Field Manual forDescribing Terrestrial Ecosystems

B.C. Ministry of Environment, Lands, and ParksB.C. Ministry of Forests

Land ManagementHandbook NUMBER

ISSN 0229-1622

1998

25

•1•

Contents

Soil Description Form ............................................................... 4Field Procedure .......................................................................... 5Completing the Form ............................................................... 6

1. Surveyor .......................................................................... 62. Plot No. ........................................................................... 63. Bedrock Type .................................................................. 64. Coarse Fragment Lithology ......................................... 85. Terrain Classification .................................................... 86. Soil Classification .......................................................... 147. Humus Form .................................................................. 158. Hydrogeomorphic Units .............................................. 159. Rooting Depth ................................................................ 18

10. Rooting Zone Particle-Size ........................................... 1811. Root Restricting Layer .................................................. 2012. Water source ................................................................... 2013. Seepage Water Depth .................................................... 2114. Drainage Class and Soil Moisture Subclass ............... 2115. Flooding Regime ............................................................ 23

Organic Horizons and Layers ................................................. 2416. Horizon/Layer ............................................................... 24

Codes for master organic horizons ......................... 25Codes for subordinate organic horizons ................ 25Lowercase modifiers ................................................. 26Codes for organic layers ........................................... 27Tiers ............................................................................. 27

17. Depth .............................................................................. 2718. Fabric .............................................................................. 28

Structure ...................................................................... 28von Post scale of decomposition ............................. 29

19. Mycelial Abundance ..................................................... 3020. Fecal Abundance............................................................ 3021. Roots .............................................................................. 3122. pH .............................................................................. 3123. Comments section ......................................................... 32

Consistence ................................................................. 32Character .................................................................... 32

2 SOIL DESCRIPTION

Page

•2•

Mineral Horizons and Layers .................................................. 3524. Horizon/Layer ............................................................... 35

Codes for major horizons ......................................... 35Codes for layers ......................................................... 35Lowercase modifiers ................................................. 35Mineral diagnostic horizons .................................... 38

25. Depth .............................................................................. 3926. Colour .............................................................................. 3927. Texture ............................................................................. 4028. Percent Coarse Fragments ............................................ 4129. Roots .............................................................................. 4130. Structure .......................................................................... 4231. pH .............................................................................. 4432. Comments ....................................................................... 44

Mottling ...................................................................... 44Clay films.................................................................... 45Effervescence .............................................................. 48Horizon porosity ....................................................... 49

33. Profile diagram .............................................................. 4934. Notes .............................................................................. 49

Appendices2.1 Codes for Soil Orders, Great Groups

and Subgroups ........................................................... 512.2 Key to Soil Orders .......................................................... 552.3 Key to Humus Forms .................................................... 572.4 Key to Soil Texture ......................................................... 59

Tables2.1 Sedimentary rock codes ............................................... 62.2 Igneous rock codes ........................................................ 72.3 Metamorphic rock codes .............................................. 82.4 Terrain texture codes ..................................................... 92.5 Surficial material codes ................................................. 112.6 Surface expression codes .............................................. 122.7 Geomorphological process codes ............................... 132.8 Qualifier codes ................................................................ 142.9 Codes for humus orders and groups ......................... 15

2.10 Codes for hydrogeomorphic systems ....................... 16

Page

•3•

2.11 Codes for hydrogeomorphic subsystems ................. 162.12 Rooting zone particle size classes ................................ 192.13 Codes for root-restricting layers ................................. 202.14 Water source codes ........................................................ 202.15 Drainage classes and codes .......................................... 212.16 Soil moisture subclasses and codes ............................. 232.17 Codes for frequency of flooding ................................. 232.18 Codes for duration and timing of flooding ............... 242.19 Guidelines for differentiating between upland and

wetland organic horizons ............................................. 242.20 Degree of aggregation codes ....................................... 282.21 Kind of aggregation codes ........................................... 282.22 von Post decomposition classes .................................. 292.23 Mycelial abundance classes and codes ........................ 302.24 Fecal abundance classes and codes ............................. 302.25 Root abundance and size classes and codes

(organic layer) ................................................................ 312.26 Codes for methods of pH measurement ................... 312.27 Consistency classes and codes ..................................... 322.28 Character classes and codes ......................................... 332.29 Colour aspects and codes for mineral soils ............... 402.30 Size classes and type codes for coarse fragments ..... 412.31 Root abundance and size classes and codes

(mineral horizon) ........................................................... 412.32 Codes for kind and class of soil particle structure .... 422.33 Abundance and size codes for mottles ....................... 442.34 Contrast codes for mottles ........................................... 442.35 Clay film frequency classes .......................................... 452.36 Clay film thickness classes ............................................ 482.37 Codes to describe degree of effervescence ............... 482.38 Mineral horizon porosity classes ................................. 49

Figures2.1 Relationship of size and roundness of the clastic

textural terms ................................................................. 102.2 Rooting zone particle size classes ................................ 192.3 Major kinds of soil fauna .............................................. 342.4 Soil texture triangle ....................................................... 402.5 Diagrammatic representation of soil structure ......... 462.6 Example of profile diagram ......................................... 49

•4•

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•5•

Field Procedure

Getting Started1. Locate plot boundaries, assess variability, select pit location(s).2. Excavate pit (generally 50–75 cm in depth) leaving the face and sides

undisturbed around the ground surface.3. While excavating, observe:

• organic horizon depths and fabric;• mineral horizon depths, colours, structure, and textural changes;• percentage and shape of coarse fragments;• rooting abundance, depth, and restrictions; and• mottling, water seepage, or water table.

4. Lay out notes, forms, and soil description tools.5. Clean off face from top to bottom (and photograph if required).

• Note horizon changes and mark with knife indentations or golf tees.• Collect soil texture samples from bottom to top and put aside.

Record and Classify (see tab numbers on sample f orm, facing page)Designate horizons on form (organic and mineral horizons/layers).For each horizon (depending on survey objectives/requirements):• Record average starting and ending depths.• For organic horizon, record fabric, mycelia and fecal abundance, rooting,

and pH.• For mineral horizons, hand-texture soil samples and determine colours.

Record percent and shape of coarse fragments, rooting, structure, and pH.• Note important observations in comments (e.g. soil fauna, mottles, clay

films, etc.).• confirm original horizon designationsSketch a profile diagram to approximate scale.

Record:• rooting depth, particle size, and restricting layer• water source, seepage depth, drainage class, and flooding regimeClassify:• bedrock geology and coarse fragment lithology type(s)• terrain unit(s), soil pedon, humus form, and hydrogeomorphic unitUse the “Notes” section to summarize or describe important soil featuresnot otherwise collected on the form, or are significant to the study, classifica-tions, or management interpretations.

Check and IntegrateCheck the form to ensure there are no missing data, and then (under mostcircumstances) fill in the pit. Strike through any fields that were not assessed.Integrate the soil data with other site factors to determine and record the soilmoisture and soil nutrient regimes on the site description form.

2

1

3

4

5

•6•

Completing the Form

Numbered items below refer to circled numbers on the Soil DescriptionForm shown at the beginning of this section. See "Field Procedure" for arecommended sequence for completing the form.

1. SurveyorIndicate the first initial and last name of the person(s) who described andclassified the soil profile.

2. Plot NumberRecord the plot number from the top of the Site Description Form.

3. Bedrock TypeRecord general or specific codes (see Tables 2.1, 2.2, 2.3) for up to threerock types in the underlying bedrock, in order of dominance if possible.This is particularly important on sites with shallow soils or bedrockexposure.

TABLE 2.1. Sedimentary rock codes

Clastic,calcareous

Clastic, non-calcareous

General

Finegrained

Mediumgrained

Coarsegrained

Finegrained

Mediumgrained

Coarsegrained

Code

kf

km

kc

uf

um

uc

Specific

Calcareous SiltstoneCalcareous MudstoneCalcareous Shale

Calcareous GreywackeCalcareous ArkoseCalcareous Sandstone

Calcareous ConglomerateCalcareous Breccia

SiltstoneMudstoneShale

SandstoneGreywackeArkose

ConglomerateBreccia

Code

kzkdkh

kgkaks

knkb

zlmdsh

ssgkak

cgbx

•7•

TABLE 2.2. Igneous rock codes

Precipitates,crystalline

Organic

General

Calcareous

Non-calcareous

Calcareous

Carbonaceous

Code

pk

pu

ok

oc

Specific

TravertineLimestoneDolomite

GypsumLimoniteBarite

Mar

LigniteCoal

Code

tvlsdo

gyliba

ma

lgco

Intrusive

Extrusive

GeneralAcid (felsic)

Intermediate

Basic (mafic)

Acid (felsic)

Intermediate

Basic (mafic)

Recent lava flow

Pyroclastic

Codeia

ii

ib

ea

ei

eb

la

ep

SpecificSyeniteGraniteQuartz MonzoniteGranodiorite

Quartz DioriteDiorite

QuartzGabbroPyroxeniteDunite

TrachyteRhyoliteDacite

Andesite

Quartz BasaltBasalt

TuffVolcanic BrecciaAgglomerate

Codesygrqmgd

qddi

qggbpydu

trrhda

an

qbbs

tuvbag

•8•

TABLE 2.3. Metamorphic rock codes

4. Coarse Fragment LithologyRecord up to three rock types in order of dominance from left to right onthe form that make up the coarse fraction (i.e., gravels, cobbles, and stones)of the soil material. Characters are recorded using the same codes asoutlined for bedrock type. If the lithologies are so mixed that dominancecan not be determined, record by entering the code “mx.”

5. Terrain ClassificationFour information fields are provided for recording terrain texture, surficialmaterial, surface expression and geomorphological process, respectively(Howes and Kenk 1997) (see Tables 2.4, 2.5, 2.6, and 2.7 and Figure 2.1). Upto three codes can be entered in each of these fields. Place qualifyingdescriptor codes (Table 2.8) in the appropriate field to the right of any othercodes used in that field (superscript codes are no longer used). Code line 1for the uppermost stratigraphic layer, and code line 2 for an underlyinglayer. For those wishing to use terrain subclasses and subtypes, refer toHowes and Kenk (1997).

Foliated

Non-foliated

General

Fine grained

Medium tocoarse grained

Coarse grained

Fine grained

Medium tocoarse grained

Coarse grained

Calcareous

Code

ff

fm

fc

nf

nm

nc

nk

Specific

SlatePhylite

SchistGneissGranite GneissDiorite Gneiss

Migmatite

ArgilliteSerpentinite

QuartziteHornfelsGranulite

AmphiboliteHornblendite

MarbleDolomite MarbleSerpentine Marble

Code

slph

scgnggdg

mi

arsp

qthfgl

amhb

mbdmsm

•9•

TABLE 2.4. Terrain texture codes

Code Name Size (mm) Other Characteristics

a Blocks > 256 Angular particles

b Boulders > 256 Rounded and subrounded particles

k Cobble 64–256 Rounded and subrounded particles

p Pebbles 2–64 Rounded and subrounded particles

s Sand 0.062–2.000

z Silt 0.002–0.062

c Clay < 0.002

d Mixed > 2 Mix of rounded and angularfragments particles

g Gravel > 2 Mix of boulders, cobbles, andpebbles

x Angular > 2 Mix of blocks and rubble

r Rubble 2–256 Angular particles

m Mud < 0.062 Mix of clay and silt

y Shells — Shells or shell fragments

e Fibric — Well-preserved fibre; (40%)identified after rubbing

u Mesic — Intermediate composition betweenfibric and humic

h Humic — Decomposed organic material;(10%) identified after rubbing

•10•

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nd

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gula

r

An

gula

r

Rou

nd

ed

Rou

nd

ed/

An

gula

r

An

gula

r

boul

der

bco

bble

kpe

bble

p

sand s

silt z

clay c

bloc

ksa

grav

elg

mxe

d fr

agm

ents

d

rubb

ler

angu

lar f

ragm

ents

x

mud m

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term

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•11•

TABLE 2.5. Surficial (genetic) material codes

Code Name (Assumed Descriptionstatus)

A Anthropogenic (A) Artificial or human-modified material

C Colluvium (A) Products of mass wastage

D Weathered bedrock (A) In situ, decomposedbedrock

E Eolian (I) Materials deposited bywind action

F Fluvial (I) River deposits

FG Glaciofluvial (I) Ice contact fluvial material

I Ice (A) Permanent snow, glaciers,and icefields

L Lacustrine (I) Lake sediments; includeswave deposits

LG Glaciolacustrine (I) Ice contact lacustrinematerial

M Morainal (I) Material deposited directlyby glaciers

O Organic (A) Accumulation/decay ofvegetative matter

R Bedrock (–) Outcrops/rocks covered byless than 10 cm of soil

U Undifferentiated (–) Layered sequence; threematerials or more

V Volcanic (I) Unconsolidated pyroclasticsediments

W Marine (I) Marine sediments; includeswave deposits

WG Glaciomarine (I) Ice contact marinesediments

•12•

TABLE 2.6. Surface expression codes

Code Name Descriptiona Moderate slope Unidirectional surface; > 15° to < 26°

b Blanket A mantle of unconsolidated materials; > 1 mthick

c Cone(s) A cone or segment of a cone; > 15°

d Depression(s) A lower area surrounded by a higherterrain

f Fan(s) A segment of a cone; up to 15°

h Hummock(s) Hillocks and hollows, irregular in plan;15–35°

j Gentle slope Unidirectional surface; > 3° and < 15°

k Moderately steep Unidirectional surface; > 26° and < 35slope

m Rolling Elongate hillocks; 3–15°;parallel forms in plan view

p Plain Unidirectional surface; up to 3°

r Ridge(s) Elongate hillocks; 15–35°;parallel forms in plan view

s Steep slope Steep slopes; > 35°

t Terrace(s) Step-like topography

u Undulating Hillocks and hollows; up to < 15°; irregular inplan view

v Veneer Mantle of unconsolidated material;0.1 to 1.0 m thick

w Mantle of A layer or discontinuous layer of surficialvariable thickness materials of variable thickness that fills or

partially fills depressions in an irregularsubstrate. The thickness ranges from 0 to 3 m.

x Thin veneer A dominance of very thin surficial materialsabout 2–20 cm thick

•13•

TABLE 2.7. Geomorphological process codes

Code Name (Assumed Descriptionstatus)

A Avalanches (A) Terrain modified by snow ava-lanches

B Braiding (A) Diverging/converging channels;unvegetated bars

C Cryoturbation (A) Materials modified by frost heavingand churning

D Deflation (A) Removal of sand and silt by windaction

E Channeled (I) Channel formation by meltwater

F Slow mass (A) Slow downslope movement ofmasses of cohesive or non-cohesivematerial

H Kettle (I) Depressions in surficial materialresulting from the melting of buriedor partially buried glacier ice

I Irregular (A) A single, clearly defined mainchannel channel displaying irregular turns

and bends

J Anastomosing (A) A channel zone where channelschannel diverge and converge around many

vegetated islands

K Karst (A) Processes associated with thesolution of carbonates

L Surface (A) Zones of active seepage often foundseepage along the base of slope positions

M Meandering (A) Channels characterized by a regularchannels pattern of bends with uniformed

amplitude and wave length

N Nivation (A) Erosion beneath and along themargin of snow patches

•14•

TABLE 2.8. Qualifier codes

6. Soil ClassificationThe Canadian System of Soil Classification (Soil Classification WorkingGroup, 1998) is tabulated alphabetically by soil order. Codes for greatgroups and subgroups are given in Appendix 2.1. Appendix 2.2 includes akey to soil orders. For those wishing to use family and phase criteria, referto Soil Classification Working Group (1998) and include in “Notes.”

Code Name (Assumed Descriptionstatus)

P Piping (A) Subterranean erosion by flowingwater

R Rapid mass (A) Rapid downslope movement of dry,movement moist, or saturated debris

S Solifluction (A) Slow downslope movement ofsaturated overburden across afrozen or otherwise impermeablesubstrate

U Inundation (A) Seasonally under water because ofhigh water table

V Gully erosion (A) Parallel/subparallel ravines causedby running water

W Washing (A) Modification by wave action

X Permafrost (A) Processes controlled by thepresence of permafrost

Z Periglacial (A) Solifluction, cryoturbation, andprocesses nivation processes occurring within

a single unit

Code Name Description

A Active Used to qualify surficial material and geomorphologicalI Inactive processes with regard to their current state of activity.

•15•

7. Humus FormHumus forms are classified to order and group according to Towards aTaxonomic Classification of Humus Forms (Green et al. 1993) Use Table 2.9 toenter codes. Appendix 2.3 contains a key to humus forms. For thosewishing to use phases, refer to Green et.al. (1993), and include in “Notes.”

TABLE 2.9. Codes for humus orders and groups

Order Group Code

MOR (R) Hemimor HRHumimor URResimor RRLignomor LRHydromor YRFibrimor FRMesimor MR

MODER (D) Mormoder RDLeptomoder TDMullmoder MDLignomoder LDHydromoder YDSaprimoder SD

MULL (L) Vermimull VLRhizomull ZLHydromull YL

8. Hydrogeomorphic UnitsThe system defines broad hydrological processes which characterizelandscape units and ecosystems by water sources and hydrodynamics.Element groups divide a system by patterns of waterflow which indicategenerically hydrodynamics, water source, and connectivity in the land-scape. Record the system code first and the element group code (whereapplicable) second (e.g., Fra= alluvial river). Subsystem codes are onlypresented for lacustrine, palustrine, and fluvial sites; those for othersystems are under development. Use the codes in Tables 2.10 and 2.11.

•16•

a Modifiers: r = river (20 m+ wide); s = stream (5–20 m); c = creek (1.5–5 m); v = rivulet (< 1.5 m).

TABLE 2.10. Codes for hydrogeomorphic systems

TABLE 2.11. Codes for hydrogeomorphic subsystems

Description

Occurs adjacent to lakes and ponds and is directlyaffected by lacustrine processes (e.g., wave action,sedimentation, and relatively high nutrient contentof flood waters).

Occurs in basins and depressions with poordrainage that collect water flows from runoff,groundwater, and precipitation. Often peatlands,ponds, and marshes.

Occurs along flowing water courses, the watercourse itself, and the surrounding (riparian) terrainand vegetation. Subject to flooding and sedimenta-tion processes.

Occurs in sloping, level, and depressional sites notdescribed by other hydrogeomorphic systems.

Consists of intertidal habitats where ocean water isat least occasionally diluted by freshwater runofffrom the land. Occurs at the confluence of riversand ocean and has characteristics that reflect theflooding and salinity gradients found there.

Exposed to waves and currents of the open ocean.Water regimes are determined primarily by the ebband flow of oceanic tides.

Code System

L Lacustrine

P Palustrine

F Fluviala

U Upland

E Estuarine

M Marine

Description

Basin receives water from sur-rounding upland only, no inlet oroutlet channel.

Basin receives water from uplandonly; excess water flows through anoutlet channel.

System

Lacustrine orpalustrine;confinedbasins

ElementGroup

Closedbasin

Overflowbasin

Code

cb

ob

•17•

System

Palustrine;unconfinedslopes andhollows

Fluvial

ElementGroup

Linkedbasin

Terminalbasin

Overflowhollow

Linkedhollow

Blanketslope

Toe slope

Lobe slope

Alluvial

Code

lb

tb

oh

lh

bs

ts

ls

a

Description

Basin receives water from uplandand an inflow stream; excess waterflows though an outflow. Includesbasins with slow streams wherethere is little sedimentation orerosion.

Basin receives water from uplandand an inflow stream; no outletchannel.

Hollow receives ground water fromupslope; drains through outletchannel or watertrack.

Hollow receives water from uplandand an inflow stream; excess waterflows out through an outflow streamor watertrack. Includes gullies withslow streams where there is littlesedimentation or erosion.

Occurs in subdued topographywhere basin types are notdefineable.

Occurs on toe slope positions notconfined by basin or hollow; waterreceived from upslope, sheet orchannelled flow

Peatlands on slopes with adownslope edge elevated above theupland in the form of a lobe; waterreceived from upslope, sheet orchannelled flow.

Associated with low gradientstreams where floodplain buildingprocesses predominate; flooding andsubsequent deposition of alluviumleads to extensive floodplains ofsandy or silty soils.

•18•

9. Rooting DepthRooting depth refers to the depth (cm) from the ground surface, which is thetop of the uppermost soil horizon including organic horizons (e.g., Fm1),down to the bottom of the rooting zone (i.e., the level at which the majorityof roots stop; for example, the end of “plentiful” and beginning of “few”rooting abundance).

10. Rooting Zone Particle SizeThe particle size distribution within the mineral portion of the rooting zoneis used to make broad interpretations. After determining rooting depth,estimate the rooting zone particle-size class as a weighted average of themineral horizons within the rooting zone (Figure 2.2, Table 2.12). Whererooting is restricted to the organic horizons, use the organic material codesin Table 2.12. For the most part, class names and definitions have beenmodified from the Canadian System of Soil Classification family particlesize criteria. Rooting zone classes are greatly simplified and use onlypercent coarse fragments(> 2 mm) by volume, and texture class sizes by percent weight for sand(.05 to < 2 mm), silt (< .05 to .002 mm), and clay (< .002). Two differentclasses can be entered on the data form if strongly contrasting size classesoccur (e.g. CLS/FC= coarse-loamy over fine-clayey), however ranges ofrooting zone particle-size classes can not be shown.

ElementGroup

Transport

Headwater

Code

t

h

Description

Associated with moderate gradientstreams where neither erosion ordeposition forces predominate;floodplain development limited, in-stream bars and gravelly soilcommon.

Associated with high gradientstreams where erosive processespredominate; flood plain and bardevelopment limited; cobble, stoneor bedrock substrates common

System

•19•

Code Classa

Coarse fragments > 70%:

F Fragmental

Coarse fragments > 35 and less than 70%:

SS Sandy-skeletalCLS Coarse-loamy-skeletalFLS Fine-loamy-skeletalSIS Silty-skeletalCS Clayey-skeletal

Coarse fragments < 35 %

S SandyCL Coarse-loamyFL Fine-loamyCSI Coarse-siltyFSI Fine-siltyFC Fine-clayeyVFC Very-fine-clayey

Definitions

Particles < 2 mm of various textures

Particles < 2 mm sandyParticles < 2 mm coarse-loamyParticles < 2 mm fine-loamyParticles < 2 mm fine-silty or coarse-siltyParticles < 2 mm clayey

Organic Material Codes:F FibricM MesicH HumicW Woody

a Refer to triangle in Figure 2.2 for proportion of sand and clay in the fine particle sizes(< 2 mm) of these classes.

00

10 20 30 40 50 60 70 80 90 100

10

20

30

40

50

60

70

80

90

100

Percent sand

Per

cent

cla

y

Coarse-loamySandy

Coarse-silty

Fine-silty Fine-loamy

Fine-clayey

Very fine-clayey

FIGURE 2.2. Rooting zone particle size classes.

TABLE 2.12. Rooting zone particle size classes

•20•

12. Water SourceThe most influential source of water on a site (determined by a qualitativeassessment) is recorded using the codes in Table 2.14.

TABLE 2.13. Codes for root restricting layers

TABLE 2.14. Water source codes

Code DescriptionC Strongly cemented horizon

P Clay pan or restriction due to fines

K Compacted morainal material

L Lithic contact

W Excessive moisture; this refers to the depth where the roots arebeing restricted by excessive moisture, but does not require thepresence of free water at the time of sampling

X Excessive accumulations of chemicals within the profile whichinhibit root growth (i.e., CaCO3 )

Z Permafrost; characterized by temperatures never exceeding 0°C,ice cementation, ice lenses, or massive ice.

N No root restriction evident.

11. Root Restricting LayerIf present, enter a code for the type of root restricting layer (Table 2.13), andthe depth (cm) from the ground surface down to the top of the layer.

Code Water Source

P Precipitation

G Groundwater

S Snowmelt (prolonged through the growing season)

F Stream sub-irrigation and flooding

M Mineral spring

T Tidal, freshwater

E Tidal, saltwater

Z Permafrost

•21•

13. Seepage Water DepthIf seepage is present at the time of sampling, record the depth (cm) from theground surface to the level of temporary or permanent subsurface waterflow. Enter “NP” if not present.

14. Drainage Class and Soil Moisture SubclassDrainage class describes the speed and extent to which water is removedfrom a mineral soil in relation to additions (Table 2.15.) s

TABLE 2.15. Drainage classes and codes

Description

Water is removed from the soil very rapidly inrelation to supply. Water source is precipitationand available water storage capacity followingprecipitation is essentially nil. Soils are typicallyfragmental or skeletal, shallow, or both.

Water is removed from the soil rapidly inrelation to supply. Excess water flows down-ward if underlying material is pervious.Subsurface flow may occur on steep gradientsduring heavy rainfall. Water source is precipita-tion. Soils are generally coarse textured.

Water is removed from the soil readily, but notrapidly. Excess water flows downward readilyinto underlying pervious material or laterally assubsurface flow. Water source is precipitation.On slopes, subsurface flow may occur for shortdurations, but additions are equalled by losses.Soils are generally intermediate in texture andlack restricting layers.

Water is removed from the soil somewhatslowly in relation to supply because of impervi-ousness or lack of gradient. Precipitation is thedominant water source in medium- to fine-textured soils; precipitation and significantadditions by subsurface flow are necessary incoarse-textured soils.

Code Class

x Very rapidlydrained

r Rapidly drained

w Well drained

m Moderatelywell drained

•22•

Code Class

i Imperfectlydrained

p Poorly drained

v Very poorlydrained

Description

Water is removed from the soil sufficientlyslowly in relation to supply to keep the soil wetfor a significant part of the growing season.Excess water moves slowly downward ifprecipitation is the major source. If subsurfacewater or groundwater (or both) is the mainsource, the flow rate may vary but the soilremains wet for a significant part of thegrowing season. Precipitation is the mainsource if available water storage capacity ishigh; contribution by subsurface orgroundwater flow (or both) increases asavailable water storage capacity decreases. Soilsgenerally have a wide range of texture, andsome mottling is common.

Water is removed so slowly in relation tosupply that the soil remains wet for much of thetime that it is not frozen. Excess water isevident in the soil for a large part of the time.Subsurface or groundwater flow (or both), inaddition to precipitation, are the main watersources. A perched water table may be present.Soils are generally mottled and/or gleyed.

Water is removed from the soil so slowly thatthe water table remains at or near the surfacefor most of the time the soil is not frozen.Groundwater flow and subsurface flow are themajor water sources. Precipitation is lessimportant, except where there is a perchedwater table with precipitation exceedingevapotranspiration. Typically associated withwetlands. For organic wetlands, also evaluatethe soil moisture subclass, and when enteringon the form, separate from drainage by a slash.For example, v/ac.

•23•

Soil moisture subclasses (applied to organic soil order only) indicate thelength of time the soil is saturated (Table 2.16). Record the subclass code inthe “drainage” information field.

15. Flooding RegimeFlooding is defined as immersion of substrate by water (i.e., saturated peatsnot covered by surface water are not considered flooded). Flooding regimesmay be indicated by one- or two-letter codes as appropriate for yearlyfrequency and seasonal duration (Table 2.17 and 2.18). A range of floodingregimes may also be entered (e.g., OB = occasional brief flooding andFT–AM = frequent temporary flooding to annual moderate flooding).

TABLE 2.17. Codes for frequency of flooding

TABLE 2.16. Soil moisture subclasses and codes

Code Moisturesubclass

aq Aqueous

pa Peraquic

ac Aquic

sa Subaquic

ph Perhumid

hu Humid

Description

Free surface water

Soil saturated for verylong periods

Soil saturated formoderately longperiods

Soil saturated forshort periods

No significant waterdeficits in growingseason

Very slight deficits ingrowing season

Code Description

A Annual flood (at least once per year)F Frequent flooding (every 2–5 years)O Occasional flooding (> 5-year interval between flooding)R Rare flood (only during extreme events)X Never flooded

Saturation period (mo.)

11.5–12

> 10

4–10

< 4

< 2

< 0.5

Moist period (mo.)

< 0.5

< 2

2–8

8–11.5

8–11.5

> 11.5

•24•

Organic Horizons and Layers

The soil horizon and layer definitions and methods for field descriptionthat follow are taken or modified from Soil Classification Working Group(1998), Green et al. (1993), and Luttmerding et al. (1990).

16. Horizon/LayerRecord the organic horizon or layer designation. Two groups of masterorganic horizons are recognized: L, F, H (“upland”) horizons, and O(“wetland”) horizons. All contain > 17% organic C by mass. These twogroups are differentiated primarily by the features outlined in Table 2.19.

TABLE 2.18. Codes for duration and timing of flooding

TABLE 2.19. Guidelines for differentiating between upland and wetlandorganic horizons

Code Description

W Winter flooding

P Permanent flooding during growing season

E Extended flooding (exposed < 1 month during last part of growingseason)

M Moderate flooding (flooded for 1–3 months; exposed substrate forprolonged periods of the growing season)

T Temporary flooding (7–30 days during the growing season)

B Brief flooding (< 7 days during the growing season)

D Diurnal flooding

Property

Physiography

Soil drainage

L, F, and H horizons

Sloping to level

Very rapid toimperfect

O horizons

Depression to gentlysloping

Poor to very poor

•25•

Codes for master organic horizons:L An upland horizon consisting of relatively fresh organic residues

that are readily identifiable as to origin.

F An upland horizon comprised of partly decomposed plant residuesin which fragmented plant structures are generally recognizable asto origin.

H An upland horizon comprised of well-decomposed plant residues inwhich plant structures are generally not recognizable.

O A wetland organic horizon comprised of materials in varying degreesof decomposition.

Property

Water table

Origin ofmaterials

L, F, and H horizons

Absent in organichorizons (may fluctuatein response to waterinput)

Organic residues fromplant communitiestypically associatedwith soil moistureregimes 0–6

O horizons

At or near ground surfacefor significant durationduring the frost-freeperiod

Organic residues fromplant communitiestypically associated withsoil moisture regimes 7–8

Codes for subordinate organic horizons:Ln An L horizon composed of newly accreted and essentially

unfragmented plant residues.

Lv An L horizon exhibiting initial decay and strong discoloration.

Fm An F horizon in which plant residues are aggregated in a mattedstructure, with a tenacious consistence. Fungal mycelia are clearly apredominant biotic component; some faunal droppings may bepresent.

Fz An F horizon in which plant residues are weakly aggregated with aloose or friable consistence. Faunal droppings are typically numer-ous and easily observed under magnification with a hand lens orbinocular microscope; fungal mycelia may be present.

•26•

Fa An F horizon in which plant residues are aggregated into a weak tomoderate, non-compact matted structure. This is an intergradebetween the Fm and Fz horizons, and as such, reflects properties ofboth, but neither fungal mycelia or faunal droppings predominates.

Hh An H horizon dominated by fine substances with very few, if any,recognizable plant residues.

Hz An H horizon dominated by fine substances with very few, if any,recognizable plant residues; faunal droppings constitute most of thefabric.

Hr An H horizon dominated by fine substances, but that also containsrecognizable plant residues, usually from fine roots, wood, or bark;typically dark reddish-brown hues, around 2.5YR.

Of An O horizon comprised largely of poorly decomposed plantresidues that are readily identifiable as to origin. It has 40% or morerubbed fibre (i.e., fibre that remains after rubbing a sample about 10times between thumb and forefinger). These materials are classifiedin the von Post scale of decomposition (defined below, in Item 18,“Fabric”) as class 1 to class 4.

Om An O horizon comprised of partly decomposed plant residues whichare at a stage of decomposition intermediate between Of and Ohhorizons. Rubbed fibre usually ranges between 10 and 40% byvolume. These materials are classified in the von Post scale ofdecomposition as class 5 or 6.

Oh An O horizon of well-decomposed plant residues that for the mostpart have been transformed into humic materials. The rubbed fibrecontent is less than 10% by volume. These materials are usuallyclassified in the von Post scale of decomposition as class 7 or higher,and very rarely as class 6.

Oco Coprogenous earth, deposited or modified by aquatic organisms.

Lowercase modifiers:The following lowercase modifiers may be applied to any organic horizonwithout restriction.

i An organic horizon that contains intermixed mineral particles finerthan 2 mm, with 17–35% organic C by mass. This intermixing ofmineral particles with organic materials may result from severaldifferent processes (e.g., colluvial, eolian, alluvial, cryoturbation,silvoturbation, and zooturbation).

•27•

p, u, y May also be used with organic horizons, and are defined under“Mineral lowercase modifiers” in Item 24.

w An organic horizon that contains significant amounts (> 35% of thevolume of solids) of coarse woody debris in various stages ofdecomposition.

Codes for organic layers:S A distinct ground surface layer of living materials such as

bryophytes or “soil crusts.”

Limno A layer or layers 5 cm or more thick of sedimentary peat,diatomaceous earth, or marl.

Cumulo A 5–30 cm thick layer or layers of mineral material in Organicsoils.

Terric An unconsolidated mineral substratum not underlain by or-ganic matter, or one continuous unconsolidated mineral layermore than 30 cm thick in the middle or bottom tiers underlainby organic matter within a depth of 160 cm.

Lithic Bedrock occurring within 10–160 cm in Organic soils

Hydric A layer of water that extends from a depth of not less than40 cm from the organic surface to a depth of more than 160 cm.

Tiers:Tiers are arbitrary depth intervals used in classifying wetland Organic soils,and consist of the surface (0–40 cm), middle (40–120 cm) and bottom tiers(120–160 cm). They are not recorded.

17. DepthRecord the average depths (in centimetres) of the upper and lowerboundaries of the horizon being described. The depth of organic horizonsin mineral soils are measured upward from zero depth (e.g., L 12–9,Fm 9–2, and Ah 2–0), and in organic soils they are measured downwardfrom the ground surface, or uppermost soil horizon (e.g., S 4–0, Of 0–35,and Om 35–110).

•28•

TABLE 2.20. Degree of aggregation codes

TABLE 2.21. Kind of aggregation codes

18. FabricDescribe the structure and consistence of the upland organic horizons andrecord the von Post classes for wetland horizons. Structure is important indistinguishing between Fm, Fz, and Fa horizons, and the von Post scale ofdecomposition helps to distinguish the Of, Om, and Oh horizons.

Structure:Describe structure according to the degree and kind of themacromorphological aggregation of the material within a horizon. Recordthe structure “degree” code (Table 2.20) in the first column and the “kind”code (Table 2.21) in the second column.

Code Class Description

W Weak Disaggregated materials are dominant;< 20% distinctly aggregated

M Moderate Some disaggregated materials are found;20–60% distinctly aggregated

S Strong Aggregated materials are dominant; most materialconforms to the same arrangement;> 60% distinctly aggregated

Code Class Description

SP Single particle An incoherent mass of individual particles with noaggregation

BK Blocky Faces rectangular and flattened; vertices angular

GR Granular Spheroidal and characterized by rounded orsubrounded vertices

NM Non-compact Materials arranged along horizontal planesmatted with no compaction

CM Compact Materials arranged along horizontal planesmatted with evident compaction

ER Erect Materials arranged vertically

RC Recumbent Materials arranged in recumbent (reclining)position

MA Massive A coherent mass showing no evidence ofaggregation

•29•

von Post scale of decomposition:Squeeze a sample of the O horizon and observe the colour of the solutionthat is squeezed out between the fingers, the nature of the fibre, and theproportion of the original sample that remains in the hand. Record theclass (Table 2.22).

TABLE 2.22. von Post scale of decomposition classes

Code/Class Description

1 Undecomposed; plant structure unaltered; yields only clearwater coloured light yellow brown.

2 Almost undecomposed; plant structure distinct; yields onlyclear water coloured light yellow brown.

3 Very weakly decomposed; plant structure distinct; yieldsdistinctly turbid brown water, no peat substance passesbetween the fingers, residue not mushy.

4 Weakly decomposed; plant structure distinct; yieldsstrongly turbid water, no peat substance escapes betweenthe fingers, residue rather mushy.

5 Moderately decomposed; plant structure evident, butbecoming indistinct; yields much turbid brown water, somepeat escapes between the fingers, residue very mushy.

6 Strongly decomposed; plant structure somewhat indistinct,but more evident in the squeezed residue than in theundisturbed peat; about one-third of the peat escapesbetween the fingers, residue strongly mushy.

7 Strongly decomposed; plant structure indistinct, butrecognizable; about one-half of the peat escapes betweenthe fingers.

8 Very strongly decomposed; plant structure very indistinct;about two-thirds of the peat escapes between the fingers,residue almost entirely resistant remnants such as rootfibres and wood.

9 Almost completely decomposed; plant structure almostunrecognizable; nearly all the peat escapes between thefingers.

10 Completely decomposed; plant structure unrecognizable;all the peat escapes between the fingers.

•30•

19. Mycelial AbundanceIn most cases, fungal presence is indicated by masses of hyphae calledmycelia. While individual hyphae are generally too small to be seen, themycelial mass is usually visible. Determining mycelial abundance helps todistinguish the Fm, Fz, and Fa horizons, and therefore the humus formclassification. Describe fungal mycelia by noting their abundance class asindicated in Table 2.23.

20. Fecal AbundanceThe presence of soil fauna may be observed directly, or indirectly by thepresence of fecal droppings or casts. Determining fecal abundance helps todistinguish the Fm, Fz, and Fa horizons, and therefore the humus formclassification. Describe the presence of soil fauna by noting their abundanceclass as indicated in Table 2.24.

TABLE 2.24. Fecal abundance classes and codes

Code Class Description

X None Fungal mycelia are not visible

F Few Fungal mycelia are occasionally present, but arescattered and not easily observed

C Common Fungal mycelia are commonly observed

A Abundant Fungal mycelia are observed continuously through-out the horizon, often “matting” materialstogether and creating a “felty” tactility

TABLE 2.23. Mycelial abundance classes and codes

Code Class Description

X None No feces or fauna observed

F Few Fecal droppings or fauna occasionally observed,but scattered

C Common Droppings or fauna commonly observed

A Abundant Droppings or fauna frequently observed (drop-pings in relatively large numbers throughout thehorizon)

•31•

Size class v. fine fine medium coarse very coarseCode V F M C KSize (mm) < 1 1–2 3–5 6–15 > 15

Abundance code Reference areaand class 25 cm2 100 cm2

X None 0 0 0 0 0F Few < 10a < 10 1 1 1P Plentiful 10–50 10–50 2–10 2–5 2–5A Abundant > 50 > 50 > 10 > 5 > 5

21. RootsSince root distribution in organic horizons differs substantially from that inmineral soils, the abundance and size classes and the reference unit areasare somewhat different from those used for mineral horizons (Table 2.25).Record the most abundant size first; secondary roots can be recorded byusing a slash (/) in the columns as shown below:

Example: Abundant fine and plentiful medium roots.

22. pHRecord pH, noting the method of measurement in the column header (e.g.,pH/3 for Hellige-Truog) (Table 2.26), and the determined values for eachhorizon to one decimal place.

TABLE 2.25. Root abundance and size classes and codes

ROOTSAB.A/P

SIZEF/M

Code Method Code Method

1 Bromothymol blue 6 pH meter (0.1 M CaCl2)

2 Cresol red 7 Phenol red3 Hellige-Truog 8 Soiltex4 Lamotte-Morgan 9 Thymol blue5 pH meter (H2O) 10 pHydrion5a pH meter for ground 11 Litmus paper

water sample

TABLE 2.26. Codes for methods of pH measurement

a Values observed in reference area represent number of roots of size class

•32•

Character:This describes tactile qualities, particulate shapes, and other noteworthyqualities of materials in organic horizons. Determining the characterrequires a qualitative examination of the fabric. Use the codes in Table 2.28to describe character.

23. Comments SectionRecord any observations or measurements that are unique, unconforming,or could be of particular significance to the study, classification, or manage-ment interpretations. Examples include: consistence, character, faunalspecies, colour of mycelium, percentage of decaying wood, presence ofcharcoal, and disturbance history. When coding a property, be sure to notethe property being described.

Consistence:This describes the nature and strength of forces holding materials together.It is determined by the kind of deformation or rupture that occurs whenpressure is applied and then released. Use the codes in Table 2.27 todescribe consistency.

TABLE 2.27. Consistency classes and codes

Code Class Description

LO Loose Material has no consistence

FR Friable Material crumbles easily under gentle pressure

FM Firm Material can be crushed under moderate pressure;resistance is noticeable

PL Pliable Material is soft and plastic

RE Resilient Material is springy or elastic; assumes its original shapeafter pressure is released

TE Tenacious Material is cohesive and not easily pulled apart

•33•

TABLE 2.28. Character classes and codes

Code Class Description

MS Mushy Soft and spongy tactility; materials wet or saturated

MK Mucky Smooth and sticky tactility; materials usually wet; silt-and clay-sized mineral particles usually present

GR Greasy Smooth and greasy tactility; materials easily workablewhen moist; fine mineral particles are usually absent

GT Gritty Rough tactility produced by mineral granules or coarsefragments

LF Leafy Tactility of materials produced by deciduous foliageshowing a shingle-like layering (banded structure)

GA Grassy Tactility of materials produced by graminoid remains

MO Mossy Tactility produced by bryophytes with more or lesspreserved vegetative structures

AC Acerose Tactility produced by particles having a tip, such as theneedles of conifers

FE Felty Tactility produced by abundant fungal mycelia

FI Fibrous Tactility produced by an abundance of fibrous plantresidues which do not break down when rubbedbetween fingers (i.e., fine roots)

LG Ligneous Tactility produced by coniferous or deciduous woodfibres

CR Crusty Hard and brittle tactility of dry or desiccated materials

•34•

Fauna:When describing soil fauna, use the name (Figure 2.3), e.g., few earth-worms, several nematodes.

FIGURE 2.3. Major kinds of soil fauna.

Label Fauna Label Fauna

A Mites (Acarina) G Woodlice (Isopoda)B Springtails H Centipedes and millipedes

(Collembola) (Myriapoda)C Spiders (Araneida) I Termites (Isoptera)D Fly larvae (Diptera) J Earthworms (Lumbricida)E Beetles and larvae K Potworms (Enchytraeida)

(Coleoptera)F Ants (Hymenoptera) L Nematodes (Nematoda)

•35•

Mineral Horizons/Layers

The soil horizon and layer definitions and methods for field descriptionthat follow are taken or modified from Agriculture Canada Expert Commit-tee on Soil Survey (1997), Green et al. (1993), and Luttmerding et al. (1990).

24. Horizon/LayerRecord the mineral horizon or layer designation followed by lowercasemodifiers, e.g., Btg.

Codes for major horizons:A Mineral horizon, containing < 17% organic C by mass, that has formed

at or near the soil surface in the zone of leaching or eluviation oforganic materials in solution or suspension, or of maximum in situaccumulation of organic matter, or both.

B Mineral horizon characterized by enrichment in organic matter,sequioxides, or clay; or by the development of soil structure; or by achange of colour denoting hydrolysis, reduction, or oxidation.

C Mineral horizon comparatively unaffected by the pedogenic processesoperative in the A and B horizons, except the process of gleying (Cg),and the accumulation of calcium and magnesium carbonates (Cca)and more soluble salts (Cs, Csa).

Codes for layers:R Consolidated bedrock layer which is too hard to break with the hands.

W Layer of water in Gleysolic, Organic, or Cryosolic soils.

Lowercase modifiers:b Buried soil horizon.

c Irreversibly cemented horizon (ortstein, placic, duric, and CaCO3

cemented layers are examples).

ca Horizon > 10 cm thick of secondary carbonate enrichment in whichthe concentration of lime exceeds that in the unenriched parentmaterial.

cc Irreversibly cemented concretions.

e Horizon characterized by the eluviation of clay, Fe, Al, or organicmatter alone or in combination.

•36•

f Horizon enriched with amorphous material, principally Al and Fecombined with organic matter. It must have a hue of 7.5YR or redder,or its hue must be 10YR near the upper boundary and becomesyellower with depth. When moist the chroma is higher than three orthe value is three or less. It is used primarily with the Bf, Bhf, Bfg, andBgf codes. The following f horizons are differentiated on the basis ofthe organic C content:

Bf 0.5–5% organic CBhf > 5% organic C

g Horizon characterized by gray colours, or prominent mottling, orboth, which indicates of permanent or periodic intense reduction.Chromas of the matrix are generally one or less. It is used with theAeg, Bg, Bfg, Bgf, Bhfg, Btg, Cg, Ckg codes, and others. When usedwith the Ae, Bf, Bhf, and Bt codes, the limits set for the other modifiersmust be met. The Bgf horizons are usually prominently mottled; morethan half of the soil material occurs as mottles of high chroma. TheBgf horizons occur in Fera Gleysols and Fera Humic Gleysols andpossibly below the Bfg of gleyed Podzols.

h Horizon enriched with organic matter. It is used with the Ah, Ahe, Bh,and Bhf codes.

Ah - An A horizon enriched with humified organic matter; at least onecolour value unit lower that the underlying horizon, or 0.5% more or-ganic C than the C horizon or both.

Ahe - An Ah horizon that has undergone eluviation as evidenced bystreaks and splotches of different shades of gray, and often by platedstructure.

Bh - Contains > 1% organic C with less than 0.3% pyrophosphate-ex-tractable Fe [Fe(p)] and a ratio of C : Fe(p) of 20 or more (very rare inBritish Columbia).

Bhf - Defined under f above.

j Used with e, f, g, n, and t to denote an expression of, but failure tomeet, the specified limits of the letter code it modifies. It is placed tothe right of the letter it modifies.

k Denotes the presence of carbonate as indicated by visible effervescencewhen a dilute HCl solution is added.

•37•

m Horizon slightly altered by hydrolysis, oxidation, or solution, or allthree to give a change in colour or structure, or both. It is used withthe Bm, Bmgj, Bmk, and Bms codes.

It has:1. Evidence of one of or more of the following:

• higher chromas and redder hues than the underlyinghorizons;

• enrichment or complete removal of carbonates either asBmk or Bm; and/or

• change in structure from that of the original material.2. Illuviation too slight to meet requirements of a Bt or podzolic B.3. No cementation or induration and lacks a brittle consistence

when moist.

n Horizon with distinctive prismatic or columnar structure, darkcoatings on ped surfaces, and hard to very hard consistence when dry;the exchangeable Ca to exchangeable Na is 10 or less. It is used withBn or Bnt codes.

p Horizon disturbed by human activities, such as cultivation, logging,and habitation.

s Horizon with salts, including gypsum, which may be detected ascrystal or veins, or as surface crusts of salt crystals. It is used with anycombination of horizon codes.

sa Horizon > 10 cm thick with secondary enrichment of salts moresoluble than Ca and Mg carbonates; the concentration of salts exceedsthat in the unenriched parent material.

t An illuvial horizon enriched with silicate clay. It is used with the Bt,Btg, and Bnt codes and may be modified by j.To use Bt:• The horizon must be at least 5 cm thick.• If any part of an the eluvial horizon has < 15% total clay in the

fine fraction (< 2 mm), the Bt horizon must contain at least 3% moreclay and if > 40% total clay, then it must contain at least 8% more clay.If the eluvial horizon has > 15% and < 40% clay in the fine fraction,then the ratio of the clay in the Bt to that of the eluvial horizon mustbe 1.2 or more (e.g., Ae 25 % clay; Bt at least 30% clay).

• In massive soils, there should be oriented clay in pores and as bridgesbetween sand grains.

• If peds are present, clay films (skins) should be visible on ped surfacesand in pores.

•38•

u Horizon that is markedly disrupted by physical (e.g., blowdown oftrees, mass movement, etc.) or faunal processes (e.g., burrowinganimals), but not from cryoturbation.

x Horizon of fragipan character; loamy subsurface horizon of high bulkdensity and very low organic matter. When dry, it is hard and seemsto be cemented; when moist is has moderate to weak brittleness. Air-dried clods slake (crumble) in water.

y Horizon affected by cryoturbation. It is used with any combination ofhorizon codes.

z A frozen layer, it may be used with any horizon or layer code.

Mineral diagnostic horizons:Chernozemic A• At least 10 cm thick;• Colour value darker than 5.5 dry and 3.5 moist, chroma is lower

than 3.5 moist;• Organic C content 1–17% and C:N ratio < 17;• Structure, when dry, is neither massive and hard, nor single

grained; and• Mean annual soil temperature of 0o C or higher and a soil moisture

regime subclass drier than humid.

Duric horizonA strongly cemented horizon that does not satisfy the criteria of a podzolicB horizon. Usually has an abrupt upper boundary and a diffuse lowerboundary. Air-dried clods do not hydrate in water, and moist clods at least3 cm thick usually can not be broken in the hands.

Fragipan horizonSee definition of “x” above.

Ortstein horizonA strongly cemented Bh, Bhf, of Bf horizon at least 3 cm thick which occursin more than one-third of the exposed pedon. Generally reddish brown tovery dark reddish brown.

Placic horizonA thin layer (commonly 5 mm or less thick) or a series of thin layers that areirregular or involuted, hard, impervious, often vitreous, and dark reddishbrown to black.

•39•

Podzolic B horizon (field criteria only)• At least 10 cm thick;• Moist crushed color: hue is 7.5YR or redder or 10YR near the upper

boundary and becomes yellower with depth. The chroma is higherthan 3 or the value is 3 or less;

• Accumulation of amorphous material is indicated by brown to blackcoatings on some mineral grains or brown to black microaggregates.Silty feel when the material is rubbed wet, unless cemented; and

• Texture coarser than clay.

Solonetzic B horizonThe term includes both Bn and Bnt horizons.

Lithic layerBedrock (R) below a depth of 10 cm. The upper surface of a lithic layer is alithic contact.

25. DepthRecord the average depths (in centimetres) of the upper and lowerboundaries of the soil horizon being described, e.g., Ah 0–5, Bm 5–20. Thetop of the uppermost mineral horizon is considered as zero depth.

26. ColourSoil colour is determined by comparison with Munsell Colour Charts . Thenotation for a specific colour should be in the order of hue, value/chroma.Intermediate hues, values, and chromas may be expressed with the use ofdecimals.

ASP - Colour AspectThe colour of a soil varies with its moisture content and physical state.Record the aspect of the Munsell colour notation using the codes inTable 2.29.

•40•

TABLE 2.29. Colour aspects and codes for mineral soils

Per

cent

cla

y

Percent sand

100

90

80

70

60

50

40

30

20

10

00 10 20 30 40 50 60 70 80 90 100

HC

C

SiC

SiCL CL

SCL

LSiL

Si SL LS S

SC

27. TextureSoil texture is defined by the size distribution of primary mineral particles(2 mm diameter or less). The textural classes and codes are determinedfrom the soil texture triangle by estimating the percentage of clay (less than0.002 mm diameter) and sand (0.05 to < 2.0 mm diameter)(Figure 2.4). SeeAppendix 2.4 for a key to soil texture (and letter-code descriptions).

FIGURE 2.4. Soil texture triangle.

Description

Matrix is the main soil constituent ormaterial that encloses other soil features, forexample, peds. This colour aspect isreserved for structureless soils or weaklystructured soils whose peds crumble uponhandling.

Colour of ped surfaces in soils with moder-ately durable peds which may be brokenopen and examined.

Dominant colour of ped interiors in soilswith moderately durable peds that may bebroken open and examined.

Soil material is crushed and mixed. Surfaceof the sample is smoothed to reduceirregularities that affect colour.

Aspect

Matrix moistMatrix dry

Exped moistExped dry

Inped moistInped dry

Crushed moistCrush dry

Code

12

34

56

78

•41•

Size class Very fine Fine Medium CoarseCode V F M CSize (mm) < 1 1 to 2 3 to 5 > 5

Abundance codeand classX None 0 0 0 0F Few < 10a < 10 1 1P Plentiful 10–100 10–100 2–10 2–5A Abundant > 100 > 100 > 10 > 5

28. Percent Coarse FragmentsEstimate the percent coarse fragment (> 2 mm diameter) volume in eachsize class and record the total percent. Describe the coarse fragment shapeusing the type codes in Table 2.30.

a type codes: R = rounded; S = subrounded and subangular; A = angular; T = thin, flat.

29. RootsDescribe roots by noting their abundance and size (Table 2.31). Record themost abundant size first; secondary roots can be recorded by using a slash(/) in the columns (see example in Item 21).

Shape type: Shape type:R, S, Aa T

Size Classes Diameter (cm) Length (cm)

G - Gravel < 7.5 < 15C - Cobbles 7.5–25 15–38S - Stones and >25 > 38

boulders

TABLE 2.30. Size classes and type codes for coarse fragments

TABLE 2.31. Root abundance and size classes and codes

a Values represent number of roots of size class observed in reference area of 100 cm2.

•42•

30. StructureRecord the kind and class of structure (see Table 2.32 below and Figure 2.5).When more than one kind of primary structure is present, record thedominant under structure, and the subordinate in comments.

Kind

ABK: Angularblocky; pedsbounded byflattened, rectangu-lar faces intersectingat relatively sharpangles

SBK: Subangularblocky; pedsbounded by slightlyrounded,subrectangular faceswith verticesb oftheir intersectionsmostly subrounded

GR: Granular;spheroidal pedsbounded by curvedor very irregularfaces that do notadjoin those ofadjacent peds

PL: Platy; peds flator platelike;horizontal planesmore or less welldeveloped

Class

VF very fine angularblocky

F fine angular blockyM medium angular

blockyC coarse angular blockyVC very coarse angular

blocky

VF very fine subangularblocky

F fine subangularblocky

M medium subangularblocky

C coarse subangularblocky

VC very coarsesubangular blocky

VF very fine granularF fine granularM medium granularC coarse granularVC very coarse granular

VF very fine platyF fine platyM medium platyC coarse platyVC very coarse platy

Size (mm)a

< 5

5–1010–20

20–50> 50

< 5

5–10

10–20

20–50

> 50

< 11–22–55–10> 10

< 11–22–55–10> 10

TABLE 2.32. Codes for kind and class of soil particle structure

•43•

Kind

PR: Prismatic;vertical faces of pedswell defined andverticesb angular(edges sharp); prismtops essentially flat

COL: Columnar;vertical edges neartop of columns notsharp (verticesb

subrounded);column tops flat,rounded, orirregular

SGR: single grained

MA: Massive

CDY:

Class

VF very fine prismaticF fine prismaticM medium prismaticC coarse prismaticVC very coarse pris-

matic

VF very fine columnarF fine columnarM medium columnarC coarse columnarVC very coarse colum-

nar

Loose, incoherent mass ofindividual primaryparticles, as in sands

Amorphous; a coherentmass showing noevidence of any distinctarrangement of soilparticles; separates intoclusters of particles, notpeds

Cloddy; not a structure,used to indicate thecondition of someploughed surfaces.

Size (mm)a

< 1010–2020–5050–100> 100

< 1010–2020–5050–100> 100

a The size limits refer to measurements in the smallest dimension of platy, prismatic,and columnar peds, and to the largest of the nearly equal dimensions of blocky andgranular peds.

b Definition of vertex (plural, vertices): the intersection of two planes of a geometricalfigure.

•44•

TABLE 2.34. Contrast codes for mottles

TABLE 2.33. Abundance and size codes for mottles

Grade The degree of distinctness of aggregation of soil particles. If gradeof structure is described, record with class code separated by a slash (e.g.,S/VC = strong/very coarse).

W = WeakWM = Weak to moderateM = ModerateMS = Moderate to strongS = Strong

31. pHRecord pH by noting the method of measurement (see Table 2.26 underItem 22) and the determined values to one decimal place.

32. CommentsRecord any observations or measurements that are unique, unconforming,or could be of particular significance to the study, classification, or manage-ment interpretations. Examples include: colour and description of mottles(see colour section), description of clay films, and porosity.

Mottling:Described by recording abundance, size, and contrast and colour (see Tables2.33 and 2.34). Use Munsell Colour Charts, defaulting to aspect 7, crushedmoist, unless otherwise noted. For example, FMD 7.5YR mottles = few,medium, distinct, strong brown (crushed moist) mottles.

Abundance Size

Code Class % of Code Class Diameterexposed (mm)surface

F Few < 2 F Fine < 5C Common 2–20 M Medium 5–15M Many > 20 C Coarse > 15

Code Description

F Faint: Evident only on close examination. Faint mottles commonlyhave the same hue as the colour to which they are compared anddiffer by no more than 1 unit of chroma or 2 units of value. Somefaint mottles of similar but low chroma and value can differ by 2.5units of hue.

•45•

Clay films (skins):Accumulations of oriented clay translocated from another part of the soil.Clay films are described by recording the frequency of occurrence, andestimated thickness (see Tables 2.35 and 2.36). Most Bt horizons will exhibitclay films and should be noted. For example, FMTK clay films = Few,moderately thick clay films.

Code Description

D Distinct: Readily seen, but contrast only moderately with thecolour to which they are compared. Distinct mottles commonlyhave the same hue as the colour to which they are compared, butdiffer by 2–4 units of chroma or 3–4 units of value; or differfrom the colour to which they are compared by 2.5 units of hue, butby no more than 1 unit of chroma or 2 units of value.

P Prominent: Contrast strongly with the colour to which they arecompared. Prominent mottles are commonly the most obviouscolour feature in a soil. Prominent mottles that have mediumchroma and value commonly differ from the colour to which theyare compared by at least 5 units of hue, if chroma and value are thesame; by at least 4 units of value or chroma, if the hue is the same;or by at least 1 unit of chroma or 2 units of value, if hue differs by2.5 units.

TABLE 2.35. Clay film frequency classes

Description

No clay films present.

Clay films cover less than 2% of the total area of thespecified surface(s). Patches of film are identifiable,but their frequency is so low that the significance oftheir presence may be nil or doubtful.

Clay films cover 2–20% of the total area of thespecified surface(s).

Clay films cover 20–80% of the total area of thespecified surface(s). They may occur as discretepatches or as a continuous network.

Clay films cover more than 80% of the total area ofthe specified surface(s). Patches of these surfaces maybe free of clay films, but the films are essentiallycontinuous.

Code

X

F

C

M

CS

Class

None

Few

Common

Many

Continuous

•46•FIGURE 2.5. Diagrammatic representation of soil structure.

(mea

sure

men

ts in

mm

)

•47•FIGURE 2.5. (continued).

SC

ALE

IN M

M.

•48•

TABLE 2.36. Clay film thickness classes

Effervescence:The bubbling, hissing, or foaming that occurs when a 10% HCl solution isadded to a sample of soil. Enter the appropriate code from Table 2.37.

TABLE 2.37. Codes to describe degree of effervescence

Description

Hand lens is needed for identifica-tion; visible in cross-section with 10Xlens, but not to the unaided eye. Ifpresent, fine sand grains protrudethrough the film or are only thinlycoated and are readily apparent.

Clay films are visible in cross-sectionto the unaided eye. Fine sand grainsare enveloped by the film or theiroutlines are indistinct. Film surfacesare relatively smooth.

Clay films and their broken edges arereadily visible without magnification.Film surfaces are smooth.

Clay films are a striking feature ofthe morphology

mm

< 0.05

0.05–0.5

0.5–1.0

> 1.0

Class

Thin

Moderatelythick

Thick

Very thick

Code

TN

MTK

TK

VTK

Degree of effervescence

No evidence of effervescence

Few bubbles. (Note: ensure that the cracklingsound is from reaction rather than absorption ofliquid; compare with water).

Bubbles readily observed

Bubbles form low foam

Bubbles form thick foam

Code Class

X None

VW Very Weak

W Weak

M Moderate

S Strong

•49•

Horizon porosity:An estimate of total pore volume that reflects the combined effects of soilstructure and density. Record porosity classes for mineral horizons asdescribed in Table 2.38.

34. NotesUse this section to summarize or describe soil features not otherwiserecorded on the form or that are significant to the study, classifications, ormanagement interpretations.

33. Profile diagramSketch a cross-sectional profile diagram of the horizon boundaries, andadd other significant features (relative coarse fragment distribution andsize, piping, turbation, seepage, water table, lithic contact, etc.) (seeexample, Figure 2.6.

AeFm

Bf1

Bf2

BC

C

PROFILEDIAGRAM

20

40

60

0

10

TABLE 2.38. Mineral horizon porosity classes

FIGURE 2.6. Example of profile diagram.

Description

Closely packed structureless soil material; highlycompacted material.

Horizons with weak to moderate structure andmoderately close packing; closely packed soilswith large, well-developed peds.

Horizons that are loosely packed, and/or verywell structured with small peds.

Code Porosity class

S Slightly porous

M Moderatelyporous

H Highly porous

•50•

•51•

Appendix 2.1 Codes for Soil Orders,Great Groups and Subgroups

Brunisolic OrderMelanic Brunisol MBOrthic O.MBEluviated E.MBGleyed GL.MBGleyed Eluviated GLE.MB

Eutric Brunisol EBOrthic O.EBEluviated E.EBGleyed GL.EBGleyed Eluviated GLE.EB

Sombric Brunisol SBOrthic O.SBEluviated E.SBDuric DU.SBGleyed GL.SBGleyed Eluviated GLE.SB

Dystric Brunisol DYBOrthic O.DYBEluviated E.DYBDuric DU.DYBGleyed GL.DYBGleyed Eluviated GLE.DYB

Chernozemic OrderBrown Chernozem BCOrthic O.BCRego R.BCCalcareous CA.BCEluviated E.BCSolonetzic SZ.BCVertic V.BCGleyed GL.BCGleyed Rego GLR.BCGleyed Calcareous GLA.BCGleyed Eluviated GLE.BCGleyed Solonetzic GLSZ.BCGleyed Vertic GLV.BC

Dark Brown Chernozem DBCOrthic O.DBCRego R.DBCCalcareous CA.DBCEluviated E.DBCSolonetzic SZ.DBCGleyed GL.DBCGleyed Rego GLR.DBCGleyed Calcareous GLCA.DBCGleyed Eluviated GLE.DBCGleyed Solonetzic GLSZ.DBC

Black Chernozem BLCOrthic O.BLCRego R.BLCCalcareous CA.BLCEluviated E.BLCSolonetzic SZ.BLCVertic V.BLCGleyed GL.BLCGleyed Rego GLR.BLCGleyed Calcareous GLCA.BLCGleyed Eluviated GLE.BLCGleyed Solonetzic GLSZ.BLCGleyed Vertic GLV.BLC

Dark Gray Chernozem DGCOrthic O.DGCRego R.DGCCalcareous CA.DGCSolonetzic SZ.DGCVertic V.DGCGleyed GL.DGCGleyed Rego GLR.DGCGleyed Calcareous GLCA.DGCGleyed Solonetzic GLSZ.DGCGleyed Vertic GLV.DGC

•52•

Cryosolic OrderTurbic Cryosol TCOrthic Eutric OE.TCOrthic Dystric OD.TCBrunisolic Eutric BRE.TCBrunisolic Dystric BRD.TCHistic Eutric HE.TCHistic Dystric HD.TCLuvisolic L.TCRegosolic R.TCGleysolic GL.TC

Static Cryosol SCOrthic Eutric OE.SCOrthic Dystric OD.SCBrunisolic Eutric BRE.SCBrunisolic Dystric BRD.SCHistic Eutric HE.SCHistic Dystric HD.SCLuvisolic L.SCGleysolic Static Cryosol GL.SCRegosolic Static Cryosol R.SC

Organic Cryosol OCFibric FI.OCMesic ME.OCHumic HU.OCTerric Fibric TFI.OCTerric Mesic TME.OCTerric Humic THU.OCGlacic GC.OC

Gleysolic OrderLuvic Gleysol LGSolonetzic SZ.LGFragic FR.LGHumic HU.LGFera FE.LGOrthic O.LGVertic V.LG

Humic Gleysol HGSolonetzic SZ.HGFera FE.HGOrthic O.HG

Rego R.HGVertic V.HG

Gleysol GSolonetzic SZ.GFera FE.GOrthic O.GRego R.GVertic V.G

Luvisolic OrderGray Brown Luvisol GBLOrthic O.GBLBrunisolic BR.GBLPodzolic PZ.GBLVertic V.GBLGleyed GL.GBLGleyed Brunisolic GLBR.GBLGleyed Podzolic GLPZ.GBLGleyed Vertic GLV.GBL

Gray Luvisol GLOrthic O.GLDark D.GLBrunisolic BR.GLPodzolic PZ.GLSolonetzic SZ.GLFragic FR.GLVertic V.GLGleyed GL.GLGleyed Dark GLD.GLGleyed Brunisolic GLBR.GLGleyed Podzolic GLPZ.GLGleyed Solonetzic GLSZ.GLGleyed Fragic GLFR.GLGleyed Vertic GLV.GL

Organic OrderFibrisol FTypic TY.FMesic ME.FHumic HU.FLimnic LM.FCumulic CU.FTerric T.F

•53•

Terric Mesic TME.FTerric Humic THU.FHydric HY.F

Mesisol MTypic TY.MFibric FI.MHumic HU.MLimnic LM.MCumulic CU.MTerric T.M.Terric Fibric TFI.MTerric Humic THU.MHydric HY.M

Humisol HTypic TY.HFibric FI.HMesic ME.HLimnic LM.HCumulic CU.HTerric T.HTerric Fibric TFI.HTerric Mesic TME.HHydric HY.H

Folisol FOHemic HE.FOHumic HU.FOLignic LI.FOHistic HI.FO

Podzolic OrderHumic Podzol HPOrthic O.HPOrtstein OT.HPPlacic P.HPDuric DU.HPFragic FR.HP

Ferro-Humic Podzol FHPOrthic O.FHPOrtstein OT.FHPPlacic P.FHPDuric DU.FHP

Fragic FR.FHPLuvisolic LU.FHPSombric SM.FHPGleyed GL.FHPGleyed Ortstein GLOT.FHPGleyed Sombric GLSM.FHP

Humo-Ferric Podzol HFPOrthic O.HFPOrtstein OT.HFPPlacic P.HFPDuric DU.HFPFragic FR.HFPLuvisolic LU.HFPSombric SM.HFPGleyed GL.HFPGleyedOrtstein GLOT.HFPGleyed Sombric GLSM.HFP

Regosolic OrderRegosol ROrthic O.RCumulic CU.RGleyed GL.RGleyed Cumulic GLCU.R

Humic Regosol HROrthic O.HRCumulic CU.HRGleyed GL.HRGleyed Cumulic GLCU.HR

Solonetzic OrderSolonetz SZBrown B.SZDark Brown DB.SZBlack BL.SZAlkaline A.SZGleyed Brown GLB.SZGleyed Dark Brown GLDB.SZGleyed Black GLBL.SZ

Solodized Solonetz SSBrown B.SSDark Brown DB.SS

•54•

Black BL.SSDark Gray DG.SSGray G.SSGleyed Brown GLB.SSGleyed Dark Brown GLDB.SSGleyed Black GLBL.SSGleyed Dark Gray GLDG.SSGleyed Gray GLG.SS

Solod SOBrown B.SODark Brown DB.SOBlack BL.SODark Gray DG.SOGray G.SOGleyed Brown GLB.SOGleyed Dark Brown GLDB.SOGleyed Black GLBL.SOGleyed Dark Gray GLDG.SOGleyed Gray GLG.SO

VertisolicVertisol VOrthic O.VGleyed GL.VGleysolic GLC.V

Humic Vertisol HVOrthic O.HVGleyed GL.HVGleysolic GLC.HV

•55•

Key to Soil Orders (Soil Classification Working Group 1998)

A. Soils that have permafrost within 100 cm of the surface, or 200 cm ifstrongly cryoturbated. ...................................................... Cryosolic Order

B. Other soils with:1. Organic horizons (more than 17% organic C by mass) that extend

from the surface to one of the following:a. A depth of 60 cm or more if the surface layer is fibric

material (Of) having a bulk density of < 0.075 g/cm3.b. A depth of 40 cm or more if the surface layer consists of mesic

or humic material (Om or Oh) having a bulk density > 0.075 g/cm3.

c. A depth of more than 40 cm if composed of folic materials (L, F,and H), or at least 10 cm if a lithic contact or fragmentalmaterials are present. Folic materials must be more than twicethe thickness of a mineral soil layer if the mineral layer is lessthan 20 cm thick.

OR2. One or more mineral horizons or layers within 40 cm of

the surface in addition to the organic horizons (O) as follows:a. If a mineral horizon or layer thinner than 40 cm occurs at

the surface, the underlying organic horizon or horizonsmust have a total thickness of at least 40 cm.

b. If one or more mineral horizons or layers occur within 40 cm ofthe surface, the organic material must occupy more than40 cm of the upper 80 cm of the control section................................................................................... Organic Order

C. Other soils that have both a vertic horizon and a slickenside horizon,the top of which occurs within 1 m of the surface. ... Vertisolic Order

D. Other soils that have a podzolic B horizon and do not have a Bt horizonwithin 50 cm of the mineral surface. .............................Podzolic Order

E. Other soils that are saturated with water and under reducing conditionseither continuously or during some period of the year as indicatedeither by direct measurements of the water table and the oxidation-reduction status, or by any of the following morphological featureswithin 50 cm of the mineral surface:

Appendix 2.2 Key to Soil Orders

•56•

1. For all but red soil materials (hue 5YR or redder and colour fadesslowly on dithionite treatment).

a. Chromas of 1 or less, without mottles, on ped surfaces or inthe matrix if peds are lacking in materials that develophigher chromas under oxidizing conditions.

b. Chromas of 2 or less, in hues of 10YR and 7.5YR, on pedsurfaces or in the matrix if peds are lacking, accompanied byprominent mottles.

c. Chromas of 3 or less, in hues yellower than 10YR, on pedsurfaces or in the matrix if peds are lacking, accompanied byprominent mottles.

d. Hues bluer than 10Y, with or without mottles, on ped surfacesor in the matrix if peds are lacking. ................ Gleysolic Order

2. Other soils that have a solonetzic B horizon. ..... Solonetzic Order

G. Other soils that have a chernozemic A horizon and any one of thefollowing:1. No Ae horizon.2. A weakly expressed Ae horizon (Aej) with a dry colour value

lower than 5.3. An Ae horizon thinner than an overlying Ah or Ap horizon that

does not appear to be eluviated.4. An Ae horizon not more than 5 cm thick if the chernozemic A is

eluviated (Ahe), as indicated by grey streaks and splotches whenthe soil is dry. ................................................... Chernozemic Order

H. Other soils that have a Bt horizon. ............................. Luvisolic Order

I. Other soils that have either Bm, Btj, or Bfj horizons at least 5 cm thick,or a Bf horizon less than 10 cm in thickness. .......... Brunisolic Order

J. Other soils. ...................................................................... Regosolic Order

•57•

Key to Humus Forms

1a. Well to imperfectly drained sites; humus form not saturated forprolonged periods

2a. Combined thickness of F and H horizons > 2 cm if Ah < 2 cm

3a. > 50% thickness of F horizon(s) is Fm .......... MORS (R)

4a. Decaying wood > 35% of organic matter volume inhumus form profile ........................ Lignomor (LR)

4b. Decaying wood < 35% of organic matter volume inhumus form profile

5a. F horizon > 50% of thickness of F and Hhorizon .................................... Hemimor (HR)

5b. Hh horizon > 50% of thickness of F and Hhorizons ................................. Humimor (UR)

5c. Hr horizon > 50% of thickness of F and Hhorizons .................................... Resimor (RR)

3b. F horizon(s) includes Fz and/or Fa ......... MODERS (D)

6a. Decaying wood > 35% of organic matter volume inhumus form profile .................... Lignomoder (LD)

6b. Decaying wood < 35% of organic matter volume inhumus form profile

7a. Fa horizon > 50% of thickness of F horizons; orFm horizon present .............. Mormoder (RD)

7b. Fz horizon > 50% of thickness of F horizons

8a. F and H horizons greater than or equal tothickness of Ah horizon.................................... Leptomoder (TD)

8b. F and H horizons less than thickness of Ahhorizon ....................... Mullmoder (MD)

Appendix 2.3 Key to Humus Forms

•58•

2b. Combined thickness of F and H horizons < 2 cm and Ahhorizon > 2cm ...................................................... MULLS (L)9a. Rhizogenous Ah horizon formed from decomposition

of dense fine roots ............................... Rhizomull (ZL)

9b. Zoogenous Ah horizon formed through actions ofabundant earthworms ....................... Vermimull (VL)

1b. Poor to very poorly drained sites; humus form saturated forprolonged periods

10a. Combined thickness of F, H, and O horizons < 2 cm and Ahhorizon > 2 cm ............................................ Hydromull (YL)

10b. Combined thickness of F, H, and O horizons > 2 cm ifAh < 2 cm

11a. Thickness of F and H horizons > O horizons

12a. F horizon(s) is Fm ...................... Hydromor (YR)

12b. F horizon(s) includes Fz and/or Fa................................................. Hydromoder (YD)

11b. Combined thickness of O horizons greater than F andH horizons

13a. Of horizon > 50% of thickness of O horizons......................................................... Fibrimor (FR)

13b. Om horizon > 50% of thickness of O horizons....................................................... Mesimor (MR)

13c. Oh horizon > 50% of thickness of O horizons................................................... Saprimoder (SD)

•59•

Soil texture field tests

Graininess Test Rub the soil between your fingers. If sand is present, itwill feel “grainy.” Determining whether sand constitutes more or less than50% of the sample is the first decision in the key.

Moist Cast Test Compress some moist soil by clenching it in your hand. Ifthe soil holds together (i.e., forms a “cast”), then test the durability of thecast by tossing it from hand to hand. The more durable it is, the more clayis present.

Stickiness Test Moisten the soil thoroughly and compress it betweenthumb and forefinger. Determine degree of stickiness by noting howstrongly the soil adheres to the thumb and forefinger when pressure isreleased, and how much it stretches. Stickiness increases with clay content.

Worm Test Roll some moist soil between the palms of your hands to formthe longest, thinnest worm possible. The more clay present, the longer,thinner and more durable the worm will be.

Taste Test (Not recommended due to health concerns) Work a smallamount of moist soil between your front teeth. Silt particles are distin-guished as fine “grittiness,” unlike sand which is distinguished as indi-vidual grains (i.e., graininess). Clay has no grittiness.

Well-decomposed organic matter imparts silt-like properties to the soil.However, when subjected to the taste test, it feels non-gritty. It is generallyvery dark in colour when moist or wet, and stains the hands brown orblack. This organic matter is not used as a determinant of soil texture; anestimate of the silt content of humus-enriched mineral soils should bereduced accordingly.

Soapiness Test Work a small amount of wet soil between your thumb andfingers. Silt feels slick and not too sticky (i.e., clay) or grainy (i.e., sand); thegreater the dominance of a slick feel, the greater the silt content.

Appendix 2.4 Key to Soil Texture

•60•

mod

erat

e ca

st(e

asily

han

dled

)no

n to

s.s

ticky

(<30

% c

lay)

stro

ng c

ast

(v.e

asily

han

dled

)st

icky

(30-

40%

cla

y)

Gra

inin

ess

Test

(Org

anic

Mat

ter

Test

)M

oist

Cas

t T

est

Moi

st C

ast

Tes

tS

ticki

ness

Tes

tT

aste

Tes

t*W

orm

Tes

tS

ticki

ness

Tes

t

Tas

te T

est

(grit

tines

s)S

oapi

ness

Tes

tW

orm

Tes

t

>50

% s

and

grai

ny t

ov.

grai

ny

<50

% s

and

non-

grai

nyto

s.g

rain

y

form

s no

cas

t(<

10%

cla

y)

mod

erat

e ca

st(e

asily

han

dled

)(<

20%

cla

y)

wea

k ca

st(c

aref

ul h

andl

ing)

(<20

% c

lay)

v.w

eak

cast

(no

hand

ling)

(<15

% c

lay)

SiL

*S

ILT

LO

AM

CL

CLA

Y L

OA

M

LLO

AM

Si*

SIL

T

SiC

LS

ILT

Y C

LAY

LO

AM

gritt

y to

v.g

ritty

soap

y to

v.s

oapy

wor

m:

none

or

3 m

m d

ia(0

-50%

san

d)

non-

gritt

y to

s.g

ritty

non-

soap

y to

s.s

oapy

wor

m:

3-1.

5 m

m d

ia(2

0-45

% s

and)

s.gr

itty

to g

ritty

s.so

apy

to s

oapy

wor

m:

none

or

may

eq

ual

3 m

m d

ia(2

5-50

% s

and)

v.gr

itty

v.so

apy

wor

m:

none

or

>3

mm

dia

(0-2

0% s

and)

s.gr

itty

to g

ritty

s.so

apy

to s

oapy

wor

m:

3-1.

5 m

m d

ia(0

-20%

san

d)

LSLO

AM

Y S

AN

D

SL

SA

ND

Y L

OA

M

SS

AN

D

FS

L*F

INE

SA

ND

Y L

OA

M

non

to s

.grit

tyno

n to

s.s

ticky

wor

m:

none

(70-

90%

san

d)

non

to s

.grit

tyno

n to

s.s

ticky

wor

m:

varia

ble,

no

ne o

r >

3 m

m d

ia(4

5-80

% s

and)

non-

gritt

yno

n-st

icky

wor

m:

none

(85-

100%

san

d)

gritt

y to

v.g

ritty

non

to s

.stic

kyw

orm

: no

ne o

r 3

mm

dia

(45-

85%

fin

e sa

nd)

ST

AR

T

•61•

SA

ND

Y C

LAY

LO

AM

SC

LS

iCS

ILT

Y C

LAY

SA

ND

Y C

LAY

SC

OO

RG

AN

IC

C o

r H

CC

LAY

or

HE

AV

Y C

LAY

>30

% o

rgan

ic m

atte

r

non

to s

.grit

tys.

stic

ky t

o st

icky

wor

m:

3 m

m d

ia(4

5-80

% s

and)

s.gr

itty

to g

ritty

s.so

apy

to s

oapy

wor

m:

stro

ng;

1.5

mm

dia

(0-2

0% s

and)

non-

gritt

yst

icky

to

v.st

icky

wor

m:

3-1.

5 m

m d

ia(4

5-65

% s

and)

stro

ng c

ast

(v.e

asily

han

dled

)(2

0-55

% c

lay)

(no

text

ure)

non-

gritt

y to

s.g

ritty

non-

soap

y to

s.s

oapy

wor

m:

stro

ng;

1.5

mm

dia

(0-4

5% s

and)

Key

to

Abb

revi

atio

ns

Fin

e F

ract

ion

(par

ticle

dia

met

er)

Mea

sure

men

t C

onve

rsio

nss

= s

light

lyv

= v

ery

dia

= d

iam

eter

SA

ND

---

----

----

-- (

S)

2 -

.05

mm

SIL

T -

----

----

----

-- (

Si)

.05

- .0

02 m

mC

LAY

---

----

----

-- (

C)

<.0

02 m

mH

EA

VY

CLA

Y --

(HC

)>

60 %

cla

yLO

AM

---

----

----

- ( L

)m

ix o

f sa

nd,

silt,

and

cla

y

3.0

mm

= 1

/8"

1.5

mm

= 1

/16"

Silt

fee

ls s

lippe

ry o

r so

apy

whe

n w

et;

fine

sand

fee

ls

stiff

er,

like

grin

ding

com

poun

d or

fin

e sa

ndpa

per.

*

very

str

ong

cast

(v.e

asily

han

dled

)v.

stic

ky(>

40%

cla

y)

Percent clay

Per

cent

san

d

100 90 80 70 60 50 40 30 20 10 0

010

2030

4050

6070

8090

100

HC

C

SiC S

iCL

CL

SC

L

LS

iL

Si

SL

LSS

SC

•62•