1. APSIM at Plant & Food Research
Joanna Sharp

2. Generic Crop Template - History
26 released models use generic crop template
(cereals, legumes, vines, trees, weeds,
vegetables, pastures)

3. History Generic Crop Model problems Inflexible model structure
Programming skills needed to make changes
Solution
Next generation generic crop model
Exploits modern software systems (.Net)
Allows flexible approaches to model structure
Without needing to write code

4. Contributors Dean Holzworth - CSIRO Neil Huth - CSIRO
Robert Zyskowski – Plant and Food Research
Edmar Teixeira – Plant and Food Research
John Hargreaves - CSIRO
Derrick Moot – Lincoln University (New Zealand)

5. Plant Modeling Framework

6. Current status and future
Applied to a number of crops
Broccoli, Carrot, Field Pea, French Bean, Fodder Beet,
Grapes, Kale, Lucerne, Oat, Oil Palm, Potato
Ongoing APSIM plant model development
Plant model for APSIMX
Existing crop models to be implemented into PMF
New crop models to be build in PMF
Upcoming publication
Brown et al (in press). Plant Modelling Framework: Software
for building and running crop models on the APSIM platform.
Environmental Modelling and Simulation

7. Grapevine modelling in APSIM
Developing the model (new crop model in APSIM)
Current focus on phenology
Phenology:
Dormancy
Budding
Shoot growth
Flower development
Berry Development
Senescence
Budburst
Flowering
Veraison
Leaf fall

8. Define start of development clock
Budburst
Experimental and simulation approach to define Chill Units + Thermal time
Define start of development clock
Subsequent phenology based on thermal time

9. Irrigation Use Efficiency
Testing SoilWat
Variable rate irrigation & spatial management
Hydrophobicity
Residues & mulches

10. Testing and improving soil C & N mineralisation
Here are the experimental and modelled results for carbon mineralisation at field capacity under the range of temperatures.
APSIM greatly underestimates mineralisation at all temperatures.
Highlighting the 35 degrees data and model outputs (red lines) – at DUL or field capacity and at 35 degrees this is maximum mineralisation, so regardless of whether the temperature and moisture response functions are correct or not, the model should approximate the experimental data. Carbon mineralisation in the data is over 3 times that simulated by APSIM.
NOTE error bars are standard deviation, they are all present but some are too small to see
NOTE value for DUL was determined experimentally for this soil

11. Spatial assessment of climate change impact & adaptation
Total maize silage biomass
Production system:
- High WHC soil
Irrigated
Adaptation:
Sowing dates
Maize Hybrid
kg/ha
Running APSIM spatially using NIWA’s virtual weather for current climate and different climate scenarios
Setting up different levels of autonomous adaptation “modeled” by APSIM (change sowing date and genotype in this case)
Baseline
( )
Climate Change A2
( )

12. Sensitivity analysis on crop rotations
Impact on Nitrogen Leaching (Lincoln – preliminary only)
Kale
Winter
Forage
Field peas 3 4 5 1 2
Preliminary results to illustrate only (work under way now).
Aim is to quantify the importance (% of total variation) of each cropping system component for different impact variables.
Winter
Wheat
Winter
Forage
Barley

13. Using APSIM to test another model (OVERSEER®)
Phase I Phase II Phase III
APSIM evaluation
Long –term simulations
APSIM vs. OVERSEER®
N balance: APSIM vs. 2-3 year rotation treatment data
N balance: Phase I treatments with 30 years of weather data
N balance: Compare models & identify areas for improvement in OVERSEER®

14. Team