Nutrient tracking upgrade

Farmers, fertiliser companies and regulators such as regional councils use Overseer to determine nutrient levels and to set application rates for fertiliser.

The AgResearch scientist responsible for developing Overseer, Dr Mark Shepherd, told 200 people attending last week's Fertiliser and Lime Research Centre conference at Massey University that the upgrade will include new software and updating the science.

Shepherd says one purpose of the upgrade is to make it applicable to more farming systems. "For example more farms import or grow more supplements so that's a key part of the model we've tried to improve.

"We've looked again at some of the sub-models within Overseer to see that they are using the most up-to-date science. This is important because science is always evolving."

Shepherd says upgrading the software will also benefit users.

"One benefit will be greater opportunity to link with other software packages to avoid double data entry. The owners of that software have agreed the links will be free of charge and this could create benefits for users way into the future."

Overseer, launched in the 1990s, has always had nutrient budgeting as a primary fucntion. Its purpose has been to enable farmers to make more efficient use of their resources.

"That's always been the underlying principle and still is really," Shepherd says. "One outcome of not using nutrients as efficiently as possible is you lose them to the wider environment. They will then impact that environment."

While Overseer is used widely on farms, it's seldom actually used by farmers. Shepherd admits it's an 'expert users' tool and has to be used by trained people.

Fertiliser companies run in-house training and Massey University has courses on advanced nutrients and intermediate nutrient management. Now there is talk of having accrediting independent users to avoid perceptions that the system could be used to advantage by people with 'vested interests'.

Learning to use Overseer is not a matter of learning which buttons to press, but instead understanding farming systems, Shepherd says. It's a strategic planning tool farmers can use to manage nutrients.

Overseer must be kept relevant to users and developed in the way users want it to be developed. "A key to this is upgrading the science."