On March 30 2022, Defra published new guidance on the Farming Rules for Water to clarify the rules regarding the application of organic materials to land. The main points are summarised below, and the full guidance is available from this link – Applying the farming rules for water on GOV.UK

1) Nutrient management planning

All land managers must have a nutrient management plan which should take into account crop requirement, soil P, K and Mg supply from soil analysis and the quantity of nutrients supplied by organic manures.

The nutrient management plan should be informed either by AHDB’s Nutrient Management Guide (RB209), a recognised farm nutrient management tool such as PLANET, MANNER-NPK and Tried and Tested, or a suitably qualified professional (e.g. FACTS adviser).

2) Assessing soil and crop need

Land managers must refer to a recommendation system to assess crop N need for the growing season based on crop type, soil type, previous cropping and annual rainfall.

Organic material applications should be planned to avoid increasing the Soil Phosphorus Index (soil P index) above index level 3, or target levels for soil and crop on land (whichever is higher) over a crop rotation, unless they can demonstrate that:

  • it is not reasonably practicable to do so, and
  • they have taken all appropriate reasonable precautions to help mitigate against the risk of diffuse agricultural pollution.

3) Assessment of significant risk of agricultural diffuse pollution when planning

There are different rules for high and low readily available N (RAN) content manures.

High RAN manures have a RAN content equal or above 30% of total N (typically livestock slurries, poultry manures and digestate).

Low RAN manures have RAN contents less than 30% of total N (typically FYM, Biosolids, compost).

In Nitrate Vulnerable Zones, applications of high RAN manures are subject to closed spreading periods:


  • Sandy or shallow soils – 1 September to 31 December (4 months)
  • All other soils – 15 October to 31 January (3.5 months)

Tillage land

  • Sandy or shallow soils – 1 August to 31 December (5 months). Please note: if you sow a crop on sandy or shallow tillage land on or before 15th September, you can apply manures with high readily available nitrogen between 1st August and 15th September inclusive.
  • All other soils – 1 October to 31 January (4 months)

Outside NVZs, high RAN manures can be applied at application rates up to 30m3/ha for slurry and digestate and up to 8t/ha for poultry manure in the time periods outlined in table 4, as long as there is no repeat application within 21 days.

Regardless of timing it is important that nutrients supplied by organic materials are accounted for in nutrient management plans and that crop need is not exceeded.

Time periods when application rate limits apply for high RAN organic manure (note that there are closed periods for high RAN manures in NVZS) are:


  • Sandy or shallow soils – 1 September to the end of February
  • All other soils – 15 October to the end of February

Tillage land

  • Sandy or shallow soils – 1 August to the end of February
  • All other soils – 1 October to the end of February

4) Assessment of reasonable precautions

A green cover should be established by 15 October to reduce the risk of N leaching. Green cover is defined as any commercial crop, green manure or cover crop. Appropriate justifications for not having a green cover over winter include:

  • delaying drilling to enable activities to control persistent weeds, such as blackgrass
  • leaving medium and heavy soils to weather before a spring root crop

Where possible, organic manures should be incorporated into the soil within 12 hours of application.

For help and advice

Contact us at enquiries@adas.co.uk if you would like any support complying with these rules. Our FACTS qualified advisors are highly experienced in creating compliant and up-to-date nutrient management plans for farms all across the country.