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

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

Choice of place for Soil Profile representative place distance from roads and buildings adequate depth of profile – 150- 200cm

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

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)

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

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.

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.

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

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

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.

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

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

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

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

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

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.