Good Nutrient Management: Nitrogen, Phosphorous, and Supplementary Feed

How you can do this:

• Test regularly (Olsen P or equivalent) for each Land Management Unit to track trends and impacts.
• Tailor fertiliser applications: annually for capital, biennially for maintenance.

Identify and Manage High-Risk Areas: 

Your own industry will have its own relevant practices and support material; you can find them here: Fertiliser Association NZ Industry Booklets

You can show you meet this GMP with: 

• Olsen-P (or equivalent) soil test monitoring results.  
• A Nutrient Budget and Fertiliser Plan (e.g. OverseerFM®) prepared by a certified Nutrient Management Advisor that records and maps risk areas.
• Fertiliser invoices.  

How you can do this:

Soil tests - for each Land Management Unit: 

• Regularly test soil, including soil mineral N-testing and Olsen P to identify nutrient needs, particularly for paddocks going into crop, to identify nutrient levels. 

• Soil test:
  • At least six (6) weeks before all fertiliser applications.
  • Before any capital fertiliser applications. 
  • Biennially for all maintenance applications.
• Manage soil nutrient levels within the target ranges for the soil type and farm enterprise.
• • Regularly testing soil, including soil mineral N-testing and Olsen P.
  • Identify nutrient needs, particularly for paddocks going into crop.

              ➡️ See industry-specific guidance below. 

Fertiliser Application Records:

• Record all fertiliser applications – product, rate, date, location.
• Record weather conditions - including soil temperature,  soil moisture deficit, and forecasted rainfall.
• Record irrigation scheduling. 

Nutrient budgets – prepared annually by a certified Nutrient Management Advisor:  

• Use a predictive nutrient budget (such as OverseerFM®) to manage nutrients on all land that supports your farm. Account for all sources of nutrients:
  • Soil nutrient states (including soil pH). 
  • Organic fertilisers – including liquid effluent and manure.
  • Imported feed and composts.
  • Previous land use (grazing and crops).  

➡️ A nutrient budget sets annual fertiliser applications for each Land Management Unit and guides decisions on nutrient inputs to meet pasture and crop demand. It should be updated yearly or whenever the farm system changes.

Science-based fertiliser guidance for New Zealand farm systems.

Fertiliser application

• Identify the targeted amount of fertiliser for the expected yield or annual production.
• Ensure N fertilisers for pasture production are focused on meeting anticipated feed demand using feed budgets.
• Include all on-farm N and P sources, such as legumes, effluent, feed, and compost, when calculating inputs to meet pasture and crop demand.
• Match N fertliser application and timing with crop growth stage, weather conditions and soil temperature.
  • Avoid the winter months.
  • Assess soil temperature prior to applying N-fertiliser to ensure the crop/pasture is actively growing – minimum soil temperature at 6 °C and increasing.
  • Assess soil moisture levels to determine whether the soil is not saturated or is forecast to become saturated.
• Avoid applying fertiliser close to waterways, including ephemeral waters and Critical Source Areas (CSAs), when heavy rainfall is forecast, and run-off is likely.
• Follow expert guidelines (like using crop calculators), expert agronomic advice or codes of practice where appropriate.
• Adjust the rates of fertiliser based on soil or plant test results as appropriate.
• Investigate the use of legumes to reduce nitrogen fertiliser requirements.
• Adjust nitrogen fertiliser for readily available and mineralisable soil N, previous crops, and other sources like effluent.

Dairy:

• Ensure your farm's audited nitrogen management system contains recording and reporting requirements for N fertiliser (including milking platform and any contiguous support land).
• Assess pasture/crop growth against feed requirements before applying N.
• Apply N – ‘little and often' and when the pasture is actively growing.  

➡️ Find Specific Guidance Relevant to Your Industry: 

• The Fertiliser Association of NZ Code of Practice for Nutrient Management also provides practical science-based information about fertiliser use for a range of New Zealand farm systems.
• Use your industry's crop-specific fertiliser application guidelines: Fertiliser Association NZ Industry Booklets

You can show you meet this GMP with: 

A Nutrient Budget prepared by a certified Nutrient Management Advisor.  

• Soil and plant test results.  
• Records of products applied (including the percentages of each nutrient).
• Records of the weather forecast at the time of application.
• Irrigation scheduling records. 
• Fertiliser proof of placement records – product, rate, date, location.
• Pasture walk data /Feed wedge and Feed Budget. 
• A predictive Nutrient Budget (eg OverseerFM®) and Nutrient Plan.
• N-cap records.

N-Cap records refer to the National Regulations limiting the use of synthetic N fertilisers on grazed land. Farmers must record their usage annually, ensuring it doesn't exceed 190 kgN/ha/yr. To find out more about what's required of you and get guidance on what you need to do, visit our Synthetic Nitrogen Fertiliser page.

How you can do this:

• Locate storage sites at least 50m away from permanent or intermittent waterways, ephemeral flow paths, Critical Source Areas (CSAs), and areas prone to flooding and run-off.
• Ensure stored fertiliser is fully contained with an impervious floor, bunded, and protected from rain.
• Collect and divert any rain or water away from the storage area.

You can show you meet this GMP with: 

• A Farm Map with fertiliser storage site(s) identified.  
• Fertiliser storage and handling policy.  
• Photographs and field observations of fertiliser storage areas.  

How you can do this:

• Ensure any contractors used for spreading fertiliser are accredited. The current industry standard is Spreadmark. You can learn more about the Spreadmark quality assurance programme from the  Fertiliser Quality Council. website. 
• Calibrate your spreading equipment according to its design specifications, ensuring it is tailored to the product being spread. Be sure to check both the spreading width and volume.
• Maintain fertiliser spreading equipment, following manufacturer's instructions.
• Check for ‘paddock stripes’ after spreading.  

You can show you meet this GMP with:   

• Calibration and maintenance records.
• Records of calibration processes.
• A copy of your contractor's accreditation (Spreadmark) certification.
• Contractor invoices.   
   

How you can do this:

• Store feed that has the potential to create leachate in hard-sealed areas, collect any leachate produced, and add this to an existing effluent management system or ensure storage sumps are big enough for leachate collection of about 3m³/100T silage.
• Site and divert overland flow and rainwater away from feed storage areas.
• Position feed storage and feed-out areas away from all waterways, ephemeral flow paths, and critical source areas (DairyNZ advises their farmers at least 50m).  
• Ensure silage is properly wilted before stacking (slightly damp when squeezed) to minimise leachate generation and ensure it remains sealed while stored to prevent rotting. Read more here.
• Consider the forecasted weather and, if using contractors for silage storage, coordinate with them early to plan the work.
• Ensure permanent feed-out areas/facilities are sealed, and effluent is collected.
• If feeding out in paddock, distribute feed to minimise soil damage (from farm equipment and animals) and potential surface run-off to waterways, i.e., avoid Critical Source Areas. 

You can show you meet this GMP with: 

• A Farm map identifying feed storage and feed out areas.
• Feed out area design plans.
• Photographs and field observations of feed storage areas.