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You must follow this guidance if you use any manufactured fertilisers, manures or other materials that contain nitrogen on agricultural land in a nitrate vulnerable zone (NVZ).

Find out if youre in an NVZ.

You must also follow the guidance on storing organic manures in NVZs and storing silage, slurry and agricultural fuel oil if you produce or import livestock manures.

Fertilisers that contain nitrogen

Nitrogen fertilisers can be manufactured (inorganic, bagged) fertilisers that you buy, other materials containing nitrogen (like waste soil) or organic manures that you produce or bring on to your holding.

Organic manures come from animals, plants or humans. They include:

• slurry
• poultry manures
• solid manures (such as farmyard manure, sludge cake or compost)
• sewage sludge (also called biosolids)
• other liquid manures (such as abattoir waste or anaerobic digestate)

How much nitrogen you can apply to your crops

Theres a limit on the average amount of manufactured fertiliser and crop-available nitrogen from organic manure that you can apply to most crops each year - this is known as the N-max limit.

These are shown in the following table:

Crops that you can apply more nitrogen to

You can apply more nitrogen to some crops if your expected yield is higher than the standard crop yield shown in the table.

You can use an additional 80kg of nitrogen per hectare if youve used straw or paper sludge on the previous or current crop.

Wheat and barley

For wheat and barley, you can use an additional 20kg of nitrogen per hectare for every tonne that the expected yield exceeds the standard yield.

Milling wheat

On milling wheat varieties, you can use an additional 40kg of nitrogen per hectare.

Wheat and barley on shallow soils

On autumn and winter-sown wheat and winter barley you can use an additional 20kg of nitrogen per hectare on fields with a shallow soil type (except on shallow soils over sandstone).

Winter oilseed rape

On winter oilseed rape you can use up to 250kg of nitrogen per hectare. This includes a maximum autumn (closed period) application of 30kg of nitrogen per hectare of manufactured nitrogen fertiliser.

If you use 30kg of nitrogen per hectare in the autumn, you can only use up to 220kg of nitrogen per hectare in the spring. However, you can increase this by an additional 30kg of nitrogen per hectare for every half tonne that the expected yield exceeds the standard yield.

Grass

On grass thats cut at least 3 times in a year, you can use an additional 40kg of nitrogen per hectare.

Grass grown for dehydration or chlorophyll production

You can use nitrogen up to the level recommended in writing by a FACTS-qualified adviser if youre growing grass to achieve a protein content of at least 16% in the dried product.

If the land is irrigated, you must not use more than 700kg of nitrogen per hectare. If the land isnt irrigated, you must not use more than 500kg of nitrogen per hectare.

In subsequent years, you must sample these fields between 1 September and 31 October for soil mineral nitrogen levels and give your FACTS-qualified adviser the results.

How much organic manure you can use (farm and field limits)

You can apply up to 170kg per hectare of nitrogen in livestock manure (including manure deposited directly by livestock and spreading) on your holding in each calendar year. This limit is the loading limit and applies as an average across your holding. Its separate from the field limit of 250kg per hectare from organic manures.

You must not use more than 250kg of total nitrogen from all organic manures spread in any 12 month period on any single hectare of your land. This limit (the field limit) doesnt include livestock manures deposited by grazing animals.

You must use standard values to work out how much nitrogen is produced by the livestock on your farm or bought on to your farm. You must plan so that you dont exceed the limit.

You can find the standard values in the blank field records and standard values tables (134 KB).

You can apply for a grassland derogation to increase this limit if more than 80% of your holding is grassland.

Using compost

If the only organic manure you use is certified green or certified green/food compost, you can apply:

• up to 500kg of nitrogen per hectare every 2 years as mulch or worked into the ground
• up to 1,000kg of nitrogen per hectare every 4 years (only as mulch and in an orchard growing fruit of the genera Malus, Prunus or Pyrus)

The compost that you use must not contain livestock manure and must be produced to the PAS100 protocol.

Plan your nitrogen use

You must plan all your applications of nitrogen on each crop in each field (including grass). This is your fertilisation plan. You must keep it as part of your farm records.

To help with your plan, you can use farm software like PLANET or tools like the Tried and Tested nutrient management tools.

You can also use the blank field records and standard values tables (134 KB) to calculate how much nitrogen is available in different types of livestock manure.

Your plan must show youve taken the following steps before you apply nitrogen for the first time in a field where youre going to plant a crop or have planted a crop:

1. Calculate the amount of nitrogen in the soil thats likely to be available for the crop to use during the growing season.
2. Calculate the optimum amount of nitrogen that should be applied to the crop, taking into account the amount of nitrogen already available in the soil.
3. Calculate the amount of nitrogen from any planned applications of organic manure thats likely to be available to the crop in the growing season in which you spread it.
4. Calculate the amount of manufactured nitrogen fertiliser you need.

You must also carry out steps 1 and 2 before you apply any nitrogen fertiliser or manure for the first time.

You must carry out steps 3 and 4 every time you apply nitrogen fertiliser or manure.

In subsequent growing seasons, before you apply nitrogen

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