NVZ Rules in England: What the Regulations Ask of Your Farm
If any of your fields are in a nitrate vulnerable zone, five sets of rules apply to them: how much nitrogen, when you cannot spread, where you cannot spread, how much manure you must be able to store, and what you write down. Here they are in plain English, each one traced to DEFRA. Checked 4 November 2026.
The Numbers Most Farms Need
| Rule | The limit or the date | Where it bites |
|---|---|---|
| Livestock manure, whole holding | 170 kg N/ha a calendar year, on average | Grazing deposits count as well as what you spread. Check yours with our NVZ checker |
| Organic manure, any one field | 250 kg total N/ha in any 12 months | Everything spread; grazing deposits do not count here |
| N-max, each crop | From 0 (beans, peas) to 370 kg N/ha (brassicas); winter wheat 220 | Manufactured N plus the crop-available N from manure |
| Closed period, bagged N | Grass 15 Sep–15 Jan, tillage 1 Sep–15 Jan | A short list of crops may have a little; others need written FACTS advice |
| Closed period, slurry and poultry manure | From 1 Aug to 31 Jan, depending on soil and land | The full table is below |
| Slurry storage | 5 months (cattle, sheep) or 6 months (pigs, poultry) | Rain into the store counts, in a 1-in-5 wet year |
| Records | Within 1 week; livestock record by 30 April; kept 5 years | Shown when the Environment Agency inspects |
Are you in one? The Environment Agency's interactive map shows the 2025 to 2028 designations, already updated for the appeals. NVZ boundaries go round whole fields, so no field is half in, and the rules apply to each field that is in. DEFRA writes to holdings inside an NVZ, and the 28-day appeal window for this round has closed.
N-max: The Ceiling for Each Crop
Manufactured fertiliser plus the nitrogen your manure makes available to the crop, in any 12 months. The figure is multiplied by the whole area of that crop on the holding (regulation 12), so it caps the crop across the farm, not each field.
| Crop | N-max (kg N/ha) | Standard yield (t/ha) |
|---|---|---|
| Autumn or early winter-sown wheat | 220 | 8 |
| Spring-sown wheat | 180 | 7 |
| Winter barley | 180 | 6.5 |
| Spring barley | 150 | 5.5 |
| Winter oilseed rape | 250 | 3.5 |
| Sugar beet | 120 | – |
| Potatoes | 270 | – |
| Forage maize | 150 | – |
| Field beans, peas | 0 | – |
| Grass | 300 | – |
| Asparagus, carrots, radishes, swedes | 180 | – |
| Celery, courgettes, dwarf beans, lettuce, onions, parsnips, runner beans, sweetcorn, turnips | 280 | – |
| Beetroot, brussels sprouts, cabbage, calabrese, cauliflower, leeks | 370 | – |
When the ceiling goes up
- +20 kg on wheat and barley for every tonne the expected yield beats the standard yield.
- +40 kg on milling wheat varieties.
- +20 kg on winter wheat and winter barley on shallow soil (not shallow soil over sandstone).
- +80 kg where straw or paper sludge went on the current or previous crop.
- +40 kg on grass cut at least three times a year.
- Winter oilseed rape: the 250 includes up to 30 kg of autumn N; use it and spring is 220, plus 30 kg for every half tonne over the standard yield.
The two manure limits
170 kg N/ha, the holding. Nitrogen from livestock manure, averaged over the holding each calendar year, worked out from DEFRA's standard values for each kind of animal. What grazing stock leave in the field counts. Our NVZ checker does this sum from your headcount.
250 kg N/ha, the field. Total nitrogen from all organic manures spread on any one hectare in any 12 months. Grazing deposits are not counted here.
Grassland derogation. A holding that is at least 80% grass can apply to the Environment Agency to go up to 250 kg from grazing livestock manure. For 2026 the window was 10 November to 31 December 2025; GOV.UK had not yet published the 2027 window when we checked.
Closed Periods
Slurry, poultry manure, digestate
Manures with more than 30% of their nitrogen readily available: poultry manure, cattle and pig slurry, sludge, anaerobic digestate.
| Soil | Grassland | Tillage land |
|---|---|---|
| Sandy or shallow | 1 Sep–31 Dec | 1 Aug–31 Dec |
| All other soils | 15 Oct–31 Jan | 1 Oct–31 Jan |
On sandy or shallow tillage land sown on or before 15 September, these manures may go on between 1 August and 15 September. Shallow means under 40 cm deep.
Manufactured nitrogen
15 September to 15 January on grassland, 1 September to 15 January on tillage land. Inside it, only these crops, and only this much per hectare:
- Winter oilseed rape 30 kg, none after 31 October.
- Grass 80 kg, at most 40 kg at a time, none after 31 October.
- Brassicas 100 kg, at most 50 kg every four weeks until harvest.
- Asparagus 50 kg; over-wintered salad onions, parsley and bulb onions 40 kg.
Any other crop needs written advice from a FACTS-qualified adviser first.
After the closed period, until the end of February: no more than 30 m³/ha of slurry or 8 t/ha of poultry manure in one go, and at least three weeks between applications. Our closed periods article walks through this autumn's dates.
Where and How You Cannot Spread
Never on
- Land that is waterlogged, flooded or under snow.
- Land frozen for more than 12 hours in the previous 24.
- Land that is not growing a crop (grass counts as one).
Keep back from water
- 2 m from surface water for manufactured nitrogen.
- 10 m from surface water and 50 m from a spring, well or borehole for organic manure.
- 6 m is allowed for slurry, sewage sludge and digestate put on with a trailing hose, trailing shoe, dribble bar or shallow injector.
Before and after spreading
- Look at the field first for run-off risk: slope (especially over 12°), ground cover, distance to water, weather, soil and land drains.
- Slurry equipment: precision equipment, or a trajectory under 4 m, or no more than 1 mm an hour.
- Work it in within 24 hours: poultry manure, slurry and liquid digested sludge spread on bare soil or stubble, unless it went on by trailing hose, shoe, dribble bar or injector.
- Know its nitrogen first: total and crop-available N worked out, from standard values, the supplier's analysis or your own sampling, before any manure goes on a crop with an N-max.
Enough Room for the Winter
You must be able to store all the slurry you produce, and all poultry manure made in a yard or building, through the storage period: 1 October to 1 April (6 months) for pigs and poultry, and 1 October to 1 March (5 months) for cattle, sheep, goats, deer and horses. Rain, washings and anything else that runs into the store count, sized for a wetter-than-average year (1 in 5). AHDB's slurry wizard turns your average rainfall into that figure.
You can need less if you send slurry off the farm or spread some on low run-off risk land: under 3° slope, no land drains other than sealed pipes, and at least 50 m from a watercourse. Then you keep one extra week's storage in reserve.
Solid manure and field heaps
Stored in a container, on a waterproof base that catches the run-off, under a roof, or in a temporary field heap. A field heap sits at least 10 m from surface water or a land drain (30 m on a slope of 12° or more) and 50 m from a spring, well or borehole, on land that does not flood. It moves at least every 12 months, and the same spot rests for two years before it is used again.
What You Write Down, and By When
None of this is sent anywhere. It is kept for at least five years and shown if the Environment Agency inspects. The third column is where our free tools do part of the job.
| What the rules ask | By when | Our free tools |
|---|---|---|
| Fertilisation plan for each crop in each field, in four steps: soil nitrogen supply, the crop's requirement, the N from planned manure, the manufactured N needed | Steps 1 and 2 before the first nitrogen goes on; steps 3 and 4 before every application | The RB209 calculator gives the crop's recommendation from AHDB's engine. The NVZ register keeps the four steps and says which are missing |
| Field records: crop and sowing date; each manufactured N spreading; each manure spreading with area, amount, method, type, total and crop-available N | Within 1 week | The register keeps them, counts the week, and reads each spreading against N-max, the 250 kg field limit and the closed periods |
| Yield of each arable crop that had nitrogen | Within 1 week of finding it out | The register |
| Manure in or out: type, amount, date, total N, the other party's name and address, and a plan if it is not accepted | Within 1 week | The register |
| Livestock record for the previous calendar year: holding area, livestock, days on the holding, nitrogen produced | By 30 April | The NVZ checker does the sum; the register prints the record |
| Storage: capacity, the volume your stock will make, the storage you need; numbers of housed stock and field heap sites | Changes within 1 week or 1 month; the annual part by 30 April | The register's slurry storage check |
| Risk map: fields, sandy or shallow soils, slopes over 12°, drains, heap sites, water and the 10 m and 50 m zones | Updated within 3 months of a change | Not in our tools. Hand-drawn is accepted and it need not be to scale |
| Size of the holding | Updated within 1 month | – |
| Lab reports for any manure you had analysed, and any written FACTS advice | Kept with the plan | – |
Low-intensity farms (at least 80% grass, no more than 100 kg N/ha from organic manure and 90 kg from bagged fertiliser, and no manure brought in) do not record each application, but they keep the fertilisation plan and the records that show they meet those criteria. Land enclosed under glass or polytunnel for the whole year is outside the limits.
Who Checks, and What Else Applies
The Environment Agency enforces the NVZ rules. Its officers choose which farms to inspect, and DEFRA's guidance says a farm that does not comply may be prosecuted and fined. The free Farming Advice Service answers questions on them: 03000 200 301 or advice@farmingadviceservice.org.uk.
The Farming Rules for Water apply as well, to every farm in England, inside an NVZ or not. Wales, Scotland and Northern Ireland have their own rules; this page covers England only. For any decision about your own farm, talk to a FACTS-qualified adviser or your agronomist.
Frequently Asked Questions
How do I know if my land is in an NVZ?
The Environment Agency's interactive map. Boundaries go round whole fields, so a field is in or out, and the rules apply field by field.
What is the 170 kg limit?
Livestock manure nitrogen averaged over the holding, per calendar year, grazing deposits included. A holding that is at least 80% grass can apply for a grassland derogation of up to 250 kg from grazing livestock.
When is the closed period?
Bagged nitrogen: 15 September to 15 January on grass, 1 September to 15 January on tillage land. Slurry and poultry manure: between 1 August and 31 January depending on soil and land, as in the table above.
How long are NVZ records kept?
At least five years. Field records within a week of sowing, spreading or harvest; manure in or out within a week; the livestock record for the previous year by 30 April.
Does anything have to be sent in?
No. Records are kept and shown at an inspection. Farms under a grassland derogation are the exception: they send their fertilisation account to the Environment Agency by 30 April.
Who enforces the rules?
The Environment Agency. DEFRA's guidance says a farm with land in an NVZ that does not comply may be prosecuted and fined.
Where Every Rule Comes From
- GOV.UK — Using nitrogen fertilisers in nitrate vulnerable zones (N-max table and its additions; 170 and 250 kg limits; the four-step plan; run-off assessment; conditions and distances; closed periods and their exceptions; 30 m³ and 8 t limits to the end of February; incorporation within 24 hours; low-intensity farms and greenhouses; every record and its deadline; the risk map; Environment Agency inspections; the Farming Advice Service).
- GOV.UK — Storing organic manures in nitrate vulnerable zones (5- and 6-month storage periods; 1-in-5 wet year; low run-off risk land; field heaps; storage records).
- GOV.UK — NVZ designations and appeals 2025 to 2028 (the map; whole-field boundaries; the letter and the 28-day appeal).
- GOV.UK — Grassland derogations for livestock manure in NVZs (80% grass; up to 250 kg from grazing livestock; the 2026 application window; the fertilisation account by 30 April).
- The Nitrate Pollution Prevention Regulations 2015 (SI 2015/668), the law the guidance translates; regulation 12 sets N-max against the total area of each crop on the holding.
- GOV.UK — How to comply with the Farming Rules for Water (apply to every land manager in England, NVZ or not).
This page summarises DEFRA guidance and the regulations as published on the dates checked; it is not advice. For decisions about your farm, speak to a FACTS-qualified adviser.