HomeMy WebLinkAboutSW3190701_Soils Report (Soils Survey)_20190822USDA United States
Department of
Agriculture
N RCS
Natural
Resources
Conservation
Service
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
Cabarrus County,
North Carolina
August 13, 2019
Preface
Soil surveys contain information that affects land use planning in survey areas.
They highlight soil limitations that affect various land uses and provide information
about the properties of the soils in the survey areas. Soil surveys are designed for
many different users, including farmers, ranchers, foresters, agronomists, urban
planners, community officials, engineers, developers, builders, and home buyers.
Also, conservationists, teachers, students, and specialists in recreation, waste
disposal, and pollution control can use the surveys to help them understand,
protect, or enhance the environment.
Various land use regulations of Federal, State, and local governments may impose
special restrictions on land use or land treatment. Soil surveys identify soil
properties that are used in making various land use or land treatment decisions.
The information is intended to help the land users identify and reduce the effects of
soil limitations on various land uses. The landowner or user is responsible for
identifying and complying with existing laws and regulations.
Although soil survey information can be used for general farm, local, and wider area
planning, onsite investigation is needed to supplement this information in some
cases. Examples include soil quality assessments (http://www.nres.usda.gov/wps/
portal/nres/main/soils/health/) and certain conservation and engineering
applications. For more detailed information, contact your local USDA Service Center
(https://offices.sc.egov.usda.gov/locator/app?agency=nres) or your NRCS State Soil
Scientist (http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/?
cid=nres142p2_053951).
Great differences in soil properties can occur within short distances. Some soils are
seasonally wet or subject to flooding. Some are too unstable to be used as a
foundation for buildings or roads. Clayey or wet soils are poorly suited to use as
septic tank absorption fields. A high water table makes a soil poorly suited to
basements or underground installations.
The National Cooperative Soil Survey is a joint effort of the United States
Department of Agriculture and other Federal agencies, State agencies including the
Agricultural Experiment Stations, and local agencies. The Natural Resources
Conservation Service (NRCS) has leadership for the Federal part of the National
Cooperative Soil Survey.
Information about soils is updated periodically. Updated information is available
through the NRCS Web Soil Survey, the site for official soil survey information.
The U.S. Department of Agriculture (USDA) prohibits discrimination in all its
programs and activities on the basis of race, color, national origin, age, disability,
and where applicable, sex, marital status, familial status, parental status, religion,
sexual orientation, genetic information, political beliefs, reprisal, or because all or a
part of an individual's income is derived from any public assistance program. (Not
all prohibited bases apply to all programs.) Persons with disabilities who require
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alternative means for communication of program information (Braille, large print,
audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice
and TDD). To file a complaint of discrimination, write to USDA, Director, Office of
Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or
call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity
provider and employer.
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Contents
Preface............................................................................................................. .
How Soil Surveys Are Made............................................................................
Soil Ma
SoilMap..........................................................................................................
Legend............................................................................................................
MapUnit Legend............................................................................................
MapUnit Descriptions.....................................................................................
Cabarrus County, North Carolina................................................................
ChA—Chewacla sandy loam, 0 to 2 percent slopes, frequently flooded.
KkB—Kirksey silt loam, 1 to 6 percent slopes .........................................
Soil Information for All Uses...........................................................................
SoilReports....................................................................................................
AOIInventory..............................................................................................
Map Unit Description (Brief, Generated) .................................................
Building Site Development..........................................................................
Roads and Streets, Shallow Excavations, and Lawns and Landscaping
Land Classifications....................................................................................
Taxonomic Classification of the Soils ......................................................
Soil Physical Properties..............................................................................
Engineering Properties............................................................................
Physical Soil Properties...........................................................................
Soil Qualities and Features.........................................................................
SoilFeatures...........................................................................................
References....................................................................................................... .
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How Soil Surveys Are Made
Soil surveys are made to provide information about the soils and miscellaneous
areas in a specific area. They include a description of the soils and miscellaneous
areas and their location on the landscape and tables that show soil properties and
limitations affecting various uses. Soil scientists observed the steepness, length,
and shape of the slopes; the general pattern of drainage; the kinds of crops and
native plants; and the kinds of bedrock. They observed and described many soil
profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The
profile extends from the surface down into the unconsolidated material in which the
soil formed or from the surface down to bedrock. The unconsolidated material is
devoid of roots and other living organisms and has not been changed by other
biological activity.
Currently, soils are mapped according to the boundaries of major land resource
areas (MLRAs). MLRAs are geographically associated land resource units that
share common characteristics related to physiography, geology, climate, water
resources, soils, biological resources, and land uses (USDA, 2006). Soil survey
areas typically consist of parts of one or more MLRA.
The soils and miscellaneous areas in a survey area occur in an orderly pattern that
is related to the geology, landforms, relief, climate, and natural vegetation of the
area. Each kind of soil and miscellaneous area is associated with a particular kind
of landform or with a segment of the landform. By observing the soils and
miscellaneous areas in the survey area and relating their position to specific
segments of the landform, a soil scientist develops a concept, or model, of how they
were formed. Thus, during mapping, this model enables the soil scientist to predict
with a considerable degree of accuracy the kind of soil or miscellaneous area at a
specific location on the landscape.
Commonly, individual soils on the landscape merge into one another as their
characteristics gradually change. To construct an accurate soil map, however, soil
scientists must determine the boundaries between the soils. They can observe only
a limited number of soil profiles. Nevertheless, these observations, supplemented
by an understanding of the soil -vegetation -landscape relationship, are sufficient to
verify predictions of the kinds of soil in an area and to determine the boundaries.
Soil scientists recorded the characteristics of the soil profiles that they studied. They
noted soil color, texture, size and shape of soil aggregates, kind and amount of rock
fragments, distribution of plant roots, reaction, and other features that enable them
to identify soils. After describing the soils in the survey area and determining their
properties, the soil scientists assigned the soils to taxonomic classes (units).
Taxonomic classes are concepts. Each taxonomic class has a set of soil
characteristics with precisely defined limits. The classes are used as a basis for
comparison to classify soils systematically. Soil taxonomy, the system of taxonomic
classification used in the United States, is based mainly on the kind and character
of soil properties and the arrangement of horizons within the profile. After the soil
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Custom Soil Resource Report
scientists classified and named the soils in the survey area, they compared the
individual soils with similar soils in the same taxonomic class in other areas so that
they could confirm data and assemble additional data based on experience and
research.
The objective of soil mapping is not to delineate pure map unit components; the
objective is to separate the landscape into landforms or landform segments that
have similar use and management requirements. Each map unit is defined by a
unique combination of soil components and/or miscellaneous areas in predictable
proportions. Some components may be highly contrasting to the other components
of the map unit. The presence of minor components in a map unit in no way
diminishes the usefulness or accuracy of the data. The delineation of such
landforms and landform segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, onsite
investigation is needed to define and locate the soils and miscellaneous areas.
Soil scientists make many field observations in the process of producing a soil map.
The frequency of observation is dependent upon several factors, including scale of
mapping, intensity of mapping, design of map units, complexity of the landscape,
and experience of the soil scientist. Observations are made to test and refine the
soil -landscape model and predictions and to verify the classification of the soils at
specific locations. Once the soil -landscape model is refined, a significantly smaller
number of measurements of individual soil properties are made and recorded.
These measurements may include field measurements, such as those for color,
depth to bedrock, and texture, and laboratory measurements, such as those for
content of sand, silt, clay, salt, and other components. Properties of each soil
typically vary from one point to another across the landscape.
Observations for map unit components are aggregated to develop ranges of
characteristics for the components. The aggregated values are presented. Direct
measurements do not exist for every property presented for every map unit
component. Values for some properties are estimated from combinations of other
properties.
While a soil survey is in progress, samples of some of the soils in the area generally
are collected for laboratory analyses and for engineering tests. Soil scientists
interpret the data from these analyses and tests as well as the field -observed
characteristics and the soil properties to determine the expected behavior of the
soils under different uses. Interpretations for all of the soils are field tested through
observation of the soils in different uses and under different levels of management.
Some interpretations are modified to fit local conditions, and some new
interpretations are developed to meet local needs. Data are assembled from other
sources, such as research information, production records, and field experience of
specialists. For example, data on crop yields under defined levels of management
are assembled from farm records and from field or plot experiments on the same
kinds of soil.
Predictions about soil behavior are based not only on soil properties but also on
such variables as climate and biological activity. Soil conditions are predictable over
long periods of time, but they are not predictable from year to year. For example,
soil scientists can predict with a fairly high degree of accuracy that a given soil will
have a high water table within certain depths in most years, but they cannot predict
that a high water table will always be at a specific level in the soil on a specific date.
After soil scientists located and identified the significant natural bodies of soil in the
survey area, they drew the boundaries of these bodies on aerial photographs and
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Custom Soil Resource Report
identified each as a specific map unit. Aerial photographs show trees, buildings,
fields, roads, and rivers, all of which help in locating boundaries accurately.
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Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
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Custom Soil Resource Report
3 Soil Map
0
$M
W
543460 543490 543MO 54WM 54.3580 543610 543640
35° 14' 59" N
g
35° 14' 5Y' N
543460 543490 543MO 543550 543580 543610
3
0
Map Scale: 1:1,480 i printed on A landscape (11" x 8.5") sheet.
Meters
$ N 0 20 40 80 120
Feet
0 50 100 200 300
Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
9
543670 543-M 543M
543640 543670 543700 543730
3
F
$M
W
543760
35' 14' 5T N
35° 14' 5Y' N
543760
3
i
MAP LEGEND
Area of Interest (AOI)
0
Area of Interest (AOI)
Soils
0
Soil Map Unit Polygons
im 0
Soil Map Unit Lines
■
Soil Map Unit Points
Special
Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
.4
Gravelly Spot
0
Landfill
Lava Flow
Marsh or swamp
+
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
oa
Sodic Spot
Custom Soil Resource Report
MAP INFORMATION
A
Spoil Area
The soil surveys that comprise your AOI were mapped at
1:24,000.
Stony Spot
Very Stony Spot
Warning: Soil Map may not be valid at this scale.
Wet Spot
Enlargement of maps beyond the scale of mapping can cause
Other
misunderstanding of the detail of mapping and accuracy of soil
.-
Special Line Features
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
Water Features
scale.
-
Streams and Canals
Transportation
Please rely on the bar scale on each map sheet for map
�}}
Rails
measurements.
Interstate Highways
Source of Map: Natural Resources Conservation Service
US Routes
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Major Roads
Local Roads
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
Background
distance and area. A projection that preserves area, such as the
Aerial Photography
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Cabarrus County, North Carolina
Survey Area Data: Version 17, Sep 10, 2018
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 18, 2011—Nov
25, 2017
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
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Custom Soil Resource Report
Map Unit Legend
Map Unit Symbol
Map Unit Name
Acres in AOI
Percent of AOI
ChA
KkB
Chewacla sandy loam, 0 to 2
percent slopes, frequently
flooded
0.0
4.2
1.1 %
Kirksey silt loam, 1 to 6 percent
slopes
98.9%
Totals for Area of Interest
4.2
100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
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Custom Soil Resource Report
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha -Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
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Custom Soil Resource Report
Cabarrus County, North Carolina
ChA—Chewacla sandy loam, 0 to 2 percent slopes, frequently flooded
Map Unit Setting
National map unit symbol: 2m9vk
Elevation: 200 to 1,400 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: Prime farmland if drained and either protected from flooding
or not frequently flooded during the growing season
Map Unit Composition
Chewacla, frequently flooded, and similar soils: 85 percent
Minor components: 8 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Chewacla, Frequently Flooded
Setting
Landform: Flood plains
Down -slope shape: Concave
Across -slope shape: Linear
Parent material: Loamy alluvium derived from igneous and metamorphic rock
Typical profile
A - 0 to 4 inches: loam
Bw1 - 4 to 26 inches: silty clay loam
Bw2 - 26 to 38 inches: loam
Bw3 - 38 to 60 inches: clay loam
C - 60 to 80 inches: loam
Properties and qualities
Slope: 0 to 2 percent
Depth to restrictive feature: More than 80 inches
Natural drainage class: Somewhat poorly drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to
high (0.57 to 1.98 in/hr)
Depth to water table: About 6 to 24 inches
Frequency of flooding: Frequent
Frequency of ponding: None
Available water storage in profile: High (about 11.5 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4w
Hydrologic Soil Group: B/D
Hydric soil rating: No
Minor Components
Wehadkee, undrained
Percent of map unit: 5 percent
Landform: Depressions on flood plains
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Custom Soil Resource Report
Down -slope shape: Concave
Across -slope shape: Linear
Hydric soil rating: Yes
Riverview
Percent of map unit: 3 percent
Landform: Flood plains
Down -slope shape: Linear
Across -slope shape: Linear
Hydric soil rating: No
KkB—Kirksey silt loam, 1 to 6 percent slopes
Map Unit Setting
National map unit symbol: 3r5p
Elevation: 200 to 650 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Kirksey and similar soils: 80 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Kirksey
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from metavolcanics and/or residuum
weathered from argillite
Typical profile
Ap - 0 to 7 inches: silt loam
Bt - 7 to 37 inches: silty clay loam
C - 37 to 49 inches: silt loam
R - 49 to 80 inches: unweathered bedrock
Properties and qualities
Slope: 2 to 6 percent
Depth to restrictive feature: 40 to 60 inches to lithic bedrock
Natural drainage class: Moderately well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately
high (0.00 to 0.57 in/hr)
Depth to water table: About 18 to 36 inches
Frequency of flooding: None
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Custom Soil Resource Report
Frequency of ponding: None
Available water storage in profile: Moderate (about 7.4 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: C
Hydric soil rating: No
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Soil Information for All Uses
Soil Reports
The Soil Reports section includes various formatted tabular and narrative reports
(tables) containing data for each selected soil map unit and each component of
each unit. No aggregation of data has occurred as is done in reports in the Soil
Properties and Qualities and Suitabilities and Limitations sections.
The reports contain soil interpretive information as well as basic soil properties and
qualities. A description of each report (table) is included.
AOI Inventory
This folder contains a collection of tabular reports that present a variety of soil
information. Included are various map unit description reports, special soil
interpretation reports, and data summary reports.
Map Unit Description (Brief, Generated)
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions in this
report, along with the maps, provide information on the composition of map units
and properties of their components.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
The Map Unit Description (Brief, Generated) report displays a generated description
of the major soils that occur in a map unit. Descriptions of non -soil (miscellaneous
areas) and minor map unit components are not included. This description is
generated from the underlying soil attribute data.
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Custom Soil Resource Report
Additional information about the map units described in this report is available in
other Soil Data Mart reports, which give properties of the soils and the limitations,
capabilities, and potentials for many uses. Also, the narratives that accompany the
Soil Data Mart reports define some of the properties included in the map unit
descriptions.
Report —Map Unit Description (Brief, Generated)
Cabarrus County, North Carolina
Map Unit: ChA—Chewacla sandy loam, 0 to 2 percent slopes, frequently flooded
Component: Chewacla, frequently flooded (85%)
The Chewacla, frequently flooded component makes up 85 percent of the map unit.
Slopes are 0 to 2 percent. This component is on flood plains, valleys. The parent
material consists of loamy alluvium derived from igneous and metamorphic rock.
Depth to a root restrictive layer is greater than 60 inches. The natural drainage class
is somewhat poorly drained. Water movement in the most restrictive layer is
moderately high. Available water to a depth of 60 inches (or restricted depth) is
high. Shrink -swell potential is low. This soil is frequently flooded. It is not ponded. A
seasonal zone of water saturation is at 15 inches during January, February, March,
December. Organic matter content in the surface horizon is about 3 percent.
Nonirrigated land capability classification is 4w. This soil does not meet hydric
criteria.
Component: Wehadkee, undrained (5%)
Generated brief soil descriptions are created for major soil components. The
Wehadkee, undrained soil is a minor component.
Component: Riverview (3%)
Generated brief soil descriptions are created for major soil components. The
Riverview soil is a minor component.
Map Unit: KkB—Kirksey silt loam, 1 to 6 percent slopes
Component: Kirksey (80%)
The Kirksey component makes up 80 percent of the map unit. Slopes are 2 to 6
percent. This component is on interfluves, uplands. The parent material consists of
residuum weathered from metavolcanics and/or residuum weathered from argillite.
Depth to a root restrictive layer, bedrock, lithic, is 40 to 60 inches. The natural
drainage class is moderately well drained. Water movement in the most restrictive
layer is very low. Available water to a depth of 60 inches (or restricted depth) is
moderate. Shrink -swell potential is low. This soil is not flooded. It is not ponded. A
seasonal zone of water saturation is at 27 inches during January, February, March,
April, December. Organic matter content in the surface horizon is about 1 percent.
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Custom Soil Resource Report
Nonirrigated land capability classification is 2e. This soil does not meet hydric
criteria.
Building Site Development
This folder contains a collection of tabular reports that present soil interpretations
related to building site development. The reports (tables) include all selected map
units and components for each map unit, limiting features and interpretive ratings.
Building site development interpretations are designed to be used as tools for
evaluating soil suitability and identifying soil limitations for various construction
purposes. As part of the interpretation process, the rating applies to each soil in its
described condition and does not consider present land use. Example
interpretations can include corrosion of concrete and steel, shallow excavations,
dwellings with and without basements, small commercial buildings, local roads and
streets, and lawns and landscaping.
Roads and Streets, Shallow Excavations, and Lawns
and Landscaping
Soil properties influence the development of building sites, including the selection of
the site, the design of the structure, construction, performance after construction,
and maintenance. This table shows the degree and kind of soil limitations that affect
local roads and streets, shallow excavations, and lawns and landscaping.
The ratings in the table are both verbal and numerical. Rating class terms indicate
the extent to which the soils are limited by all of the soil features that affect building
site development. Not limited indicates that the soil has features that are very
favorable for the specified use. Good performance and very low maintenance can
be expected. Somewhat limited indicates that the soil has features that are
moderately favorable for the specified use. The limitations can be overcome or
minimized by special planning, design, or installation. Fair performance and
moderate maintenance can be expected. Very limited indicates that the soil has one
or more features that are unfavorable for the specified use. The limitations generally
cannot be overcome without major soil reclamation, special design, or expensive
installation procedures. Poor performance and high maintenance can be expected.
Numerical ratings in the table indicate the severity of individual limitations. The
ratings are shown as decimal fractions ranging from 0.01 to 1.00. They indicate
gradations between the point at which a soil feature has the greatest negative
impact on the use (1.00) and the point at which the soil feature is not a limitation
(0.00).
Local roads and streets have an all-weather surface and carry automobile and light
truck traffic all year. They have a subgrade of cut or fill soil material; a base of
gravel, crushed rock, or soil material stabilized by lime or cement; and a surface of
flexible material (asphalt), rigid material (concrete), or gravel with a binder. The
ratings are based on the soil properties that affect the ease of excavation and
grading and the traffic -supporting capacity. The properties that affect the ease of
excavation and grading are depth to bedrock or a cemented pan, hardness of
bedrock or a cemented pan, depth to a water table, ponding, flooding, the amount of
large stones, and slope. The properties that affect the traffic -supporting capacity are
soil strength (as inferred from the AASHTO group index number), subsidence, linear
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Custom Soil Resource Report
extensibility (shrink -swell potential), the potential for frost action, depth to a water
table, and ponding.
Shallow excavations are trenches or holes dug to a maximum depth of 5 or 6 feet
for graves, utility lines, open ditches, or other purposes. The ratings are based on
the soil properties that influence the ease of digging and the resistance to
sloughing. Depth to bedrock or a cemented pan, hardness of bedrock or a
cemented pan, the amount of large stones, and dense layers influence the ease of
digging, filling, and compacting. Depth to the seasonal high water table, flooding,
and ponding may restrict the period when excavations can be made. Slope
influences the ease of using machinery. Soil texture, depth to the water table, and
linear extensibility (shrink -swell potential) influence the resistance to sloughing.
Lawns and landscaping require soils on which turf and ornamental trees and shrubs
can be established and maintained. Irrigation is not considered in the ratings. The
ratings are based on the soil properties that affect plant growth and trafficability after
vegetation is established. The properties that affect plant growth are reaction; depth
to a water table; ponding; depth to bedrock or a cemented pan; the available water
capacity in the upper 40 inches; the content of salts, sodium, or calcium carbonate;
and sulfidic materials. The properties that affect trafficability are flooding, depth to a
water table, ponding, slope, stoniness, and the amount of sand, clay, or organic
matter in the surface layer.
Information in this table is intended for land use planning, for evaluating land use
alternatives, and for planning site investigations prior to design and construction.
The information, however, has limitations. For example, estimates and other data
generally apply only to that part of the soil between the surface and a depth of 5 to 7
feet. Because of the map scale, small areas of different soils may be included within
the mapped areas of a specific soil.
The information is not site specific and does not eliminate the need for onsite
investigation of the soils or for testing and analysis by personnel experienced in the
design and construction of engineering works.
Government ordinances and regulations that restrict certain land uses or impose
specific design criteria were not considered in preparing the information in this table.
Local ordinances and regulations should be considered in planning, in site
selection, and in design.
Report —Roads and Streets, Shallow Excavations, and Lawns
and Landscaping
[Onsite investigation may be needed to validate the interpretations in this table and
to confirm the identity of the soil on a given site. The numbers in the value columns
range from 0.01 to 1.00. The larger the value, the greater the potential limitation.
The table shows only the top five limitations for any given soil. The soil may have
additional limitations]
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Custom Soil Resource Report
Roads and Streets, Shallow Excavations, and Lawns and Landscaping-Cabarrus County, North Carolina
Map symbol and soil
Pct. of
Lawns and landscaping
Local roads and streets
Shallow excavations
name
map
Rating class and
Value
Rating class and
Value
Rating class and
Value
unit
limiting features
limiting features
limiting features
ChA-Chewacla
sandy loam, 0 to 2
percent slopes,
frequently flooded
Very limited
Chewacla, frequently
85
Very limited
Very limited
flooded
Flooding
1.00
Flooding
1.00
Depth to saturated
1.00
zone
Depth to saturated
0.94
Depth to saturated
0.94
Flooding
0.80
zone
zone
Low exchange
0.75
Low strength
0.55
Dusty
0.12
capacity
Dusty
0.12
Unstable excavation
0.01
walls
Wehadkee, undrained
5
Very limited
Very limited
Very limited
Flooding
1.00
Depth to saturated
1.00
Depth to saturated
1.00
zone
zone
Depth to saturated
1.00
Flooding
1.00
Flooding
0.80
zone
Low exchange
0.50
Low strength
1.00
Dusty
0.05
capacity
Dusty
0.05
Unstable excavation
0.0
walls
Riverview
3
Very limited
Very limited
Somewhat limited
Flooding
1.00
Flooding
1.00
Flooding
0.80
Low exchange
0.75
Low strength
0.17
Depth to saturated
0.61
capacity
zone
Dusty
0.07
Dusty
0.07
Unstable excavation
0.01
walls
KkB-Kirksey silt
loam, 1 to 6 percent
slopes
Kirksey
80
Somewhat limited
Very limited
Very limited
Low exchange
0.75
Low strength
1.00
Depth to saturated
1.00
capacity
zone
Dusty
0.12
Depth to saturated
0.04
Depth to hard bedrock
0.54
zone
Depth to saturated
0.04
Dusty
0.12
zone
Unstable excavation
0.01
walls
KIII
Custom Soil Resource Report
Land Classifications
This folder contains a collection of tabular reports that present a variety of soil
groupings. The reports (tables) include all selected map units and components for
each map unit. Land classifications are specified land use and management
groupings that are assigned to soil areas because combinations of soil have similar
behavior for specified practices. Most are based on soil properties and other factors
that directly influence the specific use of the soil. Example classifications include
ecological site classification, farmland classification, irrigated and nonirrigated land
capability classification, and hydric rating.
Taxonomic Classification of the Soils
The system of soil classification used by the National Cooperative Soil Survey has
six categories (Soil Survey Staff, 1999 and 2003). Beginning with the broadest,
these categories are the order, suborder, great group, subgroup, family, and series.
Classification is based on soil properties observed in the field or inferred from those
observations or from laboratory measurements. This table shows the classification
of the soils in the survey area. The categories are defined in the following
paragraphs.
ORDER. Twelve soil orders are recognized. The differences among orders reflect
the dominant soil -forming processes and the degree of soil formation. Each order is
identified by a word ending in sol. An example is Alfisols.
SUBORDER. Each order is divided into suborders primarily on the basis of
properties that influence soil genesis and are important to plant growth or properties
that reflect the most important variables within the orders. The last syllable in the
name of a suborder indicates the order. An example is Udalfs (Ud, meaning humid,
plus alfs, from Alfisols).
GREAT GROUP. Each suborder is divided into great groups on the basis of close
similarities in kind, arrangement, and degree of development of pedogenic horizons;
soil moisture and temperature regimes; type of saturation; and base status. Each
great group is identified by the name of a suborder and by a prefix that indicates a
property of the soil. An example is Hapludalfs (Hapl, meaning minimal horizonation,
plus udalfs, the suborder of the Alfisols that has a udic moisture regime).
SUBGROUP. Each great group has a typic subgroup. Other subgroups are
intergrades or extragrades. The typic subgroup is the central concept of the great
group; it is not necessarily the most extensive. Intergrades are transitions to other
orders, suborders, or great groups. Extragrades have some properties that are not
representative of the great group but do not indicate transitions to any other
taxonomic class. Each subgroup is identified by one or more adjectives preceding
the name of the great group. The adjective Typic identifies the subgroup that typifies
the great group. An example is Typic Hapludalfs.
FAMILY. Families are established within a subgroup on the basis of physical and
chemical properties and other characteristics that affect management. Generally,
the properties are those of horizons below plow depth where there is much
biological activity. Among the properties and characteristics considered are particle -
size class, mineralogy class, cation -exchange activity class, soil temperature
regime, soil depth, and reaction class. A family name consists of the name of a
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Custom Soil Resource Report
subgroup preceded by terms that indicate soil properties. An example is fine -loamy,
mixed, active, mesic Typic Hapludalfs.
SERIES. The series consists of soils within a family that have horizons similar in
color, texture, structure, reaction, consistence, mineral and chemical composition,
and arrangement in the profile.
References:
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service. U.S. Department of Agriculture Handbook 436.
Soil Survey Staff. 2006. Keys to soil taxonomy. 10th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. (The soils in a given survey
area may have been classified according to earlier editions of this publication.)
Report —Taxonomic Classification of the Soils
[An asterisk by the soil name indicates a taxadjunct to the series]
Taxonomic Classification of the Soils—Cabarrus County, North Carolina
Soil name
Family or higher taxonomic classification
Chewacla
Kirksey
Fine -loamy, mixed, active, thermic Fluvaquentic Dystrudepts
Fine -silty, siliceous, subactive, thermic Aquic Hapludults
Riverview
Fine -loamy, mixed, active, thermic Fluventic Dystrudepts
Wehadkee
Fine -loamy, mixed, active, nonacid, thermic Fluvaquentic Endoaquepts
Soil Physical Properties
This folder contains a collection of tabular reports that present soil physical
properties. The reports (tables) include all selected map units and components for
each map unit. Soil physical properties are measured or inferred from direct
observations in the field or laboratory. Examples of soil physical properties include
percent clay, organic matter, saturated hydraulic conductivity, available water
capacity, and bulk density.
Engineering Properties
This table gives the engineering classifications and the range of engineering
properties for the layers of each soil in the survey area.
Hydrologic soil group is a group of soils having similar runoff potential under similar
storm and cover conditions. The criteria for determining Hydrologic soil group is
found in the National Engineering Handbook, Chapter 7 issued May 2007(http://
directives.sc.egov.usda.gov/OpenNonWebContent.aspx?content=17757.wba).
Listing HSGs by soil map unit component and not by soil series is a new concept for
the engineers. Past engineering references contained lists of HSGs by soil series.
Soil series are continually being defined and redefined, and the list of soil series
names changes so frequently as to make the task of maintaining a single national
list virtually impossible. Therefore, the criteria is now used to calculate the HSG
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Custom Soil Resource Report
using the component soil properties and no such national series lists will be
maintained. All such references are obsolete and their use should be discontinued.
Soil properties that influence runoff potential are those that influence the minimum
rate of infiltration for a bare soil after prolonged wetting and when not frozen. These
properties are depth to a seasonal high water table, saturated hydraulic conductivity
after prolonged wetting, and depth to a layer with a very slow water transmission
rate. Changes in soil properties caused by land management or climate changes
also cause the hydrologic soil group to change. The influence of ground cover is
treated independently. There are four hydrologic soil groups, A, B, C, and D, and
three dual groups, A/D, B/D, and C/D. In the dual groups, the first letter is for
drained areas and the second letter is for undrained areas.
The four hydrologic soil groups are described in the following paragraphs:
Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly
wet. These consist mainly of deep, well drained to excessively drained sands or
gravelly sands. These soils have a high rate of water transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well drained
soils that have moderately fine texture to moderately coarse texture. These soils
have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of water
transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay layer at
or near the surface, and soils that are shallow over nearly impervious material.
These soils have a very slow rate of water transmission.
Depth to the upper and lower boundaries of each layer is indicated.
Texture is given in the standard terms used by the U.S. Department of Agriculture.
These terms are defined according to percentages of sand, silt, and clay in the
fraction of the soil that is less than 2 millimeters in diameter. "Loam," for example, is
soil that is 7 to 27 percent clay, 28 to 50 percent silt, and less than 52 percent sand.
If the content of particles coarser than sand is 15 percent or more, an appropriate
modifier is added, for example, "gravelly."
Classification of the soils is determined according to the Unified soil classification
system (ASTM, 2005) and the system adopted by the American Association of
State Highway and Transportation Officials (AASHTO, 2004).
The Unified system classifies soils according to properties that affect their use as
construction material. Soils are classified according to particle -size distribution of
the fraction less than 3 inches in diameter and according to plasticity index, liquid
limit, and organic matter content. Sandy and gravelly soils are identified as GW, GP,
GM, GC, SW, SIP, SM, and SC; silty and clayey soils as ML, CL, OL, MH, CH, and
OH; and highly organic soils as PT. Soils exhibiting engineering properties of two
groups can have a dual classification, for example, CL-ML.
The AASHTO system classifies soils according to those properties that affect
roadway construction and maintenance. In this system, the fraction of a mineral soil
that is less than 3 inches in diameter is classified in one of seven groups from A-1
through A-7 on the basis of particle -size distribution, liquid limit, and plasticity index.
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Custom Soil Resource Report
Soils in group A-1 are coarse grained and low in content of fines (silt and clay). At
the other extreme, soils in group A-7 are fine grained. Highly organic soils are
classified in group A-8 on the basis of visual inspection.
If laboratory data are available, the A-1, A-2, and A-7 groups are further classified
as A-1-a, A-1-b, A-2-4, A-2-5, A-2-6, A-2-7, A-7-5, or A-7-6. As an additional
refinement, the suitability of a soil as subgrade material can be indicated by a group
index number. Group index numbers range from 0 for the best subgrade material to
20 or higher for the poorest.
Percentage of rock fragments larger than 10 inches in diameter and 3 to 10 inches
in diameter are indicated as a percentage of the total soil on a dry -weight basis. The
percentages are estimates determined mainly by converting volume percentage in
the field to weight percentage. Three values are provided to identify the expected
Low (L), Representative Value (R), and High (H).
Percentage (of soil particles) passing designated sieves is the percentage of the soil
fraction less than 3 inches in diameter based on an ovendry weight. The sieves,
numbers 4, 10, 40, and 200 (USA Standard Series), have openings of 4.76, 2.00,
0.420, and 0.074 millimeters, respectively. Estimates are based on laboratory tests
of soils sampled in the survey area and in nearby areas and on estimates made in
the field. Three values are provided to identify the expected Low (L), Representative
Value (R), and High (H).
Liquid limit and plasticity index (Atterberg limits) indicate the plasticity
characteristics of a soil. The estimates are based on test data from the survey area
or from nearby areas and on field examination. Three values are provided to identify
the expected Low (L), Representative Value (R), and High (H).
References:
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
24
Custom Soil Resource Report
Absence of an entry indicates that the data were not estimated. The asterisk" denotes the representative texture; other
possible textures follow the dash. The criteria for determining the hydrologic soil group for individual soil components is
found in the National Engineering Handbook, Chapter 7 issued May 2007(http://directives.sc.egov.usda.gov/
Open NonWebContent.aspx?content= 1 7757.wba). Three values are provided to identify the expected Low (L),
Representative Value (R), and High (H).
25
Custom Soil Resource Report
Engineering Properties—Cabarrus County, North Carolina
Map unit symbol and
Pet. of
Hydrolo
Depth
USDA texture
Classification
Pct Fragments
Percentage passing sieve number—
Liquid
Plasticit
soil name
map
gic
limit
y index
unit
group
Unified
AASHTO
>10
3-10
4
10
40
200
inches
inches
In
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
ChA—Chewacla sandy
loam, 0 to 2 percent
slopes, frequently
flooded
Chewacla, frequently
85
B/D
0-4
Loam, sandy loam,
CL, CL-
A-4, A-6,
0-0-0
0-0-0
98-98-1
93-95-1
65-85-1
44-63-
16-28
4-9 -22
flooded
silt loam
ML, ML
A-7-6
00
00
00
79
-44
4-26
Silty clay loam, silt
CL, ML A-4, A-6,
0-0-0
0-0-0
96-98-1
91-94-1
79-94-1
70-84-
30-34
4-13-22
loam, clay loam
A-7-6
00
00
00
94
-44
26-38
Loam, sandy clay
SC-SM, A-4, A-6,
0-0-0
0-0-0
96-98-1
91-95-1
80-84-1
58-61-
18-25
4-8 -22
loam, sandy loam
ML A-7-6
00
00
00
80
-44
38-60
Clay loam, silt loam,
CL, CL-
A-4, A-6,
0-0-0
0-0-0
87-93-1
65-81-1
52-74-
39-58-
20-34
5-13-22
silty clay loam
ML
A-7-6
00
00
96
77
-44
60-80
Loam, sandy loam,
SM, SC-
A-6,
0-0-0
0-0-0
76-96-1
75-96-1
54-86-1
36-63-
10-27
NP-9
fine sandy loam,
SM, SC,
A-7-6,
00
00
00
79
-44
-22
sandy clay loam
CL, ML
A-4
Wehadkee, undrained
5
B/D
0-8
Loam, sandy loam,
SC, SC-
A-2, A-4
0-0-0
0-0-0
100-100
95-96-1
73-85-
49-61-
20-25
NP-5
fine sandy loam
SM,
-100
00
99
74
-30
-10
SM, ML
8-43
Silty clay loam,
CL, CL-
A-4, A-6,
0-0-0
0-0-0
100-100
98-98-1
77-85-
41-50-
25-42
6-16-25
loam, silt loam,
ML, ML,
A-7
-100
00
95
59
-58
clay loam, sandy
SC
clay loam
43-80
Loam, sandy loam,
SC, ML
A-4, A-2-4
0-0-0
0-0-0
100-100
91-95-1
59-73-
24-36-
20-25
NP-5
silt loam, sand,
-100
00
89
51
-30
-10
clay loam
Riverview
3
B
0-18
Silt loam, loam, fine
CL, CL-
A-4, A-6
0-0-0
0-0-0
95-98-1
86-96-1
69-85-
48-62-
15-23
3-9 -14
sandy loam
ML, ML
00
00
97
73
-30
18-46
Loam, silty clay
CL
A-6
0-0-0
0-0-0
94-98-1
85-96-1
69-87-
51-66-
20-30
3-12-20
loam, sandy clay
00
00
99
77
-40
loam
26
Custom Soil Resource Report
Engineering Properties—Cabarrus County, North Carolina
Map unit symbol and
Pet. of
Hydrolo
Depth
USDA texture
Classification
Pct Fragments
Percentage passing sieve number—
Liquid
Plasticit
soil name
map
gic
limit
y index
unit
group
Unified
AASHTO
>10
3-10
4
10
40
200
inches
inches
In
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
L-R-H
SC-SM, A-4, A-6
46-55
Sandy loam, clay
0-0-0
0-0-0
95-96-1
85-91-1
59-69-
26-35-
15-23
3-9 -14
loam, sandy clay
SM, CL-
00
00
89
51
-30
loam
ML, CL,
ML
55-72
Clay loam, sandy
SC-SM,
A-4, A-6
0-0-0
0-0-0
95-96-1
85-91-1
61-83-
45-65-
15-23
3-9 -14
loam, sandy clay
SM, CL-
00
00
96
77
-30
loam
ML, CL,
ML
72-80
Loam, silty clay
CL
A-6
0-0-0
0-0-0
94-98-1
85-96-1
69-87-
51-66-
20-30
3-12-20
loam, sandy clay
00
00
99
77
-40
loam
KkB—Kirksey silt
loam, 1 to 6 percent
slopes
Kirksey
80
C
0-7
Silt loam
ML
A-4
0-0-0
0-1-1
89-94-1
76-87-1
70-86-1
60-75-
15-28
NP-4 -8
00
00
00
95
-40
7-37
Silty clay loam, clay
CL, CL-
A-4, A-5,
0-0-0
0- 1- 1
94-96-1
83-90-1
73-89-1
69-85-1
20-35
7-17-26
loam, silt loam
ML
A-6,
00
00
00
00
-50
A-7-6
37-49
Silt loam, fine sandy
CL, CL-
A-4, A-6
0- 1- 1
0- 5- 10
94-96-1
82-90-1
73-89-1
66-82-1
15-28
NP-6
loam, loam
ML, ML
00
00
00
00
-40
-12
49-80
Unweathered
—
—
—
—
—
—
—
—
—
—
bedrock
27
Custom Soil Resource Report
Physical Soil Properties
This table shows estimates of some physical characteristics and features that affect
soil behavior. These estimates are given for the layers of each soil in the survey
area. The estimates are based on field observations and on test data for these and
similar soils.
Depth to the upper and lower boundaries of each layer is indicated.
Particle size is the effective diameter of a soil particle as measured by
sedimentation, sieving, or micrometric methods. Particle sizes are expressed as
classes with specific effective diameter class limits. The broad classes are sand,
silt, and clay, ranging from the larger to the smaller.
Sand as a soil separate consists of mineral soil particles that are 0.05 millimeter to 2
millimeters in diameter. In this table, the estimated sand content of each soil layer is
given as a percentage, by weight, of the soil material that is less than 2 millimeters
in diameter.
Silt as a soil separate consists of mineral soil particles that are 0.002 to 0.05
millimeter in diameter. In this table, the estimated silt content of each soil layer is
given as a percentage, by weight, of the soil material that is less than 2 millimeters
in diameter.
Clay as a soil separate consists of mineral soil particles that are less than 0.002
millimeter in diameter. In this table, the estimated clay content of each soil layer is
given as a percentage, by weight, of the soil material that is less than 2 millimeters
in diameter.
The content of sand, silt, and clay affects the physical behavior of a soil. Particle
size is important for engineering and agronomic interpretations, for determination of
soil hydrologic qualities, and for soil classification.
The amount and kind of clay affect the fertility and physical condition of the soil and
the ability of the soil to adsorb cations and to retain moisture. They influence shrink -
swell potential, saturated hydraulic conductivity (Ksat), plasticity, the ease of soil
dispersion, and other soil properties. The amount and kind of clay in a soil also
affect tillage and earthmoving operations.
Moist bulk density is the weight of soil (ovendry) per unit volume. Volume is
measured when the soil is at field moisture capacity, that is, the moisture content at
1/3- or 1/10-bar (33kPa or 10kPa) moisture tension. Weight is determined after the
soil is dried at 105 degrees C. In the table, the estimated moist bulk density of each
soil horizon is expressed in grams per cubic centimeter of soil material that is less
than 2 millimeters in diameter. Bulk density data are used to compute linear
extensibility, shrink -swell potential, available water capacity, total pore space, and
other soil properties. The moist bulk density of a soil indicates the pore space
available for water and roots. Depending on soil texture, a bulk density of more than
1.4 can restrict water storage and root penetration. Moist bulk density is influenced
by texture, kind of clay, content of organic matter, and soil structure.
Saturated hydraulic conductivity (Ksat) refers to the ease with which pores in a
saturated soil transmit water. The estimates in the table are expressed in terms of
micrometers per second. They are based on soil characteristics observed in the
field, particularly structure, porosity, and texture. Saturated hydraulic conductivity
(Ksat) is considered in the design of soil drainage systems and septic tank
absorption fields.
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Custom Soil Resource Report
Available water capacity refers to the quantity of water that the soil is capable of
storing for use by plants. The capacity for water storage is given in inches of water
per inch of soil for each soil layer. The capacity varies, depending on soil properties
that affect retention of water. The most important properties are the content of
organic matter, soil texture, bulk density, and soil structure. Available water capacity
is an important factor in the choice of plants or crops to be grown and in the design
and management of irrigation systems. Available water capacity is not an estimate
of the quantity of water actually available to plants at any given time.
Linear extensibility refers to the change in length of an unconfined clod as moisture
content is decreased from a moist to a dry state. It is an expression of the volume
change between the water content of the clod at 1/3- or 1/10-bar tension (33kPa or
10kPa tension) and oven dryness. The volume change is reported in the table as
percent change for the whole soil. The amount and type of clay minerals in the soil
influence volume change.
Linear extensibility is used to determine the shrink -swell potential of soils. The
shrink -swell potential is low if the soil has a linear extensibility of less than 3
percent; moderate if 3 to 6 percent; high if 6 to 9 percent; and very high if more than
9 percent. If the linear extensibility is more than 3, shrinking and swelling can cause
damage to buildings, roads, and other structures and to plant roots. Special design
commonly is needed.
Organic matter is the plant and animal residue in the soil at various stages of
decomposition. In this table, the estimated content of organic matter is expressed
as a percentage, by weight, of the soil material that is less than 2 millimeters in
diameter. The content of organic matter in a soil can be maintained by returning
crop residue to the soil.
Organic matter has a positive effect on available water capacity, water infiltration,
soil organism activity, and tilth. It is a source of nitrogen and other nutrients for
crops and soil organisms.
Erosion factors are shown in the table as the K factor (Kw and Kf) and the T factor.
Erosion factor K indicates the susceptibility of a soil to sheet and rill erosion by
water. Factor K is one of six factors used in the Universal Soil Loss Equation
(USLE) and the Revised Universal Soil Loss Equation (RUSLE) to predict the
average annual rate of soil loss by sheet and rill erosion in tons per acre per year.
The estimates are based primarily on percentage of silt, sand, and organic matter
and on soil structure and Ksat. Values of K range from 0.02 to 0.69. Other factors
being equal, the higher the value, the more susceptible the soil is to sheet and rill
erosion by water.
Erosion factor Kw indicates the erodibility of the whole soil. The estimates are
modified by the presence of rock fragments.
Erosion factor Kf indicates the erodibility of the fine -earth fraction, or the material
less than 2 millimeters in size.
Erosion factor T is an estimate of the maximum average annual rate of soil erosion
by wind and/or water that can occur without affecting crop productivity over a
sustained period. The rate is in tons per acre per year.
Wind erodibility groups are made up of soils that have similar properties affecting
their susceptibility to wind erosion in cultivated areas. The soils assigned to group 1
are the most susceptible to wind erosion, and those assigned to group 8 are the
least susceptible. The groups are described in the "National Soil Survey Handbook."
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Custom Soil Resource Report
Wind erodibility index is a numerical value indicating the susceptibility of soil to wind
erosion, or the tons per acre per year that can be expected to be lost to wind
erosion. There is a close correlation between wind erosion and the texture of the
surface layer, the size and durability of surface clods, rock fragments, organic
matter, and a calcareous reaction. Soil moisture and frozen soil layers also
influence wind erosion.
Reference:
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. (http://soils.usda.gov)
30
Custom Soil Resource Report
Three values are provided to identify the expected Low (L), Representative Value (R), and High (H).
31
Custom Soil Resource Report
Physical Soil Properties-Cabarrus County, North Carolina
Map symbol
Depth
Sand
Silt
Clay
Moist
Saturated
Available
Linear
Organic
Erosion
Wind
Wind
and soil name
bulk
hydraulic
water
extensibility
matter
factors
erodibility
erodibility
density
conductivity
capacity
group
index
ML-
W
Kw
Kf
T
In
Pct
-WI
Pct
Pct
g/cc
micro m/sec
In/In
Pct
Pct
ChA-
Chewacla
sandy loam, 0
to 2 percent
slopes,
frequently
flooded
Chewacla,
0-4
-40-
-38-
3-23- 35
1.30-1.45-
4.00-9.00-14.00
0.15-0.20-0.2
0.0- 1.5- 2.9
1.0- 2.5-
.28
.28
5
6
48
frequently
1.60
4
4.0
flooded
4-26
-17-
-53-
18-30- 35
1.30-1.40-
4.00-9.00-14.00
0.15-0.20-0.2
0.0- 1.5- 2.9
0.5- 1.3-
.37
.37
1.50
4
2.0
26-38
-43-
-38-
18-19- 35
1.30-1.45-
4.00-9.00-14.00
0.12-0.16-0.2
0.0- 1.5- 2.9
0.5- 1.3-
.37
.37
1.60
0
2.0
38-60
-34-
-37-
18-30- 35
1.30-1.40-
4.00-9.00-14.00
0.15-0.20-0.2
0.0- 1.5- 2.9
0.5- 1.3-
.28
.28
1.50
4
2.0
60-80
-41-
-37-
5-22- 35
1.30-1.40-
4.00-23.00-42.0
0.11-0.12-0.1
0.0- 1.5- 2.9
1.0-2.0-
.28
.28
1.50
0
3
3.0
Wehadkee,
0-8
-44-
-40-
5-16- 27
1.35-1.48-
14.00-28.00-42.
0.10-0.13-0.1
0.0- 1.5- 2.9
2.0- 3.5-
.28
.28
5
5
56
undrained
1.60
00
5
5.0
8-43
-56-
-18-
18-27- 35
1.30-1.40-
4.00-9.00-14.00
0.16-0.18-0.2
0.0- 1.5- 2.9
0.0-0.5-
.20
.20
1.50
0
1.0
43-80
-67-
-15-
5-18- 30
1.35-1.48-
4.00-23.00-42.0
0.10-0.15-0.2
0.0- 1.5- 2.9
0.0- 0.3-
.20
.20
1.60
0
0
0.5
Riverview
0-18
-43-
-39-
10-19- 27
1.30-1.45-
4.00-9.00-14.00
0.16-0.20-0.2
0.0- 1.5- 2.9
0.5- 1.3-
.32
.32
5
5
56
1.60
4
2.0
18-46
-38-
-36-
18-27- 35
1.20-1.30-
4.00-9.00-14.00
0.15-0.19-0.2
0.0- 1.5- 2.9
0.5- 0.8-
.32
.32
1.40
2
1.0
46-55
-67-
-15-
10-18- 30
1.20-1.35-
4.00-9.00-14.00
0.08-0.12-0.1
0.0- 1.5- 2.9
0.0- 0.3-
.20
.20
1.50
5
0.5
55-72
-34-
-37-
10-30- 35
1.20-1.35-
4.00-9.00-14.00
0.08-0.12-0.1
0.0- 1.5- 2.9
0.0- 0.3-
.32
.32
1.50
5
0.5
32
Custom Soil Resource Report
Physical Soil Properties-Cabarrus County, North Carolina
Map symbol
Depth
Sand
Silt
Clay
Moist
Saturated
Available
Linear
Organic
Erosion
Wind
Wind
and soil name
bulk
hydraulic
water
extensibility
matter
factors
erodibility
erodibility
density
conductivity
capacity
group
index
Kw
Kf
T
In
Pct
Pct
Pct
g/cc
micro m/sec
In/In
Pct
Pct
72-80
-38-
-36-
18-27- 35
1.20-1.30-
4.00-9.00-14.00
0.15-0.19-0.2
0.0- 1.5- 2.9
0.5- 0.8-
.32
.32
1.40
2
1.0
KkB-Kirksey
silt loam, 1 to
6 percent
slopes
Kirksey
0-7
-21-
-67-
4-12- 20
1.20-1.30-
4.00-9.00-14.00
0.15-0.19-0.2
0.0- 1.5- 2.9
0.5- 1.3-
.49
.49
3
5
56
1.40
2
2.0
7-37
- 7-
-64-
18-29- 35
1.20-1.30-
1.40-3.00-4.00
0.12-0.15-0.1
0.0- 1.5- 2.9
0.0- 0.3-
.49
.49
1.40
8
0.5
37-49
-14-
-71-
5-15- 25
1.20-1.30-
4.00-9.00-14.00
0.11-0.13-0.1
0.0- 1.5- 2.9
0.0- 0.3-
.55
.55
1.40
5
0.5
49-80
-
-
-
-
0.00-7.00-14.00
0.00-0.00-0.0
-
-
1
33
Custom Soil Resource Report
Soil Qualities and Features
This folder contains tabular reports that present various soil qualities and features.
The reports (tables) include all selected map units and components for each map
unit. Soil qualities are behavior and performance attributes that are not directly
measured, but are inferred from observations of dynamic conditions and from soil
properties. Example soil qualities include natural drainage, and frost action. Soil
features are attributes that are not directly part of the soil. Example soil features
include slope and depth to restrictive layer. These features can greatly impact the
use and management of the soil.
Soil Features
This table gives estimates of various soil features. The estimates are used in land
use planning that involves engineering considerations.
A restrictive layer is a nearly continuous layer that has one or more physical,
chemical, or thermal properties that significantly impede the movement of water and
air through the soil or that restrict roots or otherwise provide an unfavorable root
environment. Examples are bedrock, cemented layers, dense layers, and frozen
layers. The table indicates the hardness and thickness of the restrictive layer, both
of which significantly affect the ease of excavation. Depth to top is the vertical
distance from the soil surface to the upper boundary of the restrictive layer.
Subsidence is the settlement of organic soils or of saturated mineral soils of very
low density. Subsidence generally results from either desiccation and shrinkage, or
oxidation of organic material, or both, following drainage. Subsidence takes place
gradually, usually over a period of several years. The table shows the expected
initial subsidence, which usually is a result of drainage, and total subsidence, which
results from a combination of factors.
Potential for frost action is the likelihood of upward or lateral expansion of the soil
caused by the formation of segregated ice lenses (frost heave) and the subsequent
collapse of the soil and loss of strength on thawing. Frost action occurs when
moisture moves into the freezing zone of the soil. Temperature, texture, density,
saturated hydraulic conductivity (Ksat), content of organic matter, and depth to the
water table are the most important factors considered in evaluating the potential for
frost action. It is assumed that the soil is not insulated by vegetation or snow and is
not artificially drained. Silty and highly structured, clayey soils that have a high water
table in winter are the most susceptible to frost action. Well drained, very gravelly,
or very sandy soils are the least susceptible. Frost heave and low soil strength
during thawing cause damage to pavements and other rigid structures.
Risk of corrosion pertains to potential soil -induced electrochemical or chemical
action that corrodes or weakens uncoated steel or concrete. The rate of corrosion of
uncoated steel is related to such factors as soil moisture, particle -size distribution,
acidity, and electrical conductivity of the soil. The rate of corrosion of concrete is
based mainly on the sulfate and sodium content, texture, moisture content, and
acidity of the soil. Special site examination and design may be needed if the
combination of factors results in a severe hazard of corrosion. The steel or concrete
in installations that intersect soil boundaries or soil layers is more susceptible to
34
Custom Soil Resource Report
corrosion than the steel or concrete in installations that are entirely within one kind
of soil or within one soil layer.
For uncoated steel, the risk of corrosion, expressed as low, moderate, or high, is
based on soil drainage class, total acidity, electrical resistivity near field capacity,
and electrical conductivity of the saturation extract.
For concrete, the risk of corrosion also is expressed as low, moderate, or high. It is
based on soil texture, acidity, and amount of sulfates in the saturation extract.
35
Custom Soil Resource Report
Soil Features—Cabarrus County, North Carolina
Map symbol and
Restrictive Layer
Subsidence
Potential for frost
Risk of corrosion
soil name
action
Kind
Depth to
Thickness
Hardness
Initial
Total
Uncoated steel
Concrete
top
Low -RV-
Range
Low-
Low -
High
High
High
In
In
In
In
ChA—Chewacla
sandy loam, 0 to
2 percent slopes,
frequently flooded
Chewacla,
—
—
0
—
None
High
Moderate
frequently
flooded
Wehadkee,
—
—
0
—
None
High
Moderate
undrained
Riverview
—
—
0
—
None
High
Moderate
KkB—Kirksey silt
loam, 1 to 6
percent slopes
Kirksey
Lithic bedrock
40-
—
Very strongly
0
—
None
High
High
49-60
cemented
36
References
American Association of State Highway and Transportation Officials (AASHTO).
2004. Standard specifications for transportation materials and methods of sampling
and testing. 24th edition.
American Society for Testing and Materials (ASTM). 2005. Standard classification of
soils for engineering purposes. ASTM Standard D2487-00.
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of
wetlands and deep -water habitats of the United States. U.S. Fish and Wildlife
Service FWS/OBS-79/31.
Federal Register. July 13, 1994. Changes in hydric soils of the United States.
Federal Register. September 18, 2002. Hydric soils of the United States.
Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric
soils in the United States.
National Research Council. 1995. Wetlands: Characteristics and boundaries.
Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service.
U.S. Department of Agriculture Handbook 18. http://www.nres.usda.gov/wps/portal/
nres/detail/national/soils/?cid=nres 142p2_054262
Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for
making and interpreting soil surveys. 2nd edition. Natural Resources Conservation
Service, U.S. Department of Agriculture Handbook 436. http://
www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053577
Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of
Agriculture, Natural Resources Conservation Service. http://
www. nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nres142p2_053580
Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and
Delaware Department of Natural Resources and Environmental Control, Wetlands
Section.
United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of
Engineers wetlands delineation manual. Waterways Experiment Station Technical
Report Y-87-1.
United States Department of Agriculture, Natural Resources Conservation Service.
National forestry manual. http://www.nres.usda.gov/wps/portal/nres/detail/soils/
home/?cid=nres142p2_053374
United States Department of Agriculture, Natural Resources Conservation Service.
National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/
detail/national/landuse/rangepasture/?cid=stelprdb1043084
37
Custom Soil Resource Report
United States Department of Agriculture, Natural Resources Conservation Service.
National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/
nres/detail/soils/scientists/?cid=nres142p2_054242
United States Department of Agriculture, Natural Resources Conservation Service.
2006. Land resource regions and major land resource areas of the United States,
the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook
296. http://www.nres.usda.gov/wps/portal/nres/detail/national/soils/?
cid=nres142p2_053624
United States Department of Agriculture, Soil Conservation Service. 1961. Land
capability classification. U.S. Department of Agriculture Handbook 210. http://
www.nrcs.usda.gov/lnternet/FSE—DOCUMENTS/nrcsl 42p2_052290.pdf
38