In this section we will run the PS1 model for Rajkot2004 and for other weather stations and years.
What do you need?
- weather data for a specific location and for a specific year (inspected before),
- crop data containing parameters for a specific crop,
- management data with 3 values to be able to start the simulation.
For your convenience, all data was packaged into a zip file: IndiaData.zip. Download the zip file, and extract the files that it contains to your local hard disk. Remember in which directory/folder you stored the files.
Also for your convenience, a PDF was created with which you can quickly lookup the julian day number and calendar dates, see daynrs_calendardates.pdf.
Starting the ProductionAlgorithm program
Start the following Java webstart link ProductionAlgorithm.
The ProductionAlgorithm Java program is downloaded to your local computer, and it opens with the following screen:
ProductionAlgorithmform contains a number of sections, which may not be very clear to a new user:
- An Import button at the top of the form to enable a user to import weather data, crop-related variables, and management data from separate files. If used, the input section as described below is automatically filled with the information as read from the input files.
- An input section where a user has to specify:
- input required for the PS1 model: weather data, crop-related variables, and management data
- additional input required for the PS2 model: some more crop information, input data for canopy temperatures.
- An output section where calculated values will appear immediately after you click the
The maximum yield has to be found in the
S_StorageOrgancolumn. The maximum value in the
S_StorageOrgancolumn does not necessarily appear at the very botton of the output section.
- A button pane at the bottom of the form:
Calculatebutton to start the calculation for the selected crop, starting at the germination day, calculating until the relative development stage (based on Tsum and Tleaf) reaches value 1.0.
Writebutton to write any input and output information currently in the form to an xml file. The xml file can be read back into the form again when you restart the application in a later stage.
Readbutton to read previously stored form-information back into the form.
ProductionAlgorithmform is active, you can change any input values; if you click the
Calculatebutton again, all output values are automatically recalculated.
Reading the data files
Import Input Filesbutton at the top left-hand side of the
This will bring up a dialog box where you can pick a weather file, a crops file and choose a crop from there, and a management data file.
- Select the
- Select the
crops.crpcrop data file; then select the crop
- Select the
After you selected the files from your hard disk, the form should look as follows:
When you click the
OKbutton, all required data for PS1 is automatically read into the
- The format of the weather data files was already discussed before in Inspecting the weather data as ASCII data, first section.
crops.crpfile contains a number of crop variables: ...
groundnut_management.txtfile contains only 3 comma-separated values: germination day number, amount of germinating material (kg/ha), mortality rate (0-1).
From www.ikisan.com/links/ap_groundnutCrop%20Establishment.shtml we assume a germination date around 1 July (day nr 183). From the same link, we find a sowing rate between 120 to 200 kg/ha. However, we will use an initial value for germinating dry matter of only 10 kg/ha. Lastly, we assume a mortality rate of 0.1.
As you have unzipped the files onto your local hard disk, you can inspect the input files yourself with any ASCII editor.
When you return to the
ProductionAlgorithmdialog box, browse through the form. See that the weather data is filled out, the crop data, and the 3 management variables. The middle part of the form, directly after the management data is only used in case of PS2, so this can be skipped.
- Scroll to the Output section of the form.
- Click the
Calculatebutton at the lower part of the
Inspecting the results
- After 75 days, at day nr 257 (13 Sept), a maximum yield (S_StorageOrgan) is reached of 1163 kg/ha.
From www.ikisan.com/links/ap_groundnutHistory.shtml we find a FAO yield for groundnut in India of 967 kg/ha. Other groundnut yield values may be found at www.ficciagroindia.com/general/agriculture-statistics/4.15AllIndiaAreaProductionandYieldofGroundnut.pdf (groundnut yield India 2004 of 1020 kg/ha)or from www.icrisat.org/GroundNut/GroundNut.htm (average yield worldwide 1348 kg/ha).
Running the model again, without fixed relative humidity
You may run the model again in the same dialog box.
- Just below the weather data, find the check box "Use fixed relative humidity" and switch it off.
- Then click the calculate button again.
You now find a maximum yield of 1141 kg/ha.
- Run the ProductionAlgorithm again using the Dhanduka2004, and then the Amreli2004 weather data. You can use the same crop data and the same management data.
- To start the program, you can click the following Java webstart link ProductionAlgorithm.
- What is the maximum yield for Dhanduka2004? And what is the maximum yield for Amreli2004? Write the results of each calculation to an xml file.Answers:
Maximum yield Amreli2004: 6174 kg/ha
Maximum yield Dhanduka2004: 444 kg/ha;
Maximum yield Rajkot2004: 1163 kg/ha;
- If time permits, repeat for the other years 2000 - 2004 and for all weather stations.
Maximum yields (kg/ha) Amreli Dhanduka Rajkot 2000 2001 2002 2003 2004
Maximum yields (kg/ha) Amreli Dhanduka Rajkot 2000 3146 409 973 2001 734 574 558 2002 665 346 337 2003 6284 504 1345 2004 6174 444 1163
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