Presentation on theme: "University of Çukurova Departments of Soil Science and Archaeometry"— Presentation transcript:
1University of Çukurova Departments of Soil Science and Archaeometry LEPTOSOLSDr. Selim KAPURUniversity of ÇukurovaDepartments of Soil Science and ArchaeometryAdana, TURKEY
2Mineral Soils conditioned by Topography and Age The development of the profile is limited by the erosion exceeding soil formation or by the influence of topographic positionThe Reference Soil Group of the Leptosols accommodates very shallow soils over hard rock or highly calcareous material but also deeper soils that are extremely gravelly and/or stony.They are particularly common in mountain regions. Leptosols correlate with the `Lithosols' taxa of many international classification systems (USA, FAO) and with `Lithic' subgroups of other soils groupings. In many systems, Leptosols on calcareous rock are denoted `Rendzinas'; those on acid rock are also called `Rankers'.
4DEFINITION Soils having continuous hard within 25 cm from the soil surface; or a horizon with a thickness between 10 and 25 cm directly overlying material with a calcium carbonate equivalent of more than 40 percent, or less than 10 percent (by weight) fine earth from the soil surface down to a depth of 75 cm; andno diagnostic horizons other than a or horizon.DEFINITION
5Mollic A-horizon, surface horizon with dark color due to organic matter; Base saturation exceeds 50%.Ochric A horizon, surface without stratification and lacking the characteristics of (A histic H-horizon, or) a mollic, umbric or fimic A-horizonUmbric, similar to a mollic A-horizon but base saturation lower than 50%Yermic, an A horizon with aridic properties and a pavement that is varnished or includes wind-shaped gravel or stones ("ventifacts"); or a pavement and a vesicular crust; or a vesicular crust above a platy A-horizon, without a pavement, or a biological crust, 1 -2 mm thick.
11PETROCALCIC HORIZON CALCAREOUS ROCK SOIL May be a shallow soil overlying calcareous material but a petrocalcic horizon integrates it to a Calcisol, NOT A LEPTOSOL
12Parent material Various kinds of rock or unconsolidated materials with less than 10 percent fine earth.Environment: High or medium altitude and with strongly dissected topography. Leptosols are found in all climatic zones, particularly in strongly eroding areas.
13Profile development: A(B)R or A(B)C profiles with a thin A-horizon Profile development: A(B)R or A(B)C profiles with a thin A-horizon. Many Leptosols in calcareous weathering material have a mollic A-horizon that shows signs of intensive biological activity with a thin argic B.
14Regional distribution of Leptosols From Tropics to the cold polar regions and from sea level to the highest mountains.Widespread in mountain areas,Can be found on hard rocks or where erosion has kept pace with soil formation or removed the top of the soil profile.
16Associations with other Reference Soil Groups Shallow soils with continuous hard rock within 25 cm from the soil surface, excluding cemented layers such as a petrocalcic (laminar calcium carbonate on rock or sediment = 50% by weight, root penetration limited, extremely hard consistence when dry) or petroplinthic (Fe cementation, OC less 0.6%, limited restriction) horizon.However, the definition includes also deeper soils, provided that these have less than 10% fine earth over a depth of at least 75 cm.WHEN DISCUSSING LINKAGES BETWEEN (DIVERSE!) LEPTOSOLS AND OTHER REFERENCE SOIL GROUPS, ONE MIGHT MAKE A DISTINCTION BETWEEN LEPTIC SOIL UNITS OF OTHER REFERENCE SOIL GROUPS AND SOIL UNITS OF LEPTOSOLS.
17Young soils, a thin A-horizon over an incipient B-horizon or directly over the unaltered rock. Presence of pedogenic differentiation despite the shallowness.Integration to other soils is common, thus they occur as associations ie undularting, mountainous, sloping soilscapes are composed of integrates of Leptosols to;I. Cambisols: with the development of a cambic horizon.II. Andosols: if tephric soil material is present in profileIII. Podzols: The definition of the spodic horizon leaves the possibility open that a full-fledged Podzol exists within the depth limits of Leptosols. Such (mature!) soils are not Leptosols, despite the presence of hard rock within 25 cm from the surface, but are classified as (Leptic) Podzols.IV. Luvisols: The definition of the argic horizon (a relict Bt on the surface) precludes that an argic horizon can be present within the depth limits of Leptosols, unless there is an abrupt textural transition from the overlying horizon to the (more than 7.5 cm thick) argic horizon. In that case the soil is classified as a (Leptic) Luvisol (or Acrisol or Lixisol, depending on CEC, clay and base saturation).GENESIS
18V. Gleysols: "Gleyic properties" in Leptosols are exclusive to (deeper) soils that qualify as Leptosols because they have less than 10 percent (by weight) fine earth to a depth of at least 75 cm. "Stagnic properties" may have to be considered both in Leptosols with continuous hard rock within 25 cm of the surface and in Leptosols with less than 10 percent of fine earth to a depth of 75 cm, but Leptosols with stagnic properties have not been sufficiently documented so far.VI. Mollisols: A thin mollic epipedon overyling unalterned rock particulary at mountaionus conditions under dense natural pasture vegetation of Turkey most probably similar to the Rendzic units of Spain, Italy, France, Albania, and Crotia qualifying as LeptosolsGENESIS
19Characteristics Morphological an A(B)R or A(B)C sequence Rendzic (with white limestone fragments and abrupt boundary to the rock) & Mollic units more pronounced with dark brown color or black calcareous organo-mineral surface soilCharacteristicsMorphologicalStable granular structure + vermicular with earthworm activityBlocky structure with increasing smectite
20HYDROLOGICAL CHEMICAL PHYSICAL Free-draining soils with exceptions of shallow groundwater.Shallowness, stoniness, low water holding capacityEarthworms and enchytraeid worms are the chief organisms important in carbon sequestrationHYDROLOGICALCHEMICALPHYSICALenchytraeid wormsEarthworms
21Abandoned Roman Terraces inducing biodiversity and soil development +A resource potential for wet-season grazing, olive orchards, and vineyard.MANAGEMENTAbandoned Roman Terraces inducing biodiversity and soil development
22Terrace walls on karstic landscape for water harvesting +Human induced Erosion is the greatest threat. But natural erosion is almost nil beacuse of vegetation cover coupled with cracks with clay infills to retain water & inhibit movement on bare karstic surface+High population pressure (tourism), overexploitation and increasing environmental pollution lead to increasing deterioration of forests and threaten large areas of vulnerable Leptosols.Terrace walls on karstic landscape for water harvesting
23carob, fig production on Chromic/Luvic Leptosols +Man-made terraces for SLM allocated for grazing, grain and vineyard, olive,carob, fig production on Chromic/Luvic Leptosols