عترعتر 201201

LabLab

11 اسبوعاسبوع

التربة التربة تطور تطورصخور & تربة

من الناتج المفكك من الجزء الناتج المفكك الجزءاآلصلية اآلصلية الصخور الصخور

من تعرية تعرية ==تربةتربة من الجزء الجزء

لها حدث الذى لها الصخور حدث الذى الصخور

تعريةتعرية

bedrockbedrockBedrock

النربة النربة قطاع قطاع طبفات على طبفات يحتوى على يحتوى

A

E

B

C

Bedrock

Bedrock

soil تربة

Developmentالقطاع نطور

المواد المواد انتقال التربة Development/Development/انتقال التربة تطور تطور

تربة افاقSoil Horizons

قطاعSoil Profile تربة قطاع

Soil Horizonsالتربة افاق

Soil Profileتربة قطاع

A

Bw

CC

EEEE

BEBE

BBtbtb

Master Horizons

O horizon-Organic

A horizon-Mineral & Organic

E horizon-Eluviation (Loss)

B horizon-Illuviation (Gain)

C horizon- little Alteration from Parent Material

R horizon- Bedrock

O horizons: Layers dominated by organic material. Some are saturated with water for long periods or were once saturated but are now artificially drained; others have never been saturated.

الرئيسى األفقMaster Horizons

A horizons: Mineral horizons th

at formed at the surface or below an O horizon, that exhibit obliteration of all or much of the original rock structure

-an accumulation of humified organic matter

intimately mixed with the mineral fraction and not

dominated by properties characteristic of E or B horizons

-properties resulting from cultivation, pasturing,

or similar kinds of disturbance.

Master Horizons الرئيسى األفق

E horizons: Mineral horizons in which the main

feature is loss (eluviation) of silicate clay, organic matter, iron, aluminum, or some combination of these, leaving a concentration of sand and silt particles.

Master Horizons الرئيسى ألفق

B horizons: Horizons that formed below an A, E, or O

horizon and are dominated by obliteration of all or much of the original rock structure

(1) (illuvial) concentration of silicate clay, iron, aluminum, humus, carbonates, gypsum, or silica

(2)coatings of sesquioxides that make the horizon lower in value, higher in chroma, or redder in hue than overlying and underlying horizons

(3)alteration that forms granular, blocky, or prismatic structure

Master Horizons

C horizons or layers: Horizons or layers, excluding

hard bedrock, that are little affected by pedogenic processes and lack properties of O, A, E, or B horizons. Most are mineral layers.

R horizons or layers: Hard Bedrock

Master Horizons

12 Soil Orders

I AM A SUAVE HOGor

I GAVE US OMAHA

Compliments of Prof. M.J. LaForce

I AM A SUAVE HOGInceptisol- Soils with weakly developed subsurface horizons

Alfisol- Soils with a subsurface zone of silicate clay accumulation and >35% base saturation

Mollisol- Grassland soils with high base status

Andisol- Soils formed in volcanic ash

Spodosol-Acid soils with a subsurface accumulation of metal-humus complexes

Ultisol- Subsurface zone of silicate clay accumulation and<35% base saturation

Aridosol- Soils in Arid environments with moderate to strong development

Vertisol- Clayey soils with high shrink/swell capacity

Entisol- Soils with little or no morphological development

Histosol- Organic soils

Oxisol- Intensely weathered soils of tropical and subtropical environments

Gelisol- Soils with permafrost within 2 m of the surface

I AM A SUAVE HOG

Twelve Soil Orders

Entisol (recent)

Inceptisol (L.-inceptum, begging)

Mollisol (L.-mollis, soft)

Alfisol (pedalfter)

Ultisol (L.-ultimus, last)

Oxisol (Fr.-oxide)

Increasing Soil Depth

Maturation (loss of Si)

Aridisol (L.-aridus, dry)

Spodosol (Gr.-spodos, wood ashes

Gelisol (Gr.-gelid, very cold)

Vertisol (L.-verto, turn)

Andisol (L.-aridus, dry)

Histosol (Gr.-histos, tissue)

Twelve Soil Orders

Climate Specific

Material Specific

Rock

Entisol

Inceptisol

Alfisol

Ultisol

Oxisol

Mollisol

Spodosol(cool and wet)

Aridisol (dry climate)

Vertisol (clay mineralogy)

Ideal Weathering Series

Entisol-(ent)

• Shallow to bedrock.

•Limited use and management.

• The most common uses are rangeland

• Steep slopes and cool climate slow soil development.

• Inceptisols are widely distributed and occur under a wide range of environmental settings.

Inceptisol- (ept)

•

•

MollisolMollisol -(oll)-(oll)

•Soil formation under Soil formation under native grassland vegetationnative grassland vegetation

•Alfisols are mostly found in temperate humid and subhumid regions of the world.

• Developmentally just past Mollisols

Alfisol (-alf)

• Organic matter is highly Organic matter is highly decomposed and has few decomposed and has few remaining plant fibers. remaining plant fibers.

HistosolHistosol-(ist)-(ist)

Vertisol-(ert)

• Abundant, ‘active’ clay particles are dominant

Aridosol-(id)

• Form in dry climatesForm in dry climates

• White crust at the soil White crust at the soil surface is a mixture of surface is a mixture of various soluble salts various soluble salts (definitely not snow!). (definitely not snow!).

Gelisol-(el)

• Permafrost persists Permafrost persists below 38 cm year-around. below 38 cm year-around.

•The lack of significant The lack of significant microbial activity in these microbial activity in these soils leads to an soils leads to an accumulation of organic accumulation of organic matter.matter.

Gelisols are in very cold climates and typically contain permafrost

NRCShttp://www.statlab.iastate.edu/soils/photogal/orders/soiord.htm

Web Sites of Interest

Universitieshttp://soils.ag.uidaho.edu/soilorders/index.htm

Keys to Soil Taxonomyhttp://www.statlab.iastate.edu/soils/keytax/

http://soils1.cses.vt.edu/MJE/CSES3124/Laboratories.html