Guidance

Use organic manures and manufactured fertilisers on farmland

Published 22 December 2016

If you’ve got an Environmental or Countryside Stewardship agri-environment agreement on land outside an NVZ, and you have the relevant reduced fertiliser options, you must follow this guide.

Call Natural England on 0300 060 3900 (Monday to Friday, 8:30am to 5pm) to find out what your reduced fertiliser options are.

Find out about call charges.

1. Planning organic manure and manufactured fertiliser management

You should plan how you apply fertilisers and manure, including anaerobic digestion (AD) digestates and sewage sludge, according to soil type, nutrient status and crop needs.

You should calculate the crop nutrient requirement for each land parcel using a manual like the Defra Fertiliser Recommendations RB209 or a professionally produced nutrient management plan (for example produced by an agronomist).

Alternatively, you can use farm software like PLANET or nutrient management tools like Tried and Tested.

Order a copy of the PLANET software online or by telephone: 0345 3451302.

1.1 Account for nutrients available in the soil

You should account for the amount of nutrients available in the soil. You should carry out soil testing on cultivated land at least every 5 years and factor the results into your calculations. For example by using a fertiliser recommending tool such as RB209 for how much fertiliser you need.

You should test the levels for all of the following:

• phosphorus
• potassium
• magnesium
• pH

You can assess nitrogen levels through the soil nutrient supply approach using the index tables in section 1 of RB209. Assessing your soil at each crop rotation is good practice and if you exceed the nutrient requirements for your crop you risk:

• wasting money and resources
• increasing the amount of nutrients lost through run-off or leaching
• damaging the environment

1.2 Record keeping

You should keep accurate records for each land parcel including:

• area spread (in hectares)
• how much organic manure or manufactured fertiliser you applied
• the date applied
• the method of application
• the type of organic manure, manufactured fertiliser, or other materials (for example dredgings and soil from the processing of sugar beet) you used as fertilisers
• the amount of total and available nitrogen and phosphorus applied

2. Nitrogen limits from organic manure

You should not spread more than 250kg of total nitrogen in organic manures on a hectare in any 12-month period. The amount of readily available nitrogen in manure must not exceed the crop nitrogen requirement. This may mean applying less than the 250kg total nitrogen maximum amount.

You can record the total and available nitrogen in organic manure that is readily available to crops using the PLANET Nutrient Management software’s MANNER-NPK function.

3. Applying manufactured fertiliser

You should only apply manufactured fertiliser and organic manures to a crop when the crop can use the nutrients.

You should not apply manufactured fertiliser to:

• grass between 15 September and 15 January
• other crops between 1 September and 15 January unless there’s a specific crop requirement at this time as highlighted in RB209 or your nutrient management plan

You should apply manufactured fertiliser as accurately as possible.

4. Applying organic manures

Certain organic manures (such as cattle and pig slurries, poultry manure, AD digestate and liquid digested sewage sludge) contain a high proportion of readily available nitrogen (meaning that more than 30% of total nitrogen is present in a readily available form). Find out when to use manures with high readily available nitrogen.

You may spread organic manures that don’t contain much readily available nitrogen if field conditions are suitable to avoid causing nitrogen leaching.

These organic manures include:

• farmyard manure
• sewage sludge cake
• compost made from green waste

Find out what percentage of readily available nitrogen for each of these organic manures you can use in MANNER-NPK or section 2 of RB209.

4.1 How to spread organic manures

You should prepare a manure management plan. On bare land or stubble you should reduce the risk of run-off reaching surface water by incorporating manures into soil within 24 hours of applying it. Incorporating manures within 6 hours of application allows for the best use of the applied nitrogen.

You should spread organic manures as accurately as possible. When spreading slurry by broadcasting, use equipment that regularly moves to ensure even spreading and has 1 of the following:

• a trajectory of less than 4m from the ground
• a trajectory of 4m or more from the ground and can achieve a maximum slurry application rate of 1mm per hour when operating continuously

5. When and where to avoid applying organic manures and manufactured fertilisers

You should not apply manufactured fertilisers or organic manures (including digestates) when:

• the soil is waterlogged, flooded, frozen or snow-covered
• there’s a significant risk of run-off to surface water, leaching to groundwater and run-through beyond crop use

You should consider:

• the slope of the land (greater than 12 degrees), as a steeper incline is more likely to cause run-off
• weather conditions
• the timing of the organic manure
• method of application
• characteristics of the organic manure
• ground cover
• closeness to surface water
• soil type and conditions
• land drains

You should avoid applying manufactured fertilisers and organic manures close to watercourses and boreholes to reduce the risk of pollution.

You should not spread manures, AD digestate or liquid digested sewage sludge in November or December. You should only spread in January, February and October if your nutrient management plan identifies a specific crop need. Find out your crop need by using MANNER-NPK.

5.1 Avoid surface waters and water sources

You should not spread organic manures:

• within 10m of surface waters, including dry ditches
• within 50m of a spring, well or borehole

You should not apply manufactured fertiliser:

• directly to surface waters (including dry ditches)
• within 2m of surface water

For further information read the application guidance in GAEC 1: Establishment of buffer strips along watercourses.

6. Other rules you should follow

You should also follow the rules for:

• storing silage and slurry and agricultural fuel oil - these rules apply to all farmers
• managing nutrients in nitrate vulnerable zones
• using nitrogen fertilisers in nitrate vulnerable zones
• managing sewage sludge, slurry and silage on your land