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The Fertiliser Association of New Zealand promotes and encourages responsible and scientifically-based nutrient management.
Compliance with the law is essential, both legally and to meet the terms of this Code. You must comply with the legal requirements which apply to the particular nutrient management activities undertaken on the property. These include those contained in the applicable Regional Council’s plans, enacted through resource consent conditions or through the conditions applying to permitted activities. Some industries have additional requirements.
Ask the relevant industry organisations and/or Regional Council to supply a list of their requirements to ensure that you are fully aware of what applies to local operations. These requirements may not have changed since last year’s NMP was drawn up but it is good practice to check.
Knowledgeable staff will be available for all of these bodies. It is much easier to discuss the options before completing or implementing the plan than to fix a mistake later.
Fertiliser type, application rates and timing are key management factors that can be greatly varied to meet NMP objectives, balancing information about the environmental risks, present nutrient levels, capital or maintenance dressings, and the objectives for the property. Fertiliser recommendations must take into account the environmental risks and best management practices presented in this Code and the results of nutrient budgets. Many land managers use their fertiliser company representative or consultant to assist in fertiliser planning.
Good records of results achieved from previous fertiliser applications will help. Where problems have been encountered (e.g. dry matter production targets have not been met, nitrate leaching to groundwater) then planned management practices need to prevent or remedy these when future fertiliser is applied.
This phase of planning may identify several different fertiliser types that could be used to supply the required nutrients in suitable forms and proportions while managing environmental risks. Decisions on the best types and application rates to meet the plan’s objectives will then be based on financial and physical compatibility factors. Many consultants use computer software to select the least cost fertiliser combination (types and application rates) to meet nutrient application objectives.
Nutrient management activities associated with this Code require preparation of a nutrient budget. The nutrient budget is done to assess the cumulative effects of nutrient use. This will allow adjustment of inputs, such as fertiliser, if necessary.
There are several ways to prepare a nutrient budget. One popular approach is to use the nutrient budgeting software, ‘Overseer’.
Typically the nutrient budget will use historical fertiliser applications (e.g. in a ‘maintenance’ fertiliser programme) and the latest soil test results. For other situations – e.g. where increased fertiliser and increased production are expected – then the nutrient budget should be prepared to evaluate these objectives. This situation may require several nutrient budgets to compare alternative scenarios. This is easily achieved with Overseer once base farm information has been entered.
A nutrient budget compares inputs and outputs to establish changes in soil nutrient levels. Inputs include nutrient:
Nutrient outputs and losses occur in:
It is important to realise that a ‘balanced budget’ is not always desirable. Keeping the nutrient budget in balance will, in the long term, maintain soil fertility at its current level but this is not always the best result. For example, if present soil nutrient status for, say, phosphorus (P) is low, then the land manager may want greater P inputs than outputs so that soil P rises – i.e. they will apply capital P dressings. Conversely, if the soil has very high P levels then greater outputs than inputs (or even no P fertiliser inputs at all) could be appropriate.
A nutrient budget is not a fertiliser recommendation.
A nutrient budget can be used as a modelling tool to test different nutrient scenarios providing a feedback loop to fertiliser recommendations.
Some land managers may wish to prepare their own nutrient budget or alternatively seek the services of a fertiliser company representative or consultant who should be an accredited nutrient management advisor. Regardless of who prepares it, accurate input information is required if the nutrient budget is to have credibility and be of use as a management guide. Nutrient budgets can be difficult to interpret and guidance on what the output data means may be necessary in situations where a land manager has prepared their own budget.
Best Management Practices And Considerations - Fertiliser sets out considerations and best management practices for fertiliser handling, use and application to overcome any significant environmental risks identified in Step 3. The NMP must list the best management practices selected to reduce the risks on the property. The best management practices listed in Best Management Practices And Considerations - Fertiliser are written in such a way that they can be directly transferred into the NMP to provide a definite statement of management intent. Actual practice can then be compared with the planned practices and improvements can be made if they are needed.
The environmental risks identified as important for the situation will prompt selection of practices or products to avoid or minimise these risks. However, there may be further practices that are important to overcoming the risk of adverse environmental effects, which are specific to the area and operation. It is important to include these as part of the listed best management practices.
Some land managers might also set additional preferred management practices to meet personal objectives – e.g. annual soil testing or a limit on total nitrogen applied, independent of any Regional Council or industry specification.
This Code addresses in detail best management practices for fertiliser handling, use and application. Other best management practices to be considered include riparian management, wetlands, winter grazing, herd homes and nitrification inhibitors.
When including nutrient management activities such as dairy effluent disposal, in the NMP it may be useful to contact the local Regional Council or industry advisor for the best practices appropriate to the activities and area.
NOTE: If you have assessed the environmental risks from a nutrient management activity (e.g. fertiliser use, dairy effluent irrigation and cropping) as being of medium to high significance a separate management guide should be prepared for those that are medium to high. The management guide(s) should address all identified LMU’s.
The management guide needs to include reference to all legal and industry requirements and the identified best management practices relating to the particular activity. If the management guide relates to a specific fertiliser nutrient (e.g nitrogen) then it should also include the fertiliser type and amount recommended for that nutrient plus any supporting information such as nutrient budget results.