General
Name
CCC
Program type
Excel / VBA
Available since
Description
The Cropping Calendar Construction (CCC) model was developed to investigate if it is possible to fit 2 or 3 crops (all the same species) in one year, possibly with a part of the year blocked for growing a crop of another species. The model generates a rerun file which is input for a standalone single crop models (e.g. LINTUL, SUCROS, WOFOST, ORYZA2000). Simulations results of this model are pasted back into the Excel file, then the macro constructs all possible crop rotations (possible in terms of phenology), ranks these from highest to lowest total yield and quantifies "flexibility", i.e. is the crop rotation still possible of delay in sowing occurs, how much delay is possible?
This model is designed for a specific application domain, namely cropping systems with limited carry-over effects and with one main crop. In rainfed systems, water uptake by one crop has a big impact on soil moisture available to the next crop. In such systems, models such as APSIM are better suited. Some crops are more vulnerable to build up of pests and diseases when grown continuously. Such cropping systems are better simulated with models such as PermVeg.
The CCC model was originally developed to test if potato double cropping would be possible in the Netherlands, now and with climate change (combi of CCC model and WOFOST). This was a crazy idea. Later a more realistic application was developed for irrigated rice in the Senegal River Valley (combi of CCC model and adapted versions of ORYZA2000)
Specifications
Scale of application
field
Spatial resolution
field
Key outputs
single crop options ranked by simulated potential yield
double crop rotation options ranked by simulated potential yield
triple crop rotation options ranked by simulated potential yield
comparison between single/double/triple cropping systems
flexibility quantified: how much room for manoeuvre, for delay in operations
option to block part of the year for other crop, without simulating the other crop
Time horizon
year
Time step of modeling
day
Software requirements
Required to run
A sheet called "Instructions" is included in the Excel file. Four cases are distinguished with increasing technical difficulty:
1. Same site, same model -> you only want to construct calendars -> this is easy, only need the Excel file
2. New site, same model -> edit the macros in the Excel file (specify new site as parameter), reconfigure crop model input, run the .exe, paste result back into Excel, run macros to generate and compare all crop rotations
3. Climate change, same model -> edit the macros in the Excel file (specify CO2 & temp), reconfigure crop model input, run the .exe, paste result back into Excel, run macros to generate and compare all crop rotations
4. new crop = new model -> edit the macros in the Excel file (specify CO2 & temp), reconfigure crop model input, run the .exe, paste result back into Excel, run macros to generate and compare all crop rotations. This is technically the most difficult case, but not impossible
Required to develop
no particular software needed, but standalone crop growth model for the crop of interest is needed
Database I/O
N/A
Examples
Applications & Use
Investigate options for intensification (increase production per unit of land). The following options can be simulated:
1. Increasing the cropping intensity: 1, 2 or 3 crops grown per year. Focus is on one particular crop (example rice), optionally a part of the year can be blocked (e.g. for a vegetable crop)
2. Sowing date optimisation to avoid growing the crop(s) in parts of the year with less favourable climate
3. Short / medium / long duration varieties
4. Varieties better more tolerant to particular climate, for example rice varieties more tolerant to heat or cold sterility
Contact
Address
Wageningen
Email
p.vanoort@cgiar.org; pepijn.vanoort@wur.nl