Soil Surveys, Environmental Assessment & Land Management

Agricultural Land Classification

What is Agricultural Land Classification (ALC)?

Agricultural Land Classification (ALC) is a system used in England and Wales to grade the quality of land for agricultural use, according to the extent by which physical or chemical characteristics impose long-term limitations. It is used to inform planning decisions affecting greenfield sites. The system classifies land into five grades:

Grade 1 - excellent quality agricultural land with no or very minor limitations.

Grade 2 - very good quality agricultural land with minor limitations which affect crop yield, cultivations or harvesting.

Subgrade 3a – good quality agricultural land with moderate limitations that affect the choice of crop, timing and type of cultivation/harvesting or level of yield. This land can produce moderate to high yields of a narrow range of crops or moderate yields of a wide range of crops.

Subgrade 3b – moderate quality agricultural land with strong limitations that affect the choice of crop, timing and type of cultivation/harvesting or level of yield. This land produces moderate yields of a narrow range of crops, low yields of a wide range of crops and high yields of grass.

Grade 4 – poor quality agricultural land with severe limitations which significantly restrict the range and level of yield of crops.

Grade 5 - very poor quality agricultural land with very severe limitations which restrict use to permanent pasture or rough grazing with the exception of occasional pioneer forage crops.

Grades 1, 2 and subgrade 3a are considered within the ‘best and most versatile’ land category in the current planning system. This land is deemed the most flexible, productive and efficient in response to inputs, it is the best to deliver future crops for food and non-food uses (such as biomass, fibres and pharmaceuticals).

Cranbrook_ALC_resized.jpg

Do I need an ALC? 

If you’re developing agricultural land...probably!

The National Planning Policy Framework (paragraph 170) requires planning authorities to "recognise the economic and other benefits of the best and most versatile agricultural land” when making decisions on development proposals.

The policy is relevant to all planning applications, including on smaller land parcels, although it is for the planning authority to decide how significant the agricultural land issues are and the need for information. Natural England/Welsh Government are the statutory consultees. Applications for mineral working or waste disposal are also required to produce an ALC where agricultural land is to be affected.

The Agricultural Land Classification Process

In order to grade the land, a desk based study and field survey are required to assess the factors that affect the site and their interactions. The main factors affecting land grade are:

  • Climate: temperature and rainfall, aspect, exposure and frost risk
  • Site: gradient, micro-relief and flood risk
  • Soil: texture, structure, depth and stoniness, chemical properties (which cannot be corrected)
  • Climate and flood risk are determined during the desk based survey. This is then used to inform the field survey which involves taking soil observations (using a hand held auger) across the site, usually at a sample density of one observation per hectare. Soil and site factors are recorded on a field sheet at each point; these details are used alongside the climate and flood risk to determine the most limiting factor and so a land grade is allocated for each point. A small trial pit is dug on each soil type/land grade identified to better describe the soil profile and confirm auger findings.

    Following the survey, a report is issued to the client that covers the following:

  • Site description (site environment and a review of published information relating to soils, geology and available ALC);
  • Soil resources within the site;
  • Agricultural land grades identified at site;
  • Brief explanation of general soil handling principals (it is advised that a site specific Soil Management Plan be produced should the development go ahead);
  • Observation log;
  • Map of survey observations and Agricultural Land Classification grade boundaries and a map of soil types (if appropriate).
  • Our reports and associated maps are professionally produced to the format required by the statutory authorities, helping to reduce consultation delays when determining planning applications.

    If you wish to discuss ALC requirements, please contact us on +44 (0)1509 670570 or email info@lra.co.uk

    LRA_contact_us.png