OVERSEER®

Purpose

OVERSEER® is an agricultural management tool which assists farmers and their advisers to examine nutrient use and movements within a farm to optimise production and environmental outcomes. The computer model calculates and estimates the nutrient flows in a productive farming system and identifies risk for environmental impacts through nutrient loss, including run off and leaching, and greenhouse gas emissions.

Description

OVERSEER® is a nutrient budgeting model that is widely used in New Zealand and is required to be used under some regional council policies. It can assist farmers and regulators with the following:

• Calculating on-farm budgets for a wide range of nutrients and farming systems (pastoral, arable/vegetable and fruit crops) based on data inputs readily available from the farm.
• Understanding the fate of these nutrients is an important precursor to developing a Nutrient Management Plan.
• Calculating and reports farm-level emissions (greenhouse gases) for farms based on the farm-specific methods that are related to the National Inventory methodology.
• Emissions are reported on a per hectare and per product basis. This allows users to identify major sources on farms and to test management strategies for decreasing emissions.
• Calculating maintenance nutrient applications for pastoral farms, i.e. the levels of nutrients required to maintain the current soil test values.

Is a useful fertiliser planning tool on its own, additional software is used by fertiliser companies to provide farm specific econometric information for further developing fertiliser recommendations. This information can support farmers and their advisors in planning nutrient use and assessing the potential environmental losses. OVERSEER® modelling can also support environmental policy development, most notably around Lake Taupo and as a part of Horizons One Plan. OVERSEER® does not include economic analysis, so outputs needs to be combined with other economic models to assess impacts of options on the farm business.

The OVERSEER® model has its own website which provides a full explanation of the model, how to use it, benefits of use, and it provides a range of publications and science papers. https://www.overseer.org.nz/

Latest Version	6.3.0 (2018)
State of Development	Released and updated
Current Development Activity	Overseer Farm Modelling (FM) software - a new online application of Overseer is due for release in May 2018

Scope

Outcome Areas	Environmental
Management Domains	Land, Freshwater
Subdomains	Contaminant Losses, Crop/Farm Systems
Intended End Users	Fertiliser representatives, farmers, scientists, policy researchers
Spatial Resolutions	Unknown
Spatial Extents	Land or Business Unit
Spatial Dimensions	1D
Temporal Resolutions	Years
Temporal Extents	Unknown
Steady State or Dynamic	Steady State
Level of Integration	Environmental

Input & Output Data

Key Input Data	Land Use, Rainfall
Input Data Formats	XLS(X)
Key Output Data	Drainage nutrient loss

Accessibility

Open/Closed Source	Closed Source
Licence Type	No Licence

User Information

Operating Systems	MS Windows
Software Needed	Unknown
User Interface	Graphical desktop
Ease of Use	Easy
Use in Policy Process	Plan (Policy Formulation), Do (Policy Implementation), Check (Policy Evaluation)
Documentation	For Manuals, release notes, guides and technical manuals see: https://www.overseer.org.nz/technical-description-of-overseer https://www.overseer.org.nz/publications
Support	Training courses available

Technical Considerations

Methods included for managing uncertainty	https://www.overseer.org.nz/uncertainty-in-model-results
Analytical Techniques	Input/output
Model Structure
Keywords	fertiliser, nutrient budgeting, nutrient management planning, greenhouse gas
Linkages to other Models	Catchment Land Use for Environmental Sustainability (CLUES)
Key References	See:  https://www.overseer.org.nz/  for general information or https://www.overseer.org.nz/publications for range of publications Technical Description of OVERSEER - 2015 (PDF)

Associated Case Studies