Dr Justin Sexton ~ Postdoctoral Research Fellow

Overview

Recently Justin has been contributing to the development of the Opticane.net web app. This has included working with integrating weather forecast data and on-line crop model as well as contributing to the development of the front end user experience. 

Justin Sexton is currently a postdoctoral research fellow at James Cook University. He has recently completed his PhD at JCU in the area of Near Infra-Red Spectroscopy (NIRS). Justin has a background in statistical analysis. His research focus has primarily been within the Australian Sugarcane industry. 

Aside from NIRS, Justin's research projects has included climate change analysis, agricultural systems simulation and crop model calibration. Justin has also contributed to research in mathematics and science teaching.  

 

Current Projects

CSSIP (2020 - ): Climate Smart Sugarcane Irrigation Partnership

The CSSIP project aims to help farmers improve their sugarcane irrigation management. We are:

• Developing improved weather forecasts that account for variability across the Burdekin catchment;
• Integrating the weather forecasts within a crop model such as IrrigWeb; and
• Building software that empowers farmers to irrigate more efficiently.

The CSSIP project will develop weather forecasts with improved spatial resolution, accounting for the regional variability across the Burdekin catchment. Using historical weather data, we have identified five climate zones. The project will generate different weather forecasts for each zone. These will be based upon the Bureau of Meteorology forecasts but “downscaled” to account for systematic differences between zones. Improved spatial resolution in weather forecasts means that farmers can access more accurate information, allowing for better decision making and improved farm management. A current version of the web-app associated with this project is available here.

 

Higher Education Projects

 

PhD (2020): Statistical data mining algorithms for optimising analysis of spectroscopic data from on-line NIR mill systems

This Thesis looked at the idenitification of atypical (deteriorated) sugarcane samples using on-line Near Infrared (NIR) sensors. It was found that identifying atypical samples could help remove bias in estimates of Commercial Cane Sugar (CCS), a primary measure used in cane payment calculations. The methodology developed in this thesis could be used to track occurrences of atypical cane or improve quality estimates providing benefits at various stages along the industry value chain. The full thesis can be found here.

 

MSc (2014): Bayesian statistical calibration of variety parameters in a sugarcane crop model

The objectives of this thesis were to:

1. investigate the capability of the APSIM‐Sugar model to simulate yield differences between sugarcane varieties under different climatic conditions;
2. investigate the sensitivity of model outputs such as biomass and sucrose yields to key model input parameters; and
3. evaluate the use of two Bayesian approaches to calibrate variety parameters in the APSIM‐Sugar model.

This thesis developed and tested a methodological framework which include performing a global sensitivity analysis and a Bayesian approach to calibrate variety parameters in APSIM-Sugar. The methodological framework provided a validated strategy for improving and updating variety definitions. The full thesis can be found here.

Interests

Research

• Crop Modelling
• Bayesian calibration and uncertainty analysis
• Sensor data analysis
• Data visualization and interaction

Experience

• 2019 to 2021 - Postdoctoral Research Fellow, James Cook University (Townsville)
• 2016 to 2019 - Associate Lecturer, James Cook University (Townsville)
• 2014 to 2015 - Research Officer, James Cook University (Townsville)
• 2010 to 2013 - Casual Research Worker, James Cook University (Townsville)

Research Disciplines

• Agriculture, land and farm management (3002)
• Crop and pasture production (3004)
• Statistics (4905)

Socio-Economic Objectives

• Industrial crops (2606)

Awards

• 2017 - Mac Hogarth Agricultural Award: Awarded for Best student paper in the Agricultural session of the 39th ASSCT conference
• 2014 - JCU Citation for Outstanding Contributions to Student Learning: Maths in Science Teaching, Research and Development Team
• 2014 - Office for Learning & Teaching Citation for Outstanding Contributions to Student Learning: Maths in Science Teaching, Research and Development Team

These are the most recent publications associated with this author. To see a detailed profile of all publications stored at JCU, visit ResearchOnline@JCU. Hover over Altmetrics badges to see social impact.

Journal Articles

• Biggs J, Everingham Y, Skocaj D, Schroeder B, Sexton J and Thorburn P (2021) The potential for refining nitrogen fertiliser management through accounting for climate impacts: an exploratory study for the Tully region. Marine Pollution Bulletin, 170.
• Sexton J, Everingham Y, Donald D, Staunton S and White R (2020) Investigating the identification of atypical sugarcane using NIR analysis of online mill data. Computers and Electronics in Agriculture, 168.
• Sexton J, Everingham Y, Donald D, Staunton S and White R (2018) A comparison of non-linear regression methods for improved on-line near infrared spectroscopic analysis of a sugarcane quality measure. Journal of Near Infrared Spectroscopy, 26 (5). pp. 297-310
• Sexton J, Everingham Y and Inman-Bamber G (2017) A global sensitivity analysis of cultivar trait parameters in a sugarcane growth model for contrasting production environments in Queensland, Australia. European Journal of Agronomy, 88. pp. 96-105
• Everingham Y, Sexton J, Skocaj D and Inman-Bamber G (2016) Accurate prediction of sugarcane yield using a random forest algorithm. Agronomy for Sustainable Development, 36 (27). pp. 1-9
• Sexton J, Everingham Y and Inman-Bamber G (2016) A theoretical and real world evaluation of two Bayesian techniques for the calibration of variety parameters in a sugarcane crop model. Environmental Modelling & Software, 83. pp. 126-142

Conference Papers

• Sexton J, Melville B, Schepen A, Philippa B, Attard S, Davis M and Everingham Y (2022) Opticane: an irrigation and weather support tool. Proceedings of the Australian Society of Sugar Cane Technologists. In: ASSCT 2022: 43rd Annual Conference of the Australian Society of Sugar Cane Technologists, 18-22 April 2022, Mackay, QLD, Australia
• Stringer J, Skocaj D, Rigby A, Olayemi M, Everingham Y and Sexton J (2019) Productivity performance of climatological sub-regions within the Tully mill area. Proceedings of the 41st Annual Conference of the Australian Society of Sugar Cane Technologists. In: ASSCT 2019: 41st Annual Conference of the Australian Society of Sugar Cane Technologists, 30 April - 3 May 2019, Toowoomba, QLD, Australia
• Sexton J, Everingham Y, Donald D, Staunton S and White R (2018) A feasibility test for detection of atypical cane samples using near infrared spectroscopy. Proceedings of the 40th Annual Conference of the Australian Society of Sugar Cane Technologists. In: ASSCT 2018: 40th Annual Conference of the Australian Society of Sugar Cane Technologists, 17-20 April 2018, Mackay, QLD, Australia
• Thorburn P, Biggs J, Skocaj D, Schroeder B, Sexton J and Everingham Y (2018) Crop size and sugarcane nitrogen fertiliser requirements: Is there a link? Proceedings of the 40th Annual Conference of the Australian Society of Sugar Cane Technologists. In: ASSCT 2018: 40th Annual Conference of the Australian Society of Sugar Cane Technologists, 17-20 April 2018, Mackay, QLD, Australia
• Sexton J, Everingham Y, Skocaj D, Biggs J, Thorburn P and Schroeder B (2017) Identification of climatological sub-regions within the Tully mill area. Proceedings of the 39th Annual Conference of the Australian Society of Sugar Cane Technologists. In: ASSCT 2017: 39th Annual Conference of the Australian Society of Sugar Cane Technologists, 3-5 May 2017, Cairns, QLD, Australia
• Sexton J, Everingham Y and Donald D (2017) A comparison of data mining algorithms for improving NIR models of cane quality measures. Proceedings of the 39th Annual Conference of the Australian Society of Sugar Cane Technologists. In: ASSCT 2017: 39th Annual Conference of the Australian Society of Sugar Cane Technologists, 3-5 May 2017, Cairns, QLD, Australia