Composts, Plant Raising Media and Mulches

"The health of man, beast, plant and soil is one indivisible whole; the health of the soil depends on maintaining its biological balance and, starting with a truly fertile soil, the crops grown on it, the livestock fed on those crops and the humans fed on both have a standard of health and power of resisting disease and infection greatly in advance of anything ordinarily found in this country"
[Lady Eve Balfour, The Living Soil, 1943]

Fertility in organic systems 

Organic farming is a holistic, low-input agricultural production system working with, rather than against, natural systems. The soil is the heart of an organic system, feeding plants via intricate relationships with microflora and fauna. Microbial activity within the soil processes organic matter to provide a range of minerals and nutrients. These are used by the crop to achieve healthy, vigorous growth. Biodiversity within the system and optimum crop health, work together to minimise the incidence of pest and disease attack.

The nutrient cycle is completed by returning organic matter/fertility back to the soil that has been removed through production and harvest of the crop. The building and maintenance of soil structure and the provision of essential nutrients and minerals, including N, P & K, is therefore achieved using a number of fundamental processes, including:

  • Planting legumes
  • Effective crop rotations
  • Incorporating green manures
  • Appropriate application and incorporation of composts and composted farm yard manure (FYM).

It is essential that these principles and practices are seen as the primary tools to maintain an effective organic system. Any additional inputs should be viewed only as supplements - and not substitutes - to the system, and should only be called upon when absolutely necessary.

If you do recognise a need to supplement the fertility-building process, an examination of the system, such as a nutrient budget and/or full soil analysis, will normally be required.

What composts and plant raising media are included in this online directory?

All products in this directory have been verified as acceptable for use by organic producers under EU regulation 2092/91 and the Defra Compendium of Organic Standards for organic food production. These products contain only substances that can either be used with or without prior permission from your certification body. A soil or leaf analysis may be required for products that require permission or approval to be granted before use. You may need to provide justification to use such products by filling in a restricted practice form. You can get these forms from your certification body.

The Soil Association is unable to take responsibility for the efficacy of any of the products listed in this fact sheet.

What if I want to use a compost or plant raising media which is not registered in the online directory?

Media approved for use in organic plant raising must always be used when propagating organic crops. Acceptable media can either be your own or bought-in; either way the media should be composed of acceptable ingredients. Some suppliers may sell both organic and non-organic plant raising media. Therefore, be sure to specify that the media must be acceptable under organic standards when ordering.
While media that is not registered with an organic certification scheme may not necessarily be prohibited, any grower using a non-certified media must be able to prove that the media is composed only of ingredients approved by your certification body. This proof can be provided in the form of a letter from the manufacturer giving a list of ingredients and a GMO-free declaration.
Note: Purchasing media from a garden centre with 'organic' written on it is not adequate. If you are in any doubt contact the Soil Association’s Producer Support Team on 0117 914 2400, or your certification body.

Genetic Modification

Inputs used on organic farms must not be derived from or produced using, genetically modified organisms (GMOs) or their derivatives. If you wish to use brought-in non-organic manures, green waste composts, propagating composts and slaughterhouse waste products not listed on the online directory, a GMO declaration may be required. GMO declaration forms are available from your certification body.

How do I know what level of approval is required before using a product?

The term "prior approval required" used in the online directory and by Soil Association Certification Ltd (SACL) is equivalent to the terms "must be approved before use" used by Organic Farmers and Growers (OF&G), and "need recognised by inspection authority" used by Defra Compendium of Organic Standards.

The categories  for use of organic products are as follows:

Permitted:    You may use this product.

Permitted with justification provided at inspection:

You may use this product but you must be able to justify its use at your inspection with evidence such as test results, records, forms a plan etc. For example you must record why you needed to use that particular product

Prior approval required:

Before you use the product you must have been given approval by your certification body. This approval may cover more than one use. For example you may submit an annual plan to your certification officer that will then need to be approved before you can use the product.

What are the Soil Association standards on the use of compost produced from green waste?

Organic farms must sustain and build soil fertility by recycling nutrients to achieve crop and livestock health. The responsible and effective use of plant wastes is essential for the effective cycling of nutrients. Composting results in a stabilised product, free of pests, pathogens and weed seeds, that is an excellent material for building soil organic matter and supporting soil microbial communities.Although the organic ideal is the cycling of nutrients within the farm system, the Soil Association recognises that municipal green wastes can be a good source of feedstock, as well as providing an important diversion of these biodegradable wastes from landfill.
The Soil Association recognises that the use of green waste compost is compatible with the basic principles of sustainability and can be used as part of an on-farm fertility and soil health programme. However, organic farmers must get prior approval from SACL before a green waste product can be used on organic land and crops.
If you are certified with Soil Association Certification you will need to get permission before you can bring in compost or materials for composting from outside your farm. This can be done by contacting the team on 0117 914 2412.

What are the requirements for Soil Association approval of farm-produced green waste compost?

In order to provide approval, Soil Association Certification would require details of the source of origin for material used - green garden/amenity waste (no food waste, although the Soil Association would consider raw waste trimmings/spoils from a packing plant if GM issues were satisfied).
Records of intakes and quantities should also be kept.
For green waste from kerbside collection schemes, Soil Association Certificiation would require details of the screening process and details of the process to separate the waste to ensure contaminants are removed. Analysis of the finished compost should include heavy metal, microbiological and seed germination checks. There should be a clearly defined site management plan that prevents cross contamination of feedstock. Composting sites must comply with all other legal requirements.

How can I register a product to be included in this online directory?

If you are not intending to use all of the green waste compost produced on farm and plan to sell the excess, or a company wishing to verify your compost for use in organic systems - Soil Association run a verification scheme to verify your compost for use in organic systems. You can download a verified input application pack here Please also contact a member of our friendly team on 0117 914 2406 who will be happy to answer your queries.

What is BSI PAS100?

If you are looking for assurances about the quality of compost you are buying in for use on your holding, The British Standards Institution's Publicly Available Specification(BSI PAS 100) provides guarantees about the composting process. The BSI PAS 100 for composted material was developed in conjunction with WRAP (the Waste & Resources Action Programme) and the Association for Organics Recycling. It sets out the minimum requirements for the process of composting, the selection of materials from which compost is made, and even how it is labelled.

For full details of the specification visit the WRAP and Association for Organics Recycling websites:
Compost can be certified to BSI PAS 100 as well as being certified for use in organic production by an organic certification body. Products and companies that have achieved PAS 100 certification are marked below as 'BSI PAS 100'.
Organic producers need to use compost that is approved for use in organic systems, but they can choose a product which also has the PAS 100 certification. Soil Association organic standards require all Soil Association certified compost producers to be certified to the PAS 100 standard