Independent review of nutrient tracking technology

Overseer is a tool that supports farmers and growers to improve performance and reduce losses to the environment through better use of nutrients on-farm. The suitability of Overseer as a regulatory tool is currently being investigated. 

Technical review of the software

An independent science advisory panel is conducting a technical review of the Overseer environmental modelling software.

The review consists of two parts

The first part will be an assessment of whether Overseer’s modelling approach is fit to use as a decision-making and regulatory tool. If it is, the advisory panel will look at which aspects should be subject to a more in-depth review. The draft report from Part 1 of the Technical Review is in the process of being reviewed. Once the panel has finalised the report, it will be provided to Ministers, and the scope for the second part of the review finalised. The review’s second part is dependent on these findings, and would take place over a year.

An additional $4 million per year has been allocated to a new contestable fund. This is to commission longer-term research to develop and evaluate new technologies and systems to improve freshwater quality.

In addition, funding has been allocated to extend the coverage of S-Map across New Zealand. S-Map is a digital soil map for New Zealand that collates a range of data and information. Produced by Manaaki Whenua – Landcare Research, S-Map is one of the underlying databases that Overseer draws on and is used by regional councils in environmental modelling.

Plans to review and improve Overseer pre-date and complement recommendations of the Parliamentary Commissioner for the Environment to ensure Overseer is suitable as a regulatory tool.

Biographies of the members of the Independent Science Advisory Panel

Dr Ian Johnson

Dr Johnson is a mathematician with experience in developing and writing biophysical computer simulation models incorporating environmental physics, plant, crop and pasture growth, soil hydrology, soil organic matter and nutrient dynamics, and animal growth and metabolism. Early in his career he was with the Biomathematics Department at the Grassland Research Institute in the UK and then the Department of Agronomy and Soil Science at the University of New England in Armidale, NSW. More recently, as director of IMJ Consultants, he has developed models in collaboration with universities and industry bodies in Australia and New Zealand.

He is widely published in the scientific literature, including as co-author of the textbook Plant and Crop Modelling (Thornley and Johnson, 1990, 2000). 

Dave Clark

Dave Clark is a dairy industry and research consultant. Between 1991 and 2013, he was Principal Scientist at the Dairying Research Corporation/Dexcel/DairyNZ. His research during that time looked at the intersection of farm economics and environmental impact, and was underpinned by a philosophy that environmental protection and profitable dairy farming are not mutually exclusive. 

In 2009 he was awarded the New Zealand Grassland Trust – Ray Brougham Trophy for services to New Zealand farming systems. He carried out mainly hill country research when he worked at Grassland Division, Department of Scientific and Industrial Research in the early stage of his career. 

Dr Brent Clothier

Principal Scientist with Plant & Food Research, Dr Clothier has extensive experience in soil science, especially with the measurement and modelling of water and solute movement in soil. He has published more than 300 peer-reviewed publications. 

He was elected a Fellow of the Royal Society Te Apārangi in 1994, and was the President of the New Zealand Society of Soil Science from 2008 to 2010. He is an Academician (Foreign) of the Chinese Academy of Engineering (Agriculture Division). 

Dr Donna Giltrap

Currently Research Priority Area Leader for Agricultural Greenhouse Gases Emissions and Mitigation at Manaaki Whenua – Landcare Research, Dr Giltrap is a modeller with a background in physics and mathematics. Her PhD is in physics and she also holds a Graduate Diploma in Applied Statistics.

She was part of the team that reviewed the nitrous oxide component of Overseer in 2018. She is a member of the New Zealand Soil Science Society.

Dr Clint Rissman

Dr Rissmann is the founder and Director of Land and Water Science Limited. He is also a Senior Adjunct Fellow in the Waterways Centre for Freshwater Management – a partnership between the University of Canterbury and Lincoln University. He has more than 10 years’ experience in earth systems science, specialising in water quality, biogeochemistry, greenhouse gases and systems thinking. He has co-authored a number of peer-reviewed publications researching soil and water quality in New Zealand.

He is a leading proponent of the physiographic approach which involves understanding water quality outcomes based on an integrated understanding of landscape properties.

Dr Nick Roskruge

Dr Roskruge is of Atiawa ki Taranaki and Ngāti Tama-ariki descent. He is Associate Professor in Horticulture at Massey University, and since 2003, has been Chairperson of Tāhuri Whenua, which represents Māori interests in the horticulture sector. He is a member of the Māori Advisory Board for Resilience to Nature’s Challenges – a National Science Challenge - and is also a member of the HSNO Committee of the Environmental Protection Authority (EPA). Previously he was Chair of Ngā Kaihautū Tikanga Taiao, the EPA’s Māori advisory committee.

He holds a PhD in soil science with his doctoral thesis looking at Māori land development through traditional knowledge, and the soil and horticultural sciences. He has had sabbatical periods in Peru and Chile, where he worked on crop genetics and indigenous systems projects. He was the 2013 recipient of a Fullbright Scholarship, undertaken at Cornell University (USA).

Dr Peter Thorburn

Dr Thorburn is a Chief Research Scientist and Research Group Leader in the Commonwealth Science and Industrial Research Organisation (CSIRO) in Queensland. He is responsible for agricultural systems research and is internationally recognised for his expertise in crop systems modelling. 

He represents CSIRO on the Agricultural Production Systems Simulator initiative, which owns the APSIM advanced farming systems model, and is co-lead for crop modelling in the international AgMIP program. He has extensive experience in scientific advisory groups, including as a member of groups on managing water quality in Great Barrier Reef catchments and reviewing or advising on Overseer in 2012 and between 2014 and 2017. 

Dr Robin White 

Dr White is Assistant Professor of Integrated Beef Systems Management at Virginia Tech in the United States. She is a member of the American Dairy Science Association, an editor for the Farm Systems Analysis and Economics and Resources and Environment sections of the Journal of Dairy Science, and an Editorial Board member of the Journal of Animal Science. 

Her research focuses on leveraging data analysis and animal nutrition to enhance the sustainability of food production systems. She graduated from Washington State University as a Doctor of Philosophy in Animal Sciences.