Feeding the world’s growing population

New Zealand’s reputation as a quality food producer is growing.

Optimising food production

Over the next 50 years farmers around the world will need to produce more food than has been grown over the past 10,000 years.

Best use from a limited resource

Fertiliser helps farmers produce food efficiently by replenishing the soil. But fertiliser needs to be used responsibly.

Responsible and sustainable nutrient management

The Fertiliser Association invests in research and tools to ensure farm profitability while minimising nutrient losses to the environment.

The Fertiliser Association of New Zealand promotes and encourages responsible and scientifically-based nutrient management.

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Appendix 3: Fertiliser Activities And Environmental Concerns

Nitrate leaching to groundwater

Indicator: Increasing nitrate nitrogen in groundwater 

Note: Nitrate leaching is not easily measured by users so the emphasis should be on avoiding leaching by following best management practices such as nitrogen fertiliser application, animal grazing and dairy effluent irrigation rather than remedial action after it has occurred.

Possible cause Best practice for remedial action
Nitrogen input exceeding nitrogen uptake
  • Reduce nitrogen input.
  • Increase nitrogen uptake in plants by matching nitrogen applications to plant growth.
  • Ensure low or excessive pH is not directly or indirectly restricting N uptake.
  • Ensure pastoral growth is sufficiently abundant to cope with the uptake. Pasture should be at least 25 mm high (approx. 1000 kg DM per ha) before nitrogen is applied.
  • Balance nutrients (fertiliser inputs).
  • Avoid winter application of N when the temperature is low and /or it is wet.
High nitrogen application rates (e.g. greater than 200 kg N/ha/yr)
  • Reduce nitrogen input.
  • Ensure high nitrogen uptake by:
    • Timing for growth periods
    • Splitting dressings
    • Ensure appropriate placement
Applying nitrogen in a single application
  • Split the nitrogen applications so that smaller amounts are applied more frequently.
Heavy rainfall (i.e. >20mm within a day of applying N) or irrigation within a day of applying fertiliser
  • Check weather forecast and avoid application if heavy rain seems likely.
  • Avoid applying fertiliser when soil is above field capacity (i.e. puddles on the ground).
  • Select a less mobile nitrogen fertiliser (containing ammonium N rather than nitrate N).
  • Apply fertiliser after irrigation (e.g. border-dyke irrigation) especially when ground cover is low (>80%).
Permeable soils which can cause nitrogen leaching. (i.e. if puddles disappear quickly after heavy rainfall)
  • Apply smaller amounts of fertiliser more often.
  • Reduce the amount of nitrogen applied.
  • Select a less mobile nitrogen fertiliser e.g. Ammonium N rather than nitrate.
Nitrogen fertiliser not securely stored
  • Ensure nitrogen is contained within the storage area on an impervious floor.
  • Protect stored N from rain.
High water table present
  • Reduce amount of N applied per application.
    Match application to plant uptake.
Contamination from loading sites
  • Ensure no spillage when loading in or out of storage, or into application equipment.

 

Contamination of surface water from fertiliser run-off

Indicator: Algal blooms/excessive weed growth – elevated nutrient levels (e.g. nitrogen and phosphate)

Possible cause Best practice for remedial action
Slope too steep for vehicle access or natural drainage lines running down to open water
  • Use slower release fertilisers, or split fertiliser applications. Apply smaller amounts more frequently.
  • Develop and maintain riparian strips.
  • Avoid applying fertiliser when the ground is saturated.
  • Increase buffer distance between application site and the open water.
High rainfall or irrigation within a day of fertiliser application
  • Check weather forecast and avoid application if heavy rain seems likely. Avoid irrigation in excess of field capacity.
  • Use slower release fertilisers, or reduce the fertiliser application rates in wetter conditions.
  • Split the application rates. Apply smaller amounts more frequently.
  • Apply fertiliser after irrigation (in the case of, border-dyke irrigation) especially when the ground cover is low (>80%).
  • Check irrigation technique is appropriate for the crop.
Less than 80% ground cover (e.g. pasture less than 25 mm high or approx. 1000 kg DM/ha)
  • Increase ground cover before applying fertiliser.
  • Maintain resilient and productive ground cover that is capable of efficiently using the fertiliser.
  • Plant row crops on contour.
  • Ensure pasture is not over-grazed (reduce stocking rate or grazing time).
  • Avoid pugging damage.
  • Install and maintain riparian strips.
  • Surface incorporate, drill or directly apply fertiliser to the root zone.
Saturated soils (puddles forming)
  • Delay fertiliser application until soil conditions improve.
  • Use a less soluble or slow release fertiliser.
Excessive rates of application
  • Set realistic crop yield goals and apply fertiliser at times of maximum plant uptake.
  • Account for all sources of nutrients and apply nutrients in correct proportions.
Uneven application
  • Use equipment suitable for the conditions.
  • Use calibrated equipment and experienced operators.
Soil permeability low, soil cracking (macropores)
  • Improve soil draining characteristics (subsoiling).
  • Reduce soil compaction.
  • Reduce stocking rate.
  • Split fertiliser application rates. Apply less fertiliser more often.
Storage site too close (less than 50 metres) to open water
  • Improve the storage facility so that all fertiliser is effectively contained (under a roof).
Loading site too close (less than 50 metres) to open water
  • Minimise spillage of fertiliser when loading into or out of storage.
  • Move loading site away from open waterway.
Outflow from tile drainage system
  • Apply fertiliser when tile drains are not running.
  • Avoid application when soil is saturated.
Drought (excessively dry soils allowing high surface run-off because of slow infiltration rate)
  • Delay applying fertiliser until sufficient regrowth has occurred after rain.

 

Contamination of open water from direct application of fertiliser

Indicator: Algal blooms/excessive weed growth – evidence of elevated nutrient levels (e.g. nitrogen and phosphate)

Possible cause Best practice for remedial action
Aerial application
  • Use fertiliser with larger particle sizes (less wind effect).
  • Choose alternative aerial techniques to allow more precise placement e.g. use of GPS and GIS.
  • Use methods other than aerial application.
  • Use selective application techniques (cover part of the area).
Ground application close to open water (e.g. less than 10m away)
  • Allow a larger margin between fertilised area and open water.
  • Use application techniques that direct or specifically place the fertiliser.
  • Use fertiliser with larger particle size.
  • Erect a physical barrier/riparian strip around the water.
Wind speed greater than 5km/hr towards open water
  • Apply fertiliser when wind direction is away from open water.
  • Use fertiliser products and application techniques that confine fertiliser to the target zone.
  • Change application techniques e.g. drill fertiliser at planting rather than broadcast.
Fertiliser particle sizes with poor ballistic properties (e.g. less than 1 mm in diameter for dry material)
  • Use fertiliser with larger particle sizes.
  • Use application techniques that direct or specifically place the fertiliser.
Storage site within 50 metres of open water
  • Move storage site away from open water.
  • Ensure the storage facility effectively contains the stored fertiliser (under a roof).
Fertiliser loading/handling operations less than 50 metres from open water
  • Relocate the loading site away from open water.
  • Use wind shelters around the loading site to contain fertiliser.

 

Social/ third party effects

Indicator: Complaints from affected parties

Possible cause Best practice for remedial action
Use of dusty fertiliser
  • Use fertiliser with a larger particle size (dry material).
    Use other forms of fertiliser (e.g. slurry/liquid/suspensions).
  • Ensure the wind is blowing away from sensitive areas.
  • Apply fertiliser only at agreed times.
Noise during fertiliser application
  • Change to quieter application equipment.
    Change time of day when fertiliser is applied.
  • Change operational technique to reduce effects of noise on affected parties.
  • Apply fertiliser only at agreed times.
Off-target contamination (solids and liquids)
  • Use fertiliser with larger particle size.
  • Use precise application techniques.
  • Apply fertiliser only when the wind direction is away from affected parties.
  • Apply fertiliser only at agreed times.

 

The Fertiliser Association of New Zealand and Dairy NZ funded development of the Nutrient Management Adviser Certification Programme (NMACP). This industry-wide certification aims to ensure that advisers have the learning, experience and capability to give sound nutrient advice.

Find out more

8 August 2018

The Fertiliser Association of New Zealand has signed a 30-year lease with AgResearch to ensure the long-term fertiliser research trials at Winchmore Research Station in Canterbury continue.

9 July 2018

Significant reductions to nitrogen (N) leaching can be achieved by changing irrigation management practices, and new research has demonstrated just how big those benefits can be.

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