Nitrogen cap


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Nitrogen cap rule Applicable farm areas Annual reporting Resource consent requirements Additional resources

Applying synthetic nitrogen fertiliser to grazed land is limited to 190 kilograms of nitrogen per hectare per year (kgN/ha/yr), averaged across the grazed land area. Dairy farmers also must report annual nitrogen use.

Nitrogen cap rule

The nitrogen cap (N-cap) rule is one of several regulations implemented through the National Environmental Standard for Freshwater (NESF), aiming to reduce the amount of nitrogen in waterways. The rule controls the amount of synthetic nitrogen fertiliser that farmers may apply to grazed land. Exceeding the N-cap requires resource consent (see below).

You can apply more than this to your annual forage crops, but only if the average across your combined pasture, forage crops and other pastoral land use does not exceed 190 kgN/ha/year.

The N-cap applies to synthetic nitrogen fertiliser that is more than 5 percent nitrogen by dry weight, for example manufactured urea, diammonium phosphate and sulphate of ammonia.

The N-cap rule does not apply to:

  • Land that is not grazed between fertiliser applications and harvest e.g. ungrazed arable cropping, silage, hay, cut-and-carry forage, horticulture, and forestry land.
  • Biological nitrogen fertilisers e.g. minimally processed pellets, compost, dairy effluent that has not had any manufactured nitrogen added, chicken manure.

Applicable farm areas

The N-cap rule controls the application of synthetic nitrogen fertiliser based on ‘contiguous’ landholdings. For example, if the milking platform and support block are part of the same land area (i.e. adjoining or contiguous), the cap applies to both together. However, if a farm has a milking platform with a separate support block, the N-cap applies separately.

This is shown in the picture below:

  • Yellow Farm: one contiguous landholding, despite being divided by roads, rivers, and streams.
  • Blue Farm: two contiguous landholdings (A and B), separated by land not belonging to the farming operation.
  • Red Farm: four contiguous landholdings – one large (B) and three small (A, C and D).

Nitrogen cap applicable farm areas

Source: Nitrogen Cap guidance for dairy farms (Minsitry for the Environment)

Annual reporting

The N-cap rule requires all dairy farmers to report their synthetic nitrogen fertiliser use annually by 31 July for the previous 12-month period (ending 30 June). One report per contiguous landholding is to be submitted.

Regional councils and fertiliser companies have worked together to create reporting tools for farmers:

You can also submit your N-Cap reporting via a shared regional council synthetic nitrogen use recording tool. You do not need to fill out this form if you have already done so through your fertiliser company. Note that the records you provide to your dairy company are separate from the N-cap reporting.

Resource consent requirements

If your nutrient budget shows that you will exceed 190kgN/ha/year, you must either reduce your use or apply for a resource consent from your regional council.

Resource consents for breaches of the N-cap rule have non-complying status. This carries a higher test to meet under the Resource Management Act and may not be readily obtainable.

To be granted resource consent for the ongoing discharge of synthetic nitrogen exceeding the N-cap, the applicant must provide a report from a suitably qualified practitioner that includes:

  • A description of the good farming practices for applying nitrogen; and
  • A statement that the granting of the consent will not result in and exceed the base rate of nitrogen entering water. This essentially means that the rate of nitrogen entering the water based on the higher nitrogen application cannot be more than it would be if a maximum of 190kgN/ha/year was being applied.

The council can impose certain conditions relating to the baseline rate on any consent granted, along with reporting requirements. Any consent granted will have a term of no more than five years.

Please contact your regional council for more information.

Last updated: Apr 2024

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