Agricultural land grades and solar farm siting

Whether a solar farm sits on best and most versatile land is usually the first substantive question an officer asks, and the published maps cannot answer it. The provisional agricultural land classification covering most of England predates the 1988 revised guidelines and does not split grade 3 into 3a and 3b. Since best and most versatile means grades 1, 2 and 3a, the solar farm agricultural land grade question turns on exactly the distinction the map leaves out.

That is why a field survey is the normal answer, and why the ones commissioned late cost the programme more than they cost the budget.

How agricultural land classification grades work

The system grades land from 1, excellent quality with very minor limitations, to 5, very poor quality with severe limitations. Grade 3 is subdivided into 3a, good quality, and 3b, moderate quality.

Grading is not a soil test. It combines climate, site and soil factors and grades on the most limiting of them. A deep fertile soil on a steep slope in a wet upland climate is not grade 1, whatever the soil is like, because climate and gradient limit what can be grown and when it can be worked.

The factors that most often determine the grade in lowland England are wetness class, derived from soil texture, structure and drainage, and droughtiness, derived from available water capacity and rainfall. Both are inferred from profile characteristics recorded in the field.

Grades also vary across a single field. Boundaries between 3a and 3b often follow a change in soil parent material or a slight change in slope, and neither is visible from a farm gate. That is a further reason the published mapping, drawn at a strategic scale, cannot be scaled down to a site.

Best and most versatile land and the policy test

National policy asks decision makers to recognise the benefits of the best and most versatile land, and where development of agricultural land on any scale is shown to be necessary, to prefer poorer quality land. The Framework was re-issued in August 2026 with policy-coded chapters, so take the wording from the current edition rather than an older paragraph number.

Two things follow. The applicant is expected to show what grade the land is, on evidence. And where it is best and most versatile, the applicant is expected to show why lower grade land was not used.

Neither test is absolute. Solar schemes on best and most versatile land are permitted, and the benefits of renewable generation weigh in the balance. What does not work is an application that asserts a grade without survey evidence and then argues the balance.

Why a desk study is rarely enough

Start with the desk study, because it is quick and it occasionally settles the matter. Check whether a post-1988 detailed survey covers the site, look at the soil association mapping, the geology and the topography, and identify what the provisional map shows.

If the desk study shows grade 4 or 5 across the whole site, or a detailed post-1988 survey already subdivides grade 3, you may not need more. If it shows grade 3 undifferentiated, which it usually will, you do.

Officers are familiar with this and will ask. A submission relying on a provisional map to claim land is grade 3b invites a holding objection from the authority's own adviser, and the survey then has to be done anyway, several months later.

Field survey method and the season for it

The survey follows the revised guidelines, and a soil scientist carries it out.

Borings are taken on a grid across the site, at a density appropriate to the scale and variability of the land, with soil pits dug to examine structure and profile development in more detail at representative locations. Each observation records depth, texture by horizon, stoniness, colour and mottling, structure and any impeding layers.

Those observations produce a wetness class and a droughtiness assessment, which combine with climate data interpolated for the site and with site factors such as gradient and flood risk to give a grade for each parcel.

Timing matters. Frozen ground, standing water and a standing crop all prevent access or distort observations. On an arable site the practical windows are after harvest and before drilling, which on many farms is a matter of weeks.

Commission a Agricultural Land Classification survey early enough to hit one of those windows. Councils expect a suitably qualified author, and professional review is strongly advised before it forms part of a submission. PlanScope can produce an AI-assisted draft report structured to the standard sections, with every field observation marked as to be confirmed until the soil scientist supplies it.

Sequential consideration of lower grade land

Where the site includes best and most versatile land, expect to be asked about alternatives. The question is not whether a better site exists somewhere in England. It is whether the applicant has looked at lower grade land within the search area defined by the grid connection and the commercial constraints.

Set out the search properly: the area searched, the constraints applied, the sites considered, and why each was discounted. Grid connection capacity and distance to the point of connection are legitimate constraints and they carry weight when evidenced with the connection offer.

Where a scheme uses a mixture of grades, give the area breakdown in hectares and as a proportion of the site, and show it on a plan. A scheme that is 20 per cent grade 3a reads very differently from one that is 80 per cent, and the officer should not have to work it out.

The same approach to site constraints appears in mineral and waste safeguarding on farmland, where the question is again whether a use sterilises a resource.

Soil management and reversibility arguments

The reversibility case is real, and it is stronger when it is specific.

• Piled foundations rather than concrete bases, so the soil profile is disturbed at discrete points only.
• A soil resource plan covering stripping, storage and reinstatement for cable trenches, access tracks and compounds.
• Restriction of construction traffic to defined routes with temporary surfacing to limit compaction.
• Continued agricultural use through sheep grazing, with fencing and access designed for it.
• A decommissioning method statement and the obligation securing it.
• Monitoring of soil condition during the operational period.

Say what happens to the land under the panels as well. Grassland established and grazed for decades improves soil organic matter, and that is an argument worth making with evidence rather than as a general claim.

Be careful not to overreach. A claim that the land will come back in better condition than it went in needs support, and an officer who has read the same sentence on five applications will discount it unless the monitoring commitment behind it is real.

Presenting the evidence in the application

Put the survey in as a standalone appendix with its own plan, and summarise the findings in the Planning Statement with the area breakdown by grade.

Deal with the policy test directly: what the survey found, what proportion is best and most versatile, what alternatives were considered, and what mitigation is proposed. Then set that against the benefits in the planning balance.

Landscape effects usually run alongside the land quality question on the same sites, and a Landscape and Visual Impact Assessment is normally required for a scheme of any scale.

This is general guidance, not 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 reports the site needs.

PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.