1. The Suite CropSyst to Simulate Cropping Systems
Marcello Donatelli
CRA-ISCI, Italy
Claudio Stockle
BSE-WSU, USA

2. CropSyst course program
Introduction to the CropSyst suite, model evaluation
Calibration and evaluation
Crop growth
Water balance
Nitrogen balance
GIS application
Building a simulation
Optimizing water use
Nitrogen balance
Rotations

3. The Team
Claudio Stockle, BSE-WSU, USA - Main Developer and Team Leader
Roger Nelson, BSE-WSU, USA - Main Programmer (C++)
Armen Kemanian, TAES-Blackland Research Center – Development and Applications
Marcello Donatelli CRA-ISCI, Italy – Components development (C#, .NET)
Luca Bechini, DPVT-UNIMI, Italy – Applications, (VBA-Access)
Collaborators
M. Rivington, G. Campbell, F. Ferrer, F. Van Evert,, Y. Yang, P. Debecke, L. Carlini, … … …

4. CropSyst Description
Multiyear, multicrop, daily time-step crop simulation model
Technically sound, packaged in a user-friendly interface
Available for Windows and Linux
Accessible via Internet:
manuals,programs, documentation
listserver
related programs

5. Input-output fluxes in CropSyst
Evapotranspiration
Volatilization
Rainfall
Management
irrigation
tillage
fertilization
pesticides
herbicides
harvest
CROP
Runoff
Soil loss
SOIL
Percolation
Leaching
Water rise

6. CropSyst includes the simulation of:
Crop development and growth
Simulation of growth under increased atmospheric CO2 concentration
Water and nitrogen balance
Salinity
Residue fate
Soil erosion by water
Soil organic carbon changes
Greenhouse gas emissions (CO2 and N2O)

7. Crop processes in CropSyst
development
growth
ligth interception
net photosynthesis
biomass partitioning
leaf expansion
roots deepening
leaf senescence
water uptake
nitrogen uptake
water stress
nitrogen stress
light stress

8. Soil processes in CropSyst
residues fate
SOC
nitrogen transformations
water erosion
ammonia volatilization
ammonium sorption
water infiltration
water redistribution
runoff
evaporation
percolation
solutes transport
salinization
nitrogen fixation

9. CropSyst Development
CropSyst has been developed as a management-oriented tool, not as a basic research tool
Intended use is applied research:
scenario analysis of productivity and environmental impact of cropping systems and their management
climate change impact on cropping systems and alleviation management strategies

10. Parameters Required
CropSyst simulates many processes governing the relationships between weather, crop, soil and management.
A number of parameters are required to characterize the site, the crops, the soil, and the management applied.
However, for most of the parameters, there are tables in the documentation with values usable in different conditions.

11. Inputs required
Meteorological data: daily air Tmax, Tmin, Rainfall, SolarRad*, Wind*
Soil parameters, by horizon down to 1.5 m: Texture, Organic Carbon, SWCFC*, SWCPWP*, BulkDensity*
Crop: species, duration of the biological cycle*, efficiency parameters
Management: data of application, amount
* Can be estimated

12. CropSyst Management Options
Irrigation with fresh and saline water
Inorganic nitrogen fertilization
Organic nitrogen fertilization
Tillage
Crop operations: sowing, harvest, forage cuts etc.
Automatic irrigation can be activated reproducing farmer’s choices
Automatic clipping of forages is also available

13. Model Evaluation
Model calibration and evaluation has been performed for a number of sites, greatly varying for thermal and hydrological regimes.
Most of the evaluation performed has regarded the water and the nitrogen balance, and crop growth.

14. CropSyst evaluation
In general terms, the test of a cropping system model performance should be seen as an evaluation, rather than a validation.
A calibration will be performed using information provided by partners working in the area.
It is crucial to have data collected on crops grown in nearly optimal conditions
We aim at being able to capture the main components of the year by year variation, while quantifying input-otputs for different systems.

15. Programs in the CropSyst Suite
ClimGen, a weather generator which allows generating air temperature, rainfall, solar radiation, and vapour pressure deficit.
The ARCCS Cooperator allows interfacing CropSyst input-outputs to geo-referenced dataset.
Related programs and libraries
RadEst, a software to estimate solar radiation
SOILPAR, a software to estimate soil hydrological parameters
IRENE, a software to analyze CS outputs

16. The CropSyst Suite: ClimGen
ClimGen offers an array of methods that use the available weather data for extracting generation parameters.
ClimGen is able to generate approximately correct weather files based solely on monthly parameters.
ClimGen can be used anywhere in the world.

17. The CropSyst Suite: The ARCCS Cooperator
ARCCS is an interface program that constructs CropSyst simulation files that are associated to polygons in a combination map.
ARCCS controls unattended long-term simulations for a given combination map
ARCCS prepares GIS-compatible tables that are used to display user-selected simulation outputs into maps.

18. “Companion” programs
RadEst allows estimating global solar radiation at ground level from site and air temperature data
SOILPAR contains a library of pedotransfer functions to estimate soil hydraulic parameters from commonly available soil data
IRENE contains a library of methods to compare estimates vs. measured data, including pattern indices and integrated indices using fuzzy logic

19. International Cooperation
We are convinced that great progress for both model development and applications can be obtained by working together in specific projects.
We are available and willing to assist users in calibrating and testing the model in different environments. We are also open to cooperation to further develop both the simulation model and the user interface.