How do soils form? Soil Profiles How do you start
Description: How do soils form? Soil Profiles How do you start describing the soil? What do you see? What is different from top to bottom? How deep do roots go? Soil Profile Descriptions Soil Profile - A vertical section of the soil extending vertically
Related Topics
Download Presentation
"How do soils form? Soil Profiles How do you start" is the property of its rightful owner. Permission is granted to download and print the materials on this website for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Presentation Transcript
slide1. How do soils form? Soil Profiles<br>
slide2. How do you start describing the soil? What do you see?
What is different from top to bottom?
How deep do roots go?<br>
slide3. Soil Profile Descriptions Soil Profile - A vertical section of the soil extending vertically through all its horizons and into the parent material.
Soil Horizon - A layer of soil, approximately parallel to the surface, with properties that differ from the horizons above or below it – the properties (characteristics) are produced by soil forming processes.
Soil Layer - A layer in the soil deposited by a geologic force (wind, water, glaciers, oceans, etc.) and not relating to soil forming process.<br>
slide4. C (parent material) R (bedrock) Earth’s surface that soils developed from<br>
slide5. Top Soil Subsoil Parent Material<br>
slide6. A Horizon B Horizon C Horizon<br>
slide7. Our
Aunt
Ethel
Bakes
Cookies
Regularly Remember the Ideal Profile Using this Pneumonic Device:<br>
slide8. Organic (O) Horizons O horizons or layers: Layers dominated by organic material.
Identification Criteria
>20% organic matter
Dark color (
Feels ‘Squishy”
Identifiable dead leaves, grass, etc. accumulated at surface<br>
slide11. A Horizons Referred to as topsoil
Typically ranging from 6-30 centimeters thick
Mineral horizon formed at the surface or below an O horizon.
Characterized by an accumulation of well decomposed organic matter intimately mixed with the mineral fraction.
Identification Criteria
Mineral soil material
Mix of well decomposed organic matter and mineral material
Surface mineral horizon
Typically dark in color-darker than underlying horizons<br>
slide12. A Horizon<br>
slide13. A Horizon<br>
slide14. E Horizons Mineral horizon in the upper part of the soil typically underlying an O or A horizon.
Light colored, leached horizons ranging from not being present to several centimeters thick
Light color due to the natural color of the mineral grains.
Formed by weak organic acids that strip coatings from mineral grains.
Field Identification
Zone of eluviation - removal of clays, Fe, Al, and humus
Lighter in color than over or underlying horizon
Near surface, below O or A horizons and above a B horizon<br>
slide15. E Horizon<br>
slide16. E Horizon<br>
slide17. B Horizons Referred to as subsoil.
The zone of accumulation (or illuviation) within the soil.
Field Identification
Subsurface horizon formed below an O, A, E horizon and above the C horizon
Formed as a result of soil forming processes
Expressed often by color
Illuvial concentration-zone of accumulation<br>
slide18. B Horizon<br>
slide19. Bg Horizon<br>
slide20. C Horizon Referred to as parent material.
These horizons and layers are little affected by soil forming processes (unweathered geologic material).
Field Identification
Little affected by soil-forming processes
Geologic layering
Color of unweathered geologic material<br>
slide22. R Horizon Hard rock
Field Criteria
Can not dig it with a shovel or backhoe<br>
slide23. Vocabulary Decompose
Bedrock
Developed Soil
Eluviated Horizon
E Horizon
Horizon
Humus
Leaching
Minerals Organic Matter
Organisms
Parent material
Soil
Soil Profile
Subsoil
Topsoil
Transform
Weathering<br>
slide24. Vocabulary A Horizon
B Horizon
C Horizon
R Horizon
O Horizon
Soil Monolith<br>
slide2. How do you start describing the soil? What do you see?
What is different from top to bottom?
How deep do roots go?<br>
slide3. Soil Profile Descriptions Soil Profile - A vertical section of the soil extending vertically through all its horizons and into the parent material.
Soil Horizon - A layer of soil, approximately parallel to the surface, with properties that differ from the horizons above or below it – the properties (characteristics) are produced by soil forming processes.
Soil Layer - A layer in the soil deposited by a geologic force (wind, water, glaciers, oceans, etc.) and not relating to soil forming process.<br>
slide4. C (parent material) R (bedrock) Earth’s surface that soils developed from<br>
slide5. Top Soil Subsoil Parent Material<br>
slide6. A Horizon B Horizon C Horizon<br>
slide7. Our
Aunt
Ethel
Bakes
Cookies
Regularly Remember the Ideal Profile Using this Pneumonic Device:<br>
slide8. Organic (O) Horizons O horizons or layers: Layers dominated by organic material.
Identification Criteria
>20% organic matter
Dark color (
Feels ‘Squishy”
Identifiable dead leaves, grass, etc. accumulated at surface<br>
slide11. A Horizons Referred to as topsoil
Typically ranging from 6-30 centimeters thick
Mineral horizon formed at the surface or below an O horizon.
Characterized by an accumulation of well decomposed organic matter intimately mixed with the mineral fraction.
Identification Criteria
Mineral soil material
Mix of well decomposed organic matter and mineral material
Surface mineral horizon
Typically dark in color-darker than underlying horizons<br>
slide12. A Horizon<br>
slide13. A Horizon<br>
slide14. E Horizons Mineral horizon in the upper part of the soil typically underlying an O or A horizon.
Light colored, leached horizons ranging from not being present to several centimeters thick
Light color due to the natural color of the mineral grains.
Formed by weak organic acids that strip coatings from mineral grains.
Field Identification
Zone of eluviation - removal of clays, Fe, Al, and humus
Lighter in color than over or underlying horizon
Near surface, below O or A horizons and above a B horizon<br>
slide15. E Horizon<br>
slide16. E Horizon<br>
slide17. B Horizons Referred to as subsoil.
The zone of accumulation (or illuviation) within the soil.
Field Identification
Subsurface horizon formed below an O, A, E horizon and above the C horizon
Formed as a result of soil forming processes
Expressed often by color
Illuvial concentration-zone of accumulation<br>
slide18. B Horizon<br>
slide19. Bg Horizon<br>
slide20. C Horizon Referred to as parent material.
These horizons and layers are little affected by soil forming processes (unweathered geologic material).
Field Identification
Little affected by soil-forming processes
Geologic layering
Color of unweathered geologic material<br>
slide22. R Horizon Hard rock
Field Criteria
Can not dig it with a shovel or backhoe<br>
slide23. Vocabulary Decompose
Bedrock
Developed Soil
Eluviated Horizon
E Horizon
Horizon
Humus
Leaching
Minerals Organic Matter
Organisms
Parent material
Soil
Soil Profile
Subsoil
Topsoil
Transform
Weathering<br>
slide24. Vocabulary A Horizon
B Horizon
C Horizon
R Horizon
O Horizon
Soil Monolith<br>