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Soil Morphology and ClassificationSoil Mor
phology and Classification
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The Language of Soils
Loamy, siliceous, hyperthermic grossarenic paleudult
Purpose
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Color
Texture
Structure
Density/Porosity
Water Movement
eactivity of mineral and organic colloidsSoil acidity and p!
Morphology and Classification of Soils
"ased on physical and chemical properties
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Color Dar#/grayish$%lac# color
&range vs' (ray colors
Texture Sandy vs' Clayey
Structure (ood vs' Poor Structure
Density Porosity, organic matter, compaction
Water Pore si)es, porosity, *ater movement, saturation
eactivity Cation exchange capacity
+cidity Plant tolerances, %uffering, %ase saturation
+ll are used to classify soils
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Soil ormation
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actors +ffecting Soil ormation
Climate
&rganisms/-egetationParent material
Topography
Time
The . soil forming factors
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Climate
Temperature and Precipitation
ates of chemical, physical, %iological processes
Cold dry climates *ea# to modest profile development
Warm, humid climates strong, deep profile development
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&rganisms/-egetation
&'M' accumulation
Profile mixing
0utrient cyclingSoil structure
Soil solution 12 "'S'3
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Parent Material
+ffects texture, vegetation, nutrientsclay mineralogy, C4C
Colluvial 1gravity3
+lluvial 1streams3
Marine 1oceans3
Lacustrine 1la#es3(lacial 1ice3
4olian 1*ind3 silt and clay
Deposition
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Topography
Configuration of land surface elevation, slope, depressions
!astens or delays climatic forces'
5mpacts depth of profile development'
Water
4rosion
-egetationSlope
+spect
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Time
Duration of *eathering and all other factors
+dditionslosses
translocations
transformations
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Shands
Limestone
Hawthorne Formation (geologic Clay)
McCarty Hall
4
Sta%le, older sediments
6ounger sediments
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Soil !ori)ons7 first step in classification
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Master !ori)onsMaster !ori)ons
& organic
+ topsoil, &'M', cycling
4 elluvial
" developed/accumulation
C parent material
%edroc#
+ hori)on
" hori)on
C hori)on
& hori)on
Soil Horizon designationsSoil Horizon designations
4 hori)on
&rganic matter
Sandy
Clays/iron
Parent
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4 hori)on
+ hori)on
" hori)on15lluvial3
14lluvial3
C hori)on
R horizon
& hori)on
Master HorizonsMaster Horizons
" hori)on
4nough information8
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Su%ordinate Distinctions
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% %uried hori)onc concretions
d root restrictive
g gleying
h illuial organic matter
# car%onatesm cementation
o ! o"ic
p plowing#distur$ance
9 secondary silica
r soft %edroc# 1saprolite3
s illuvial ses9uioxides and &'M't clay accumulation
v plinthite
w deelopment of color#structure
x $ fragipan
Su%ordinate Distinctions
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Su$ordinate %istinctionsSu$ordinate %istinctions
g gleying
h illuvial organic matter
p plo*ing/distur%ance
t clay accumulation* development of color/structure
o oxic
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(g & gleying)(g & gleying)
:'"ygen depried or reduced state due to water saturation:Reduction of iron (Fe to Fe ):low chroma:'ften used with * master horizon (*g horizon)+ also , and C horizon
gleyed
material
oxidi)ed
material
oxidi)ed
e; ?*ea#@
Commonly used *ith the
" master hori)on 1e'g' "*3"*
Su%ordinate Distinction
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o > oxic hori)on
Lo* activity clays
e* *eathera%le materialsLittle roc# structure
e and +l oxides
Su%ordinate Distinction
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Su$ordinate %istinctionsSu$ordinate %istinctions
g gleying
h illuvial organic matter
p plo*ing/distur%ance
t clay accumulation* development of color/structure
o oxic
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Su%ordinate Distinctions and &rganic Matter
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a, e, i
Denotes the degree of organic matter decomposition
in the & hori)on'
&a highly decomposed 1sapric3&e moderately decomposed 1hemic3
&i slightly decomposed 1fi%ric3
Sapric most decomposed, lo* plant fi%er, lo* *ater content
!emic intermediate decompostion
i%ric least decomposed, recogni)a%le fi%ers
Su%ordinate Distinction
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SummarySummary
Master7 &, +, 4, ", C,
Su%ordinate sym%ols7 g, h, p, t, * and a,e,i
4xamples7 &a, &e, &i"t
"g
"tg
"*
+p
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&ther Designations
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-ertical Su$diisions-ertical Su$diisionsCharacteri)ed %y similar master and/or su%ordinate
properties separated %y ?degree@'
"tB
"t=
"t;
Bt horizons
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.ransitional Horizons.ransitional Horizons
Transitional layers %et*een master hori)ons'
+44"
"4
Dominant
character
Su%ordinate
Character
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Soil Classification#.a"onomySoil Classification#.a"onomy
"ased on soil profile characteristics and
the concept of soils as a natural %ody'
&%serva%le properties7 color, texture, structure,
p!, &'M
Soil Profile!ierarchical
(enesis
B; -'-' Du#achaev7 climate, vegetation, soil
BE=F C'' Mar%ut 1ASD+3 applied to A'S' 1BEG.3
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Soil Classification/TaxonomySoil Classification/Taxonomy
:+damsville7 !yperthermic, uncoated +9uic Huart)ipsamment
ASD+ classification system
Soil Survey Staff BEG.
Soil Taxonomypu%lished BEF.
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&rder
Su%order
(reat group
Su% group
amily
Series
B=
BE,III
Soil .a"onomy HierarchySoil .a"onomy Hierarchy
G;
=.I
BJII
III
KingdomPhylum
Class
&rder
amily
(enus
Species
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/nits for Soil Classification/nits for Soil Classification
Pedon smallest three$dimensional unit that displays the full range of properties characteristic of
a given soil' 1B$BI m=of area3
$ the fundamental unit of soil classification
Polypedon group of closely associated pedons in the field
Soil Series class of soils *orld$*ide *hich share a common
suite of soil profile properties
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Soil Sampling /nitsSoil Sampling /nits
Mala$ar Series
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%iagnostic Horizons for Classification%iagnostic Horizons for Classification
Surface
Su%surface
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%iagnostic Surface Horizons%iagnostic Surface Horizons
4pipedons MollicAm%ric
&chric
!istic
Melanic
Plaggen
+nthropic
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Mollic ,pipedonMollic ,pipedon
Thic#ness B$=. cm
Color value ;'. moist
chroma ;'. moist
&rganic Car%on I'G 2
"ase Saturation .I 2Structure stronglydeveloped
&rganic car%on > organic matter x I'.F
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/m$ric ,pipedon/m$ric ,pipedon
Meets all criteria of the Mollic epipedon,
except %ase saturation .I2
Chemically different than Mollic
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'chric ,pipedon'chric ,pipedon
Too7 thin
light
lo* in &'M
Mollic
Am%ric
&chric > pale
4xtremely common
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Histic ,pipedonHistic ,pipedon
&rganic hori)on
ormed in *et areas
"lac# to dar# %ro*n
Lo* %ul# density
=I$;I cm thic#
&rganic > =I2 $ ;.2 &'M'
1*ater saturation, clay content3
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Melanic 4pipedonMelanic 4pipedon
Similar in properties to Mollic
ormed in volcanic ash
Light*eight, luffy
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+nthropic !ori)on+nthropic !ori)on
:esem%les mollic
1color, o'm'3:Ase %y humans:Shells and %ones:Water from humans
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Plaggen 4pipedonPlaggen 4pipedon
Produced %y long$term 1BIIs yrs'3 manuring
&ld, human$made surface hori)on
+%sent in A'S'
.I cm thic#
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%iagnostic Surface Horizons%iagnostic Surface Horizons
4pipedons
Mollic
Am%ric&chric
!istic
Melanic
Plaggen+nthropic
-ery common
!uman$derived
?speciali)ed@
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-egetation
esta%lished
&'M' accumulation
time
&rganic Matter +ccumulation&rganic Matter +ccumulation
!istic
Mollic, Am%ric
ochric
Parentmaterial
tmax> ;III yrs
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Diagnostic Su%$surface !ori)ons
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&rganic Matter Clays &xides
smectites
Su$surface HorizonsSu$surface Horizons
Kaolinite
+lso7 salts, car%onates, sulfides
Dar# colors
Metals 1e, +l35ron
+luminum
ormation
Translocation
Transformation
Di ti S % f
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Diagnostic Su%surfaceDiagnostic Su%surface
!ori)ons!ori)ons
+l%ic
+rgillic
Spodic&xic
Kandic
Cam%ic
Som%ricsulfuric
0atric
+gric
Calcic(ypsic
Salic
Duripan
ragipanPlacic
Su%$!ori)on Designations
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%iagnostic Su$surface Horizons%iagnostic Su$surface Horizons
+l%ic 1*hite3 !ori)on
Light$colored 1-alue G moist 3
4lluvial 14 master hori)onN3
Lo* in clay, e and +l oxides
(enerally sandy textured
Lo* chemical reactivity 1lo* C4C3
Typically overlies "h or "t hori)ons
al%ic
Nnot all 4 hori)ons are al%ic hori)ons
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+rgillic !ori)on5lluvial accumulation of silicate clays
5lluvial %ased on overlying hori)on
Clay %ridges
Clay coatings
%iagnostic Su$surface Horizons%iagnostic Su$surface Horizons
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%iagnostic Su$surface Horizons%iagnostic Su$surface Horizons
+rgillic !ori)on Kandic !ori)on
+ctivity of Clays!igh Lo*
5lluviation of clay0ecessary 0ot 0ecessary
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%iagnostic Su$surface Horizons%iagnostic Su$surface Horizons
Spodic !ori)on
Spodic
:5lluvial accumulation of organic matter
and aluminum 1
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4lluviation 14 hori)on and + hori)ons3
&rganic matter Clays
Spodic hori)on
"h hori)on "t hori)on
+rgillic hori)on
,lluiation and lluiation,lluiation and lluiation
+
4
"h
+
"t
4
%i ti S $ f%i
ti S $ f
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%iagnostic Su$surface%iagnostic Su$surface
HorizonsHorizons
&xic hori)on:!ighly *eathered 1high temperatures, high rainfall3
$ !igh in e, +l oxides
$ !igh in lo*$activity clays 1#aolinite smectite vermiculite3activity
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+l%ic
Kandic
+rgillic
Spodic
&xic
%iagnostic Horizons%iagnostic Horizons
Mollic
Am%ric&chric
!istic
Melanic
Plaggen
+nthropic
4pipedons Su%surface
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Soil .a"onomySoil .a"onomyDiagnostic 4pipedons
Diagnostic Su%surface hori)ons
Moisture egimesTemperature egimes
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