sasia manual april 2014

7/25/2019 SAsia Manual April 2014

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Fallow Water BalanceIn this exercise you will explore the major elements of interest in soil water balance during a

fallow - soil water storage, drainage, runoff, and evaporation. Changes will be examined over a

one year period in the Bhola district of southern Bangladesh. The examples assume you have

read and walked through the document: Introduction to APSIM UI

It is suggested that you first create a custom worshop directory: c:\Apsim_workshopfor saving

the simulations generated from these exercises.

Create a sub-directory: c:\Apsim_workshop\met_files to store your APSIM weather files.

Note:You may want to copy the two weather files that are required to complete these exercises,

Bhola_1998-07.metand Dinajpur.metinto your workshop met file directory from: C:\Program

Files\Apsim73\Examples\MetFiles.

1. Create a new simulation using a blank simulation as a starting point2. Choose a weather file for Bhola (Bhola_1998-07.met)

Note:Weather files can be found in the directory: C:\Program

Files\Apsim73\Examples\MetFilesor in c:\Apsim_workshop\met_files.

3. Starting date: 1/1/2001 Ending date: 31/12/2001

4. Rename paddock node to field

5. Add a soil to the field node. A suitable soil characterised for the Bhola region would be : "North

Joynags-06 No673.

6. From Soils toolbox, find and drag a Southern Bangladesh, Bhola district Silt, (Wheat PAWC =

138.5 mm, 1.5m) soil description onto the field node of the simulation tree, (located under Soils

> Bangladesh > Southern Bangladesh > Bhola > Silt (North Joynags-06 No673)). Rename

the soil to something shorter like Silt.

7. Set the starting water to 100% full - filled from the top. (expand the soil branch to see InitWater

i.e. click the "+" next to Silt)

8. At the Initial nitrogen node, set the starting NO3 to 10 kg/ha (i.e. 6and 4in the 0-20 and 20-200

layers) and starting NH4 to 5 kg/ha (i.e. 4and 1in the two layers)

9. Add Surface organic Matter to the field:

From Standard Toolbox Soil related, drag a Surface Organic Mattercomponent onto the field

node

10. Check that the default initial OM pool name is rice_stubbleand OM type is riceand the mass is

0kg/ha. (at "surface Organic matter" node)

11. From the standard Toolbox, drag a Outputfileonto the field node


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12. Select the outputfile's Variablessubcomponent. Choose these variables to report:

Component Variable name

Clock dd/mm/yyyy as Date

Year

Day

Met Rain

Silt ESW - Extractable soil water (mm)

ES Evaporation

Runoff

DRAIN Drainage

NO3 - summed over profile(Do thisby putting () next to the name in the"Variable name" column) eg. no3()(click "?" button next to variable list formore info)

DLT_N_MIN - N mineralised -summed over profile

Surface organicmatter

SURFACEOM_WT - Weight of allsurface organic materials.

SURFACEOM_COVER - Fraction ofground covered by all surface organicmaterials.

13. Select the "Outputfile" Reporting Frequencysubcomponent. Delete "daily". Choose end_day

reporting frequency for the output file. This can be found under the Clockcomponent filter

14. Rename the simulation to something more meaningful: Silt Fallow

15. Save the simulation file as "c:\Apsim_workshop\Fallow water balance.apsim"

16. Run the simulation by pressing the "Run" button at the top of the ApsimUI.

17. Create a graph of Date vs ESW.Hint:To do this, click on the Graph Toolbox at the bottom of the window to open the toolbox.

Then drag in an XY component onto the output file in your simulation. Click on the "+" symbol

next to XY component to expand the node. Click on the Plot component. In the Plot window click

on the X variables square to make sure the background of the square is pink. Now click on the

"Date" column heading. It should appear in the list in the square. Now click on the Y variables

square to make its background pink. Click on the esw column heading. It will be added to the Y

variables square. To have a clean line plotted with no points, under "Point type", choose "None".

Now click on the XY component to view the graph.

18. Once you have created a chart it is possible to make modifications by adding new variables. It is

also possible to mix the type of plots used on a graph. As an example, we will add rain as a bar

chart on the Y2 axis. To do this, drag plot onto the XY node to create a duplicate, plot1. At

plot1, remove esw and add rain as the y variable. To make the "rain" appear on the right hand

axis, click rain in the square to highlight it, then "right" mouse click on it again. In the popup menu

click on "Right Hand Axis". Select bar chart from "type" drop_down menu. Select XY node to

see the line and bar chart combination.

19. Rename the XY graph node to Soil_water_storage

The graph should show the ESW (in mm) increasing with day of year. The sudden increases are

due to rainfall events and the declines to evaporation and drainage loss. The distribution of daily

rainfall amounts helps see this more clearly.


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Note:You can also examine other components of the simulated soil water balance.

20. Drag Soil_water_storageto the outputfile node to make a copy of this graphics node. Rename

the copy to Runoff_drainage

21. At the Plot1 node underneath the Runoff_drainage graph, remove rain from the Y variables box.

Add runoff and drain to the Y variable box. Put both on the right hand axis (right click on thevariable) to create a plot similar to the below figure.


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Runoff occurs from the start of the monsoon season early in May-June, continuing through the

wet season till Nov-Dec. Drainage begins sometime after the first runoff, once the soil profile is

near full. (Remember, PAWC for wheat in this soil is 138.5 mm, so the profile is mostly in a

saturated state whenever esw is above this limit).

Additional exercise:You could also make a plot of soil evaporation. See if you can do this for

yourself.


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The effect of soil type on the water balance.

Runoff, es and drainage are affected by weather and soil water storage capacity. This simulation

will add an additional soil and compare runoff from both soil types. The user interface still

contains all the specifications provided for the previous simulation.

If you drag the Silt Fallow node in the Simulation Tree to the top node Simulations, a copy of itwill be made and your file will then have 2 simulations in it.

This second simulation can then be modified to add the characteristics of a second silt soil with

higher water holding capacity.

1. From Soils toolbox, find and drag the Bangladesh -> Southern Bangladesh -> Patuakhali district -

> "Silt (Shially-09 No783)" soil onto the paddock in the simulation tree and then remove the old

soil (Hint:highligh the soil to delete and press the "Delete" key. It is important you drag in a new

soil BEFORE you delete the old one, otherwise the simulation will lose all your soil reporting

variables. Also remember to rename your soil to something shorter eg Silt_2

2. Since now we have a new soil we will need to go and set the initial soil water (InitWater) to 100%

filled from top and initial soil nitrogen (Initial nitrogen) to NO3 to 10 kg/ha and NH4 to 5 kg/ha, as

before. When you delete soils you also delete the initial soil water conditions and initial soil

nitrogen conditions so these will need to be set similar to the conditions of the "Silt" soil.

3. Rename the simulation to "Silt2 Fallow".4. Save the simulations. (C:\Apsim_workshop\)

5. Run APSIM for the Silt2 soil simulation.


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6. Graph both the output files by dragging an XY graph onto the top node Simulations in the

simulation tree. By placing the XY graph under the "Simulations node", all output files in the

simulation area will be available for plotting in this case, the Silt and Silt2 outputs.

7. Create a graph of date vs esw and runoff(cumulative, right hand axis). To make the runoff

cumulative, it is the same procedure as to make the rain appear on the right hand axis. Only

select "Cumulative" from the popup menu instead of "Right Hand Axis". Set "Point Type" to

None.

The figure below includes a plot of drainage for the 2 soils. See if you can also add drain as

shown above to your esw-runoff plot. (Hint:create a plot1, do cumulative and right hand axis and

choose "circles" under Point Type)

The silt2 soil has only slightly higher runoff than the silt soil for all simulated events. Cumulative

runoff for both is similar at over 1800mm. Is this what you might expect, given the PAWC of

33mm and the same rainfall and 100% full profiles as starting conditions? What can be seen

from the accumulated drainage? Would runoff and drainage be the same if the initial PAWC for

silt2 at the start had been different? (ie. Silt2 InitWater = 50%)

Notes:


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Notes:

Additional exercise:explore the effect of changing curve number on the water balance. eg. for

the silt2 soil, keep previous initial Plant Available Water Content (PAWC) settings at 50% (Silt2)

and change curve number from 94 to 84 in the Soilwat node. What is the effect on accumulated

runoff and drainage?


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Changes to the water balance by ponding water on thesurface.

In the previous exercises we have investigated the APSIM water balance on free draining soils in

accumulating stored soil water and in simulating effects of runoff, drainage and soil evaporation.

The soil specified in the previous examples reflect a typical soil in a natural (cultivated or

uncultivated) state unaffected by (farmer) imposed physical constraints to the flow of water in the

landscape. Rice production particularly during the wetter months of the monsoon is grown under

paddy conditions. The natural structure of the soil surface has been modified (puddled) to reduce

drainage and bunding (ponding) imposed to reduce runoff. These conditions therefore require

some change to parameters in APSIM to simulate the effect of ponded water above the soil

surface. The following exercise will use the 'max_pond' parameter to enable ponding of surface

water and modify 'KS' (hydraulic conductivity) values for each soil layer to restrict the rate of

vertical drainage.

1. Drag Pond_depthon to the Manager Folder from "Rice Management Toolbox" -> "Rice" ->

"Manager (Pond_depth)"

2. Change properties to:Name of your soil module: Silt

Start date for ponding: 1-Jun(Start of wet season - bunds constructed)

End date for ponding: 30-Oct(Crop maturing - open bunds)

Maximum depth of pond: 150

Minimum depth of pond: 0

Enable irrigation : No(set to Noirrigation for the momemt)

Start date for irrigation: 1-Jul

End date for irrigation: 30-Oct

Maximum number of irriagtions allowed: 0

3. Edit your soil file properties - Water - KS. (hydraulic conductivity in mm/day)to:


Depth KS

0-15 1.0

15-30 1.0

30-60 24.0

60-90 24.0

90-120 24.0

120-150 24.0

4. Add additional report variables:


Met Rain

Soil DUL(1)

sw(1)

no3()

Drain

Runoff

5. Drag Irrigationon to the paddock fieldnode in the "Silt Fallow Ponding" simulation from

"Standard Toolbox" -> "Water Components (Irrigation)"6. Run APSIM for the Silt Fallow Ponding simulation.

7. Create a graph of date vs DUL(1) and SW(1) (on Y axis) after deleting previous graphs. Rename

this new graph to Ponding.


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8. Create a second graph by dragging Pondingonto your outputfile. Select runoff and drain

(Cumulative) on the Y axis. Rename this graph Drainage-Runoff.

The Pondinggraph shows the drained upper limit (DUL) of the first soil layer and volumetric soil

water (sw(1)) in mm/mm for the first soil layer. Values above the DUL line indicate soil water over

the drained upper limit and represent ponded water to a level as defined by "max_pond". The

Drainage-Runoffgraph presents simulated values for cumulative runoff (in excess of water

stored by "max_pond") and cumulative drainage from the bottom of the profile as effected by

"KS" input values.

Additional exercise:Explore the effect of changing 'KS' rates (mm/day) on the level of

cumulative runoff and drainage.


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Tracking the decline of cover as residues decompose

APSIM simulates the influence of crop residues on the efficiency with which soil water is

captured and retained during fallows. But residue cover declines as residues decompose.

Residue decomposition is simulated in APSIM in response to weather, as well as the chemical

composition of the residues and soil. By doing this simulation you will reinforce skills learned in

previous exercises and learn to do some basic editing of default values to customise your

simulations.This simulation will demonstrate how surface residue decomposes over time. You should use the

previous simulation as a starting point for this simulation. You need to add an initial amount of

surface residues.

1. Reopen the previous file Fallow water balance.apsim. (Hint:c:\Apsim_workshop\fallow water

balance.apsim)

2. Save the file as Residue.apsim(Reminder:don't forget to use the Save asbutton, NOTthe

Save, or you will save these changes to Fallow water balance.apsim)

3. Remove the Silt2 Fallow simulation. We're going to use Silt Fallowas our starting point for this

exercise. Also remove the graph components. Select the graph component and press "delete" or

right click on the component and select Delete.4. Make a copy of the Silt Fallow simulation by dragging to the top node in tree (Simulations).

5. Rename second simulation to Silt rice residue

6. Select the Surface Organic Matternode for editing:

Set Organic Matter pool name: rice_stubble.

Set Organic Matter type: rice.

Set Initial surface residue: 2000 kg/ha.

7. Run the simulation

8. Create a graph of day vs surfaceom_cover and rain(right hand axis) for the Silt rice Residue

simulation. Drag an XY graph from the "Graph toolbox" -> Graph -> "Graphs (XY)" onto the

output file, and rename it to rice_cover. Remember to set "Point type" to None. To find out how

to modify a graph see How To Modify a Graph Component

It can be seen that periods of high decomposition rate match with higher rainfall and low

decomposition with dry periods.


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The effect of cover decline on runoff

In this activity, a comparison will be made between two simulations: Silt Fallowand Silt Rice

Residue.

1. Drag the rice_covergraph that we've just created onto the simulations node at the top of the tree

to create a copy.

2. Graph Date vs runoff(cumulative)3. Rename this graph residues_runoff. Notice that data from both simulations (Silt Fallowand Silt

rice residue) appears.

4. Drag grahic node Plotto residues_runoffnode to create Plot1

5. Graph rain (this time select Type = Bar)


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The effect of residue type on speed of decomposition

The APSIM Surface Organic Matter model will decompose residues at differing rates according

to the C:N ratio of the material, amongst other parameters. To demonstrate this we will

reproduce the previous simulation but apply legume residues in the place of the rice straw

residues.

1. Create another copy of the Silt rice Residue simulation and call it Silt cowpea residue. Delete therice_cover graph

2. Select Surface Organic Matterfor editing:

Set Organic Matter pool name: cowpea_stubble.

Set Organic Matter type: cowpea.

Set Initial surface residue: 2000 kg/ha.

set C:N ratio of initial residue: 20.

(Remember you may want to change the Surface Organic Matter poolname to something like

Cowpeaas well)

3. Run this new simulation. (If you just select this simulation in the tree and click the run button it

will only run this simulation instead of all of them.

4. Create a new graph for Silt rice residueand Silt cowpea residuesimulations with residue coveras a function of time (eg date). Add rain to the right hand axis.

5. Rename the graph to "residue_type_cover".


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Nitrogen cycling

In this exercise you will observe the fate of fertiliser nitrogen in a fallow situation: Urea to

ammonium to nitrate and the loss of soil nitrate via denitrification.

This simulation will introduce us to editing a simple Manager rule and to more advanced features

of graphing simulation results. Firstly we need to set up our weather and soil data. The simulation

is on silt soil in the Bhola region in Southern Bangladesh.

1. Start with a new simulation based on Continuous Wheat

2. Change simulation name to Silt Fertilised

3. Save the file as N Fallow.apsim(C:\Apsim_workshop\N fallow.apsim)

4. Choose a weather file for Bhola (c:\Apsim_workshop\met_files\Bhola_1998-07.met)

5. Set the clock starting date: 1/1/2001 Ending date: 31/12/2001

6. Add a soil to the field node (North Joynags-06 No673)


138.5 mm, 1.5m) soil file ("Soils" > Bangladesh > Southern Bangladesh > Bhola > "Silt

(North Joynags-06 No673)") onto the fieldnode of the simulation tree. Remove the existing soil

after the addition of the new soil. Rename the soil to something short like "Silt". If you like youcan also reorder the soil component so it comes straight under the paddock. (Hint:Highlight your

soil and use the Ctrl & up arrow to move a node up the tree)

8. Set the Starting water to 50% full, evenly distributed.

9. At the Initial nitrogen node, set the starting NO3 to 10 kg/ha (i.e. 6and 4in the 0-20 and 20-200

layers) and starting NH4 to 5 kg/ha (i.e. 4and 1in the two layers)

10. Set the initial surface organic matter to 2000kg/ha wheat residues.

11. Remove the wheat component from the paddock, and all manager rules from the manager folder.

12. Drag a Fertilise on fixed dateto your Manager component. ("Standard toolbox" -> "Management"

-> "Manager (common tasks)" )

13. Select Fertilise on a fixed dateto edit:

Enter fertiliser date: 15-Jan.

Don't add fertiliser if N in top 2 layers exceeds: 1000.

Module used to apply fertiliser: fertiliser.

Amount of fertiliser to apply: 100.urea_N.

14. Make sure your simulation contains a Fertilisercomponent in your paddock. Even though it

doesn't have any changeable properties it is still necessary when fertiliser is to be applied.

15. Select OutputfileVariables.


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Illustrating the extent and conditions required fordenitrification losses

Create a new chart of Date vs Rain, DNIT (right hand axis), ESW and NO3_Total.

From this chart you can see that some nitrogen is lost via denitrification when large amounts of

nitrate is available in saturated soil conditions. But why do you think the level of denitrification is

so low (0.1 kgN/ha/day) in this case?

Exploring vertical movement of nitrate, after fertilisation,

through the soil profileLet's look at the distribution of nitrate through the soil profile at the day fertiliser is applied and

then at 1, 3 and 5 months after fertilisation.

1. Create a depth graph (from the graph toolbox), and expand all the sub-nodes. Go to the depth

node, and select (so that they show a tick mark) the dates 15/01/2001, 15/02/2001, 15/4/2001

and 15/5/2001. Go to the Plot node and select NO3 as the X variables. Leave the Y variable as

"Depth". Select the top graph node ("Depth").

Depth plots can only be done when the simulation has "dlayer" in the output file along with at

least one other layered variable. This is why we included no3 and nh4 as layered variables in theoutput file and not just the summed variables for NO3() and NO4(). (Hint:adding ()to an array

variable like "NO3" to form "NO3()" will sum the nitrate values from all the soil layers)


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From this chart you can see the change (on the X axis) in the distribution of nitrate (NO3) in the

soil profile (Y axis) over time in response to the addition of urea fertiliser and leaching processes

at the start of the wet season. (The default title "Depth" can be changed to something more

suitable ie. Change in soil NO3 over time

Question: Why is there little change before the 15th of May?

Repeat the steps above and create another graph this time selecting NH4.

Notes:

Question: What has happened to the NH4? Try changing the dates to look at NH4 at 1, 5 and 10

days after fertiliser has been applied.


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From this chart you can see the change in the distribution of NH4 in the profile occurs very

rapidly over the course of a few days. NH4 is converted to NO3.

Additional exercise: Try creating another simulation with clock set between 14/01/2001 and

31/01/2001. Create a time series graph of urea(), NO3_total and NH4_total in the profile over a

period of 15 days after fertiliser is applied. Would the simulated process be the same if the

fertiliser was applied in the middle of the wet season (August)?


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Movement of Nitrogen between Organic Matter Pools

In this exercise we track the movement of nitrogen in fresh organic matter into soil microbial

biomass and further into mineral nitrogen. We shall compare the flows in these processes for

incorporation of two types of residues wheat and cowpea.

1. Make a copy of the Silt fertilisedsimulation by dragging to the top node in the tree (Simulations)

2. Delete all the XY and Depth graphs. - This setup already includes wheat residues on the surface

at 2000kg/ha and C:N ratio of 80

3. Change starting NO3-N to 60 kg/ha (36and 24in each of the 2 layers), leaving NH4-N at 5 kg/ha

4. Remove Fertilise on fixed datefrom your paddock component

5. Drag Tillage on fixed dateto the Manager folder in your paddock component for this new

simulation. (open "Standard toolbox" -> "Management" -> "Manager (common tasks)" )

6. Change the Tillage management parameters to: date = 15-Jan

Module used to apply the tillage = Surface Organic Matter

Tillage Type = user_defined

User defined depth of seedbed preparation = 100(mm)User defined fraction of surface residues to incorporate = 1.0

7. Change simulation name to Silt wheat residues incorp.

8. Choose these variables to report:



Soil (Silt) Biom_n() as biom_n_Tot

Fom_n() as fom_n_Tot

NO3() as no3_Tot

9. Create a copy of the Silt wheat residue incorpsimulation and call it Sand cowpea residue incorp.

10. Change the initial surface residue parameters to 2000kg/ha of Cowpea(type) residue. Set the

C:N ratio to 20. (Remember you may want to change the Organic Matter pool nameto cowpea

as well. Remember to reflect this change in Tillage on a fixed date- Module used to apply tillage)

11. Run the two simulations for residue incorporation.


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12. Graph both residue incorporation simulations with fom_n_tot (left hand axis), no3_tot and

biom_n_tot (right hand axis), and fom_n_tot. (Drag an XY graph onto the top node (simulations),

open the ApsimReader node and point to the 2 output files)


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Inspect the change in fresh organic N in residues (fom_n) with time.

Note:There is a steep increase in the first few days when tillage incorporates the surface

residues and this material is passed onto the soilN modules as FOM. Soil "fom_n" for legume is

higher than for wheat residues reflecting the differences in N content of the 2 materials as

determined by the C:N ratios input to the model.

Differences between wheat and legume dynamics in decomposition of FOM and its N content

can be seen in the transfer of N into the microbial N pool (biom_n_tot), and the effects of this

transfer on the net immobilisation/mineralisation of organic N from/to the soil nitrate pool. NO3

levels increase over time reflecting changes in fom_n and biom_n pools.

Question: Would these rates of change increase during the wetter and warmer months?

In this exercise we will simulate the biomass and yield of a direct-seeded rice crop using APSIM-

ORYZA.

You will learn a bit more about specifying a Manager template, execute more than one run in

batch mode and use the simulator to do a what-if experiment with fertiliser rates and type.These skills can also be used to experiment with time of planting, rate of sowing and different

irrigation rates.

1. Start a fresh simulation using Oryza as a template

2. Select the first example Riceto use for this simulation (delete the second example:'Ponding

simulation' for the moment)

3. Choose the Bhola_1998-07.met weather file

4. Set the clock starting date: 1/1/2001, Ending date: 31/12/2001

5. Add a soil to the field node ("North Joynags-06 No673)


138.5 mm, 1.5m) soil description onto the fieldnode of the simulation tree, (located under Soils> Bangladesh > Southern Bangladesh > Bhola > Silt (North Joynags-06 No673)) removing

the existing soil description after the addition. Rename the soil to something short like Silt. If you

like you can also reorder the soil component so it comes straight under the field.

7. Set the Starting water to 100%full - filled from top.

8. Set the Starting nitrogen to 10 kg/ha of NO3 (as 6and 4in each layer, respectively) and 5 kg/ha

(4+ 1) of NH4

9. Drag a Surface Organic Matter componet from Toolbox - Soil related onto your paddock.

10. Select the Surface Organic Mattercomponent for editing: Organic Matter pool name:

rice_stubble.

Surface organic matter type: rice.

Initial surface residues: 0.

11. In the Irrigationcomponent set Automatic irrigationto off.

12. Drag a fertilisercomponent from the toolbox onto your paddock. (You may want to reorder

components above the output file)

13. In the Manager component, delete the Rice sowing rule. Drag a Rice-Direct seedingcomponent

from the Rice Management Toolbox into the Manager.

14. Change the sowing rule to:

set sowing window START to 1-Jul

set sowing window END to 1-Jul

set Cultivar to local

set number of plants per seedbed to 180


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15. Choose these variables to report:



Year

Day

Soil (Silt) ESW

NO3() as no3_totRice cropsta as crop_stage

Dae

wagt as total_biomass

wso as storage_organs

wrr as rice_yield (Variable not indrop down)tnsoil as N_avail

16. Choose an "end_day" reporting frequency.

17. Rename the simulation to Direct_seeded_rice.

18. Save the simulation file as Rice single season.apsim(C:\Apsim_workshop\Rice singleseason.apsim)

19. Run the Direct_seeded_ricesimulation

20. Graph total_biomass and rice_yield with an XY graph with Date on the X axis. (Drag or Insert the

XY graph on the top simulation nodeto plot output from both simulations)

This simulation demonstrates a local rice variety (direct seeded) grown under rainfed conditions

during the monsoon. Simulated rough rice yield and biomass indicate a favourable season for

rainfall. Investigate the rainfall during the growing season by reporting additional variables.


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21. Add additional report variables:


Met Rain

Soil (Silt) DUL(1)

sw(1)

no3()

nh4()

Drain

Irrigation Irrigation

22. Rerun simulation

23. Create a new graph by copying your XY chart onto the 'Outputfile'. Copy 'Plot' onto this XY

Chart1 to create a second Plot1. For Plot select Y variables dul(1) and sw(1) (solid line and no

points). For 'Plot1' select rain (right hand axis and type= Bar).

This graph shows volumetric soil water levels (sw(1) in mm/mm) in the top layer compared with

the drained upper limit(DUL)in layer 1. Soil water in the surface layer is effected by soil

evaporation (decline in SW(1) during the drier winter months of January to March) while surface

water occurs only during the high rainfall period of the monsoon.


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Single season transplanted rice crop under pondedconditions

In this exercise we will simulate the growth and yield response of transplanted paddy rice. Apply

fertiliser at defined stages in crop development and apply irrigaton as required to maintain

adequate water levels in a paddy.

1. Make a copy of the simulation Direct_seeded_riceby dragging it to the Simulations node at the

top of the simulation tree.

2. Rename this copy to Transplanted_paddy_rice.

3. Delete the Rice-Direct seedingmanager from the Manager folder

4. Drag Pond_depthon to the Manager Folder (from "Rice Management Toolbox" -> Rice->

"Manager (Pond_depth)"

5. Change properties to:

Name of your soil module: Silt

Start date for ponding: 1-Jun(Start of wet season - bunds constructed)

End date for ponding: 30-Oct(Crop maturing - open bunds) Maximum depth of pond: 150

Minimum depth of pond: 50(Note:This is the trigger for irrigation to be applied)Enable irrigation : No(set to Noirrigation for the momemt)

Start date for irrigation: 1-Jul

End date for irrigation: 30-Oct

Maximum number of irrigations allowed: 6

6. Edit your soil file properties - Water - KS. (hydraulic conductivity in mm/day)to:


Depth KS

0-15 24

15-30 24

30-60 2460-90 24

90-120 24

120-150 1

7. Drag Rice-Transplant Amanon to the Manager Folder (from "Rice Management Toolbox" ->

Rice-> "Manager (Rice-Transplant Aman)"


Enter sowing window START date: 1-Jul

Enter sowing window END date: 1-Jul

Duration of seedbed: 25

Number of plants on hills: 2

Fertiliser type: urea_N

Amount of fertiliser at transplant: 30

9. Save the file

10. Drag Fertilise on growth stageon to the Manager Folder (from "Rice Management Toolbox" ->

Rice-> "Manager (Fertilise on growth stage)"


Amount of fertiliser to apply: 40

Fertiliser type: urea_N

12. Drag a Rice residueon to the Manager Folder (from "Rice Management Toolbox" -> Rice->

"Manager (Rice residue)


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Select your module to apply tillage : Surface Organic Matter

Tillage type: user_defined

Depth of seedbed preparation: 0

Fraction to incorporate: 0.85

14. Run Transplanted_paddy_ricesimulation

Create an XY graph of Biomass and rice yield (XY chart copied with this simulation from

Direct_seeded_riceshould be correct)

The graph shows daily biomass development from seedling establishment until day (25) of

transplant (specified by "Duration of seedbed" in manager rules for sowing). Biomass is reduceddue to transplant shock before developing total biomass at maturity. Grain fill starts in the second

week in September and reaches full grain yield at physiological maturity in the last week of

October.


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Create a second XY graph using Plot by dragging it onto your 'Outputfile'. Graph dul(1) and sw(1)

on the left axis with rainfall and drainage (Cumulative) on the right hand axis.


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Two monsoon rice crops (TAus - TAman)

In this exercise you will simulate two rice crops grown during the monsoon period. TAusrice is

transplanted at the start of the wet season in June and followed by the a TAmancrop in late

August.

1. Open the previous simulation Rice single seasonas a template. (C:\APSIM_workshop\Rice

single season.apsim)2. Use "Save as" to create a copy of this file in the c:\APSIM_workshop\directory. Name this

simulation Rotations.

3. Make a copy of Transplanted_paddy_riceby dragging it onto the Simulationsnode.

4. Rename the copy to Rice-Rice.

5. Select the Micrometnode in paddockand delete (this is not required in these exercises)

6. Select your soil (silt) for editing and change the starting soil waterto 10% full(Evenly distributed)

7. Select the Manager -> Rice-Transplant Aman rule to edit: Enter sowing window START: 1-Aug.

Enter sowing window END: 1-Aug.

Cultivar: BR23.

Duration of seedbed: 25.

Number of plants on hills: 2.Number of hills: 25.

Number of plants per seedbed: 1000. (Plants/m2)

Fertilizer type: urea_N.

Amount of fertilizer at transplant: 100.

8. Select the Manager -> 'Pond_depth' rule to edit: Name of your soil module: Silt.

Start date of ponding: 15-Apr.

End date of ponding: 30-Oct.

Maximum depth of pond: 150.

Minimum depth of pond: 50.

Enable irrigation: yes.

Start date for irrigation: 15-May.

End date for irrigation: 30-Oct.

Max number of irrigations: 6.

9. Select the Manager -> Rice-Transplant Aus rule to edit: Enter sowing window START: 15-Apr.

Enter sowing window END: 15-Apr.

Cultivar: BR3.


Number of plants on hills: 2.

Number of hills: 25.

Number of plants per seedbead: 1000.

Fertilizer type: urea_N.Amount of fertilizer at transplant: 30.

10. Run the Rice-Ricesimulation.

Graph date (X axis) vs total_biomass and rice_yield (Y axis). ( Hint:Use your XY Chart from the

previous simulation)

Change the 'title' of your graph by renaming your 'XY Chart' to a more siutable name. (Hint:

TAus-TAman rice (biomass and yield))


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In the above simulation two rice varieties have been selected for their duration to maturity(Medium: BR23~119 DAE and Medium short: BR3~100 DAE) which enabled two rice crops to

be planted during the wetter months of the local monsoon season. Selecting the appropriate

variety (duration to maturity) is an important factor in constructing any crop rotation or cropping

sequence and can effect the outcome of any long-term cropping sequence scenario. The

previous simulations have only considered fixed sowing dates. Under dryland conditions the

opportunity to sow a crop may rely on a rainfall event due to the unavailability of irrigation. A

planting window (window of opportunity) can be defined in the manager with sowing triggered on

meeting a specific condition such as rainfall (ie. 20mm over 3 days) or level of soil water (ie.

ESW > 100mm).


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Adding a dry season crop (ie. wheat) into the rotation

The previous example demonstrated a simple crop rotation or sequence of two wet season rice

crops. In this exercise you will replace the early rice crop with a dry season crop (ie. wheat) sown

into a full profile in mid November following the TAman rice harvest.

1. Make a copy of 'Rice-Rice' by dragging it onto the 'Simulations' node.

2. Rename the copy to Rice-wheat.3. Select clock and change the start and end dates for the simulation: Start date: 1/06/2001End

date: 31/05/2002

4. Select the Manager -> Rice-Transplant Aus rule and delete:

5. Select the Manager -> Rice-Transplant Aman rule to edit: Enter sowing window START: 15-Jul.

Enter sowing window END: 15-Jul.

Cultivar: BR23.


Number of plants on hills: 2.

Number of hills: 25.

Number of plants per seedbead: 1000.

Fertilizer type: urea_N.Amount of fertilizer at transplant: 50.

6. From the "Standard Toolbox" select "Crops (wheat)" and drag onto the paddocknode. (You may

want to reorder wheatto below the ricecomponent)

7. From the Standard Toolboxselect "management" -> "Manager (common tasks)" -> (Sow using a

variable rule) and drag onto the manager folder in your 'paddock'.

8. Select Manager folder-> Sow using a variable ruleto edit:

Enter sowing window START: 1-Dec.

Enter sowing window END: 1-Dec.

Must sow: yes.

Enter name of crop: wheat.

Enter sowing density: 100.

Enter cultivar: 'prodip.

Enter crop class: plant.

Enter row spacing: 250.

From the "Standard Toolbox" select "management" -> "Manager(common tasks)(Harvesting

rule)" and drag onto the manager folder in your paddock.

9. Select 'Manager folder' -> 'Harvesting rule' to edit:

Enter name of crop to harvest when ripe: wheat.

10. From the "Standard Toolbox" select "management" -> "Manager(common tasks)(Fertilise at

sowing)" and drag onto the manager folder in your paddock.

11. Select Manager folder-> Fertilise at sowingto edit:On which module should the event come from: wheat.

On which event: sowing.

Module used to apply fertiliser: Fertiliser.

Amount of starter fertiliser at sowing: 40.

Sowing fertiliser type: urea_N.

12. From the 'Rice Management Toolbox' select 'Rice' -> 'Manager' -> (Fertilise and Irrigate rabi

crop) and drag onto the manager folder in your 'paddock'.

13. Select 'Manager folder' -> 'Fertilise and Irrigate rabi crop' to edit:

Crop type: wheat.

DAS to apply fertiliser: 20.

Module used to apply the fertiliser: Fertiliser.Amount of fertiliser to apply: 30.

Fertiliser type: urea_N.

Amount of irrigation to apply: 60


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Add additional report variables:


Wheat biomass as wheat_biom

yield as wheat_yield

14. Make a copy of Fertilise and Irrigate rabi cropby dragging it onto the Manager foldernode.

15. Select Manager folder-> Fertilise and Irrigate rabi crop1to edit:

Change DAS to apply fertiliser: 40.Change amount of fertiliser to apply: 30.

Fertiliser type: urea_N.

Amount of irrigation to apply: 60

16. From the "Standard Toolbox" select "management" -> "Manager(common tasks)(Irrigate at

sowing)" and drag onto the manager folder in your paddock.

17. Select Manager folder-> Irrigate at sowingto edit:

The module the event come from: wheat.

. Which event should irrigation be applied: sowing.

Module used to apply irrigation: Irrigation.

Amount of irrigation to apply: 60.

18. From the "Rice Management Toolbox" select "Rice" -> "Manager (Rabi residue)" and drag ontothe manager folder in your "paddock".

19. Select "Manager folder" -> "Rabi residue" to edit:

The module the event come from: wheat.

On which event should tillage be done: harvesting.

Module used to apply the tillage: Surface Organic Matter.

Tillage type: user_defined.

User_defined depth of seedbed preparation: 0.

User_defined fraction of surface residue to incorporate: 0.8.

20. Run the Rice-wheatsimulation.

Graph date (X axis) vs total_biomass, rice_yield, wheat_yield and wheat_biom (Y axis). ( Hint:

Use your XY Chart from the previous simulation and add the reporting variables selected for

wheat)

Change the 'title' of your graph by renaming your 'Chart' to a more siutable name. (Hint:TAman

rice-wheat rotation)


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The above examples introduced a crop rotation or cropping sequence where two crops (rice and

wheat) are grown in series over a single season. The previous exercises have only considered a

12 month period. In the next exercise you will evaluate a long-term scenario based on the rice-

wheat simulation that you have created. Long-term simulations require a much longer climate

record. The Bhola_1998-07.metfile contains daily records from 1998 to 2007 and enables

simulation of this cropping sequence over 9 years.

Long-term rice-wheat rotation

1. Make a copy of 'Rice-wheat' by dragging it onto the 'Simulations' node.

2. Rename the copy to Rice-wheat scenario.

3. Select clock and change the start and end dates for the simulation:

Start date: 1/06/1998.

End date: 31/05/2007.

4. Run the Rice-wheat scenariosimulation.

Evaluate the 'XY Chart' showing total biomass and yield of both wheat and rice.

Change the 'title' of your graph by renaming your 'Chart' to a more siutable name. (Hint:TAman

rice-wheat scenario)

The above graph is an example of a simple "rice-wheat" rotation where crops are sown on fixed

planting dates. In the following example you will evaluate the introduction of an opportunity crop

into this long-term rotation. Opportunity crops rely on a particular event occuring that would

enable a crop to be planted. A simple example of an event is "rainfall". (ie. During a specified

window of opportunity, did we get sufficient rainfall to enable a particular crop to be planted?)


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Add an opportunity crop (ie.mungbean) to a long-termrice-wheat rotation

1. Make a copy of 'Rice-wheat scenario' by dragging it onto the 'Simulations' node.

2. Rename the copy to Rice-wheat-mungbean opportunity.

3. From the 'Standard Toolbox' select 'Crops' -> 'mungbean' and drag onto the 'paddock' node.

(You may want to reorder 'mungbean' to below the 'wheat' component) (Hint:Ctrl + up arrow)

4. Make a copy of your 'Sow using a variable rule' in the 'Manager folder' by dragging it onto the

Manager folder node. Rename the copy to 'Sow mungbean'.

5. Select 'Sow mungbean' for editing:

Enter sowing window START date: 20-Mar.

Enter sowing window END date: 7-Apr.

Must sow: No.

Amount of rainfall: 20.

Number of days of rainfall: 3.

Enter minimum allowable available soil water: 0.

Enter name of crop to sow: mungbean.

Enter sowing density: 45.Enter sowing depth: 30.

Enter cultivar: berken.

Enter crop growth class: plant.

Enter row spacing: 250.

6. Make a copy of your 'Harvesting rule' in the 'Manager folder' by dragging it onto the Manager

folder node. Rename the copy to 'Harvesting mungbean'.

7. Select 'Harvesting mungbean' for editing:

Enter name of crop to harvest: mungbean.

8. Change report variables:

Component Variable nameWheat biomass

yield

9. Select the water node in your soil (Silt) for editing:

Make a copy of wheatby dragging it onto the waternode.

10. Rename this copy to mungbeanand select for editing:

Change "xf" values of 1at 0-90 cm and 90-120cm and 120-150cm to 0. (This restricts potential

rooting depth for mungbean to only 60cm)

11. Run the Rice-wheat-mungbean opportunitysimulation.

Graph date (X axis) vs rice_yield, wheat.yield and mungbean.yield (Y axis). Rename the graph to'Rice-wheat-mungbean opportunity' ( Hint:Edit the old XY Chart copied over from the previous

simulation)


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Question:How many years do you get a planting opportunity to sow mungbean?

The previous examples have demonstrated the process for constructing a simple croppingsequence or rotation (Rice-wheat) based on fixed sowing dates. The rice seedling nursery was

sown on the 15th of July with transplanting occuring after 25 days. The wheat was sown on the

8th of December allowing time for the TAmanrice harvest and well within the optimal planting

window for wheat at "Bhola". Mungbean was included in this simulation as an example of an

opportunity crop. The sowing criteria required 20mm of rainfall to occur over a 3 day period if the

crop was to be sown. As the graph shows, these conditions only occurred in 5 of the 9 years.

Additional exercise:Explore the effects of changing the "Sowing criteria" for mungbeans on the

frequency of a successful mungbean crop.

A simple cropping sequence: biomass, nitrogen and water

In this exercise you will construct time series graphs to help in the evaluation and discussion of

the following key components of a rice-wheat cropping system:

1. Total above ground biomass and grain production during the season for both rice and wheat

crops.

2. Soil nitrogen dynamics in response to applied fertiliser on soil nitrogen availability.

3. Soil water and ponding dynamics in response to rainfall and applied irrigation.

1. Create a copy of the Rotations.apsimfile and rename it to Rice-wheat system.apsim.(C:\Apsim_workshop\Rotations.apsim) Load the new APSIM file into the ApsimUI. Remove all

the additional simulations except for Rice-wheatby selecting a simulation node and pressing the

Deletekey.


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2. Select the outputfile-> Variablessubcomponent. Add additional variables to report:


Fertiliser fertiliser

Silt NH4()

Rice rlai as LAI(rice)

Wheat wheat.lai as LAI(wheat)

3. Run the simulation.

TAman rice-wheat rotation:Simulated biomass and grain yield for a transplanted "Aman" rice -

wheat cropping sequence.


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4. Select XY Chart1and rename to Nitrogen.

5. In the 'Plot' window in addition to the Y variables: no3(), NH4(1) and N_avail add nh4().

Nitrogen:Simulated soil nitrogen dynamics for a TAman rice - wheat cropping sequence.

6. Add an additional graph to your Outputfilenode.

In the Y variables add the following variables: dul(1)and sw(1) on the lefthand axis. On the

righthand axis add: irrigation. Create an extra plot component by dragging a 'plot' (from "Graph

Toolbox" -> Graph -> "GraphBits (Plot)" onto the 'Outputfile'. Add rain(Righthand axis) into the Yaxis in 'Plot1'. Change the type to Barand select a new colour. Rename this graph to Water.

Water:Simulated period of ponding during the monsoon rice crop. Rainfall and irrigation events

occuring over the rice - wheat cropping season.


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7. Create a graph of Leaf Area Index (LAI) for the rice and wheat crops. Plot LAI(rice) and

LAI(wheat) on the Y axis. Add a second 'Plot' component (Hint:See documentation above for

the watergraph on adding a plot component) with Y variables: total_biomassand wheat_biom

(right axis). Rename this graph to LAI.

Notes:

LAI:Simulated Leaf Area Index (LAI) for rice and wheat. Plant biomass is also included.

Climate change and agriculture are interrelated processes, both of which take place on a global

scale. Global warming is projected to have significant impacts on conditions affecting agriculture,

including temperature, carbon dioxide, glacial run-off, precipitation and the interaction of these

elements (http://en.wikipedia.org/wiki/Climate_change_and_agriculture).

This exercise aims to explore the effects of climate change using a simple wheat cropping

system. Firstly, the response of wheat to elevated CO2 is examined. For this simulation a climate

control component needs to be included.

In this analysis, you will look at seasonal changes in rainfall, evaporation, transpiration and cropyields.


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1. Construct a long term wheat simulation at 'Dinajpur'- use the Rice-wheat simulationin your

'Rotations.apsim' file as a guide. (Hint:Make a copy of Rotations .apsimand rename it to

Climate change.apsim.) Delete all the simulations except for the Rice-wheatsimulation as this

will become the template for the following exercises.

2. Rename the Rice-wheatsimulation to Wheat-350ppm.

3. Select a new met file. Use the browse button to select the Dinajpur.metfile from

c:\APSIM_workshop\met_files\.

4. Select clockfor editing:

Select the start date: 1/01/1959

Select the end date: 31/12/2009

5. Drag a ClimateControlcomponent on to the Wheat-350ppmsimulation (from "Standard Toolbox"

-> "Meteorological (ClimateControl").

6. Select ClimateControlfor editing:

Enter window to START: 1-jan.

Enter window END: 31-dec.

Change in maximum temperature: 0.

Change in minimum temperature: 0.

Relative change in daily rainfall: 0.Relative change in daily radiation: 0.

Atmospheric CO2 Concentration: 350.

(Hint:you may want to move 'ClimateControl' to below the 'met' component. Use Ctrl + up arrow)

7. Remove all the manager logic used for the previous rice simulation. (Hint:Delete Rice-

Transplant Aman, Pond_depth, Fertilise on growth stage, Rice residue.)

8. Drag a trackercomponent on to the Manager Folder (from "Standard Toolbox" -> "Management

(tracker)").

9. Add the following lines to the tracker component:

Tracker variables

sum of rain on start_of_day from sowing to now asRainSinceSowing

sum of ep on end_of_day from sowing to now as Transp

sum of es on end_of_day from sowing to now as SoilEvap

10. Choose these variables to report: (under Output node)


Clock dd/mm/yyyy as DateYear

Day

wheat wheat.yield as wheat_yield

wheat.biomass as wheat_biom

Soil (Silt) ESW

NO3()

wheat wheat.yield as wheat_yield

wheat.biomass as wheat_biom

met rain

tracker RainSinceSowing

TranspSoilEvap

11. Change 'Reporting Frequency' to harvesting. (Hint:Select question mark to display examples

for reporting frequency)


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12. Delete existing XY charts under the 'Outputfile' node.

13. Make a linked simulation of 'Wheat-350ppm' and rename it to "Wheat-450ppm". There are

several ways to make linked simulations:

a) Right clickand hold down on the source simulation and drag it to the top level (simulations)

node. A popup menu appears when you let go, select the "Create Link Here" option.

b) Select the source simulation with the left mouse button, hold the keyboards key down,

and drag it to the top level (simulations) node.

The advantage of linked simulations is that changes made to any component are made to all

linked components.

14. Select the linked simulation 'Wheat-350ppm1' (in blue) and rename to 'Wheat-450ppm'.

15. Right click on the ClimateControl component and select 'unlink this node' from the drop down

box. (The blue underlined link will change to black text)

16. Select the ClimateControlfor editing:

Change Atmospheric CO2 Concentration to 450.

17. Save and run both simulations. (Hint:select the 'Simulations' node at the top and then the run

button to run both simulations at once)

18. Create a graph comparing wheat yields from each of the simulations . Drag a Probability

Exceedencecomponent on to the 'Simulations node' (from "Graph" -> Graphs-> "Probability

Exceedence").19. Graph 'wheat_yield' (X axis) vs 'Probability' (Y axis). Rename the graph to 'Wheat response

under climate change scenario

In the above example a 'Probability of Exceedence' chart was selected to compare the probability

of grain yields under different background concentrations of atmospheric CO2 (350 ppm and 450

ppm) using 50 years of daily climate data from Dinajpur in northern Bangladesh. The graph

highlights a yield response by APSIM to an elevated CO2 level of 450 ppm. However, increasing

levels of CO2 are only one aspect to be considered in any climate change scenario with the

IPCC (2007) predicting significant increases in global temperatures over the next 50 to 100

years.

The next exercise builds on the previous example by creating two additional simulations. The first

will consider current levels of CO2 at 350 ppm but with an increase in minimum temperature of

1.5 oC. The second will maintain an increase in minimum temperature in conjunction with an

increase in CO2 to 450ppm.


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Climate change response to an increase in minimum dailytemperature

1. Make a linked simulation of Wheat-350ppmand name it Wheat-350ppm+2degC.

2. Select ClimateControlfor editing and right click and "unlink this node".

(The ClimateControlwill change from underlined blue to black text)

3. Select ClimateControlfor editing: Change in minimum temperature: 2.

4. Run this new simulation.

The Wheat response under climate change scenariograph now includes the results of this latest

simulation. Create an additional simulation based on 'Wheat-450ppm' using the steps above.

Rename this new simulation to 'Wheat-450ppm+2degC'.

5. Run new simulation.


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Question:How has increasing minimum temperature affected grain yield in relation to an

increase in the level of CO2?

Additional exercise:Explore the effects of increasing maximum temperature under thisscenario.

Changes in biomass and grain yield will have a direct effect on transpiration and soil evaporation.Create an additional graph from the 'Graph' toolbox or by copying 'Wheat response under climatechange scenario'. Selecting both SoilEvapand Transpon the X axis for graphing.


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Notes:

Climate change response to rainfallIn this exercise you will investigate changes to wheat yield in response to modifying rainfall,

temperature and CO2 by creating a simple experiment. This simulation experiment requires a

controltreatment (previous wheat simulation based on a CO2 concentration of 350 ppm) and a

number of additional treatments:

(1) Increasing CO2 to 450 ppm

(2) Increasing minimum temperature by 2 oC

(3) Decreasing rainfall by 10%

1. Drag a Foldercomponent onto the 'Simulations' node (from "Standard Toolbox" -> "Structural

(folder)").

2. Rename this folder to Senario.

3. Make a copy the Wheat-350ppmsimulation by dragging it on the Scenariofolder. Rename this

simualtion to Control.

4. Copy the Wheat-450ppmsimualtion to the Scenariofolder and rename it to C450

(CO2:450ppm). (Unlink the simulation by right clicking and selecting Unlink this node)

5. Create a copy of Wheat-450ppm+2degC. Rename this copy to C450+T2(CO2:450ppm and

minimum temperature + 2 oC).

6. Create a copy of C450+T2by dragging it onto the Scenarionode. Rename this simulation to

C450+T2-R5(CO2:450ppm and minimum temperature + 2oC and rainfall -10%).

7. Select the ClimateControlnode in C450+T2-R10for editing:Relative change in daily rainfall: -10.

8. Run all the simulations in the Scenariofolder.

(Hint:Highlight the 'Scenario' folder and press "Run" to run all simulations together)


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9. Create a box plot graph showing the results of each treatment. To do this, click on the Graph

Toolbox at the bottom of the window to open the toolbox. Then drag a 'Box Plot' component

(from "Graph" -> "Graphs (Box Plot)") and drop onto the Scenarionode.

Hint:To change the Y axis right click on the chart and select Format Graph. Select Axes. For

the 'Left Axis' untick Minimumand change value to 0. Close 'TeeChart editor.


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The "box plots" used in the above graph represent median wheat yield (dotted line) in response

to applied treatments (based on 50 years of simulation). The solid section (25th and 75th

percentiles) with whiskers representing the 10th and 90th percentiles.

Additional exercise:In the above scenario, decreasing rainfall (at CO2 levels of 450ppm) had

only a small influence on median wheat yields due to available irrigation. In this example wheat is

a dry season (Rabi) crop sown into high levels of soil water at the end of the monsoon with

additional irrigation applied during the growing season. Access to available surface or ground

water for irrigation under a declining rainfall climate change scenario may present a challenge for

future agriculture. What would the effect of reducing the amount of applied irrigation or reducing

starting soil moisture have on potential grain yield?

sasia manual april 2014

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