1. Dr Przemyslaw Wozniczka przemyslaw.wozniczka@upwr.edu.pl
Soil Morphology
Dr Przemyslaw Wozniczka

2. Soil profile descritpion
A vertical exposure of given soil horizons characteristic for each soil.
Soil horizon:
A layer of soil approximately parallel to the soil surface, differing in properties and characteristics from layers above and below

3. Choice of place for Soil Profile
representative place
distance from roads and buildings
adequate depth of profile – cm

4. Soil profile descritpion
General informations:
profile number,
date, author,
location,
elevation,
coordinates (GPS),
climate and weather conditions,
landform and topography,
land use and vegetation,
human influence,
erosion,
surface characteristics – salt, cracks, rock outcrops

5. Soil profile descritpion
Soil informations:
horizons designations
depth of horizons
horizons transition
morphology and depth of transitions
Structure of horizons
Texture of horizons
Colour
pH and carbonates presents
Moisture status
Mootling (from Fe, Mn)
Redox potential (gleyic spots)

6. Soil Horizons O horizons
These are layers dominated by organic material consisting of undecomposed or partially decomposed litter, such as leaves, needles, twigs, moss and lichens, that has accumulated on the surface; they may be on top of either mineral or organic soils.
The mineral fraction of such material is only a small percentage of the volume of the material and is generally much less than half of the weight.
O horizon is surface layer of a soil

7. Soil Horizons A horizons
Mineral horizons that formed at the surface or below an O horizon
- accumulation of humified organic matter
- properties resulting from cultivation, pasturing, or similar kinds of disturbance
If a surface horizon has properties of both A and E horizons but the dominant feature is an accumulation of humified organic matter, it is designated an A horizon.
In some places, where warm and arid climates prevail, the undisturbed surface horizon is less dark than the underlying horizon
and
contains only small amounts of organic matter. It is a morphology different from the C layer, although the mineral fraction may be similar or only slightly altered by weathering. Such a horizon is designated A because it is at the surface.

8. Soil Horizons E horizons
These are mineral horizons - main feature is loss of silicate clay, iron,
aluminium, or some combination of these, leaving a concentration of sand and silt particles
An E horizon is usually, lighter in colour than an underlying B horizon.
In some soils, the colour is that of the sand and silt particles, but in many soils coatings of iron oxides or other compounds mask the colour of the primary particles.
An E horizon is most commonly differentiated from an underlying B horizon
by colour by coarser texture; or by a combination of these properties. An
E horizon is commonly near the surface, below an O or A horizon and above a B
horizon.
However, the symbol E may be used without regard to position in the profile for any horizon that meets the requirements and that has resulted from soil genesis.

9. Soil Horizons B horizons
These are horizons that formed below an A, E, H or O horizon, and in which the
characteristic:
- illuvial concentration, alone or in combination, of silicate clay, iron,
aluminium, humus, carbonates, gypsum or silica;
- higher in chroma, or redder in hue than overlying and underlying horizons
All kinds of B horizons are, or were originally, subsurface horizons

10. Soil Horizons C horizons
These are horizons or layers, excluding hard bedrock, that are little affected by pedogenetic processes and lack properties of O, A, E or B horizons.
Most are mineral layers (but can have some shells)
C - horizon is below the zones of greatest biological activity and soil processes

11. Soil Horizons R Horizon
These consist of hard bedrock underlying the soil. Granite, basalt, quartzite and limestone or sandstone are examples of bedrock that are designated R.
Air-dry or drier chunks of an R layer when placed in water will not slake within 24 hours.
The bedrock may contain cracks, but these are so few and so small that few roots can penetrate. The cracks may be filled with clay or other material.

12. Soil Horizons SUBORDINATE DISTINCTIONS: (small letters)
„g”: strong gleying (anaerobic/reductic conditions in horizon): Cg, Bg.
„h”: illuvial accumulation of organic matter: Bh.
„k”: accumulation of carbonates (CaCO3, MgCO3): Ak, Bk, Ck.
„o”: accumulation of Fe and Al oxides: Bo.
„s”: illuvial organic matter and Fe and Al oxides: Bs.
„t”: accumulation of silicate clays: Bt

13. Transitional horizons
Gradational
When one horizon transitions into another. Transitional horizon is characteristically more like the horizon designated first
Example: AE – Transitional between A and E, but more like the A horizon.
Possible types: AB, AE, AC, EA, EB, BA, BE, BC, CA, CB

14. Transitional horizons
Mixed / interrupted
Used when individual parts of two horizons exist within one layer
Examples: E/B composed of individual parts of E and B horizon component in which E component is dominant and surrounds the B materials.
Possible types: A/E, A/C, A/B, E/A, E/B, B/A, B/E, B/C, C/B

15. Transitional horizons
boundary depths
A Abrupt 0–2
C Clear 2–5
G Gradual 5–15
D Diffuse > 15

16. Transitional horizons
Topography of boundary
S Smooth - Nearly plane surface
W Wavy - Pockets less deep than wide
I Irregular - Pockets more deep than wide
B Broken - Discontinuous

17. Vertical subdivisions
Horizons or layer designated by a single combination of letter symbols can be subdivided using Arabic numerals,
According the differents at morphological features, such as structure, colour or texture.
For example:
within a C, successive layers could be C1, C2, C3, etc.;
or:
if the lower part is gleyed and the upper part is not, the designations could be C1-C2-Cg1-Cg2 or
C-Cg1-Cg2-R.