Who is competent to carry out an ALC survey
No licence covers agricultural land classification, so competence is judged on method and track record. What to ask a soil scientist before appointing them.
There is no licence for agricultural land classification work, so ALC surveyor competence is judged by method, membership and track record rather than by a certificate. What a local planning authority and Natural England expect is a soil scientist who has applied the 1988 Ministry of Agriculture, Fisheries and Food revised guidelines in the field, who augers to a proper density, who uses agroclimatic data rather than assumptions, and whose report can be checked line by line. Where a solar farm or a housing allocation turns on whether land is Grade 3a or 3b, that check is exactly what happens.
What the survey has to produce
Agricultural land in England is classified into five grades, with Grade 3 divided into subgrades 3a and 3b. Grades 1, 2 and 3a together form best and most versatile land, and that phrase is the one that carries planning weight.
The National Planning Policy Framework, in the August 2026 edition, expects the economic and other benefits of best and most versatile land to be recognised, and where significant development of agricultural land is shown to be necessary, it directs that areas of poorer quality land are preferred to areas of higher quality. So the whole question on most rural applications is whether the boundary between 3a and 3b falls inside or outside the red line.
The deliverable is a report with a classification map, the location of every boring, the soil profile descriptions, the climatic data and its source, the areas of each grade in hectares, and a plain statement of the limiting factor that decided each grade.
Why the published maps are not enough
Natural England's provisional agricultural land classification maps, viewable through the MAGIC service, were produced at a scale of 1:250,000. They do not subdivide Grade 3, and they were never intended for site-specific use.
Officers know this, and so do objectors. Submitting an application that relies on the provisional map to argue that land is not best and most versatile invites a request for a detailed survey, usually at the point in the determination period when you have the least time. Where any part of the site could be Grade 3a, commission the survey before you apply.
Post-1988 detailed ALC surveys carried out for other purposes are sometimes available for a site, and they are worth searching for, but the classification criteria and the climatic dataset have both been revised since the earliest surveys were done.
The methodology a council expects
The 1988 guidelines assess land against limiting factors and assign the grade on the most limiting one. Climate is considered first, then site factors, then soil, then the interactive limitations.
- Climate: accumulated temperature and average annual rainfall, with field capacity days and moisture deficits derived for the location, taken from the agroclimatic dataset rather than the nearest weather station.
- Site: gradient, microrelief, flood risk.
- Soil: texture, depth, stoniness, and the presence of any impeding layer.
- Interactive: wetness and workability, droughtiness, soil erosion risk, and chemical limitations.
Fieldwork is by hand auger on a grid, commonly one boring per hectare on smaller sites, supported by soil pits where a profile needs to be seen in section. Each boring is described to at least 1.2m where the ground allows. A survey that reports a handful of borings across a large field, or that gives no boring locations at all, will not withstand scrutiny.
An Agricultural Land Classification report sets this out in a form the case officer can follow, and it should state the survey date, the weather conditions and any access constraint that limited the work.
Who is competent to do the work
No statute reserves this work to a defined profession. In practice authorities look for three things.
The first is a soil scientist rather than a general environmental consultant. Membership of the British Society of Soil Science, and chartered status as a scientist or environmentalist, are the usual markers. The second is demonstrable ALC experience, which means previous surveys assessed by Natural England or tested at appeal, not simply a stated familiarity with the guidelines. The third is field competence, since ALC is a judgement made with an auger in hand and it cannot be desk-based.
Ask a prospective surveyor three questions before appointing. How many borings will you take per hectare, and why that density? Which agroclimatic dataset will you use? Have any of your ALC reports been challenged, and what happened?
Professional review matters here. This is a report type where councils expect a suitably qualified author, and professional input is strongly advised. PlanScope drafts can give you the structure and the policy framing, and the professional directory is the route to a reviewer, but the field survey and the classification judgement are the soil scientist's.
When the survey can be done
ALC fieldwork can be carried out through most of the year, with two practical limits.
Waterlogged or frozen ground prevents proper augering and makes wetness assessment unreliable, so mid-winter surveys on heavy land are often postponed. Standing crops restrict access, and a farmer will not welcome a grid survey across wheat in June.
Late summer after harvest, and early spring before drilling, are the usual windows. Build six to eight weeks into the programme from instruction to report, longer if the site is large or access has to be arranged with more than one tenant.
What Natural England looks at
Natural England is a statutory consultee where development is not in accordance with the development plan and would lead to the loss of more than 20 hectares of grades 1, 2 and 3a land, under Schedule 4 to the Town and Country Planning (Development Management Procedure) (England) Order 2015.
Below that threshold the council consults its own advisers or relies on the submitted report. Either way the reviewer will check the boring density against the site area, whether the climatic data was interpolated for the site, whether the subgrade boundaries follow soil or convenience, and whether the report acknowledges uncertainty where it exists.
Where a scheme is temporary and reversible, such as a solar farm with a defined operational life, say so and describe the soil management and reinstatement measures. That is a separate argument from the classification, and it belongs in the planning case rather than in the soil report.
Briefing and checking the report
Give the surveyor the red line, the access arrangements, the tenancy position and the planning context in writing. Then check the returned report against a short list.
- Are boring locations mapped and numbered, with a density proportionate to the site area?
- Is the climatic data site-specific and its source named?
- Is the limiting factor stated for each grade, rather than a bare grade label?
- Do the subgrade boundaries follow observed soil changes?
- Are survey date, ground conditions and limitations recorded?
A report that answers those five questions will usually survive consultation. One that does not will come back, and it will come back late.
This is general guidance rather than legal advice. Check the position with your local planning authority or a qualified professional before relying on it.
Enter your postcode on PlanScope to see which rural reports your site is likely to need. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.
Frequently asked questions
Can I rely on the published ALC map for my site?
No. Natural England's provisional maps were produced at 1:250,000 and do not subdivide Grade 3 into 3a and 3b, which is the distinction that decides whether land is best and most versatile. They were never intended for site-specific use, and relying on one invites a request for a detailed survey mid-determination.
How many soil borings should an ALC survey take?
Commonly one hand auger boring per hectare on smaller sites, supported by soil pits where a profile needs to be seen in section, with each boring described to at least 1.2m where the ground allows. Boring locations should be mapped and numbered in the report so the density can be checked against the site area.
What qualifications should an ALC surveyor hold?
No statute reserves the work, so authorities look for a soil scientist rather than a general environmental consultant, usually with membership of the British Society of Soil Science and chartered status, plus previous ALC surveys that have been assessed by Natural England or tested at appeal.
When is Natural England consulted on loss of farmland?
Schedule 4 to the Development Management Procedure Order 2015 requires consultation where development is not in accordance with the development plan and would lead to the loss of more than 20 hectares of grades 1, 2 and 3a land. Below that threshold the council relies on its own advisers or the submitted report.
What time of year can an ALC survey be done?
Most of the year, but not when ground is waterlogged or frozen, because augering and wetness assessment both become unreliable, and not through a standing crop that blocks access. Late summer after harvest and early spring before drilling are the usual windows. Allow six to eight weeks from instruction to report.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.