To create a nutrient budget, experts enter information about a farm’s physical characteristics (soils, climate and topography) and current management practices (irrigation, stocking rates, fertiliser use, etc).
The software then runs a series of complex sub-models mimicking the changing biophysical processes operating across a farm to model the annual average inputs, transfers and outputs of nutrients and emissions of methane, nitrous oxide and carbon dioxide.
You can read more in our Overseer Technical Description.
The Overseer software is jointly owned in equal shares by the Ministry for Primary Industries (MPI), AgResearch Limited and the Fertiliser Association of New Zealand (FANZ).
The owners established an independent company Overseer Limited in April 2016 to ensure the long-term viability of Overseer and meet growing user needs.
The company is jointly owned in equal ordinary shares by AgResearch and the Fertiliser Association of New Zealand. The Ministry for Primary Industries has equal voting rights alongside the shareholders. It is therefore considered a Public Entity.
Overseer Limited is chaired by one of its two independent Directors and is required to re-invest income into the ongoing improvement of Overseer.
Overseer is a modelling tool founded on over 30 years of scientific research. There are no other products in the world providing the same level of analysis of a farm system. It has been created to inform good farm management decisions and track trends over time.
All models are simplifications of complex science, and their predictions will always involve some uncertainty. We calibrate Overseer modelling against real measured data (called the calibration data set) to improve the certainty of the model’s estimates. We also peer review and test the science behind the model.
Good quality farm data is essential to good quality Overseer predictions (rubbish in equals rubbish out) and we recommend trained professionals are involved in creating farm budgets that all users follow the Best Practice Data Input Standards.
Importantly, any uncertainty around the model does not impact its ability to track trends over time, or to test the impact of various farm management practices.
Actual leaching from a farm block will vary, sometimes quite significantly, year-on-year due to variations in weather. Because Overseer was designed to help farmers test the impact of different farm management practices, it removes short term variability (such as weather events) so farmers can make good decisions for the long-term. The model therefore estimates how much nutrient leaching or gas emissions are likely to occur in a typical year if the management system described remains in place. It is not a one-off prediction for a single year. You can read more about this in the Technical Guidance document [link]
The Overseer results are therefore best used to create a baseline for each farm, and to guide and measure improvement over time.
Overseer is continuously evolving to reflect the latest scientific research and model validation, support changing farming practices, and improve the user experience. And like all software applications, it requires regular updating to fix bugs and make improvements.
Every update improves how the modelling predicts nutrient flows on farms.
MyOverseer is a page where users access the tool’s applications and engage with us about using it. MyOverseer includes:
Overseer is currently free to use, including free software updates. However, when our new product will be available under subscription. This will ensure sustainable, ongoing investment in and development of Overseer. Our founding principles around public good and increasing value for New Zealand will underpin our charging policies.
Overseer Limited is working on a new version of the tool, to be launched in the first half of 2018 and available on a subscription basis. It will connect to the current Overseer engine, but will have new user interface that will make data entry easier and faster, and present information in a way that farmers and their consultants can better understand and engage with. We’re also centralising farm accounts to reduce duplication of effort, smooth transition between version changes, and to support trend analysis. This centralised database will provide improvements in transparency and auditability for regulators and greater data security.
Some functions, including the outdoor pig model and the green house gas emissions modelling, will not be available through the new tool at launch, but we anticipate will be available by the end of 2018. We will provide updates on this as work progresses.