Nutrient management

Fertiliser is often the largest expense for farms. It is therefore important that farmers understand how to apply fertiliser efficiently to minimise losses to water.

What's a nutrient management plan?

Nutrient management plans are like financial budgets. They're useful tools to plan ahead and keep track of what's coming in and going out on an individual farm. Taking time to understand nutrient cycling for your farming system will make it easier to achieve sustainability over the long term, both in terms of economic and environmental goals.

Nutrient management plans combine all the tools that science has produced to allow the trained nutrient management farm advisors to develop fertiliser recommendations, which maximise the productivity of individual farms while minimising or mitigating the environmental impacts of nitrogen and phosphorus loss to surface and groundwater.

The benefits of a nutrient management plan

• Huge cost savings by identifying management options to ensure the right amount and type of fertiliser is applied to maximise production and soil fertility.
• Estimation of the off-farm impacts of nitrogen and phosphorus on water quality and suggested mitigation strategies to reduce nutrient losses and environmental effects.
• Monitoring of fertiliser performance, and benefits of mitigation, for continued improvements.

Using OVERSEER

OVERSEER Nutrient Budgets (Overseer) is a software tool that estimates nutrient flows through the animal, pasture, crop and soil. It provides estimates for off-farm losses of nutrients including nutrient leaching and run-off, phosphorus run-off, risk index, and greenhouse gas emissions.

The tool requires a wide range of information, including soil type and slope, soil tests, fertiliser history, paddock use and supplementary feed. Don't be put off as you and your fertiliser representative or farm consultant probably have most of this information.

The outputs provided will be based on your current farming system, and should be considered on an annual basis (or longer if there are no changes to your farming system). While the information will be useful to you for farm planning, the quality of outputs is reliant on spending some time entering the correct data. As with any model,

OVERSEER can be manipulated, but it does represent the best approach at the moment.

What is a nutrient budget?

A nutrient budget is a statement of the total nutrient balance for a specific area or production system, taking into account all the nutrient inputs and outputs.

What's next?

Environment Southland is promoting the use of nutrient budgets as a good management practice to ensure farmers gain a greater awareness and understanding of nutrient management for their farms.

While having a nutrient management plan or nutrient budget alone won't improve water quality, the information in the budget will help you make practical decisions that could minimise nutrient losses from your farming system.

Knowing about nutrient budgets will put farmers in a good position to be involved in community discussions around setting and meeting catchment limits. Environment Southland is required to go through this process to fulfil the objectives in the National Policy Statement for Freshwater.

Where to go for assistance

It is recommended an experienced and accredited nutrient management adviser, or accredited consultant with a good understanding of nutrient management tools and farming systems, is engaged to help formulate a nutrient management plan for your farm.

For more information on nutrient management please contact:

• Your fertiliser company
• Fertiliser Association of New Zealand
• Dairy NZ or Beef and Lamb NZ
• Farm Consultants
• Foundation of Arable Research (FAR)
• Horticulture NZ (Hort NZ)