Grade 2, 3 and 4 Agricultural Land: What Each Grade Means

Grade 2 agricultural land is very good land with minor limits on crop yield, cultivation or harvesting. Grade 3 is good to moderate land, split into Subgrade 3a and Subgrade 3b. Grade 4 is poor land with severe limits, mainly suited to grass with occasional arable crops. These definitions come from the Natural England guide to assessing development on agricultural land, which applies to England.

This page gives the measured cut-offs behind each grade, such as slope, soil depth and stone content. It also shows what a grade means for planning, how to find the grade of a field, how the US system differs, and a calculator for comparing crop and grass margins on the same field.

What grade 2, 3 and 4 land mean at a glance

The Agricultural Land Classification, or ALC, ranks land from Grade 1 to Grade 5. The guidance calls it the only approved system for grading farmland quality in England and Wales. Defra and the Welsh Government published an updated edition in December 2025, with a corrected version in September 2026. The update did not change the grading criteria.

How a field gets its grade

Assessors look at the physical and chemical limits of the land over the long term. The three main groups are climate, site and soil. Climate covers temperature, rainfall, aspect, exposure and frost risk. Site covers gradient, small changes in relief and flood risk. Soil covers texture, structure, depth, stoniness and chemical problems that cannot be fixed, as Natural England’s technical note TIN049 sets out.

Climate and soil also act together. Their two main combined effects are soil wetness and droughtiness.

The worst limit sets the grade

A grade is not an average. Under the guidelines, the most limiting factor decides the result. A deep, stone-clear soil on a 15-degree slope is still capped at Grade 4 by the slope. Good soil cannot buy back the lost points, because there are no points to add up.

What the grade ignores

• Current use: TIN049 says present use or intensity of use does not affect the grade.
• Land value and yields: the guidelines say the grade does not necessarily reflect the current economic value, crop range or yield of the land.
• Farm structure: farm size, location, fixed equipment and access do not count.
• Irrigation: an irrigation system counted until 1996, but no longer does.
• Management skill: land is judged at a good, but not outstanding, standard of management.

So a high-yielding field of lettuce on irrigated land can carry a lower grade than its yield suggests. And a neglected field can hold a high grade.

▶ Why land classification matters for the environment, the economy and land use. · 20:06

The cut-offs behind grade 2, 3 and 4 land

The guidelines give numeric limits for several factors. The two simplest to check on a farm are slope and stones. Soil depth limits apply to soil over rock that cultivation tools cannot get through.

Chart

Minimum soil depth over rock by grade

Centimetres of soil over rock that cultivation tools cannot penetrate

These figures come from Tables 1, 4 and 5 of the guidelines. Stone limits are percentages by volume of hard stones. Passing them does not earn a grade. Wetness, droughtiness, climate and flood risk can still pull the land down, and those tests need a soil pit and climate data.

Flood limits

The guidelines assess flooding separately for summer and winter, and either season can set the grade. Summer floods are generally more damaging, because active roots suffer from waterlogging. On the summer table, Grade 2 allows only rare floods of short duration. Grade 4 allows occasional long floods, or frequent short or medium ones.

What is grade 2 land?

Grade 2 land is very good quality land with minor limits. The official wording says those limits affect crop yield, cultivations or harvesting. Yields are generally high, but may be lower or more variable than on Grade 1.

A wide range of farm and horticultural crops can usually be grown, with some exceptions. The official description names winter-harvested vegetables and arable root crops as the crops that may be harder on some of this land. Those are crops where a wet autumn or heavy soil can make lifting difficult.

• Slope: up to 7 degrees, suitable for most kinds of farm machinery, including precision seeding and harvesting equipment.
• Soil over rock: at least 45 cm.
• Planning status: part of best and most versatile land.
• Farm decision: protect structure and drainage, because they help keep the crop range open.

What does grade 3 land mean?

Grade 3 land has moderate limits that affect crop choice, the timing and type of cultivation, harvesting or yield. When demanding crops are grown on it, yields are generally lower or more variable than on Grades 1 and 2. The split inside the grade matters more than the grade itself.

Subgrade 3a

Subgrade 3a is good quality land. It can give steady moderate to high yields of a narrow range of arable crops, especially cereals. It can also give moderate yields of a wider range, including cereals, grass, oilseed rape, potatoes, sugar beet and less demanding horticultural crops. It counts as best and most versatile land.

Subgrade 3b

Subgrade 3b is moderate quality land. It gives moderate yields of a narrow range, mainly cereals and grass, or lower yields of a wider range. It can also give high yields of grass that is grazed or cut over most of the year. It does not count as best and most versatile land, which is why a 3a or 3b result can matter so much in a planning case.

An older map that says only “Grade 3” cannot settle this. The provisional maps of 1967 to 1974 were prepared before Grade 3 was divided, and the 1988 guidelines merged an old Subgrade 3c into 3b.

What is grade 4 agricultural land?

Grade 4 agricultural land is poor quality land with severe limits that significantly restrict the range of crops, the yields or both. It is mainly suited to grass, with occasional cereals or forage crops at variable yields. The grade also covers very droughty arable land.

Grade 4 does not always mean thin grass. In moist climates, grass yields may be moderate to high, though the guidelines warn of difficulty in using that grass. Wet ground that cattle would damage and machines cannot cross is one way this can show up on a farm.

Practical uses for Grade 4 fields

• Grazing: permanent or long-term grass, stocked to suit how wet or steep the ground is.
• Occasional forage or cereal crops: budget for variable yields rather than assuming an average.
• Woodland or agroforestry: check species against the same depth, drainage and slope limits that set the grade.
• Habitat and environmental schemes: scheme terms and payment rates change, so check the current rules before you plan on the income.

Before you take a poor field out of production, compare the options with your own margins. The calculator further down this page does that. Our page on the main types of agricultural land use covers the wider picture.

How much land is in each grade?

Three official statements exist, and they measure different things. A 1992 answer to Parliament gave the shares from the original survey of England: Grade 3 made up more than half, and Grades 1 and 2 about a fifth. That survey did not divide Grade 3.

Chart

Share of land in each grade, original survey of England

Percent, original 1960s-based survey, Grade 3 not divided

TIN049, published in December 2012, estimates that Grades 1 and 2 together form about 21% of farmland in England and that Subgrade 3a covers about another 21%. The December 2025 guidelines describe Grades 1, 2 and 3a as about one-third of agricultural land in England and Wales, and say about half of the land is Subgrade 3b or Grade 4. The remainder is Grade 5, mostly in the uplands.

The figures have different areas and dates, so do not read them as a trend. Use any of them only as background. They tell you nothing about one field.

Why the grade matters for planning

In England, best and most versatile land means Grades 1, 2 and 3a. The national planning framework asks authorities to consider the economic and other benefits of this land, and to try to use poorer land first. That is a factor to weigh, not a ban. Grade 2 land can still be developed if the planning case is strong enough.

Authorities must consult Natural England when a proposal is likely to cause the loss, or likely cumulative loss, of 20 hectares or more of this land and is not in line with an approved development plan. Smaller losses should still be taken into account if they are significant, according to the same guide.

If you are selling, leasing or objecting, get advice from a qualified land agent or planning consultant, and check the rules for your nation. Natural England’s note and the guide above apply to England. Wales has its own Welsh Government ALC page, with a predictive map and guidance.

How to find the grade of your land

1. Start with the strategic map. The 1:250,000 predictive map gives an overview, but the guide says it is not accurate enough for individual fields or sites.
2. Look for a detailed survey. Natural England has published post-1988 ALC survey records as open data. Your land may have been covered by one.
3. Check local planning files. Nearby applications may include ALC reports that describe soils like yours.
4. Walk the field with the table above. Measure slope, dig to check depth and estimate stones. This gives an early warning, not a grade.
5. Commission a survey if the result matters. The guidelines call ALC a specialist assessment that needs trained people and on-site soil work. Background maps can give an initial indication, but not a definitive grade.

Common mistakes when reading a land grade

• Using a strategic map for one field. A 1992 answer to Parliament already warned that the old maps give only a very general picture, and that a definitive grade for a site needs a resurvey at a larger scale.
• Treating Grade 3 as one thing. The planning result can turn on whether the land is 3a or 3b.
• Judging by this year’s crop. A good harvest does not prove a high grade, because cut-offs are not based on crop yields.
• Assuming a low grade has no value. The guidelines note that Subgrade 3b and Grade 4 land can be locally valuable where poorer farmland predominates.
• Reading a grade as a price. The grade does not necessarily reflect the current economic value of land, so ask a land agent about value.

Can you improve a land grade?

Sometimes, but less often than people expect. The guidelines already assume normal management and improvements. Where underdrainage or cultivation could reduce a limit, the land is graded on the limit that remains. So installing normal field drains may not lift the grade, because the assessor may have counted them already.

• Major schemes: new arterial drainage or sea defences can count if they will happen in the near future. If they are uncertain, the limit still counts.
• Slope and depth to rock: these are hard limits with little practical fix.
• Compaction: deep compaction that is hard to fix can be treated as a long-term limit through its effect on wetness and droughtiness.
• Restored land: this is not normally graded until the end of statutory aftercare, or 5 years after soil replacement.

Good soil care can still pay through better yields and easier working, even when the official grade stays the same. Those are separate questions, which leads to the sum below.

Crop or grass: compare margins on your field

A grade tells you the limits of the land. It does not tell you what pays. Enter your own figures to compare an arable crop with grass or another lower-input use on the same field. This is a planning sum and does not assign a grade.

Try the numbers for your own farm below.

ALC grades vs USDA land capability classes

If your land is in the United States, the ALC does not apply. The US uses Land Capability Classes 1 to 8, usually written as Class I to Class VIII. Cornell CALS summarises the eight classes: the numbers show growing limits, and Classes 5 to 8 are restricted to uses such as pasture, forest or wildlife, with Class 8 excluding commercial plant production.

Chart

US cropland in Class I

Million acres of non-Federal cropland, survey years

Do not convert an ALC grade to a US class. The ALC guidelines say the system was calibrated specifically for England and Wales, and neither the ALC guidelines nor the Cornell guide offer a conversion. A “Class 2” search result is a different scale from Grade 2.

Unlike England’s older grade shares, US class totals are refreshed. The USDA 2022 National Resources Inventory reports non-Federal cropland by class. Of about 364 million acres, about 188 million sit in Classes I and II, or 52%. About 21 million acres, or 6%, is farmed in Classes V to VII. Class I cropland fell from 25.7 million acres in 1982 to 23.0 million in 2022.

Scotland uses a different system too

Scotland uses the Land Capability for Agriculture classes, from Class 1 to Class 7. Classes 1 to 3.1 are known as prime agricultural land. A Scottish Class 4.1 field is not the same as an English Grade 4 field.

Chart

US cropland by land capability class

Million acres of non-Federal cropland, 2022

Using grades in farm decisions

A grade changes farm decisions in three main ways.

• Crop plan: match demanding crops to fields that can carry them. Grade 2 keeps more options open than Subgrade 3b.
• Input spend: ask which limit is holding the field back. Fertilizer will not fix a shallow soil, and a drain will not fix a droughty one. Follow product labels and local rules on any input.
• Land use: test grass, woodland or environmental schemes on the fields where crop margins are thin.

Keep your records in step with the land. Defra’s UK land use statistics show what is farmed each year, with the 2025 dataset added in December 2025, but they do not grade individual fields.

▶ How terrain analysis and data help match land to farm decisions. · 16:29

Watching a field between surveys

An ALC survey is a one-off look at long-term limits. It will not tell you which part of a field struggled this season. Satellite vegetation maps can show patches that lag behind the rest, which is a reason to walk that area and dig. They show the change, not the cause, and they do not replace a soil survey or set a grade.

The Farmonaut Satellite + AI Farm Monitoring System shows vegetation maps for fields you draw, on web, Android and iOS.

Related pages on our site: land grades summary, land use planning, intensive farming pros and cons, large farm management, fleet routing, carbon footprint reporting, product traceability, satellite data API, API developer documentation.

▶ Six plain steps to start precision farming, including seeing fields from space. · 4:18

FAQ

What is grade 4 agricultural land?

It is poor quality land with severe limits on crop range or yields. It is mainly suited to grass with occasional arable crops, and it includes very droughty arable land. Limits can include slope, shallow or stony soil, wetness and flood risk.

What is grade 2 land?

It is very good quality farmland with minor limits. A wide range of crops can usually be grown, though some land in the grade is less flexible for winter vegetables and arable roots. It counts as best and most versatile land in England.

What does grade 3 land mean?

It means good to moderate land with moderate limits on crop choice, timing or yield. Subgrade 3a is good and counts as best and most versatile. Subgrade 3b is moderate and does not.

Can you build on grade 2 or grade 3 land?

Possibly. The grade is a planning consideration, not an automatic ban. Authorities weigh the benefits of the better land and try to use poorer land first. Ask a planning professional about your site.

Does a land grade change after drainage work?

Not necessarily. Grading already takes normal underdrainage into account where it could be installed. Any official change would also need a new survey by a qualified assessor.

Is ALC Grade 2 the same as USDA Class II?

No. The two systems were built on different criteria and for different countries. For US land, look up the class for your soil map unit in the Web Soil Survey.