soils

Pedon

Pedon

________- a column of soil taken from specific location, extending from the ground surface all the way down into C.

Loess

________- a wind blow silt parent material of dust.

Components

Minerals, Organic matter ,Water ,Air

Hans Jennys factors 1941

Climate CL , Biological agents O, Relief/ topography R, Parent Material P, time T Cl O R P T

Topography

affects drainage

Loess

a wind blow silt parent material of dust

O

organic material

A

some organic material, mostly mineral, ideal for plant growth, hydrolysis happens in this layer

E

washed out layer, mineral material, Hydrolysis happens here

B

accumulations, clay particles and oxides ( all the stuff from hydrolysis ends up here)

C

parent material, weathered bed rock

R

bedrock

Pedon

a column of soil taken from specific location, extending from the ground surface all the way down into C

12 orders of Soil

Alfisols, Andisols, Aridisols, Entisols, Gelisols, Histosols, Inceptisols, Mollisols, Oxisols, Spodosols, Ultisols, Vertisols

Simonson's 4 part process

1. additions 2. depletions/ subtractions 3. transformations 4. translocations

eluviation

moves material out

illuviation

accumulates eluvial clay particles

paleosol

soil of the past

horizon O

organic material

horizon A

organic and mineral material, ideal for plant growth(Nitrogen), hydrolysis happens here

Horizon E

washed out layer, mineral material that has gone through hydrolysis, skeletal grains of quartz

Horizon B

accumulations of clay particles and oxides, all the stuff from hydrolysis of above layers

Horizon C

Parent material, weathered bed rock

Horizon R

Bedrock

Horizon K

Calcium carbonate buildup layer ( sometimes a layer not always)

pedon

a column of soil taken from specific location, extending from the ground surface all the way down into C

Solum

where soil development is most active AEB (not C)

How to describe soil

Horizon designation

Horizon boundary depths

Color

Texture

Structure

Clay films and oxidation/ reduction features

Calcium carbonate accumulations

Rock fragments

Series

the lowest most specific way to organize/ identify a soil

12 orders of soil USDA

Alfisols Andisols Aridisols Entisols Gelisols Histosols Inceptisols Mollisols Oxisols Spodosols Ultisols Vertisols

Alfisols

moderately leached soils that have relatively high native fertility, high base status forest soils with agrillic horizons ( horizons of of accumulated silicate clays)

Andisols

soils that have formed in volcanic ash or other volcanic ejecta, soils of volcanic ash

Aridisols

are CaCO3-containing soils of arid regions that exhibit subsurface horizon development, soils of dry regions

Entisols

soils of recent origin, recently formed soils

Gelisols

soils of very cold climates that contain permafrost within two meters of the surface, soils of permafrost, cyroturbation, or ice segregation

Histosols

soils that are composed mainly of organic materials,contain at least 20-30 percent organic matter by weight and are more than 40 cm thick, organic soils

Inceptisols

soils that exhibit minimal horizon development, more developed than Entisols, but still lack the features that are characteristic of other soil orders, embryonic soils with few diagnostic features

Mollisols

the soils of grassland ecosystems, soils of grasslands

Oxisols

very highly weathered soils that are found primarily in the intertropical regions of the world, often rich in Fe and Al oxides, sesquioxide rich soils

Spodosols

acid soils characterized by a subsurface accumulation of humus that is complexed with Al and Fe, soils with subsoil accumulations of hummus and sesquioxides

Ultisols

strongly leached, acid forest soils with relatively low native fertility, found primarily in humid temperate and tropical areas of the world, low base status forest soils

Vertisols

clay-rich soils that shrink and swell with changes in moisture content, shrinking and swelling dark clay soils

Sand

0.05 - 2mm feels gritty

Silt

0.002-0.05 mm feels smooth

Clay

less than 0.0002 mm feels sticky

Vertisols

shrinking and swelling dark clay soils

alfisols

high base status forest soils with agrillic horizons

andisols

volcanic ash soils

Aridisols

soils of dry regions

Entisols

new soils / recently formed soils

Gelisols

cold climate soils

Histosols

mostly organic material soils

inceptisols

soils with few diagnostic features

mollisols

grass land soils

spodosols

acidic soils with subsoil accumulations of humus and sesquioxides

oxisols

sesquioxide rich intertropical soils

ultisols

low base status forest soils