Soil and the Soil Soil and the Soil EcosystemEcosystem

Soil CharacteristicsSoil CharacteristicsProfilesProfilesTextureTextureClassesClasses

Soil ProfilesSoil ProfilesA vertical slice through the A vertical slice through the

different horizonsdifferent horizonsHorizons- horizontal layers in Horizons- horizontal layers in

soilsoil

O HorizonO HorizonDead organic matter (detritus)Dead organic matter (detritus)Primary energy source for the Primary energy source for the

soil ecosystemsoil ecosystemHumus- bottom of O, Humus- bottom of O,

advanced decompositionadvanced decomposition

A HorizonA HorizonTopsoil- mixture of mineral soil Topsoil- mixture of mineral soil

and humusand humusRoots presentRoots presentUsually darkUsually dark

E HorizonE HorizonEluviation- leaching minerals Eluviation- leaching minerals

downward by water movementdownward by water movementPale in colorPale in color

B HorizonB HorizonMinerals from A and E Minerals from A and E

deposited heredeposited hereHigh in iron, aluminum, calcium, High in iron, aluminum, calcium,

and othersand othersSubsoilSubsoilHigh clay content, reddish/ High clay content, reddish/

yellowyellow

C HorizonC HorizonParent mineral materialParent mineral materialWeathered rock, glacial Weathered rock, glacial

deposits, volcanic ashdeposits, volcanic ash

Soil TextureSoil TextureSmall StonesSmall StonesSandSandSiltSiltClayClay

Particle SizeParticle SizeSand- 2.0 - 0.02 mmSand- 2.0 - 0.02 mmSilt- 0.02 – 0.002 mmSilt- 0.02 – 0.002 mmClay- <0.002 mmClay- <0.002 mm

LoamLoamCommon proportionCommon proportion40% sand40% sand40% silt40% silt20% clay20% clayTriangleTriangle

PropertiesPropertiesLarger particles have larger Larger particles have larger

spaces separating themspaces separating themSmaller particles have more Smaller particles have more

surface area relative to volumesurface area relative to volumeNutrient ions and water Nutrient ions and water

molecules cling to surfacesmolecules cling to surfaces

Soil ClassesSoil ClassesTaxonomy of soilTaxonomy of soilFour major classesFour major classes

MollisolsMollisolsOxisolsOxisolsAlfisolsAlfisolsAridisolsAridisols

MollisolsMollisolsFertile, dark soilFertile, dark soilTemperate grassland biomeTemperate grassland biomeGood agricultureGood agricultureMidwest US, Ukraine, Russia, Midwest US, Ukraine, Russia,

Mongolia, ArgentinaMongolia, ArgentinaDeep A horizon, rich in topsoilDeep A horizon, rich in topsoil

OxisolsOxisolsTropical rain forestTropical rain forestIron and aluminum oxides in B Iron and aluminum oxides in B

horizonhorizonLittle O horizonLittle O horizonLimited fertility for agricultureLimited fertility for agricultureMinerals leached down by Minerals leached down by

rainfallrainfall

AlfisolsAlfisolsWidespread, moderately Widespread, moderately

weathered forest soilweathered forest soilWell-developed O, A, E, BWell-developed O, A, E, BMoist, temperate forest biomeMoist, temperate forest biomeSuitable for agriculture, need Suitable for agriculture, need

organic matter/fertilizer addedorganic matter/fertilizer added

AridisolsAridisolsDrylands and desertsDrylands and desertsUnstructured verticallyUnstructured verticallyLight coloredLight coloredIrrigation leads to salinizationIrrigation leads to salinization

Article: Windsor SoilsArticle: Windsor SoilsWhat are Windsor soils?What are Windsor soils?Why is this type of soil important Why is this type of soil important

to CT?to CT?What specific crops benefit from What specific crops benefit from

Windsor soils?Windsor soils?How are Windsor soils formed?How are Windsor soils formed?Describe the Windsor soil profile.Describe the Windsor soil profile.