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Jonathan Ojeda

Crop Physiologist – Crop Modeller

University of Tasmania

Biography

Jonathan is a Junior Research Fellow at the Tasmanian Institute of Agriculture, University of Tasmania. His research interests are in quantifying the effects of crop management and climate variability on soil-crop processes and integrating data into mechanistic models at different spatial scales. He has a passionate interest in disentangling sources of uncertainties in biophysical and mathematical models to better predict crop growth, both yield and quality and environmental impacts in agricultural systems. This requires a broad understanding of how the environment influences crop growth and development; how rainfall, irrigation, and fertilizer influence soil conditions; how crops obtain water and nutrients from the soil; how soil processes contribute to the loss of carbon and nitrogen; and how all these processes interact.

Interests

  • Crop modelling across scales
  • Environmental data analysis
  • Soil-plant-climate interactions
  • Crop model development
  • Climate change assessments

Education

  • PhD in Agricultural Sciences, 2017

    National University of Mar del Plata, Argentina

  • Agricultural Engineer, 2011

    National University of Entre Ríos, Argentina

Skills

Python

R

Markdown

GitHub

Statistics

Plotting

International Networking

Communication

Team work

Experience

 
 
 
 
 

Junior Research Fellow

Tasmanian Institute of Agriculture, University of Tasmania

Nov 2017 – Present Hobart, Tasmania, Australia
Responsibilities:

Basic research and methods

  • Uncertainty analysis in climate change impact studies for irrigated maize systems in Spain.
  • Impact assessment of livestock farm performances regionally under different climate change scenarios in Australia, Argentina, and Uruguay.
  • Development of a tool to download gridded climate data in an APSIM format from SILO datasets across Australia.
  • Model phenological variation with sowing date and cultivar for lentil and faba bean against the climatic patterns of frost and heat in Australia.
  • Coupling existing multiple-scaling and remote-sensing techniques with advanced biophysical models to evaluate drivers of yield variability in Australia, Argentina, and Uruguay.
  • Quantification of crop model uncertainties (input, structure and parameter uncertainty) using sensitivity analysis tools such as Sobol, Morris, ANOVA.
  • Examine alternative existing model-scaling techniques and assess drivers of yield variability at the regional scale (gridded based crop simulations).
  • Point-based crop model calibration/validation under the Water for Profit program in Tasmania, Australia.
  • Develop a new potato module in APSIM Next Generation. Evaluating how accurately APSIM NG simulates potato productivity across several agricultural systems worldwide.

Applied research and industry engagement

  • Develop a virtual tool to analyze future scenarios to decision support for dual-purpose crops (canola and wheat) in Tasmania (Australia) in collaboration with GRDC and CSIRO.
  • Collect and organize several potato agricultural datasets (climate, soil and crop management) from industry partners across Tasmania (Simplot and McCain) for modelling purposes and scenario analysis with farmers.
  • Conduct workshops with Australian farming groups under a CRC Soil project focused on model development to evaluate the effect of soil constraints on crop and soil productivity.
  • Lead workshops with livestock industry decision-makers who will perform foresight exercises to explore alternative futures under climate change scenarios in Argentina, Uruguay, and Australia.

Coaching, supervision and leadership activities

  • Supervise Ph.D. students in collaboration with external co-supervisors (CSIRO Brisbane and Toowoomba).
  • UTAS Data Network Co-director (Mar-2019 to Nov-2019). Lead discussion and meeting for a group of researchers interested in data management across the University.
Funded by:

Tasmanian Institute of Agriculture (AUD $336,423)

 
 
 
 
 

Postdoctoral Research Fellow - Graduate Teaching Assistant

Research Council of Argentina, CONICET - Ecophysiology and Forage Production, National University of Entre Ríos

Apr 2017 – Nov 2017 Parana, Entre Rios, Argentina
Responsibilities:

Research

  • Participate actively in the preparation for national and international proposals and research grants.
  • Participate in dissemination activities related to my research line.
  • Collect, analyze and interpret results, prepare seminars, workshop presentations, and present oral and written scientific reports papers in high-quality journals.

Teaching

  • Post-graduate (~15 students) and undergraduate (~50 students) courses on crop ecophysiology and agricultural systems.
  • Advised one Honours thesis (Bachelor’s degree in Agronomy) at the National University of Entre Ríos. Honors thesis description: Impact of cover crops with different defoliation levels on soil carbon.
Funded by:

Research Council of Argentina, CONICET (AUD $35,568)

 
 
 
 
 

Postgraduate Research Fellow - Graduate Teaching Assistant

Research Council of Argentina, CONICET - Ecophysiology and Forage Production, National University of Entre Ríos

Apr 2012 – Apr 2017 Balcarce, Buenos Aires, Argentina
Responsibilities:

Research

  • Apply ecophysiology concepts to the management of annual/perennial cropping systems for forage and grain production through field experimentation and biophysical simulation models, with emphasis on improving resource use efficiency with minimal environmental impact.
  • Use simulation models to analyze and predict the long-term productivity and stability of different cropping systems, encouraging the sustainable intensification of farm crop/forage production systems and improving environmental resources management strategies (solar radiation, soil water, and nutrients [mainly N]) while reducing environmental risks and climatic uncertainty.
  • Analyze and organize data for climate, soil, crop production, and management from five locations across Argentinian Pampas.
  • Calibrate and validate APSIM to predict biomass production at the crop and sequence level.
  • Design and conduct a 3-year field experiment in Balcarce, Argentina (May 2012 to May 2015).
  • Conduct probe calibration for Argiudoll soil in Balcarce, Argentina.
  • Data analysis and dissertation manuscript writing.

Teaching

  • Research and teaching “Crop Physiology and Ecology”.
  • Undergraduate course (~50 students).
  • Supervision of staff (international students).
  • Supervision of Honours theses.
Funded by:

Research Council of Argentina, CONICET (AUD $69,240)

 
 
 
 
 

Industry Assistant and Agricultural Consultant

DASER AGRO S.A, Dow AgroSciences

Apr 2011 – Apr 2012 Maria Grande, Entre Rios, Argentina
Responsibilities:

Consultancy

  • Responsible for field experiments.
  • Assistant for the seed marketing project.
  • Private consultant in agricultural systems.
  • Invited talks for growers.
 
 
 
 
 

Undergraduate Teaching Assistant in Mathematics

National University of Entre Ríos

Apr 2007 – Apr 2011 Oro Verde, Entre Rios, Argentina
Responsibilities:

Teaching

  • Research and teaching “Mathematics”.
  • Undergraduate course (>100 students).
  • Design and conduct a field experiment in Paraná (Argentina) for one summer season.
  • Data analysis and dissertation manuscript writing.
Funded by:

Argentinian Ministry of Education (AUD $9,471)

Publications

Modelling phenology to probe for trade-offs between frost and heat risk in lentil and faba bean

We model phenological variation with sowing date and cultivar for lentil and faba bean against the climatic patterns of frost and heat.

Modelling inter-annual variation in dry matter yield and precipitation use efficiency of perennial pastures and annual forage crops sequences

We compared two forage landcovers, the sequence oats-maize and pure alfalfa across a mean annual precipitation gradient.

Vertical distribution of root biomass and soil carbon stocks in forage cropping systems

We assessed the association between root biomass, C-OM, C in mineral-associated organic matter (C-MAOM), and C in particulate organic …

Partners

International Visitors

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Jose Capuano

Agricultural Engineer

Horticultural industry, Biosecurity, Potatoes, Perennial crops, Systems analysis

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Bahareh Kamali

Postdoctoral Researcher

Large scale agro-hydrological modeling, Model calibration, Parameter estimation, MONICA model

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Fernando Lattanzi

Research Director

Pasture ecophysilogy, C and N dynamics, Forage crops, Dairy, Farm systems modelling

International Collaborators

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Hamish Brown

Scientist

Crop model development, Genotype-environment interactions, Crop eco-physiology, Model development, Soil-plant-climate interactions

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Gonzalo Irisarri

Senior Researcher

Remote sensing, Livestock production, Pastures, Forage crops, Climate change, Spatial variability

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Ehsan Eyshi Rezaei

Senior Researcher

Development of crop models, Crop phenology, Model up-scaling, Climate change, Heat stress, Drought stress

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Heidi Webber

Head of Integrated Crop System Analysis Group

Modelling crop stress responses, Soil and water conservation in cropping systems, Develop modelling approaches, Integrated biophysical, economic and policy assessment

Collaborators in Australia

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Keith Pembleton

Associate Professor

Farming systems, Decision support systems, Crop modelling, Whole-farm analysis, Systems modelling, Dairy systems

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Katharina Waha

Team Leader Food Systems and Global Change

Regional and global climate change, Model uncertainty analysis, Cross-scale spatial analysis and data integration, Agricultural Systems modelling

Research Exchange and Courses

ZALF

2020 - Visiting Researcher

University of Entre Rios

2019 - Course Coordinator

University of Gottingen

2019 - Visiting Researcher

Purdue University

2015 - Visiting Researcher

Talks and poster presentations

Historical and current approaches to decompose uncertainty in crop model predictions (poster)

We explored the diverse statistical approaches used to decompose crop model uncertainty

Contact

  • +61 492 507 910
  • Rm 3.03 Level 3 Old Medical Science Building Private Bag 141, Hobart, TAS 7001
  • Enter Old Medical Science Building and take the stairs to Office 303 on Floor 3
  • Monday to Friday 08:00 to 16:00