OVERSEER models the flow of nutrients on a farm, and produces nutrient budgets and greenhouse gas footprint reports.

While a growing number of farmers are required to report on their nitrogen and phosphorus losses to Regional Councils, OVERSEER looks at all seven major farm nutrients – nitrogen (N), phosphorus (P), potassium (K), sulphur (S), calcium (Ca), magnesium (Mg) and sodium (Na) – as well as acidity for pastoral blocks - to provide a full picture of the farm’s nutrient health.

Nutrient cycling on farms and OVERSEER

A farm is a complex living system; made up of soil, plants, water and often animals – which all contain nutrients. The changing nature of a farm adds to the complexity of modelling nutrient flows, because different farming practices and preferences affect how nutrients cycle around the farm.

To create a nutrient budget, OVERSEER captures information about how a farm is run and models it through a series of complex sub-models that mimic the known bio-physical processes operating across a farm system.

There is a full technical description of how OVERSEER works in the OVERSEER Technical Description.

Greenhouse gas reporting with OVERSEER

Agriculture contributes almost half of New Zealand’s greenhouse gas (GHG) emissions (49% of emissions were from agriculture in 2014).

OVERSEER helps users identify the major sources of GHG losses on farms. It models farm-level emissions, based on the New Zealand Greenhouse Gas Inventory methodology, reporting on a per-hectare and per-product basis.

GHG emissions from farms are not regulated in New Zealand. However, there is growing pressure on farmers and growers to manage emissions. In response, some New Zealand farms include GHG management strategies in their farm plans.