Natural Resources Conservation Service Helping People Help the Land SOIL – The Fundamental...
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Transcript of Natural Resources Conservation Service Helping People Help the Land SOIL – The Fundamental...
Natural ResourcesConservation Service
Helping People Help the Land
SOIL –SOIL – The Fundamental The Fundamental
ConceptsConcepts
SOILSOIL
Geologic definition: Loose surface of the Geologic definition: Loose surface of the earth as distinguished from solid bedrock; earth as distinguished from solid bedrock; support of plant life not required.support of plant life not required.
SOILSOIL
Traditional definition: Material which Traditional definition: Material which nourishes and supports growing plants; nourishes and supports growing plants; includes rocks, water, snow, air.includes rocks, water, snow, air.
SOILSOIL
Component definition: Mixture of mineral Component definition: Mixture of mineral matter, organic matter, water, and air.matter, organic matter, water, and air.
Air 25%
Mineral Matter 45%
Water 25%
Organic Matter 5%
SOILSOIL
Component definition: Mixture of mineral Component definition: Mixture of mineral matter, organic matter, water, and air.matter, organic matter, water, and air.
Example:Example:
SOILSOIL
Soil Taxonomy definition: Soil Taxonomy definition: Collection of natural Collection of natural bodies of the earth’s surface, in places modified or even bodies of the earth’s surface, in places modified or even made by man or earthy materials, containing living made by man or earthy materials, containing living matter and supporting or capable of supporting plants matter and supporting or capable of supporting plants
out of doors.out of doors. Its upper limit is air or shallow water and its lower limit is Its upper limit is air or shallow water and its lower limit is the depth to which soil weathering has been effective.the depth to which soil weathering has been effective.
SOILSOIL
As a portion of the landscape: As a portion of the landscape: Collection of Collection of natural bodies occupying portions of the earth’s surface natural bodies occupying portions of the earth’s surface that support plants and that have properties due to the that support plants and that have properties due to the integrated effect of climate and living matter, acting upon integrated effect of climate and living matter, acting upon parent material, as conditioned by relief, over periods of parent material, as conditioned by relief, over periods of time.time.
Soil Forming ProcessesSoil Forming Processes
TranslocationsTranslocations
TransformationsTransformations
AdditionsAdditions
LossesLosses
Mineral matterMineral matter
Organic matterOrganic matter
AirAir
WaterWater
Major ComponentsMajor Components
Physical Properties Physical Properties of Soilof Soil
Soil textureSoil texture
Soil structureSoil structure
Soil colorSoil color
Bulk densityBulk density
Granular
Platy
Blocky
(Angular)(Subangular)
Wedge
ColumnarPrismatic
Examples of Soil StructureExamples of Soil Structure
Aspects of Soil StructureAspects of Soil Structure
The arrangement into aggregates of The arrangement into aggregates of desirable shape and sizedesirable shape and size
The stability of the aggregateThe stability of the aggregate
The configuration of the poresThe configuration of the pores
Factors that Affect Aggregate Factors that Affect Aggregate StabilityStability
Kind of clayKind of clay
Chemical elements associated with the Chemical elements associated with the clayclay
Nature of the products of decomposition Nature of the products of decomposition or organic matteror organic matter
Nature of the microbial populationNature of the microbial population
Factors that Affect Factors that Affect Soil StructureSoil Structure
Kind of clayKind of clay
Amount of organic matterAmount of organic matter
Freezing and thawingFreezing and thawing
Wetting and dryingWetting and drying
Action of burrowing organismsAction of burrowing organisms
Growth of root systems of plantsGrowth of root systems of plants
Important NoteImportant Note
All of these have a loosening effect on All of these have a loosening effect on the soil, but they have no effect on the soil, but they have no effect on aggregate stabilityaggregate stability
Bulk DensityBulk Density
Determined by dividing the weight of Determined by dividing the weight of oven-dry soil in grams by its volume in oven-dry soil in grams by its volume in cubic centimeterscubic centimeters
The variation in bulk density is due The variation in bulk density is due largely to the difference in total pore largely to the difference in total pore spacespace
Effects of Bulk DensityEffects of Bulk Density
Engineering propertiesEngineering properties
Water movementWater movement
Rooting depth of plantsRooting depth of plants
Soil ColorSoil Color
Indicator of different soil typesIndicator of different soil types
Indicator of certain physical and Indicator of certain physical and chemical characteristicschemical characteristics
Due to humus content and chemical Due to humus content and chemical nature of the iron compounds present in nature of the iron compounds present in the soilthe soil
Major Forms of Iron and Effect Major Forms of Iron and Effect on Soil Coloron Soil Color
Form Chemical Formula Color
Ferrous oxide FeO Gray
Ferric oxide (Hematite) Fe2O3 Red
Hydrated ferric oxide (Limonite) 2Fe2O3 3H2O Yellow
Want to learn more Want to learn more about soil?about soil?
Visit NRCS’ website at the National Soil Visit NRCS’ website at the National Soil Survey Center at www.soils.usda.govSurvey Center at www.soils.usda.gov
Prepared by Earl D. LockridgePrepared by Earl D. LockridgeNational Soil Survey CenterNational Soil Survey CenterLincoln, NELincoln, NEUSDA NRCS ~ An equal opportunity provider and employerUSDA NRCS ~ An equal opportunity provider and employer
We KNOW Soil!
Natural ResourcesConservation
ServiceHelping People Help the Land