EPA 904-R-95-003
FIELD
INDICATORS
OF
HYDRIC SOILS
IN THE
UNITED STATES
6/14/95
reprinted by:
U. S. Environmental Protection Agency
Region 4, Water Division, Wetlands Section
61 Forsyth Street, S. W.
Atlanta, Georgia, U. S. A. 30303-3415
(404) 562-9900 voice
(404) 562-8339 TTY/TDD
(800) 241-1754 voice
WEB site: http://www.epa.gov/docs/Region4Wet/wetlands.html
e-mail: burnett.thomas@epamail.epa.gov
-------
FIELD INDICATORS OF HYDRIC SOILS
IN THE UNITED STATES
by: UNITED STATES DEPARTMENT OF AGRICULTURE.
NATURAL RESOURCES CONSERVATION SERVICE
in cooperation with:
Environmental Protection Agency,
U.S. Fish and Wildlife Service,
U.S. Army Corps of Engineers, and
North Carolina State University
Forward: Field Indicators of Hydric Soils in the United States have been developed by Natural
Resources Conservation Service (NRCS) soil scientists in cooperation with soil and other scientists from
the U.S. Fish and Wildlife Service, the U.S. Army Corps of Engineers, the Environmental Protection
Agency, various regional, state, and local agencies, universities, and the private sector. Included are the
official hydric soil-indicators for use by NRCS and others identifying and verifying the pressence of
hydric soils in the field.
-------
TABLE OF CONTENTS
Tonic
Introduction
Concept
Cautions
Procedure
To Comment on the Indicators
References
Land Resource Region Map
Field Indicators of Hydric Soils in the United States
All Soils
Sandy Soils
Loamy and Clayey Soils
Test Indicators of Hydric Soils
All Soils
Sandy Soils
Loamy and Clayey Soils
Glossary
List of Field Indicators by LRR
Correlation with COE 87 Manual
Page
1
1
2
2
4
5
7
8
8
12
16
21
21
21
23
28
33
35
-------
FIELD INDICATORS OF HYDRIC SOILS IN THE UNITED STATES
VER. 2.0, June, 1995)
INTRODUCTION:
The "Field Indicators of Hydric Soils in the United States (Indicators)" is a tool to help identify
and delineate hydric soils in the field. The Indicators are designed to meet the requirements contained in the
definition and criteria of hydric soils. The Indicators are used to identify the hydric soil component of
wetlands, however, there may be some hydric soils that lack one of the currently listed Indicators. Therefore,
these indicators are considered to be dynamic and changes and additions are anticipated. The section To
Comment on the Indicators provides guidance to recommend changes, deletions, and additions. Any changes,
deletions, or additions to the Indicators must be approved by the Interagency Field Indicator Committee. In
order to properly use the Indicators, a basic knowledge of soil landscape relationships and soil survey
procedures is necessary.
CONCEPT:
Nearly all hydric soils exhibit characteristic morphologies as a result of having undergone repeated
periods of saturation for more than just a few days. The combination of this saturation and/or inundation
along with microbiological activity in the soil results in a depletion of oxygen. This anaerobiosis promotes
biogeochemical processes such as the accumulation and differential decomposition of organic matter and the
reduction, translocation, and accumulation of iron and other elements. These processes result in characteristic.
morphologies which reflect the periodic cycles of saturation and/or inundation, reduction, and oxidation in,
soil. These morphologies persist in the soil during both wet and dry periods, malting them particularly use
for identifying.hydric soils.
Hydric soil indicators reflect predominately the accumulation or loss of materials composed of
iron/manganese, sulfur, and carbon. The presence of hydrogen sulfide gas (rotten egg odor) is a strong
indicator of a hydric soil, but the indicator often found in only the wettest of sites. While indicators related to
Fe/Mn depletions or concentrations are (the most) common, they cannot form in soils whose parent materials
contained low amounts of Fe/Mn initially. Soil formed in such materials may have low chroma colors that are
not related to saturation and reduction. For such soils, features related to organic carbon depletions or
accumulations should be used. These features are identified in this document, in part to handle soils whose
parent materials may have had low amounts of Fe/Mn and where hydrogen sulfide gas is not detected.
-------
CAUTIONS:
There are hydric soils that have soil conditions which are difficult to interpret or seem inconsistent with
the landscape, vegetation, or hydrology such as disturbed areas, soils formed in low chroma, red, or low iron
content parent material; soils with high pH or low organic matter content; Mollisols and Vertisols; and soils
with relict redoximorphic features and areas that have disturbance such as cultivated soils, filled areas.
Morphological features of hydric soils indicate that saturation and anaerobic conditions have existed
under either current or former hydrologic regimes. Features that do not reflect current hydrologic conditions
of saturation and anaerobiosis are relict features. Artificially drained or protected (such as by levees) hydric
soils are hydric if the soil in its undisturbed state would have met the criteria for hydric soils. These soils
should also have at least one of the Hydric Soil Field Indicators. Occasionally it is difficult to ascertain
whether morphological features being observed are the result of current or former hydrologic regimes unless
other hydrologic features can be verified. When soil conditions are inconclusive, other hydrologic features are
onobservable, or soil conditions seem inconsistent with the landscape, vegetation, or observable hydrology, it
may be necessary to obtain the assistance of an experienced soil scientist and/or wetland scientist.
PROCEDURE:
To document a hydric soil first remove all loose leaf matter, needles, bark, and other easily identified
plant parts to expose the surface. Depth of excavation and examination is usually SO cm (20 inches {in.}), but
may be greater if determination of an appropriate Indicator so requires. It is always recommended that soils be
excavated and described as deep as necessary to understand the redoximorphic processes. For example, this
may be less than SO cm (20 in.) in soils with surface horizons of organic material or mucky sand. It will often
be greater than SO cm (20 in.) in Mollisols. In many sites it will be necessary to make some exploratory
observations to a meter or more to determine the hydromorphic processes and soil morphological distinctions
appropriate for the site. These observations should be made with the intent of documenting and understanding
the variability in soil properties and hydrologic relationships.
Particular attention should be paid to changes in microtopography and parent materials over short
distances. Small changes in elevation may result in sequences of hydric-nonhydric soils. In addition, the
shape of the local landfonn surface can greatly affect the movement of water through the landscape.
Significant changes in parent material or lithologic discontinuities in the soil can affect the hydrologic
properties of the soil. After sufficient exploratory observations have been made to understand the soil-
hydrologic relationships at the site, subsequent excavations may then be shallower if interpretations of the
Indicators identified are appropriate to the site.
-------
Depths used in the Indicators are measured from the mineral surface. Unless otherwise specified, all
colors refer to moist Munsell colors. For simplicity, soil colors specified in the Indicators do not have decimal
points listed; however, colors do occur between Munsell chips. Soil colors should not be rounded to qua
meeting an Indicator. For example: a soil ped with a chroma of between 2 and 3 should be listed as havii.B _
chroma of 2+. This soil does not have chroma of 2 and would not meet any indicator that requires a chroma of
2 (or less). Compare the soil characteristics in the soil to those recorded in the soil profile description for
completeness. Using the completed soil description and comparing the soil features required by each
Indicator, specify which Indicators have been matched with the conditions observed in the soil.
-------
TO COMMENT ON THE INDICATORS:
Hydric soils are soils typically found in wetlands. As field data are collected to improve our
understanding of hydric soil processes, the list of Indicators will be revised and updated to include indicators
for all hydric soils.
If you know an area where the plant community and hydrologic data strongly suggest that an area is a
wetland and there is no indicator that identifies that soil condition, please write to one of the persons listed
below. To be most helpful, please provide suggestions for modifications you feel are needed and supporting
documentation to:
Russell F. Pringle
USDA, NRCS, National Wetlands Staff
PO Box 2890, Cotton Annex Mezz 1
Washington, DC 20013
G. Wade Hurt
USDI, Fish & Wildlife Service
National Wetlands Inventory
9720 Executive Center Drive, Suite 101
St. Petersburg, FL 33702
Ray Miles
USDA, NRCS, WNTC
101 SW Main St. Suite 1300
Portland, OR 97204-3221
Blake Parker
EPA Representative
PO Box 173
Woodland, AL 36280
Porter B. Reed, Jr.
USDI, Fish & Wildlife Service
National Wetlands Inventory
9720 Executive Center Drive, Suite 101
St. Petersburg, FL 33702
H. Chris Smith
USDA, NRCS, NNTC
160 East 7th Street
Chester, PA 19013
Dr. Steve Sprecher_
US Army Corps of Engineers
Waterways Experiment Station
3909 Halls Ferry Road
Vicksburg, MS 39180-6199
Dr. Michael J. VeprasKas
North Carolina State Univ.
Department of Soil Science
Box 7619
Raleigh, NC 27695
P. Michael Whitedr
USDA, NRCS, MNTC
Federal Bldg., Rm. 152, MS22
100 Centennial Mall North
Lincoln, NE 68508-3866
DeWayne Williams
USDA, NRCS, SNTC
PO Box 6567
Fort Worth, TX 76115
All services and programs of the US Department of Agriculture. Natural Resources Conservation Service, are offered on a
nondiscriminatory basts, without regard to race, color, national origin, religion, sex, age, marital status or handicap.
-------
REFERENCES
Unless otherwise noted the following references contain definitions of terms used throughout this
document. They also contain additional information concerning the terms in the glossary at the back q
this document unless otherwise noted.
Federal Register. Feb. 24, 1995. Hydric Soils of the United States. Washington, DC.
Florida Soil Survey Staff. 1992. Soil and Water Relationships of Florida's Ecological Communities. G. W.
Hurt (ed.). USDA, Soil Conservation Service (SCS), Gainesville, FL.
Kollmorgen Instruments Corporation. 1994. Munsell Soil Color Charts. Munsell Color, Baltimore, MD.
Mausbach, M. J. and J. L. Richardson. 1994. Biogeochemical Processes in Hydric Soils, p. 68-127. In Current
Topics in Wetland Biogeochemistry vol. 1, 1994. Wetland Biogeochemistry Institute, Louisiana State
University, Baton RougeTLA.
Soil Science Society of America. 1987. Glossary of Soil Science Terms. Soil Science Society of America,
Madison, WI.
Soil Science Society of America. 1993. Special Publication #31. Proceedings of the Symposium on Soil Color.
October 21-26,1990. San Antonio, TX. J. M. Bigham and E. J. Ciolkosz (eds.). Soil Science Society of
America, Madison, WI.
Soil Survey Staff. 1994. Keys to Soil Taxonomy, Sixth Edition. USDA, Soil Conservation Service,
Washington, D.C.
Soil Conservation Service. 1981. Land Resource Regions and Major Land Resource Areas of the United
States. USDA-SCS Agricultural Handbook 296. U.S. Govt. Printing Off., Washington, DC.
Soil Survey Staff. 1993a. National Soil Survey Handbook. USDA, Soil Conservation Service, U.S. Govt.
Print. Off., Washington, DC.
Soil Survey Staff. 1951. Soil.Survey Manual. USDA Agricultural Handbook 18. U.S. Govt. Print. Off.,
Washington, DC.
Soil Survey Division Staff. 1993b. Soil Survey Manual. USDA Agricultural Handbook 18. U.S. Govt. Print.
Off., Washington, DC.
Soil Survey Staff. 1975. Soil Taxonomy: A basic system of soil classification for making and interpreting soil
surveys. USDA Agricultural Handbook 436. U.S. Govt. Print. Off., Washington, DC.
-------
U. S. Dept. of Agriculture. Soil Conservation Service. 1991. Hydric Soils of the United States. Soil
Conservation Service. In Cooperation with the National Technical Committee for Hydric Soils, Washington,
DC.
Vepraskas, M. J. 1992. Redoximorphic Features for Identifying Aquic Conditions. Tech. Bulletin 301. North
Carolina Ag. Research Service, North Carolina State Univ., Raleigh, North Carolina.
-------
LAND RESOURCE REGIONS
OF THE
UNITED STATES
v « 4 * P r v * t S* T ~ " I
itt«lk*itti*««t**«*«> VW «
i § « « i i »y 11
U t t\ t * i i i i i !< fl t '
^A^ ! 11 i t t j t t i
xsl::«::!! i-j-Hj*:::::::
HESOUUCt MCCKMS *HO 4MCM
AS or Jtfoxrr
I/MO Rf SOUBCl RlOOtn (UM
-------
FIELD INDICATORS OF HYDRIC SOILS
The following list of Field Indicators of Hydric Soils are structured as follows:
1. Alpha Numeric Listing
2. Short Name
3. Applicable Land Resource Region(s) (LRRs)
4. Description of the Field Indicator
5. User Notes
For example, Al indicates the first indicator for all soils; Histosol is the short name; the indicator is for
use in all LRRs; Classifies as a Histosol, except Folists is the indicator description; and user notes are added.
Unless otherwise indicated, all mineral layers above any of the hydric soil indicators have
dominant chroma of 2 or less, or the layer(s) with dominant chroma of 3 or more are less than IS cm
(6 in.) thick. In addition, unless otherwise stated, nodules and concretions are not considered to be
redoi concentrations for the purposes of this document.
ALL SOILS
All soils refer to soils with any USDA soil texture. Use the following hydric soil indicators regardless of
texture:
Al. Histosol. For use in all LRRs except P, T, and U. Classifies as a Histosol, except Folists.
Histosol User Notes: A Histosol has 40 cm (16 in.) or more of the upper 80 cm (32 in.) as organic soil
material. Organic soil material has an organic carbon content (by weight) of 12 to 18 percent, or more,
dependent upon the clay content of the soil. These materials include muck (sapric soil material), mucky peat
(hemic soil material), or peat (fibric soil material). Use of this indicator requires the presence of aquic
conditions or artificial drainage.
A2. Histic Epipedon. For use in all LRRs except P, T, U, W, X', and Y. Presence of a Histic epipedon.
Histic Epipedon User Notes: Most histic epipedons are surface horizons 20 cm (8 in.) or more thick of organic
soil material. Aquic conditions or artificial drainage are required. See Keys to Soil Taxonomy, page 3 (Soil
Survey Staff, 1994). Slightly lower organic carbon contents are allowed in plowed soils (See Keys to Soil
Taxonomy, page 4).
-------
A3. Black His tic. For use in all LRRs except P, T, U, W, X, and Y. Presence of a surface layer of peat,
mucky peat, or muck 20 cm (8 in.) or more thick having hue 10YR or yellower and value 3 or less and
chroma 1 or hue of N.
Black Histic User Notes: Unlike Indicator A2 (above) use of this indicator does not require proof of aquic
conditions or artificial drainage.
A4. Hydrogen Sulflde. For use in all LRRs. Presence of hydrogen sulfide odor within 30 cm (12 in.) of
the surface.
Hydrogen Sulfide User Notes: This "rotten egg smell" indicates that sulfate-sulfur has been reduced and
therefore the soil is anaerobic. In most hydric soils, the presence or absence of a sulfidic odor is dependent
upon current hydrology.
AS. Stratified Layers. For use in LRRs O, P, R, T, and U. Presence of stratified layers in the upper 15
cm (6 in.). At least one layer has value 3 or less with chroma 1 or hue of N and/or it is muck, mucky
peat, peat, or mucky modified mineral texture. The remaining layers have chroma 2 or less.
Stratified Layers User Notes: The presence of stratified layers in soils that fail NTCHS hydric soil criteria and
fail anaerobic conditions are not indicative of hydric soils. Many alluvial soils have stratified layers at greater
depths; these are not hydric soils. Many alluvial soils have stratified layers at the required depths but lack
chroma 2 or less; these do not fit this indicator. Use of this indicator may require assistance from a trained;
scientist with local experience. The minimum organic carbon content of at least one layer of this indicator i
slightly less than required for Mucky Modified Mineral Texture; at least 70 percent of soil material is covered,
coated, or similarly masked with organic matter. An undisturbed sample must be observed. A hand lens is an
excellent tool to aid this decision.
A6. Organic Bodies. For use in LRRs P, T, and U. Presence of 2% or more organic bodies of muck or a
mucky modified mineral texture, approximately 1 to 3 cm (0.5 to 0.75 in.) in diameter within the upper
15 cm (6 in.) of the mineral soiL
Organic Bodies User Notes: The percent organic carbon in organic bodies is the same as in the Muck or
Mucky Texture indicators. This indicator includes the indicator previously named "accretions" (Florida Soil
Survey Staff, 1992). Many organic bodies lack the required amount of organic carbon and are not indicative
of hydric soils. The content of organic carbon should be known before this indicator is used. Muck or mucky
mineral as organic bodies within hemic (mucky peat) and/or fibric (peat) soil materials qualify as this
indicator.
-------
A7. 5 cm Mucky Mineral. For use in LRRs P, T, and U. Presence of a mucky modified mineral surface
layer 5 cm (2 in.) or more thick.
5 cm Mucky Mineral User Notes: "Mucky" is a USDA texture modifier for mineral soils. The organic carbon
content, is at least 5 and ranges as high as 18 percent. The percentage requirement is dependent upon the clay
content of the soil; the higher the clay content, the higher the organic carbon requirement. An example is
mucky fine sand, which has at least 5 percent organic carbon but not more than about 12 percent organic
carbon. Another example is mucky sandy loam, which has at least 7 percent organic carbon but not more than
about 14 percent organic carbon. See glossary for definition of mucky modified mineral texture.
AS. Muck Presence. For use in LRRs V and V. Presence of a surface layer of muck with value 3 or less
and chroma 1 or hue of N.
Muck Presence User Notes: Muck is sapric soil material with at least 12 to 18 percent organic carbon.
Organic soil material is called muck (sapric soil material) if virtually all of the material has undergone
sufficient decomposition to limit recognition of the plant parts. Hemic (mucky peat) and fibric (peat) soil
materials do not qualify. To determine if muck is present, first remove loose leaves, needles, bark, and other
easily identified plant remains. This is sometimes called a leaf/root mat. Then, examine for decomposed
organic soil material. Generally muck is black and has a "greasy" feel, sand grains should not be evident. The
presence of a leaf or root mat is not indicative of hydric soils or upland soils; it indicates that the vegetation
present produces a large amount of biomass. Hydric soil indicator determinations are made below the leaf or
root mat; however, root mats that meet the definition of hemic or fibric soil material are included in the
decision making process for Mucky Peat, Peat, Organic Bodies, or Histic Indicators. See glossary for
definition of muck.
A9. 1 cm Muck. For use in LRRs D, F, G, H, P, and T. Presence of a surface layer of muck 1 cm
(0.5 in.) or more thick with value 3 or less and chroma 1 or hue of N.
1 cm Muck User Notes: Muck is sapric soil material with at least 12 to 18 percent organic carbon. Organic
soil material is called muck (sapric soil material) if virtually all of the material has undergone sufficient
decomposition to limit recognition of the plant parts. Hemic (mucky peat) and fibric (peat) soil materials do
not qualify. To determine if muck is present, first remove loose leaves, needles, bark, and other easily
identified plant remains. This is sometimes called a leaf/root mat Then, examine for decomposed organic
soil material. Generally muck is black and has a "greasy" feel, sand grains should not be evident. The
presence.of a leaf or root mat is not indicative of hydric soils or upland soils; it indicates that the vegetation
present produces a large amount of biomass. Hydric soil indicator determinations are made below the leaf or
root mat; however, root mats that meet the definition of hemic or fibric soil material are included in the
decision making process for Mucky Peat, Peat, Organic Bodies, or Histic Indicators. See glossary for
definition of muck.
10
-------
A10. 2 cm Muck. For use in LRR M. Presence of a surface layer of muck 2 cm (0.75 in.) or more thick
with value 3 or less and chroma 1 or hue of N.
2 cm Muck User Notes: Muck is sapric soil material with at least 12 to 18 percent organic carbon. Organic
soil material is called muck (sapric soil material) if virtually all of the material has undergone sufficient
decomposition to limit recognition of the plant parts. Hemic (mucky peat) and fibric (peat) soil materials do
not qualify. To determine if muck is present, first remove loose leaves, needles, bark, and other easily
identified plant remains. This is sometimes called a leaf/root mat. Then, examine for decomposed organic
soil material. Generally muck is black and has a "greasy" feel, sand grains should not be evident. The
presence of a leaf or root mat is not indicative of hydric soils or upland soils; it indicates that the vegetation
present produces a large amount of biomass. Hydric soil indicator determinations are made below the leaf or
root mat; however, root mats that meet the definition of hemic or fibric soil material are included in the
decision making process for Mucky Peat, Peat, Organic Bodies, or Histic Indicators. See glossary for
definition of muck.
-------
SANDY SOILS
Sandy soils refer to those soils with a USDA texture of loamy fine sand and coarser. Use the following
sandy hydric soil indicators if all layers are sandy to a depth of 25 cm (10 in.):
SI. Sandy Mucky Mineral For use in all LRRs except P, T, U, W, X, and Y. Presence of a mucky
modified mineral surface layer 5 cm (2 in.) or more thick.
Sandy Mucky Mineral User Notes: "Mucky" is a USDA texture modifier for mineral soils. The organic
carbon content is at least 5 and ranges as high as 14 percent The percentage requirement is dependent upon
'the clay content of the soil; the higher the clay content, the higher the organic carbon requirement. An
example is mucky fine sand, which has at least 5 percent organic carbon but not more than about 12 percent
organic carbon. In sandy soils a quick field test for mucky is: place one unbroken ped of soil between thumb
and ringers; rub twice only, if you can neither see or feel sand grains it is likely mucky. See glossary for
definition of mucky modified mineral texture.
S2. 3 cm Mucky Peat or Peat For use in LRRs GandH. Presence of a surface layer of mucky peat or
peat 3 cm (1 in.) or more thick with value 4 or less and chroma 3 or less.
3 cm Mucky Peat and Peat User Notes: Mucky peat (hernic soil material) and peat (fibric soil material) have
at least 12 to 18 percent organic carbon. Organic soil material is called peat if virtually all of the plant remains
are sufficiently intact to permit identification of plant remains. Mucky peat is an intermediate stage of
decomposition between peat and highly decomposed muck. To determine if mucky peat and/or peat are
present, first remove loose leaves, needles, bark, and other easily identified plant remains. This is sometimes
called a leaf/root mat. Then, examine for undecomposed to partly decomposed organic soil material. The
presence of a leaf or root mat is not indicative of hydric soils or upland soils; it indicates that the vegetation
present produces a large amount of biomass. See glossary for definition of mucky peat and peat.
S3. 5 cm Mucky Peat or Peat For use in LRRs F and M. Presence of a surface layer of mucky peat or
peat 5 cm (2 in.) or more thick with value 3 or less and chroma of 2 or less.
5 cm Mucky Peat and Peat User Notes: Mucky peat (hemic soil material) and peat (fibric soil material) have
at least 12 to 18 percent organic carbon. Organic soil material is called peat if virtually all of the plant remains
are sufficiently intact to permit identification of plant remains. Mucky peat is an intermediate stage of
decomposition between peat and highly decomposed muck. To determine if mucky peat and/or peat are
present, first remove loose leaves, needles, bark, and other easily identified plant remains. This is sometimes
called a leaf/root mat 'Then, examine for undecomposed to partly decomposed organic soil material. The
presence of a leaf or root mat is not indicative of hydric soils or upland soils; it indicates that the vegetation
present produces a large amount of biomass. See glossary for definition of mucky peat and peat.
12
-------
S4. Sandy Gleyed Matrix. For use in all LRXs except tV, X, and Y. Presence of a gleyed matrix within
15 cm (6 in.) of the soil surface.
Sandy Gleyed Matrix User Notes: Gley colors are not synonymous with gray colors. Gley colors are those
colors that are found on the gley page (Kollmorgen Instruments Corporation, 1994). They have hue 5GY,
10GY, 5G, 10G, 5BG, 10BG, 5B, 10B, or 5BP; or hue is neutral (N) with value 4 or more. The gleyed matrix
only has to be present within 15 cm of the surface. Soils with gleyed matrices are saturated for significant
duration; this is why no thickness of the layer is required. See glossary for definition of gleyed matrix.
S5. Sandy Redox. For use in allLRRs except V, W, X, and Y. Presence of a layer with an upper
boundary within 15 cm (6 in.) of the soil surface that is at least 10 cm (4 in.) thick and has a matrix'
chroma 3 or less with 2% or more distinct or prominent redox concentrations as soft masses and/or
pore linings.
Sandy Redox User Notes: Distinct and prominent are defined in National Soil Survey Handbook (Soil Survey
Staff, 1993a). Redox concentrations include iron and manganese masses (reddish mottles) and pore linings
(Vepraskas, 1992). Included within this concept as redox concentrations are iron/manganese bodies as soft
masses with diffuse boundaries. The iron/manganese masses are 2 to 5 mm in size and have a value of 3 or
less and a chroma of 3 or less; most commonly they are black. Iron/manganese masses should not be confused
with the larger and redder iron nodules (Soil Survey Staff, 1993a) associated with plinthitic soils or relic
concretions. Common to many redox concentrations (Soil Survey Staff, 1993b) are required.
S6. Stripped Matrix. For use in att LRRs except V, W, X, and Y. Presence of a layer within 15 cm (6 i ,
of the surface in which iron/manganese oxides and organic matter have been stripped from the matrix
exposing the primary base color of soil materials. The translocated oxides and organic matter forms a
diffuse splotchy pattern of two or more colors. The stripped zones are 10% or more of the volume,
rounded, and 1 to 3 cm (0.5 to 1 in.) in diameter.
Stripped Matrix User Notes: This indicator includes the indicator previously named "polychromatic matrix"
(Florida Soil Survey Staff, 1992) as well as the undefined term "streaking". Common to many (Soil Survey
Staff, 1993b) areas of stripped (uncoated) soil materials 1 to 3 cm 1(0.5 to I in.) in size is a requirement.
Commonly the splotches of color have value 5 or more and chroma 1 and/or 2 (stripped) and chroma 3 and/or
4 (unstripped). The matrix may lack the 3 and/or 4 chroma material. The mobilization and translocation of
the oxides and/or organic matter is the important process and should result in splotchy coated and uncoated
soil areas.
-------
S7. Dark Surface. For use in LRRs N, P, R, 5, T, U, and V. Presence of surface layer 10 cm (4 in.) or
more thick with matrix value 3 or less and chroma 1 or less. At least 70% of the visible soil particles
must be covered, to represent the matrix color, this is determined on individual soil particles covered or
masked with organic material. The matrix color of the layer immediately below the dark surface must
have value 4 or more and chroma 2 or less.
Dark Surface User Notes: The organic carbon content of this indicator is slightly less than required for
"mucky". At least seventy percent of the soil material is covered, coated, or similarly masked with organic
matter. An undisturbed sample must be observed. A hand lens is an excellent tool to help aid this decision.
Many wet soils have a ratio of about SO percent soil particles, which are covered or coated with organic matter,
and about SO percent uncoated or uncovered soil particles, giving the soil a salt and pepper appearance. This
SO/SO ratio is not a hydric indicator.
SC. Alaska Gleyed. For use in LRRs W, X, and Y. Dominant hue of 5GY, 10GY, SG, 10G, 5BG, 10BG,
SB, 10B, or 5BP; or hue is neutral (N) with value 4 or more in the matrix within 30 cm (12 in.) of the
mineral surface, and underlain by hue of SY or redder in the same type of parent material.
Alaska Gleyed User Notes: Gley colors are not synonymous with gray colors. Gley colors are those colors
that are found on the gley page (Kollmorgen Instruments Corporation, 1994). They have hue 5GY, 10GY, 5G,
10G, SBG, 10BG, SB, 10B, or SBP; or hue is neutral (N) with value 4 or more. Color comparison to
underlying material must be based on material of the same type or lithology.
S9. Sandy Gray Surface. For use in LRRs R andS. Presence of a surface layer with value 3 or less and
chroma 1 or less immediately underlain by a layer(s) with value 4 or less and chroma 1 or less to a depth
of 30 cm (12 in.) or to the spodic horizon, which ever is less. At least 70% of the visible soil particles in
the surface layer must be covered to represent the matrix color, this is determined on individual soil
particles covered, coated, or masked with organic material
Thin Dark Surface User Notes: This indicator describes soils with a very dark gray or black surface less than
10 cm (4 in.) thick, where organic matter has been evenly incorporated into the underlying eluvial (E) horizon.
The chroma of 1 or less is critical because it limits application of this indicator to only those soils which are
depleted of iron. This indicator commonly occurs in hydric Spodosols; however, the identification of a spodic
horizon is not required.
14
-------
S10. Polyvalue Organic Concentrations. For use in LRRs R and S. Presence of a surface layer with
value 3 or less and chroma 1 or less, underlain by a layer where translocated organic matter unevenlv
covers the soil material forming a diffuse splotchy pattern. At least 70% of the visible soil particles
the surface layer must be covered to represent the matrix color, this is determined on individual soi.
particles covered, coated, or masked with organic material. The organic coating occupies 5% or more
of the soil volume with value 3 or less and chroma 1 or less, and the remainder of the soil volume has
chroma 1 or less.
Polyvalue Organic Concentrations User Notes: This indicator describes soils with a very dark gray or black
surface layer less than 10 cm (4 in.) thick where organic matter has been preferentially carried downward by
flowing water into the eluvial (E) horizon. It may also cover the anaerobic decay of roots previously growing
in the E horizon. The preferential flow creates a splotchy pattern that is sometimes referred to as "streaking".
The indicator keys on vertical striations as well as a coarse diffuse pattern similar to redox concentrations in
sands except the whole color sequence is in shades of black and gray without any brown. The chroma of 1 or
le ;s is critical because it limits application of this indicator to only those soils which are depleted of iron.
Because the chroma is at the lower limit, 1 or less, the splotchy pattern refers only to changes in value. The
uneven distribution of organic matter may also be referred to as polyvalue.
-------
LOAMY AND CLAYEY SOILS
Loamy and clayey soils refer to those soils with USDA textures of loamy very fine sand and finer. Use
the following loamy and clayey hydric soil indicators if any layer is loamy or clayey within the upper 25
cm (10 in.) of the soil:
Fl. Loamy Mucky Mineral For use in all LRRs except P, T, U, V, W, X, and Y. Presence of a mucky
modified mineral surface layer 10 cm (4 in.) or more thick.
Loamy Mucky Mineral User Notes: "Mucky" is a USDA texture modifier for mineral soils (Soil Survey Staff,
1951,1993a, and 1993b). The organic carbon is at least 8 percent but can range up to 18 percent. The
percentage requirement is dependent upon the clay content of the soil; the higher the clay content, the higher
the organic carbon requirement. An example is mucky sandy loam, which has at least 7 percent organic
carbon but not more than about 14 percent organic carbon. See glossary for definition of mucky modified
mineral textur\
F2. Loamy Gleyed Matrix. For use in all LRRs except W, X, and Y. Presence of a gleyed matrix which
occupies 60% or more of a layer within 30 em (12 in.) of the surface.
Loamy Gleyed Matrix User Notes: Gley colors are not synonymous with gray colors. Gley colors are those
colors that are found on the gley pages (Kollmorgen Instruments Corporation, 1994). They have hue SGY,
10GY, 5G, 10G, 5BG, 10BG, SB, 10B, or SBP; or hue is neutral (N) with value 4 or more. The gleyed matrix
only has to be present within 30 cm (12 in.) of the surface. Soils with gleyed matrices are saturated for
significant duration, this is why no thickness of the layer is required. See glossary for definition of gleyed
matrix.
F3. Depleted Matrix. For use in all LRRs except W, X, and Y. Presence of a layer at least 15 cm (6 in.)
thick with 60% or more depleted matrix starting within 25 cm (10 in.) of the surface.
Depleted Matrix User Notes: Redox concentrations include iron and manganese masses (reddish mottles)
and/or pore linings. The low chroma matrix must be due to wetness and not a relict or parent material feature.
See glossary for definition of depleted matrix.
F4. Depleted Below Dark Surface. For use In all LRRs except P, T, U, W, X, and Y. Presence of a layer
at least 15 cm (6 in.) thick with 60% or more depleted matrix starting within 30 cm (12 in.) of the
surface. The layer(s) above the depleted matrix have value 3 or less and chroma 2 or less.
Depleted Below Dark Surface User Notes: This indicator often occurs in Mollisols but also applies to soils
with Umbric epipedons and dark colored Ochric epipedons. This indicator is most often associated with soils
in depressional landscape positions. For soils with dark colored epipedons greater than 30 cm (12 in.) thick
use Indicator FS.
16
-------
F5. Thick Dark Surface. For use in allLRRs except P, T, U, W, X, and Y. Presence of a layer at least 15
cm (6 in.) thick with 60% or more depleted or gleyed matrix starting below 30 cm (12 in.) of the surfacj
The layer(s) above the depleted or gleyed matrix have hue N and value 3 or less to a depth of 30 cm (
in.) and value 3 or less and chroma 1 or hue of N in the remainder of the epipedon.
Thick Dark Surface User Notes: The soil has a black or very dark gray surface layer 30 cm (12 in.) or more
thick. The dark colored subsoil has value of 3 or less, chroma 1 or hue of N. Below the dark colored epipedon
is a depleted matrix or gleyed matrix. This indicator is most often associated with overthickened soils in
concave landscape positions.
F6. Redox Dark Surface. For use in allLRRs except P, T, U, W, X, and Y. Presence of a layer at least 10
cm (4 in.) thick entirely within the upper 30 cm (12 in.) of the mineral soil that has:
a. matrix value 3 or less and chrama 1 or less and 2.% or more distinct or prominent redox
concentrations as soft masses or pore linings, or
b. matrix value 3 or less and chroma 2 or less and 5% or more distinct or prominent redox
concentrations as soft masses or pore linings.
Redox Dark Surface User Notes: Redox concentrations in high organic matter mineral soils with dark surfaces
are often difficult to see. The organic matter "masks" some or all of the concentrations that may be present.
Careful examination is required in order to see what are often brownish "mottles" in the darkened materials.
In some instances, drying of the samples makes the concentrations (if present) easier to see. Dried colors, if
used, need to have matrix chromas of 1 or 2 and the redox concentrations need to be distinct or prominent.
soils which are wet due to a subsurface water table, the layer immediately below the dark epipedon should
have a depleted or gleyed matrix. Soils which are wet due to ponding or shallow perched water tables may noi
always have a depleted/gieyed matrix below the dark surface. It is recommended to evaluate the hydrologic
source and to examine and describe the layer below the dark colored epipedon when applying this indicator.
F7. Depleted Dark Surface. For use in all LRRs except P, T, U, W, X, and Y. Presence of redox
depletions, with value 5 or more and chroma 2 or less or hue of N, in a layer at least 10 cm (4 in.) thick
entirely within the upper 30 cm (12 in.) of the mineral soil that has:
a. matrix value 3 or less and chroma 1 or hue of N and* 10% or more redox depletions, or
b. matrix value 3 or less and chroma 2 or less and 20% or more redox depletions.
Depleted Dark Surface User Notes: Care should be taken not to mistake mixing of an E or calcic horizon into
the surface layer as depletions. The "pieces" of E and calcic horizons are not redox depletions. Knowledge of
local conditions is required in areas where E and/or calcic horizons may be present. In soils which are wet due
to a subsurface water table, the layer immediately below the dark surface should have a depleted or gleyed
matrix.
-------
F8. Redox Depressions. For use in all LRRs except P, R, T, U, W, X, and Y. In closed depressions
subject to ponding, 5% or more distinct or prominent redox concentrations as soft masses or pore
linings in a layer 5 cm (2 in.) or more thick within the upper 15 cm (6 in.).
Redox Depressions User Notes: Most often soils pond water because of two reasons: they occur in landscape
positions that collect water and/or they have a restrictive layers) that prevent water from moving downward
through the soil. For these landscape positions there is no restriction on matrix value and chroma.
F9. Vernal Pools. For use in LRRs C and D. In closed depressions subject to ponding, presence of a
depleted matrix in a layer 5 cm (2 in.) thick within the upper 15 cm (6 in.).
Vernal Pools User Notes: Most often soils pond water because of two reasons: they occur in landscape
positions that collect water and/or they have a restrictive layers) that prevent water from moving downward
through the soil.
F10. Mart. For use in LRR U. A surface texture of mart.
Marl User Notes: Marl is a limnic material deposited in water by precipitation of algae as defined in Soil
Taxonomy (Soil Survey Staff. 1975 and 1994). Marl is not carbonatic substrate material associated with
limestone bedrock.
Fl 1. Depleted Ochric. For use In LRR O. Presence of a layers) 10 cm (4 in.) or more thick that has
60% or more of the matrix with value 4 or more and chroma 1 or less. The layer is entirely within the
upper 25 cm (10 in.).
Depleted Ochric User Notes: This indicator is most applicable on backswamps, meander troughs, and oxbows
of the Mississippi River Delta.
F12. Iron/Manganese Masses. For use in LRRs P and T. On floodplains, a layer 10 cm (4 in.) or more
thick with a 40% or more depleted matrix and 2% or more distinct or prominent redox concentrations
as soft iron/manganese masses with diffuse boundaries. The layer occurs entirely within 30 cm (12 in.)
of the surface. Iron/manganese masses have value 3 or less and chroma 3 or less; most commonly they
are black. The thickness requirement is waived if the layer is the mineral surface layer.
Iron/Manganese Masses User Notes: Iron/ manganese masses most commonly are near the soil surface and
within the upper 15 cm (6 in.) of the soil. They are 2 to 5 mm in size and have a value 3 or less and a chroma
3 or less; most commonly they are black. The low chroma must be due to wetness and not a relict or parent
material feature. Iron/manganese masses should not be confused with the larger and redder iron nodules (Soil
Survey Staff, 1993a) associated with plinthitic soils or with concretions that,have abrupt boundaries in the
region. This indicator occurs on floodplains of rivers such as the Apalachicola, Congaree, Mobile, and
Savannah Rivers.
18
-------
F13. Umbric Surface. For use in LRRs P and T. On concave positions of Intel-stream divides; and in
depressions, a surface layer 15 cm (6 in.) or more thick with value of 3 or less and chroma of 1 or hu* of
N immediately underlain by a layer 10 cm (4 in.) or more thick with chroma of 2 or less.
Umbric Surface User Notes: Thickness requirements are slightly less that those required by an umbric
epipedon. Other requirements are the same. Umbric surfaces on higher landscape positions, such as
Umbrepts, are excluded.
F14. Hawaii Gleyed. For use in LRR V. Presence of a layer within 30 cm (12 in.) of the surface that has
dominate hue N, 10Y, 5GY, 10GY, 5G, 10G, 5BG, 10BG, SB, 10B, or 5PB.
Hawaii Gleyed User Notes: Gley colors are not synonymous with gray colors. Gley colors are those colors
that are found on the gley page (Kollmorgen Instruments Corporation, 1994). They have hue 10Y, SGY,
10GY, 5G, 10G, 5BG, 10BG, SB, 10B, or 5PB; or h»«e is neutral (N) with value 4 or more.
F15. Alaska Redoi Gleyed. For use in LRRs Wt X, and Y. Presence of a layer that has dominant matrix
hue of 5Y with chroma 3 or less, or hues of 10Y, SGY, 10GY, 5G, 10G, 5BG, 10BG, 5B, 10B, 5PB, or N
with 10% or more redoi concentrations as pore linings with value and chroma of 4 or more. The layer
occurs within 30 cm (12 in.) of the soil surface.
Alaska Redox Gleyed User Notes: Presence of 10 percent redox concentrations as pore linings in a
dominantly gieyed matrix is required. Gleyed colors have hue of 10Y, SGY, 10GY, 5G, 10G, 5BG, 1 OB«
SB, 10B 5PB, or N with 10% or mote redox concentrations. Pore linings must have value and chroma of . _.
more.
F16. Alaska Depleted Macropores. For use in LRRs W, X, and Y. Presence of a layer that has dominant
hue of 2.5 Y or redder and chroma 2 or less with 10% redoi depletions with hue of 5Y SGY, SG, 5BG,
SB, or N with value 4 or more and chroma 1 or less that occur along non-living root channels. The layer
occurs within 30 cm (12 in.) of the surface.
Alaska Depleted Macropores User Notes: Presence of 10 percent redox depletions with low chroma in a low
chroma matrix is required.
F17. Alaska Gleyed Pores. Far use in LRRs W, X, and Y. Presence of 10% hue of SGY, IOGY, 5G, 10G,
SBG, 10BG, SB, 10B, 5PB, or N with value 4 or more in the matrix or along non-living root channels
within 30 cm (12 in.) of the surface. The matrix has dominant chroma of 2 or less.
Alaska Gleyed Pores User Notes: Presence of 10 percent gieyed root channels or within the matrix in a low
chroma matrix are required.
-------
F18. High Plains Depressions. For use in MLRA 's 72 and 73 ofLRR H. In closed depressions subject to
ponding, the presence of a layer at least 10 cm (4 in.) thick within the upper 35 cm (13.5 in.) of the
mineral soil that has chroma of 1 or hue of N and:
a. 1% or more redoz concentrations as nodules or concretions, or
b. redoz concentrations as nodules or concretions with distinct or prominent halos.
High Plains Depressions User Notes: This indicator is for closed depressions (FSA "playas") in western
Kansas, southwestern Nebraska, eastern Colorado, and southeastern Wyoming. It occurs in soils such as the
Ness and Pleasant series. The matrix color of the 10 cm (4 in.) layer must be a chroma of 1 or less, chroma 2
matrix colors are excluded; value is usually 3. The nodules/concretions are rounded, hard to very hard, range
in size from < 1 mm to 3 mm, and most commonly are black or reddish black. The halos usually are reddish
brown, strong brown, or yellowish brown. The nodules/concretions can be removed from the soil and the
halos will occur as coatings on the concentration or will remain attached to the soil matrix. Use of 1 OX to 15X
magnification aids in the identification of these features.
20
-------
TEST INDICATORS OF HYDRIC SOILS
The indicators listed above should be tested for use in LRRs other than those listed. Other indicators for
testing are listed below. Please note that some of the indicators below have been approved for use in certai
Major Land Resource Regions (MLRA's) of a certain LRRs. They are listed as Test Indicators due to their
limited use extent and'because of the urgent need for testing in other areas.
ALL SOILS
TAl. Natric Horizon. For testing in LRR D. Presence of a natric horizon within 30 cm (12 in.) of the
surface with value 5 or more and chroma 2 or less at least IS cm (6 in.) thick.
TA2. Playa Rim Stratified Layers. For testing in LRR D.. Presence of stratified layers in the upper IS cm
(6 in.). At least one layer has value 3 or less and chroma 1 or it has value 2 or more and chroma 2 or less with
2% or more distinct or prominent redox concentrations as soft masses or pore linings. The upper IS cm (6 in.)
has dominant chroma 2 or less.
Playa Rim Stratified Layers User Notes. This indicator is for the playas of the western United States. Unlike
the national Stratified Layer Indicator (AS), this indicator does not require continuous chroma 2 or less. Thin
layers of chroma 3 or higher may occur as long as the upper IS cm (6 in.) is dominantly chroma 2 or less. A
minimum amount of organic carbon is not required. A layer with redox concentrations is substitutional for the
dark layer. As inferred, this indicator occurs on vegetated rims adjacent to the non-vegetated playas.
A dominant vegetative species is Allenrolfea nccidentalis.
TA3. Stratified Layers. For testing in LRRs F, K, L, M, N, S, and V. Presence of stratified layers in the
upper 1S cm (6 in.). At least one layer has value 3 or less with chroma 1 or hue of N and/or it is muck, mucky
peat, peat, or mucky modified mineral texture. The remaining layers have chroma 2 or less.
Stratified Layers User Notes: The presence of stratified mineral and/or organic layers in soils that fail NTCHS
hydric soil criteria and fail anaerobic conditions are not indicative of hydric soils. Many alluvial soils have
stratified layers at greater depths; these are not hydric soils. Many alluvial soils have stratified layers at the
required depths but lack chroma 2 or less; these do not fit this indicator. Use of this indicator may require
assistance from a trained soil scientist with local experience. The percent organic carbon in one or more layers
is at least 1 percent. The minimum organic carbon content of at least one layer of this indicator is slightly less
than required for Mucky Modified Mineral Texture; at least 70 percent of soil material is covered, coated, or
similarly masked with organic matter. An undisturbed sample must be observed. A hand lens is an excellent
tool to aid this decision.
-------
SANDY SOILS
TSl. Iron Staining. For testing in LRRs W, X, Y. Presence of continuous zone, 3 cm (1.2 in.)or more thick,
of iron staining with value 4 or more and chroma 6 or more within 15 cm (6 in.) of the mineral surface. The
zone is immediately below a horizon in which iron/manganese oxides have been removed from the matrix
exposing the primary base color of the silt and sand grains.
TS2. ? cm Muck. For testing in LRRs K. L Presence of a surface layer of Muck ? cm thick with value 3 or
less and chroma 1 or hue of N.
TS3. Thick Sandy Dark Surface. For testing in LRR F. Presence of a layer at least 15 cm (6 in.) thick with
60% or more depleted or gleyed matrix starting below 30 cm (12 in.) of the surface. The layers) above the
depleted or gleyed matrix have hue N and value 3 or less; or hue 10YR or yellower with value 2 or less and
chroma 1 to a depth of 30 cm (12 in.) and chroma 1 or less in the remainder of the epipedon.
TS4. Dark Surface 2. For testing in LRR O. Presence of a surface layer 10 cm (4 in.) or more thick with
matrix value 2 or less and chroma 1 or hue of N. At least 70% of the soil materials are covered, coated, or
masked with organic matter. The matrix color of the layer immediately below the dark surface must have
value 4 or more and chroma 2 or less.
TS5. Thin Dark Surface. For testing in LRRs K and L. Presence of a surface layer with value 3 or less and
chroma 1 or hue of N immediately underlain by a layers) with value 4 or less and chroma 1 or hue of N to a
depth of 30 cm (12 in.) or to the spodic horizon, whichever is less. At least 70% of the visible soil particles in
the surface layer must be covered to represent the matrix color, this is determined on individual soil particles
covered, coated, or masked with organic material.
22
-------
LOAMY AND CLAYEY SOILS
TFl. ? cm Muck. For testing in LRRs K, I. Presence of a surface layer of muck ? cm thick with value of 3
or less and chroma 1 or hue of N.
TF2. ? cm Mucky Peat or Peat For testing in LRRs F, G. H, andM Presence of a surface layer of mucky
peat or peat ? cm thick with value 4 or less and chroma 3 or less.
TF3. Red Parent Material For testing in LRR's G, H, K, L, R, S. Presence of a layer at least 10 cm (4 in.)
thick with a matrix hue 7.5YR or redder with chroma 3 or less and 2% or more redox depletions and/or redox
concentrations as soft masses and/or pore linings. The layer is entirely within 30 cm (12 in.) of the surface.
TF4. Alaska Concretions. For testing inW,X,Y. Within 30 cm (12 in.) of the mineral surface, presence 01
redox concentrations as nodules or concretions greater than 2 mm in diameter that occupy more than
approximately 2 percent of the soil volume in a layer 10 cm (4 in.) or more thick with a matrix chroma of 2 or
less.
TF5. 2.5Y/5Y Below Dark Surface. For testing in LRRs F and M. Presence of a layer at least 15 cm (6 in.)
thick with 60% qr more hue 2.5 Y or yellower, value 4 or more and chroma 1; or hue 5Y or yellower value 4
or more and chroma 2 or less starting within 30 cm (12 in.) of the surface. The layers) above the 2.5Y/5 Y
layer have value of 3 or less and chroma 2 or less.
2.5Y/5Y Below Dark Surface User Notes: Further testing is required to investigate whether these colors
below a Mollic are indicative of wetness.
TF6. 2.5Y/5Y Below Thick Dark Surface. For testing in LRRs F and M. Presence of a layer at least 15cm
(6 in.) thick with 60% or more hue 2.5 Y or yellower, value 4 or more and chroma 1; or hue 5Y or yellower
value 4 or more and chroma 2 or less starting below 30 cm (12 in.) qf the surface. The layers) above the
2.5Y/5 Y layer have hue N and value 3 or less; or have hue 10YR or yellower with value 2 or less and chroma
1 or hue of N to a depth of 30 cm (12 in.) and value 3 or less and chroma 1 or hue of N in the remaining of the
epipedon.
-------
lakic Dark Surface. For testing in LRRs F. G, and M. A layer with an accumulation of ca'cium
:te (CaCOj), or calcium carbonate equivalent, occurs within 40 cm (16 in.) of the surface. It is overlain
jy a Iayer(s) with value 3 or less and chroma 1 or hue of N. The layer of CaCOj accumulation is underlain by
a layer within 75 cm (30 in.) of the surface 15 cm (6 in.) or more thick having 60% or more by volume one or
more of the following:
a. depleted matrix, or
b. gteyed matrix, or
c. hue 2.5Y or yellower value 4 and chroma of I.
Calcic Dark Surface User Notes: This indicator is the Soil Taxonomy criteria that separates Aerie
Calciaquolls from Typic Calciaquolls, with an additional criteria of black or very dark gray surface layers. In
the Midwest, the hydric/nonhydric boundary has generally been accepted as the "line" between Aerie and
Typic Calciaquolls. Further documentation is needed to determine if all Typic Calciaquolls are hydric.
TF8. Thick Dark Surface 2/1. For testing in all LRSs except LRJts O, P. T, AND U. Presence of a layer at
least 15 cm (6 in.) thick with 60% or more depleted or gleyed matrix starting below 30 cm (12 in.) of the
surface. The layer(s) above the depleted or gleyed matrix have hue IOYR or yellower, value 2.5 or less and
chroma 1 to a depth of 30 cm (12 in.) and value 3 or less and chroma 1 or hue of N in the remainder of die
epipedon.
ck Dark Surface 2/1 User Notes: The soil has a black surface layer 30 cm (12 in.) or more thick. The dark
jred subsoil has value of 3 or less, chroma 1. Below the mollic (urabric) epipedon is a depleted matrix or
gleyed matrix. This indicator is most often associated with overtbickened soils in concave landscape
positions. Further testing is needed to determine if cumulic soils with surface hues of IOYR or yellower are
hydric. Testing notes need to indicate what landscape positions this indicator "fails". It may be necessary to
limit the use of this indicator to concave landscapes.
24
-------
TF9. Redoxed Spring Seeps. For testing in LRR D. Presence of a layer with value 2 or less and chroma 2 or
more with 2 percent or more distinct or prominent redox concentrations as soft masses or pore linings. The
layer is at least 5 cm (2 in.) thick and is within the upper 15 cm (6 in.) of the mineral soil.
Redoxed Spring Seeps User Notes: This indicator is similar to Indicator F9 (Vernal Pools), however, in order
to more fully correlate hydric soils to wetland vegetation, values 1 and 2 and chroma 2 and 3 are included in
this indicator as well as the redox concentrations portions of the depleted matrix concept. This indicator is not
unique to depressional landscapes; therefore, that requirement is dropped. As inferred, this indicator occurs in
seeps and flow-through areas adjacent to springs and up-slope end of drainageways as well as depressional
seeps surrounded by uplands. A dominant vegetative species is Phragmities austral is.
TF10. Depleted Below Dark Surface. For testing in LRRs W, X. and Y. Presence of a layer at least IS cm
(6 in.) thick with 60% or more depleted matrix starting within 30 cm (12 in.) of the surface. The layers)
above the depleted matrix have value 3 or less and chroma 2 or less.
Depleted Below Dark Surface User Notes: This indicator also applies to soils with urnbric epipedons. This
indicator is most often associated with soils in slightly concave to concave landscape positions. For soils with
dark colored epipedons greater than 30 cm (12 in.) thick use Indicator FS.
TF11. Thick Dark Surface. For testing in LRRs W,X,andY. Presence of a layer at least 15 cm (6 in.) thick
with 60% or more depleted or gleyed matrix starting below 30 cm (12 in.) of the surface. The layers) above
the depleted or gleyed matrix have hue N and value 3 or less to a depth of 30 cm (12 in.) and value 3 or less
and chroma 1 or hue of N in the remainder of the epipedon.
Thick Dark Surface User Notes: The soil has a black surface layer 30 cm (12 in.) or more thick. The dark
colored subsoil has value of 3 or less, chroma 1 or hue of N. Below the dark surface epipedon-is a depleted
matrix or gleyed matrix. This indicator is most often associated with overthickened soils in concave landscape
positions.
-------
'F12. Redo* Dark Surface. For testing in LRRs W,X,andY. Presence of a layer at least 10 cm (4 in.) thick
[itirely within the upper 30 cm (12 in.) of the mineral soil that has:
a. matrix value 3 or less and chroma 1 or hue of N and 2% or more distinct or prominent redox
concentrations as soft masses or pore linings, or
b. matrix value 3 or less and chroma 2 or hue of N and 5% or more distinct or prominent redox
concentrations as soft masses or pore linings.
Redox Dark Surface User Notes: Redox concentrations in high organic matter mineral soils with dark surfaces
are often difficult to see. The organic matter "masks" some or all of the concentrations that may be present.
Careful examination is required in order to see what are often brownish "mottles" in the darkened materials.
In some instances, drying of the samples makes the concentrations (if present) easier to see. Dried colors, if
used, need to have matrix chromas of 1 or 2 and the redox concentrations need to be distinct or prominent. In
soils which are wet due to a subsurface water table, the layer immediately below the dark colored epipedon
should have a depleted or gleyed matrix. Soils which are wet due to ponding or shallow perched water tables
may not have a depleted/gleyed matrix below the dark colored surface. It is always best to consider the
hydrologic source and to examine and describe the layer below the dark colored epipedon when applying this
indicator.
TF13. Depleted Dark Surface. For testing in LRRs W, X, and Y. Presence of redox depletions, with value 5
or more and chroma 2 or hue of N, in a layer at least 10 cm (4 in.) thick entirely within the upper 30 cm (12
in.) of the mineral soil that has:
a. matrix value 3 or less and chroma 1 or hue of N and 10% or more redox depletions, or
b. matrix value- 3 or less and chroma 2 or less and 20% or more redox depletions.
Depleted Dark Surface User Notes: Care should be taken not to mistake mixing of an E or calcic horizon into
the surface layer as depletions. The "pieces" of E and calcic horizons are not redox depletions. Knowledge of
local conditions is required in areas where E and/or calcic horizons may be present.
TF14. Redox Depressions. For testing in LRRs R, W,X,andY. In closed depressions subject to ponding,
5% or more distinct or prominent redox concentrations as soft masses or pore linings in a layer 5 cm (2 in.) or
more thick within the upper 15 cm (6 in.).
Redox Depressions User Notes: Most often soils pond water because of two reasons: they occur in a
landscape positions that collect water and they have a restrictive layers) that prevent water from moving
downward through the soil. For these landscape positions there is no restriction on matrix value and chroma.
26
-------
TF15. High Plains Depressions. For use in MLRA 's 72 and 73 ofLRR H. For testing in other MLRA 's of
LRR H. In closed depressions subject to ponding, the presence of a layer at least 10 cm (4 in.) thick within the
upper 35 cm (13.5 in.) of the mineral soil that has chroma of 1 or less and:
a. 1% or more distinct or prominent redox concentrations as soft to hard iron/manganese masses, (
b. Distinct or prominent redox concentrations as nodules or concretions with distinct or
prominent halos.
High Plains Depressions User Notes: This indicator is for closed depressions (FSA "playas") in western
Kansas, southwestern Nebraska, eastern Colorado, and southeastern Wyoming. It occurs on soils such as the
Ness and Pleasant series. The matrix color of the 10 cm (4 in.) layer must be a chroma of 1 or less, chroma 2
matrix colors are excluded; value is usually 3. The nodules/concretions are rounded, hard to very hard, range
in size from < 1 mm to 3 mm, and most commonly are black or'reddish black. The halos usually are reddish
brown, strong brown, or yellowish brown. The nodules/concretions can be removed from the soil and the
halos will occur as coatings on the concentration or will remain attached to the soil matrix. Use of 1 OX to 15X
magnification aids in the identification of these features.
TF16. Delta Ochric. For testing in LRR O. Presence of a layer 10 cm (4 in.) or more thick that has 60% or
more of the matrix with value 4 or more and chroma 2 or less with no redox concentrations. This layer occurs
entirely within the upper 30 cm (12 in.) of the surface.
Delta Ochric User Notes: This indicator is applicable in accreting areas of the Mississippi River Delta.
-------
GLOSSARY
A Horizon - A mineral horizon that formed at the surface or below an 0 horizon where organic material is
accumulating.
Accreting Areas - Landscape position accumulating soil material through deposition from higher
elevations or upstream positions as opposed to loss of soil material through erosion.
Anaerobic - A condition in which molecular oxygen is virtually absent from the soil.
Aquic Conditions - Are conditions in the soil represented by one or more of the following: saturation
(endosaturation, episaturation, anthric saturation), degree of reduction, and redoximorphic features.
Calcic Horizon - An illuvial horizon in which secondary calcium carbonates, or-other carbonates have
accumulated to a significant extent.
Calcium Carbonate - Chemical formula of CaCO3. Calcium carbonate effervesces when treated
with cold dilute hydrochloric acid.
Closed Depressions - A low-lying area surrounded by higher ground with no natural outlet for surface drainag
Coated Sand Grains - Sand grains coated, covered, or masked with organic matter, silicate clay, iron,
aluminum, or some combination of these.
COE- US Army Corps of Engineers
Concave Landscapes - A landscape whose surface curves downward (depressional landform).
* Depleted Matrix A depleted matrix refers to the volume of a soil horizon or subhorizon from which iron
has been removed or transformed by processes of reduction and translocation to create colors of low chroma
and high value. A, E and calcic horizons may have low chromas and high values and may therefore be
mistaken for a depleted matrix; however, they are excluded from the concept of depleted matrix unless
common or many, distinct or prominent redox concentrations as soft masses or pore linings are present. In
some places the depleted matrix may change color upon exposure to air (reduced Matrix), this phenomena is
included in the concept of depleted matrix. The following combinations of value and chroma identify a
depleted matrix:
1. Matrix value 5 or more and chroma 1 or less with or without redox concentrations as soft masses
and/or pore linings; or
2. Matrix value 6 or more and chroma 2 or less with or without redox concentrations as soft masses
and/or pore linings; or
3. Matrix value 4 or 5 and chroma 2 and has 2% or more distinct or prominent redox concentrations
as soft masses and/or pore linings; or
4. Matrix value 4 and chroma 1 and has 2% or more distinct or prominent redox concentrations
as soft masses and/or pore linings.
28
-------
Diffuse - Changes in color occur over more than 2 mm.
'Distinct - Readily seen but contrast only moderately with the color to which they are compared. Distinct
monies commonly have the same hue as the color to which they are compared but differ by
2 to 3 units of chroma or 3 to 4 units of value; or differ to which they are compared by
2.5 units (one card) of hue but by no more than 1 unit of chroma or 2 units of value.
E Horizon - A mineral horizon in which the main feature is loss of silicate clay, iron, aluminum,
organic matter, or some combination of these, leaving a concentration of sand and silt particles.
EPA - US Environmental Protection Agency.
Epipedon - A soil horizon that has developed at the soil surface.
Fe/Mn Concretions - Firm to extremely firm ii regularly shaped bodies with diffuse boundaries and composed
mainly of iron and/or manganese compounds. When broken in half concretions have concentric layers.
Fe/Mn Nodules - Firm to extremely firm irregularly shaped bodies with diffuse boundaries and composed
mainly of iron and/or manganese compounds. When broken in half nodules have a uniform
internal fabric.
Fibric - See peat
FWS -United States Department of Interior Fish and Wildlife Service.
Glauconite - A greenish micaceous mineral.
*Gleyed Matrix - Soils with a gleyed matrix have the following combinations of hue, value, and
chroma and the soils are not glauconitic:
1. 5GY, 1OGY, 1OG, 5BG, 1OBG, 5B, 1 OB, or 5BP with value 4 or more and chroma is 1; or
2. 5G with value 4 or more and chroma is 1 or 2; or
3. N with value 4 or more.
In some places the gleyed matrix may change color upon exposure to air (reduced Matrix), this
phenomena is included in the concept of gleyed matrix.
*Hemic - See Mucky peat
Histic Epipedon - A thick (20-60 cmX8-24 in.) organic soil horizon that is saturated with water at
some period bfjthe year unless artificially drained and that is at or near the surface of a mineral soil.
Histosob - Organic soils that have organic soil materials in more than half of the upper 80 cm (32 in.),
or that are of any thickness if overlying rock or fragmental materials that have interstices
filled with organic soil materials.
-------
Horizon - A layer, approximately parallel to the surface of the soil, distinguishable from adjacent
layers by a distinctive set of properties produced by soil-forming processes.
Hydric Soil - A soil that formed under conditions of saturation, flooding, or ponding long enough
during the growing season to develop anaerobic conditions in the upper part.
Hydrogen Sulfide Odor - An odor of H2O gas similar to rotten eggs.
Hydromorphic - Features in die soil caused or farmed by water.
Lithologic Discontinuity - Occurs in a soil that has developed in more than one type of parent material.
Commonly determined by a significant change in particle-size distribution, mineralogy, etc. that
indicates a difference in material from which the horizons formed. Lithologic discontinuities are
designated in soil profile descriptions by use of an Arabic number preceding the master soil horizon
designation (ex. 2C). Soil survey manuscripts published prior to about 1980 use a roman numeral
preceding the master horizon designation to indicate lithologic discontinuities (ex. IIC).
LRR - Land Resource Region. LRRs are geographic areas characterized by a particular pattern of soils, climat
water resources, and land use. Each LRR has a different letter of the alphabet (A-Z).
Marl - An earthy, unconsolidated deposit consisting chiefly of calcium carbonate mixed with clay in
approximately equal proportions; formed primarily under fiesh water lacustrine conditions.
Masked - A covering or coating of individual silt and sand grains by organic matter.
Matrix - The dominant soil volume which is continuous in appearance and envelops microsites.
When three colors exist, such as when a matrix, depletions, and concentrations are present,
the matrix may represent less than 50 percent of the total soil volume.
MLRA - Major Land Resource Areas. MLRAs are geographically associated divisions of Land Resource
Regions.
Mollic Epipedon - A mineral surface horizon that is relatively thick, dark colored, humus rich, and
has high base saturation of more than SO percent.
Mollisols - Mineral soils that have a mollic epipedon and base saturation > 50 percent.
*Muck - A sapric organic soil material with virtually all of the organic material is decomposed not allowing
identification of plant forms. Bulk density is normally 0.2 or more; muck has
-------
Vlucky Modified Texture A USDA soil texture modifier i.e. mucky sand. Mucky modified mineral soils
with 0% clay has between 5 and 12 percent organic carbon. Mucky modified mineral soils with 60
percent clay has between 11 and 18 percent organic carbon. Soils with an intermediate amount of clay
have an intermediate amount of organic carbon.
Mucky Peat - A hemic organic material with intermediate decomposition between fibric and sapric organic
material. Bulk density is normally between 0.1 and 0.2. Mucky peat does not have fiber content (after
rubbing) or sodium pyrophosphate solution extract color requirements for either fibric or sapric soil
material.
Nodules - See Fe/Mn nodules.
NRCS - Natural Resources Conservation Service formerly Soil Conservation Service.
NTCHS - National Technical Committee forHydric Soils.
Organic Matter- Material derived from plant remains and other biologic materials.
*Peat - A fibric organic soil material with virtually all of the organic material allowing for identification
of plant forms. Bulk density is normally <0.1. Peat has 3/4 or more fibers after rubbing, or, 2/5
or more fibers after rubbing and sodium pyrophosphate solution extract color of 7/1,7/2,8/2, or 8/3.
Plinthite - Reddish brown, iron-enriched bodies that are low in organic matter and are coherent enough
to be separated readily from the surrounding soil.
Poo ding - Standing water in a closed depression which is removed only by percolation, evaporation, or
transpiration.
Pore Linings - Zones of accumulation that may be either coatings on a pore surface or impregnations
of the matrix adjacent to the pore.
"Prominent - Contrast strongly with the color to which they are compared. Prominent mottles are commonly
the most obvious color feature of the section described. Prominent mottles commonly differ from the
color to which they are compared by 5 units (two pages) of hue if chroma and value are the same;.at
least 4 units of value and/or chroma if the hue is the same; or at least 1 unit of chroma or 2 units of
value if hue differs by 2.5 units (one card).
Redox Concentrations - Bodies of apparent accumulation of Fe/Mn oxides. Redox concentrations include sof
masses, pore linings, nodules, and concretions. For the purposes of the Indicators nodules and concretio
are excluded from the concept of redox concentrations unless otherwise specified by specific indicators.
Redox Depletions - Bodies of low chroma (<2) having values of 4 or more where Fe-Mn oxides alone
have been apparently removed or where both Fe-Mn oxides and clay have been apparently removed.
-------
Redoximorphic Features - Features formed by the processes of reduction, translocation, and oxidation of
Fe and Mn oxides. Formerly called mottles and low chroma colors.
Reduced Matrix - Soil matrices that have low chroma and high value in situ, but whose color changes
in hue or chroma when exposed to air.
'Reduction - For the purpose of the indicators, reduction occurs when the redox potential (Eh) is below the
ferric/ferrous iron threshold as adjusted for pH. In hydric soils, this is the point when the transformatio
of ferric iron (Fe+++) to ferrous iron (Fe++) occurs.
Relict Features - Soil morphological features that do not reflect the current hydrologic conditions of
saturation and anaerobiosis.
*Sapric - See muck.
Saturation - When the soil water pressure is zero or positive. That is when most all the soil pores are
filled with water.
Soft Masses - Referring to redox concentrations, soft bodies, frequently within the matrix, whose
shape is variable.
SCS - Soil Conservation Service now Natural Resources Conservation Service.
Soil Texture - Is the weight proportion of the separates of mineral soil particles less than 2 mm.
Spodic Horizon - A mineral soil horizon that is characterized by the illuvial accumulation of amorphous
materials composed of aluminum and organic carbon with or without iron. The spodic horizon
has certain minimum thickness, and a minimum quantity of oxalate extractable carbon plus aluminum.
It also has specific color requirements.
Umbric Epipedon - A thick, black mineral surface horizon with base saturation of less than SO percent.
USD A - United States Department of Agriculture.
Vertisols - A mineral soil with 30 percent or more clay in the soil surface. These soils expand and shrink
depending on moisture content.
Wetland - An area that has hydrophytic vegetation, hydric soils, and wetland hydrology.
* These terms, as defined in this glossary, are either defined for the first time or they have definitions that are
slightly different from the definitions in the referenced materials. These definitions are to assist users of this
document and are not intended to add to or replace definitions in the referenced materials.
32
-------
LIST OF FIELD INDICATORS
BY
LAND RESOURCE REGION (LRR)
LRR Field Indicators
A Al, A2, A3, A4, SI, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TF8.
B Al, A2, A3, A4, SI, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TF8.
C Al, A2, A3, A4, SI, S4, S5, S6,, Fl, F2, F3, F4, F5, F6, F7, F8, F9, TF8.
D Al, A2, A3, A4, A9, SI, S4, S5, S6, FI, F2, F3, F4, F5, F6, F7, F8, F9, TA1, TA2, TF8, TF9.
E Al, A2, A3, A4, SI, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TF8.
F Al, A2, A3, A4, A9, SI, S3, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TA3, TS3, TF2. TF5, TF6,
TF7, TF8, TF9.
G Al, A2, A3, A4, A9, SI, S2, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TS4, TF2, TF3, TF7,
TF8.
H Al, A2, A3, A4, A9, SI, S2, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8., FJ8, TF2, TF3, TF5,
TF8.
I Al, A2, A3, A4, SI, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TF8.
J Al, A2, A3, A4, SI, S4, S5, S6, S10, Fl, F2, F3, F4, F5, F6, F7, F8, TF8.
K Al, A2, A3, A4, SI, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TA3, TS2, TS5, TF1, TF3, TF8.
L Al, A2, A3, A4, SI, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7; F8, TA3, TS2, TS5, TF1, TF3, TF8.
M Al, A2, A3, A4, AS, A10, SI, S3, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TA3, TF2, TF5
TF6, TF7, TF8.
N Al, A2, A3, A4, AS, SI, S4, S5, S6, S7, Fl, F2, F3, F4, F5, F6, F7, F8, TA3, TF8.
O Al, A2, A3, A4, AS, SI, S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, Fl 1, TF16.
-------
JLRR Field Indicators
P A4, A5, A6, A7, A9, S4, SS. S6, S7, F2, F3, F12, F13,
R Al, A2, A3, A4, AS, SI, S4, S5, S6, S7, S9, S10, Fl, F2, F3, F4, F5, F6, F7, TF3, TF8, TF14.
S Al, A2, A3, A4, A5, SI, S4, S5, S6, S7, S9, S10, Fl, F2, F3T F4, F5, F6, F7, F8, TA3, TF3, TF8.
T A4, A5, A6, A7, A9, S4, S5, S6, S7, F2, F3, F12, F13.
U A4, A5, A6, A7, A8, S4, S5, S6, S7, F2, F3, F5, FIO.
V Al, A2, A3, A4, A8, SI, S4, S7, F2, F3, F4, F5, F6, F7, F8, F15, TA3, TF8.
W Al, A4, S8, F14, F16, F17, TS1, TF4, TF8, TF10, TF11, TF12, TF13, TF14.
X Al, A4, S8, F14. F16. F17, TS1, TF4, TF8, TF10, TF11. TF12, TF13, TFI4.
Y Al,A4,S8,F14,F16,F17,TSl,TF4fTF8,TF10,TFll,TF12,TF13,TF14.
Z Al, A2, A3, A4, SI. S4, S5, S6, Fl, F2, F3, F4, F5, F6, F7, F8, TF8.
-------
CORRELATION OF 1987 MANUAL AND DRAFT 1995 HYDRIC SOIL INDICATORS
1987 Manual June 199S Indicator*
NON-SANDY SOILS:
a. Organic soils (Histosols)
b. Histic Epipedon
c. Sulfidic material
d. Aquic or peraquic moisture regime
e. Reducing soil conditions
f (1). Gleyed soils (gray color)
f (2). Soils with bright mottles
and/or low matrix chroma
g. Soil appearing on the hydric soils list
h. Iron and Manganese concretions
Al (Histosols)
A2 (Histic Epipedon)
A3 (Black Histic)
A4 (Hydrogen sulflde)
F2 (Loamy Gleyed Matrix)
F1S (Alaska Redox Gleyed)
F14 (Hawaii Gleyed)
Fl7 (Alaska Gleyed Pores)
F3 (Depleted Matrix)
F8 (Redox Depressions)
F9 (Vernal Pools)
Fl 1 (Depleted Ochric)
F16 (Alaska Depleted Macro-pores)
F18, TF15 (High Plains Depressions)
TAl(Natric Horizon)
TF9 (Redox Spring Seeps)
F12 (Iron/Manganese Masses)
TF4 (Alaska Concretions)
Not listed in the 1987 Manual
AS, TA3 (Stratified Layers)
A6 (Organic Bodies)
A7 (5 cm Mucky Mineral)
A8 (Muck Presence)
A9 (1cm Muck) '
A10(2cmMuck)
Fl (Loamy Mucky Mineral)
F4, TF10 (Depleted Below Dark Surface)
FS, TFl 1 (Thick Dark Surface)
F6, TF12 (Redox Dark Surface)
F7, TF13 (Depleted Dark Surface)
FlO(Marl)
Fl 3 (Umbric Surface)
TF5 (2.5Y/5Y Below Dark Surface)
TF6 (2.5Y/5Y Below Thick Dark Surface)
TF7 (Calcic Dark Surface)
TA2 (Playa Rim Stratified Layers)
TFl(?cmMuck)
TF2 (? cm Mucky Peat or Peat)
TF3 (Red Parent Material)
TF 11 (Thick Dark Surface)
-------
.Tune 199S Indicators
SANDY SOILS
a. Organic soils (Histosols)
b. Histic Epipedon
c. Sulfidic material
d. Aquic or peraquic moisture regime
e. Reducing soil conditions
f. Iron and Manganese concretions
g. High organic matter content in
the surface horizon
h. Streaking of subsurface horizons
by organic matter
i. Organic pan
j. Soils appearing on the hydric soils list
Not listed in the 1987 Manual
Al (Histosols)
A2 (Histic Epipedon)
A3 (Black Histic)
A4 (Hydrogen sulfide)
S5 (Sandy Redox)
A6 (Organic Bodies)
A7 (5 cm Mucky Mineral)
A8 (Muck Presence)
A9 (1 cm Muck)
A10 (2 cm Muck)
SI (Sandy Mucky Mineral)
S2 (3 cm Mucky Peat or Peat)
S3 (5 cm Mucky Peat or Peat)
S7 (Dark Surface)
TF5 (2.5Y/5Y Below Dark Surface)
TF6 (2.5Y/5Y Below Thick Dark Surface)
TF7 (Calcic Dark Surface)
TS2 (? cm Muck)
TS3 (Thick Sandy Dark Surface)
TS4 (Dark Surface 2)
S6 (Stripped Matrix)
S10 (Polyvalue Organic Concentrations)
S9, TS5 (Thin Dark Surface)
A5, TA3 (Stratified Layers)
S4 (Sandy Gleyed Matrix)
S8 (Alaska Gleyed)
TA1 (Natric Horizon)
TA2 (Playa Rim Stratified Layers)
TS1 (Iron Staining)
36
-------
1987 Manual
PROBLEM SOILS
Recently deposited sandy materials
Soils with thick dark A horizons
Soils with red parent material
June 1995 Indicators
A5, TA3 (Stratified Layers)
S6 (Stripped Matrix)
SIO (Polyvalue Organic Concentrations)
TA2 (Playa Rim Stratified Layers)
F4, TFIO (Depleted Below Dark Surface)
F5, TF11 (Thick Dark Surface)
F6, TF12 (Redox Dark Surface)
F7, TF13 (Depleted Dark Surface)
Fl 3 (Umbric Surface)
F18, TF1S (High Plains Depressions)
TF5 (2.5Y/5Y Below Dark Surface)
TF6 (2.5Y/5Y Below Thick Dark Surface)
TF7 (Calcic Dark Surface)
TS3 (Thick Sandy Dark Surface)
TF8 (Thick Dark Surface 2/1)
F8, TF14 (Redox Depressions)
F9 (Vernal Pools)
TS1 (Iron Staining)
TF3 (Red Parent Material)
TF9 (Redox Spring Seeps)
-------
LIST OF FIELD INDICATORS
ALL SOILS
Al Histosols
A2 Histic Epipedon
A3 Black Histic
A4 Hydrogen Sulfide
A5.TA3 Stratified Layers
A6 Organic Bodies
A7 5 cm Mucky Mineral
A8 Muck Presence
A9 1 cm Muck
A10 2 cm Muck
TA1 Natrc Horizon
TA2 Playa Rim Stratified Layers
SANDY SOILS
SI Sandy Mucky Mineral
S2 3 cm Mucky Peat or Peat
S3 5 cm Mucky Peat or Peat
S4 Sandy Gleyed Matrix
SS Sandy Redox
S6 Stripped Matrix
S7 Dark Surface
S8 Alaska Gleyed
S9, TS5 Thin Dark Surface
S10 Polyvalue Organic Concentrations
TS1 Iron Staining
TS2 ? cm Muck
TS3 Thick Sandy Dark Surface
TS4 Dark Surface 2
LOAMY AND CLAYEY SOILS
Fl Loamy Mucky Mineral
F2 Loamy Gleyed Matrix
F3 Depleted Matrix
F4, TF10 Depleted Below Dark Surface
F5.TF11 Thick Dark Surface
F6, TF12 Redox Dark Surface
F7.TF13 Depleted Dark Surface
F8, TF14 Redox Depressions
F9 Vernal Pools
F10 Marl
Fll Depleted Ochric
F12 Iron/Manganese Masses
F13 Umbric Surface
F14 Hawaii Gleyed
F1S Alaska Redox Gleyed
F16 Alaska Depleted Macropores
F17 Alaska Gleyed Pores
F18 TF1S High Plains Depressions
TF1 ? cm Muck
TF2 ? cm Mucky Peat or Peat
TF3 Red Parent Material
TF4 Alaska Concretions
TF5 2.5Y/5Y Below Dark Surface
TF6 2.5Y/5Y Below Thick Dark Surface
TF7 Calcic Dark Surface
TF8 Thick Dark Surface 2/1
TF9 Redoxed Spring Seeps
TF16 Delta Ochric
38
------- |