Environmental Engineering Reference
In-Depth Information
and, for some crops, reproductive phenological stages, at a rate that depends on
physiological time, expressed as a temperature sum. The timing of readiness for
harvest is also simulated. Potential crop growth is defined by temperature, radiation
and crop phenology. The crop growth and development model simulates both
potential growth and attainable growth, which is limited by water and nitrogen
availability. The crop component uses a generic crop simulator in which parameters
and modelling approaches can differ according to the crop simulated.
The crop component has been based on the concept of light interception and
utilization from the Lintul model. However, modifications and additions have
been introduced to extend the list of crop types for which the model can be used.
These changes include the implementation of alternative modelling approaches
for each of the main crop physiological processes, such as:
-
Leaf area expansion
-
Biomass accumulation (Monteith
1977)
Biomass partitioning (van Keulen and Seligman
-
1987)
-
Phenology (van Keulen and Seligman
1987
; Streck et al.
2003
; Hearn
1994)
-
Senescence
-
N dynamics (Shibu et al.,
2009)
The model set-up allows new approaches for modelling these processes to be
included easily. Parameter sets for 19 crops are currently available, including cereals,
legumes, roots and tuber crops, and comprising determinate and indeterminate, and
winter and spring crop types. The crop list can be extended not only by adding new
crops but also varieties suitable for a particular environment, by editing existing
parameter sets of the relevant crop type. In SEAMLESS-IF, these parameters are
fine-tuned for regional applications by defining two correction factors that adjust
crop cycle duration and crop radiation use efficiency.
CropML: Crop Development and Growth
The CropML (Crop Model Library) was developed by JRC, CRA, and UNIMI.
The component implements alternative modelling solutions from those in the Crop
component using different generic and crop-specific crop models. The architecture
adopted allows easy extension of the component through the incorporation of other
models. In fact, the fine granularity used for coding the different processes related
to crop growth and development allow the re-use of the same strategies for other
modelling approaches where common algorithms are present.
CropML is implemented as two separate components, CropML and CropML.
Interfaces. The first includes all the algorithms (the models), the second interfaces,
domain classes, and information about crop model parameters. Three versions of
the component were developed: CropML, CropML.WaterLimited, and CropML.
NitrogenLimited. The last two extend, respectively, CropML - CropML.Interfaces
and CropML.WaterLimited - CropML.WaterLimited.Interfaces.
The models currently implemented are the plant growth and development approaches
of CropSyst (Stockle et al.
2003)
, WOFOST (van Keulen and Wolf
1986)
, and WARM
