Last reviewed 1 Oct 2026 · 6 min read
Why classify land?
Land capability classification groups land according to how intensively it can be used without permanent damage, so that each piece of land gets the use and treatment it needs — cultivation, pasture, forestry or protection. It is the base of land-use planning, soil conservation planning and watershed management.
Principles:
- It is based on permanent (inherent) properties — slope, soil depth, texture, drainage, erosion, climate — not on management that can change (crop, fertility).
- It is independent of location, distance to market or ownership.
- It is a ranking by degree of limitation, assuming good (but not heroic or capital-intensive) management.
- It does not rank land by profit.
Eight capability classes (USDA system)
Classes I–IV are suitable for cultivation (arable); V–VIII are generally not suitable for cultivation (non-arable). As the class number rises, limitations increase and choice of use narrows.
| Class | Description | Typical use |
|---|---|---|
| I | Very few limitations; nearly level, deep, well-drained, fertile; no erosion hazard | Any crop; intensive cultivation with ordinary good practices |
| II | Moderate limitations — gentle slope, slight erosion, moderate depth, slightly wet; need simple practices (contouring, rotation, drainage) | Cultivation with simple conservation |
| III | Severe limitations — moderate slope, moderate to severe erosion, shallow soil, poor drainage, or low fertility | Cultivation with special practices (terraces, strip cropping) |
| IV | Very severe limitations — steep slope, severe erosion or shallow soils | Occasional or limited cultivation; close-growing crops, pasture |
| V | Little or no erosion hazard but other limitations (frequent flooding, wetness, stones, rocks) not removable — generally level | Pasture, forest, wildlife (not cultivation) |
| VI | Severe limitations; unsuited to cultivation | Grazing, forestry |
| VII | Very severe limitations — steep, rocky, very shallow | Grazing or forestry with restrictions |
| VIII | No agricultural value — rock outcrops, sand dunes, swamps, steep mountain faces | Wildlife, recreation, water supply, aesthetic |
(Classes I–IV with their allowed uses: I → intensive cultivation; II → moderate; III → limited; IV → very limited.)
Subclasses
A letter after the class shows the main kind of limitation:
| Subclass | Meaning |
|---|---|
| e | Erosion hazard or past damage (steep slope) |
| w | Excess water (wetness, drainage, flooding, high water table) |
| s | Soil limitations in the root zone (shallow, stony, low moisture-holding capacity, low fertility, salinity or alkalinity) |
| c | Climatic limitation (too cold or too dry) |
Class I has no subclass; Class V has no "e" subclass, since by definition there is little erosion hazard. Examples: IIe (gently sloping, erodible), IIIw (poorly drained), IVs (stony and shallow).
Capability units
A capability unit is a group of soil mapping units within a subclass that have similar potentials and hazards and need similar management; it is the most detailed (farm planning) level (class → subclass → unit).