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How does NVZ affect farms

What is NVZ?

NVZ stands for Nitrate Vulnerable Zones. About 55% of all land in England has been designated as Nitrate Vulnerable Zones (NVZs). These are areas seen as being at risk from agricultural nitrate pollution.

The NVZ rules are part of cross compliance requirements known as Statutory Management Requirement 1. The Rural Payments Agency carries out cross compliance inspections to check farmers and landowners are complying with these rules.

All landowners must meet all NVZ rules, as well as other cross compliance requirements to qualify for full payments from:

  • the Basic Payment Scheme (BPS)
  • Rural Development Programme for England (RDPE) schemes, such as Countryside Stewardship and Countryside Productivity.

How NVZ affect farms

If your land is within one of the NVZ, there are rules that you legally have to follow:

  • When you use nitrogen fertiliser
  • When you store organic manure

You will probably already know if you are within one of these zones.  However, if your land was in an NVZ for the first time in 2017, you did not have to comply with some of the NVZ rules straight away.  There are a variety of rules already in force, started on 1st January 2018, and there are some that will come into force by 31st July 2019, and at this stage you will need to be totally compliant.

Using nitrogen fertiliser – manufactured or organic

Nitrogen fertilisers can be manufactured fertilisers that you purchase, or organic manures that you produce, or bring onto your farm.

There are limits to the average amount of manufactured fertiliser, and nitrogen from organic manure that you can apply to crops each year – the N-max limit.

N-max limit (kilograms of nitrogen per hectare)

Autumn or early winter-sown wheat  220
Spring-sown wheat  180
Winter barley  180
Spring barley  150
Winter oilseed rape  250
Sugar beet  120
Potatoes  270
Forage maize  150
Field beans/Peas  0
Grass  300
Asparagus, carrots, radishes, swedes, individually or in any combination  180
Celery, courgettes, dwarf beans, lettuce, onions, parsnips, runner beans, sweetcorn, turnips individually or in any combination  280
Beetroot, brussels sprouts, cabbage, calabrese, cauliflower, leeks individually or in any combination  370


All applications of nitrogen on each crop in each field (including grass) must be planned, and this is your fertilisation plan. The plan must be kept as part of the farm records. For help keeping farm records, talk to our farm consultants in Wiltshire.

There are a series of steps that have to be taken before you apply nitrogen; these vary according to whether it is the first time of application or following growing seasons.

Livestock manure, and any organic manure have to be treated in a different way with the total and crop-available nitrogen levels needing to be calculated before application.

Run-off risk

Whenever nitrogen fertilisers are used then it is essential that an assessment be made of the risk of run-off.

  • land that’s sloping, especially if the slope is over 12 degrees
  • ground cover provided by vegetation
  • the distance to surface water
  • weather conditions
  • the soil type and condition
  • the presence of land drains

Restrictions to spreading manufactured nitrogen fertiliser

There is closed period for spreading manufactured nitrogen fertiliser

  • 15 September to 15 January on grassland
  • 1 September to 15 January on tillage land

There are some exceptions to this rule, such as winter oilseed rape, but there are still strict criteria about quantity of fertiliser and times. There are also exceptions for greenhouses and low-intensity farms.  Visit the government website to find out more.

Manufactured fertilisers or organic manures should be spread as accurately as possible and they should not be spread if a field is either:

  • waterlogged, flooded or covered in snow
  • frozen for more than 12 hours in the previous 24 hours

You must not spread:

  • manufactured nitrogen fertiliser within 2 metres of surface water
  • manufactured nitrogen fertilisers within a 2-metre zone from the centre of an established hedge (this only applies if you need to meet cross compliance requirements)
  • organic manure within 50 metres of a spring, well or borehole or 10 metres of surface water

You must only spread manufactured nitrogen fertilisers and manures on agricultural land that you’re using to grow crops (including grass).

Organic manure

Organic manures come from animals, plants or humans. Included in the term organic manure are:

  • 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)

Slurry is liquid organic manure that is produced by livestock (other than poultry) while in a yard or building. It includes animal bedding and water that drains from areas where animals are kept.

Storing organic manure

All slurry and poultry manure produced must be able to be stored in a yard or building for a closed period:

  • 1 October to 1 April inclusive for pigs and poultry
  • 1 October to 1 March inclusive for cattle, sheep, goats, deer and horses

This is all slurry produced by the farm that has not been:

  • Sent off your farm
  • Spread on your fields with low risk of runoff

While storing the slurry you produce, any rainfall, washings or other liquid that enters the store needs to be contained during the storage period.

Calculations for overall storage capacity, average rainfall figures for your postcode area, and understanding how much manure your animals will make, can be worked out with the help of Defra PLANET and MANNER NPK management tools.

Equipment for spreading slurry

Slurry needs to be spread by precision spreading equipment

  • Low spreading trajectory (below 4 metres from the ground)
  • Maximum rate of no more than 1 millimetre per hour

Spreading organic manure

Some organic fertilisers are called ‘highly readily available nitrogen manures’; they have more than 30% of their total nitrogen content immediately available to crops.  Poultry manure is one of these.  There are restrictions as to when you can spread these manures on different types of soil, and the amount you can spread.

Separating slurry

Slurry that is being separated into liquid and solid parts must be fully controlled and monitored.  This can be done either by using a purpose-built machine, or by collecting all draining liquid on a waterproof surface.

Record keeping for manure

For all the above whether using manufacturer nitrogen fertilisers or organic manures you will need to keep comprehensive records, (which have to be retained for 5 years) be able to calculate storage volumes accurately, and produce a risk map for the area. 

You will need to prevent water pollution from your farm whether or not your land is an NVZ.

For more information, full details and advice on what is required for NVZ planning, and for help and advice on all farming legislative matters speak to our farm consultants and NVZ planners at Douglas Green Consulting.

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Douglas Green Consulting
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Chippenham
SN15 5DF
UK

t: 01666 817278
e: douglas@douglasgreenconsulting.co.uk