Delivering value from agricultural systems
research:
Success and challenges for modelling
Dr Peter Thorburn
CSIRO AGRICULTURE
Some milestones in agro-ecosystem modelling
Adapted from Carberry, Farming Systems Design Workshop, 2009
HL Penman 1948. Natural evaporation from
open water, bare soil and grass
1950
CT de Wit, 1971. A dynamic model of plant
and crop growth
JT Ritchie 1972. Model for predicting
evaporation from a row crop with incomplete
cover
JR Williams 1983. EPIC, The ErosionProductivity Impact Calculator
1960
1970
1980
Hochman et al 2009. Re-inventing modelbased DSS: YieldProphet®
Jones et al 1984. The CERES wheat and
maize models
IBSNAT, 1988. Experimental design and data
collection procedures for IBSNAT
1990
Li et al 1992. A model of N2O evolution from
soil driven by rainfall events-DNDC
McCown et al 1996. APSIM: a novel software
system for model development, model testing
& simulation in agricultural systems research
Hunt et al 2001. Agronomic data: advances in
documentation and protocols for exchange
and use (ICASA)
Duncan et al 1967. A model for simulating
photosynthesis in plant communities
Seligman & van Keulen 1981. PAPRAN: A
simulation model of annual pasture production
limited by rainfall and nitrogen
W Parton 1987. CENTURY: soil organic
matter (C) formation model
Tsuji et al 1994. Decision Support System for
Agro-technology Transfer (DSSAT)
van Bavel 1953 A drought criterion & its
application in evaluating drought incidence &
hazard.
2000
Stöckle et al 1994. CropSyst, a cropping
systems model: water/N budgets & crop yield
W Parton 1998. DayCent: Daily time-step soil
organic matter & N model
2010
Rosenzweig et al 2010. AgMIP. Agricultural
Model Intercomaprison Program
Some milestones in agro-ecosystem modelling:
Models of processes
HL Penman 1948. Natural evaporation from
open water, bare soil and grass
1950
CT de Wit, 1971. A dynamic model of plant
and crop growth
JT Ritchie 1972. Model for predicting
evaporation from a row crop with incomplete
cover
JR Williams 1983. EPIC, The ErosionProductivity Impact Calculator
1960
1970
1980
Hochman et al 2009. Re-inventing modelbased DSS: YieldProphet®
Jones et al 1984. The CERES wheat and
maize models
IBSNAT, 1988. Experimental design and data
collection procedures for IBSNAT
1990
Li et al 1992. A model of N2O evolution from
soil driven by rainfall events-DNDC
McCown et al 1996. APSIM: a novel software
system for model development, model testing
& simulation in agricultural systems research
Hunt et al 2001. Agronomic data: advances in
documentation and protocols for exchange
and use (ICASA)
Duncan et al 1967. A model for simulating
photosynthesis in plant communities
Seligman & van Keulen 1981. PAPRAN: A
simulation model of annual pasture production
limited by rainfall and nitrogen
W Parton 1987. CENTURY: soil organic
matter (C) formation model
Tsuji et al 1994. Decision Support System for
Agro-technology Transfer (DSSAT)
van Bavel 1953 A drought criterion & its
application in evaluating drought incidence &
hazard.
2000
Stöckle et al 1994. CropSyst, a cropping
systems model: water/N budgets & crop yield
W Parton 1998. DayCent: Daily time-step soil
organic matter & N model
2010
Rosenzweig et al 2010. AgMIP. Agricultural
Model Intercomaprison Program
Some milestones in agro-ecosystem modelling:
Crop “models” ( cropping systems models)
HL Penman 1948. Natural evaporation from
open water, bare soil and grass
1950
CT de Wit, 1971. A dynamic model of plant
and crop growth
JT Ritchie 1972. Model for predicting
evaporation from a row crop with incomplete
cover
JR Williams 1983. EPIC, The ErosionProductivity Impact Calculator
1960
1970
1980
Hochman et al 2009. Re-inventing modelbased DSS: YieldProphet®
Jones et al 1984. The CERES wheat and
maize models
IBSNAT, 1988. Experimental design and data
collection procedures for IBSNAT
1990
Li et al 1992. A model of N2O evolution from
soil driven by rainfall events-DNDC
McCown et al 1996. APSIM: a novel software
system for model development, model testing
& simulation in agricultural systems research
Hunt et al 2001. Agronomic data: advances in
documentation and protocols for exchange
and use (ICASA)
Duncan et al 1967. A model for simulating
photosynthesis in plant communities
Seligman & van Keulen 1981. PAPRAN: A
simulation model of annual pasture production
limited by rainfall and nitrogen
W Parton 1987. CENTURY: soil organic
matter (C) formation model
Tsuji et al 1994. Decision Support System for
Agro-technology Transfer (DSSAT)
van Bavel 1953 A drought criterion & its
application in evaluating drought incidence &
hazard.
2000
Stöckle et al 1994. CropSyst, a cropping
systems model: water/N budgets & crop yield
W Parton 1998. DayCent: Daily time-step soil
organic matter & N model
2010
Rosenzweig et al 2010. AgMIP. Agricultural
Model Intercomaprison Program
Some milestones in agro-ecosystem modelling:
NRM models
HL Penman 1948. Natural evaporation from
open water, bare soil and grass
1950
CT de Wit, 1971. A dynamic model of plant
and crop growth
JT Ritchie 1972. Model for predicting
evaporation from a row crop with incomplete
cover
JR Williams 1983. EPIC, The ErosionProductivity Impact Calculator
1960
1970
1980
Hochman et al 2009. Re-inventing modelbased DSS: YieldProphet®
Jones et al 1984. The CERES wheat and
maize models
IBSNAT, 1988. Experimental design and data
collection procedures for IBSNAT
1990
Li et al 1992. A model of N2O evolution from
soil driven by rainfall events-DNDC
McCown et al 1996. APSIM: a novel software
system for model development, model testing
& simulation in agricultural systems research
Hunt et al 2001. Agronomic data: advances in
documentation and protocols for exchange
and use (ICASA)
Duncan et al 1967. A model for simulating
photosynthesis in plant communities
Seligman & van Keulen 1981. PAPRAN: A
simulation model of annual pasture production
limited by rainfall and nitrogen
W Parton 1987. CENTURY: soil organic
matter (C) formation model
Tsuji et al 1994. Decision Support System for
Agro-technology Transfer (DSSAT)
van Bavel 1953 A drought criterion & its
application in evaluating drought incidence &
hazard.
2000
Stöckle et al 1994. CropSyst, a cropping
systems model: water/N budgets & crop yield
W Parton 1998. DayCent: Daily time-step soil
organic matter & N model
2010
Rosenzweig et al 2010. AgMIP. Agricultural
Model Intercomaprison Program
Some milestones in agro-ecosystem modelling:
Crop “models”  Decision support ( social science)
HL Penman 1948. Natural evaporation from
open water, bare soil and grass
1950
CT de Wit, 1971. A dynamic model of plant
and crop growth
JT Ritchie 1972. Model for predicting
evaporation from a row crop with incomplete
cover
JR Williams 1983. EPIC, The ErosionProductivity Impact Calculator
1960
1970
1980
Hochman et al 2009. Re-inventing modelbased DSS: YieldProphet®
Jones et al 1984. The CERES wheat and
maize models
IBSNAT, 1988. Experimental design and data
collection procedures for IBSNAT
1990
Li et al 1992. A model of N2O evolution from
soil driven by rainfall events-DNDC
McCown et al 1996. APSIM: a novel software
system for model development, model testing
& simulation in agricultural systems research
Hunt et al 2001. Agronomic data: advances in
documentation and protocols for exchange
and use (ICASA)
Duncan et al 1967. A model for simulating
photosynthesis in plant communities
Seligman & van Keulen 1981. PAPRAN: A
simulation model of annual pasture production
limited by rainfall and nitrogen
W Parton 1987. CENTURY: soil organic
matter (C) formation model
Tsuji et al 1994. Decision Support System for
Agro-technology Transfer (DSSAT)
van Bavel 1953 A drought criterion & its
application in evaluating drought incidence &
hazard.
2000
Stöckle et al 1994. CropSyst, a cropping
systems model: water/N budgets & crop yield
W Parton 1998. DayCent: Daily time-step soil
organic matter & N model
2010
Rosenzweig et al 2010. AgMIP. Agricultural
Model Intercomaprison Program
Some milestones in agro-ecosystem modelling:
Emergence of informatics issues
HL Penman 1948. Natural evaporation from
open water, bare soil and grass
1950
CT de Wit, 1971. A dynamic model of plant
and crop growth
JT Ritchie 1972. Model for predicting
evaporation from a row crop with incomplete
cover
JR Williams 1983. EPIC, The ErosionProductivity Impact Calculator
1960
1970
1980
Hochman et al 2009. Re-inventing modelbased DSS: YieldProphet®
Jones et al 1984. The CERES wheat and
maize models
IBSNAT, 1988. Experimental design and data
collection procedures for IBSNAT
1990
Li et al 1992. A model of N2O evolution from
soil driven by rainfall events-DNDC
McCown et al 1996. APSIM: a novel software
system for model development, model testing
& simulation in agricultural systems research
Hunt et al 2001. Agronomic data: advances in
documentation and protocols for exchange
and use (ICASA)
Duncan et al 1967. A model for simulating
photosynthesis in plant communities
Seligman & van Keulen 1981. PAPRAN: A
simulation model of annual pasture production
limited by rainfall and nitrogen
W Parton 1987. CENTURY: soil organic
matter (C) formation model
Tsuji et al 1994. Decision Support System for
Agro-technology Transfer (DSSAT)
van Bavel 1953 A drought criterion & its
application in evaluating drought incidence &
hazard.
2000
Stöckle et al 1994. CropSyst, a cropping
systems model: water/N budgets & crop yield
W Parton 1998. DayCent: Daily time-step soil
organic matter & N model
2010
Rosenzweig et al 2010. AgMIP. Agricultural
Model Intercomaprison Program
Where are we now?
 Focus and blurring
 The “Big 5” cropping systems models*
• APSIM, DSSAT, CropSyst, EPIC , STICS
 The “Big 5” NRM models?
• DayCent, CENTURY, DNDC, SWAT, RZWQM
 Blurring between the groups
•
•
•
•
EPIC ‘moved’ from NRM to CS
DSSAT crops in RZWQM
DayCent N & C in DSSAT
APSIM’s capability in NRM
– Soil C, nitrate leaching, nitrous oxide, erosion
 Emerging concepts on inter-operability
*Holzworth et al. (2014). EM&S
On-farm benefits derived from farming systems
modelling
 Pathway to novel farming systems
•
•
•
•
Spring-sown mungbeans
Aflatoxin management in peanuts
New roles for short or long season varieties
ect…
 Breeding (more so OS)
 Decision support
 Yield gap definition (& diagnosis)
Policy benefits of farming systems modelling
Protecting the Great Barrier Reef
 Threatened by agricultural-based
pollutants
 $290M Federal Govt investment in
improved practices
 Farming systems models central to
evaluation program (& hence to $’s !)
Brodie et al. (2013)
Carroll et al. (2012)
Looking forward – models
data
 Models help overcome lack of data
 Modelling drives acquisition of data
• e.g., mapping PAWC in Australian grains lands
 Explosion of data
• Proximal and remote sensing
• Coordination, storage, access
 In a world of big and rich data, what will our models look like?
• Bigger? Smaller?
• Bias-variance tradeoff
“Universal truth” –
Intensification leads to pollution
Gourley et al. (2012)
N surplus (kg/ha)
Thorburn & Wilkinson (2013)
Catchment discharge
Thorburn et al. (2013)
Milk production (L/ha)
On farm
Systems modelling 
• Pathways to sustainable farming
systems (prediction for prevention)
• Drive and focus data acquisition
• Support new farming systems
Thank you
[email protected]
Data and the bias variance trade-off
Domain space
Model
Data
Data and the bias variance trade-off