much for your reply. I will continue to try to modify what you mentioned for the simulation. I would like to know the difference between Maize, MaizeGDD, and MaizeChampionGDD and Wheat, WheatGDD, and WheatLongGDD. And which one to choose for my simulation.
Can you help with this, please?

[tfoster88]

@Rachael001l Wheat vs WheatGDD (or equivalents for other crops) are the files set up to run in either calendar days or growing degree days modes. The other two files you mention are customised crop files used in some of the testing we did of the code. Should you wish to further customise some of the crop parameters, there are instructions on how to do this in the Notebook 1 (Appendix C section)

[Rachael001l]

@tfoster88 I see, thanks a lot for your reply. I'm working on the crop parameter rates for the model, and I've looked very carefully at note 1, I'd like to know what some of the crop parameters mean exactly so I can correspond better. For example, in note 1, it is mentioned that SenescenceCD is the number of days from sowing to senescence, which period does senescence refer to? HIstartCD?MaxRootingCD? Do you have any recommendations for papers or manuals where I can find out exactly what they mean? Or do you have a recommendation for a paper or manual that explains the principles of the model more understandably? I am very confused. Thank you very much for your help!