1 soilcolors handout
TRANSCRIPT
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Accelerated Certification Training, Soil
Color Interpretation, October 2012
David Hammonds, Environmental Manager
Florida Department of Health
Division of Disease Control and Health Protection
Bureau of Environmental Health
Onsite Sewage Programs
850-245-4570
ACT PRESENTATION 1
COLOR INTERPRETATION ANDSOIL TEXTURES
OCTOBER 2012
Materials for the soils training
section were provided by the
FDOH, USDA NRCS, Wade Hurt,
Dr. Willie Harris, Dr. Mary
Collins, Dr. Rex Ellis, the
Florida Association of
Environmental Soil Scientists,
Dr. Michael Vepraskas, the
University of Minnesota and the
US EPA Design Manual
Why is soil color so important?
Many physical and chemicalcharacteristics of the soil can bemeasured in the laboratory. This isoften a time consuming and expensive
process. However, some characteristicsof the soil such as color and texture (soilmorphology), can easily and quickly beestimated in the field and correlated withphysical and chemical properties thatwould otherwise have to be measured inthe laboratory.
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Why is soil color so important?
Information that can be obtained
from soil color includes:Relative organic matter content
Mineralogy
Depth to seasonal high water table
Geologic history
Genesis of diagnostic features in thesoil.
Why is it important to use the Munsell
Soil Color Book when determining a soil
color? Soil color is extremely important to the
classification of soils. The Munsell soil
color charts provide a standard
reference by which all soil samples can
be compared. Anyone who has a
Munsell Soil Color Book can precisely
communicate soil color data to another
person who uses the system. Proper
coloring methodology must be used.
Do some areas of the state
lack vivid, highly contrasting
soil colors?
Yes. The soils that are on some Florida
landscapes exhibit very subtle colorpatterns, and they may be more difficult
to discern than color patterns with
highly contrasting boundaries.
Routine consultation with your areasoil scientist will help you with SHWT
determinations.
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Is it less important to describe
subtle soil colors and color
patterns?
Absolutely not. All colors andcolor patterns must be described.
Subtle soil colors and patterns
carry no less weight in the
determination of soil properties.
They are simply more difficult to
discern.
Is it less important to describe
the color of disturbed soils and
fill material? No. The color and color patterns in
newer fill material are indicative ofwetness and other conditions at thesite from which the material wasexcavated. Although the color ofrecently placed fill material provides noinformation about the fill site, the colorof the fill can provide us informationabout the nature of the material.
(continued)
Also, contrasting colors of materials atthe fill site can help us distinguish the
boundary between the fill material and
the natural soil below. Finally, changes
in color that occur in the drainfield (or
surrounding areas) after the material
has been in place for several months
can provide helpful information
concerning system function and
seasonal high water tables.
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Properly identifying soil morphology
(characteristics observable in the field) is
the most important step leading to a
properly permitted, functional onsitesewage treatment and disposal system.
If you make mistakes at this step, the
worst-case scenario is that the system
will not meet required health standards
and put the public at risk of waterborne
disease.
Properties used in
describing soil layers
Color: A key property in soil interpretation
Most evident
Influenced by Organic Matter (OM) andredox-sensitive metals (Iron, Manganese)
REDOX=Oxidation/Reduction reaction- aprocess in which one or more substances
are changed into others
Wetness affects OM and redox-sensitivemetals
Properties used in describing
soil
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Basics: Soil Color- the dominant morphological
feature used to predict the SHWT
Matrix dominant (background) color of
soil horizon Mottle splotch of color, opposite ofmatrix
Redoximorphic (Redox) Featuresspecific features formed from oxidation-reduction reactions used to predictseasonal high water tables, includescertain types and amounts of mottles.They are caused by the presence of waterand minerals in the soil.
QUESTIONS???
HOW TO PROPERLY
COLOR SOI L SAMPLES
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ColorAn organized,
quantitative, andefficient way of
describing what we
see.
We must be
consistent in how we
gauge color. We use
the Munsell System.
Proper Methodology
USDA Notation and terminology must
be used for determination of soil
textures and soil colors.
USDA NRCS methodology is referenced
by DOH regulations and therefore MUST
be used for ALL OSTDS purposes.
No other methodology is acceptable.
The Munsell Soil Color Charts
The current edition is the 2009revised edition.
Can use older books if consistentwith current information (more
later).
Replacement sheets no longeravailable.
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Munsell Color Chart White Page
A Munsell white page shows half
steps from value 8.5 to 9.5 withchromas of 1 and 2 for hues N, 7.5YR,
10YR, and 2.5Y.
These may be of most use foridentifying stripped matrix, as they are
very high value, low chroma colors.
Munsell 10Y and 5Y Chart
This was added for glauconite soils.
Glauconite does not exist in Florida.
If these colors exist in the soil, it is not
due to glauconite (a specific green-
colored mineral).
Current
Cover
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Used to describe soils so there is accurate
communication about soil color. Three
descriptive elements are used.
In order they are:
HUE
VALUE
CHROMA
Munsell Color Notation
They are written in a specific
order:
HUE VALUE/CHROMA
Example: 10R 5/8
HUE Identifies the basis spectral color or
wavelength (Red, Yellow, Yellowish-
Red, etc.)
Each Hue consists of a different page
in the Munsell color book (except forGley colors more later)
Most commonly used Hue in Florida is10YR (but dont just look on that page)
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HUE Symbols (letter abbreviations)
R = Red; YR = Yellow-Red; Y = Yellow
Gley Charts include B (Blue);G (Green); P (Purple) and N (Neutral)
The letter is preceded by numbers 0 to 10
Within each letter range the Huebecomes more yellow and less red as the
numbers increase. For example:
2.5YR is more red than 5YR
7.5YR is less yellow than 10YR
HUE Symbols The middle of the letter range is at 5
and the 0 point is the same as the 10
point of the next redder Hue.
Therefore, 5YR is in the middle of the
yellow-red Hue, which extends from
10R (0YR) to 10YR (0Y).
Pages in Munsell Book are prearrangedfrom most red through most yellow.
Hue- basis spectral color; wavelength
RED
Hues in blue are the
common soil hues.
0R 2.5R 5R 7.5R 10R
0YR 2.5YR 5YR 7.5YR 10YR
SAME
HUES
YELLOW-RED
0Y 2.5 Y 5Y 7.5Y 10Y
SAME
HUES
YELLOW
Note increments of 2.5
between each
consecutive hue (this
is one unit of hue)
Moving from left to right
becomes more yellow,
even within groups
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VALUE Indicates the degree of lightness or
darkness, or reflectance of an object
viewed in daylight
Scale is from 0 for the ideal black to 10
for the ideal white, in steps (units) that
are visually equal.
Lightness increases from black at the
bottom of page, through the grays, to
nearly white at the top of the page.
Value
A color with a Value of 5/ isvisually halfway between
absolute white and absolute
black
A Value of 7/ is 70% of the wayfrom black to white and midway
between values of 6/ and 8/
Value
The
Lightness or
Darkness of
Spectral
Color
PURE WHITE 10/0
GRAY 5/0
PURE BLACK 0/0
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Value Is a measure of soil
Organic Matter
Value 7 colors are
lighter than Value 3
colors (when
compared at same
Chroma) due to
amount of organic
matter (OM)
CHROMA The color intensity, saturation or relative
strength of color. Indicates the degree
of departure from a gray of the same
Value.
The scale is from 0 - 8 on the Munsell
Color Chart. 0 indicates no strength (no
color; gray) and 8 greatest strength
(most color). Numbers are units of
Chroma.
Read from left (lowest) to right (highest).
Increasing strength of color (at same Value)
Neutral
Color
Pure
Color
1 2 3 4 6 8
Increasing grayness
CHROMA strength of color
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Chroma How intense the color
is.
This is a measure ofcoloring agents (e.g.
iron).
Chroma 6 colors are
more intense (vivid)
than Chroma 2 colors
(when compared at the
same Value).
Colors BETWEEN Chroma Chips
Colors do exist between Chroma chips
They are noted differently than others
If the chroma is between two chips, note
the lower one and add a + as a
notation.
Example: The soil has more color than10YR 6/1 and not enough for a 10YR 6/2.
The proper notation would be 10YR 6/1+
Colors BETWEEN Chroma Chips
DO NOT ROUND UP TO THE NEXTHIGHER CHROMA.
THIS IS ESSENTIAL WHENDECIDING IF SPECIFIC COLORS
CAN BE USED AS AN INDICATOR OF
SEASONAL HIGH WATER TABLE
(more later).
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Munsell Notationand color names
Read/Write only in this
format:
HUE VALUE/CHROMA
Correct Coloring
Hold soil behind the hue card with thecolor chips (the right side of theMunsell Book).
Find the closest match from allchoicesin the book, read Hue Value/Chromanotation.
Look to left side and match HueValue/Chroma from right side for soilcolor name.
See next slide for examples.
COLOR NAME DIAGRAM MUNSELL NOTATIONS
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When using the Munsell book
Use the book properly Pages must beusable!!!
Do not take too long to read the color Use the chip masks if necessary
Use black chip mask for dark samples, grayor white for neutral and light soil samples.
The use of a chip mask will facilitate colormatching when there is difficulty in choosing
a color. The mask allows only 4 chips to be
seen at one time. Located inside the back
cover of the Munsell Book.
CHIP MASKS
QUESTIONS???
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PROPER COLORINGTECHNIQUE WHEN
DETERMINING SOIL
COLORS
Reading soil colors
Optimum
conditions
Natural light
Clear, sunny day
Midday
Light at right
angles
Soil is moist (not
wet or dry)
What is moist? A moist sample will not get any darker
when water is added to the sample, andit will not glisten. A sample that is toowet will glisten in the sunlight, or the
water puddles on the sample. When texturing, the soil should be
easily manipulated by your thumb andforefinger.
In non-sandy soils, this could becompared to moist putty.
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Properly Coloring Soil
Correct Moisture Content
DRY SOIL MOIST SOIL
MUST USE
THIS ONE
TOO WET
Sun over RT shoulder
RT angle to page
READING SOIL COLORS
NO Sunglasses!!!
Pages are
UNALTERED/
ORIGINAL/
CLEAN
Small/Moist sample BEHIND
the hue card!NEVER
ON THE PAGE!!
Sample size
Note sample size.
Use what you
need to color,no more
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Sample is behind the hue card
Sample
NOT THE RIGHT WAY!!!
Different types of
Colors:
The GLEYchartsThese are read
differently than the
other charts
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GLEY CHARTSTwo supplemental charts containing
grayish, bluish and greenish colorsoften found in very wet mineral soils
are contained on these charts. The
charts also contain a Neutral Hue
(no chroma). Soils with specific
colors on these charts are very wet
and will be discussed in a separate
presentation.
The Gley ChartsHues are found in
EACH INDIVIDUAL
COLUMN at the bottom
of the page.
Values are on left, like
other charts.
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Values
on left
side
Hues on bottom
What about the CHROMAfor the Gley Charts?
Read the chroma from theEnglish name (color name
diagram) side of the charts.
Chroma designation will be
to the right of the forward
slash. See next slide.
Read Chroma from right of
forward slash
NO CHROMA
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Note that all hues on the Gley
Charts are chroma 1, except for
two hues:
N (Neutral) having 0 (no) chroma(this is due to lack of iron giving
any color), and
5G _/2.
QUESTIONS???
Examples of Munsell Books
(The Good, the Bad and the Ugly)
Which Munsell books/Hue cards
you should and should not use, or
how to know when to get a new
Hue card (or new book)
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Some of the problems
Values or chromas have changed within
the same hue between editions
Addition of new hues
Missing chips
Dirty chips (no longer are correct color)
Some of the problems
Cracked/faded/discolored chips
Chips taped to page
The pages have been laminated.
The book has been left in the rain
and has mildewed, obscuring the
colors.
Two 10R
pages
from
differentyears.
Note
new
chips.
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This is really
a new row
This column
deleted
New columns of color
Tape over
chips,
missing
chips,
cracked
chips,
discolored
(dirty/faded)
chips.
Current and
clean page
on right.
Comparison
of 2 cards
(New behindold, look at
differences
in colors)
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Comparison
of both cards
Old over new.Compare
colors at
same colored
arrows
Use of the older cards would
result in misidentification of
soil colors, including the
SHWT identification features,
which will result in improper
determination of the SHWT.
Determining Differences
between soil colorsSoil Color Contrast
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Hue Difference
First must determine the differencein the HUES of each color
Should use color wheel (later slide)
Quick method for most colors is tocount pages in accordance with
following diagram. (Note: signifieschange in and h signifies Hue;
therefore h means change in Hue)
h=1 per page, count # of pagesh1 per page. Count
# of 2.5-unit intervals.
Use of the Munsell
Hue CircleUSDA NRCS Technical
Note 2
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The hues shown in RED are the approved soil
hues. In a clockwise
direction, hues
of5R through 5Y
are spaced at2.5-unit intervals.
These hues arenormal soil
hues.
This equates toone unit of hue
between each
hue.
Of theremaining
approved soil
hues (in red),
between 5Y
and 5PB the
interval
between each
soil hue is
TWO 2.5-unit
intervals.
Thiscorrelates to
two units of
hue between
each soil hue
To calculate Hue Change: To determine the "difference in hue"
between colors, COUNT THE NUMBER OF
2.5-UNIT INTERVALS.
For example, hues of 2.5Y and 7.5YRdiffer by two 2.5-unit intervals (7.5-2.5=5,
which is two 2.5 unit intervals), and so
their difference in hue is counted as "2.
Hues of 5Y and 5GY differ by four 2.5-unitintervals, and so their difference in hue is
counted as "4.
Could also just use the wheel.
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Hue change from
Neutral
The Hue change fromNEUTRAL to ANY
OTHER HUE is a
change of ONE UNIT
OF HUE.
Units of Value Change Units of value range from 0 to 10. Normally,
there is a one unit change between each
color, but there may be less.
For example:
The difference in Value between a
10YR 5/1 and a 10YR 7/1 is 2 UNITS. (The
difference between 5 and 7 is 2.)
The difference in Value between a
7.5YR 2.5/1 and a 7.5YR 3/1 is 0.5 UNITS
(3-2.5=0.5, or
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VERY
IMPORTANT!!! TO DETERMINE VALUE
CHANGE, CALCULATE
DIFFERENCE BETWEEN THE
UNITS
(Value of 2.5, 3, 4, etc.)
DO NOT COUNT CHIPS !!
Units of Chroma Change
Units for Chroma range from 0 to 8.There is a one or two unit changebetween each color.
1 UNIT CHANGE/CHIP 2 UNIT CHANGE/CHIP
VERY
IMPORTANT!!! TO DETERMINE CHROMA
CHANGE, CALCULATEDIFFERENCE BETWEEN
THE UNITS(Chroma of 1, 2, 3, 4, etc.) DO NOT COUNT CHIPS !!
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Units of Chroma Change For example:
The difference in Chroma between a
7.5YR 5/1 and a 10YR 5/2 is 1 unit. (2-
1=1)
The difference in Chroma between a
10YR 5/3 and a 10YR 5/6 is 3 units
(6-3=3).
Note that there is a change oftwo chips
but is actually a change of 3 units of
chroma.
Note When reading values and chromas,
only those units are considered.Compare Value to Value andChroma to Chroma.
Change in hue does not affect thecalculation of the differencebetween values or chromas, theyare independent of each other.
Simply determine the value or
chroma in each color and calculatethe difference without regard to hue.
QUESTIONS???
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Contrast between Soil Colors
Contrast refers to the degree of visual
distinction between associated colors.Faint contrasts that are evident only
on close examination.
Distinct -- contrasts that are readily
seen but are only moderately expressed
Prominent -- contrasts that are
strongly expressed.
Can different people
uniformly and
consistently judge these
subjective criteria with
no other guidelines?
QUESTION -
Not very likely!!!!
We need a method by which wecan be more objective with our
determination. So, we use
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USDA NRCS Soil
Survey Technical NoteNo. 2
May 2002Soil Color Contrast
Definitions
This is
the cover
page
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In the following slides, the symbol
(delta) means change or
difference in. For example:
h=1 means the change ofhuebetween the two colors is one
2.5-unit interval.
Example 7.5YR TO 10YR
Use the method given in the
technical note to determine hue
difference.
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h = 0:
3 Faint
9 Distinct
5 Prominent(Note that a
value or
chroma 4
is prominent)
h = 1
2 Faint
4 Distinct
4 Prominent(Note that a
value or
chroma 3
is prominent
h = 2
1 Faint
2 Distinct
3 Prominent(Note that a value or chroma 2 isprominent)
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h = 3
All color contrast is prominent bydefinition -
EXCEPT FOR THOSE VALUES 3AND CHROMAS2, WHICH ARE
FAINT BY DEFINITIONREGARDLESS OF HUE CHANGE
Using matrix Color 10YR 4/2 (red box area)
the soil color contrast comparison is:
FAINT
DISTINCT
PROMINENT
FAINT
DISTINCT
PROMINENT
DISTINCT
PROMINENT
FAINT
If you believe you have
found a discrepancy in
the chart:
USE DEFINITION OF
SOIL COLOR
CONTRAST TERMS
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Or: Few, Common or Many RedoxFeatures?
The quantity (volume) of the redoximorphicfeatures in the soil sample is important in
the determination of the estimated seasonalhigh water tables.
Redoximorphic features mustbe at least COMMON, but can
also be MANY.
They CANNOTbe FEW.
So, what is the required volume
redox features must occupy to
count as common or
many?
Quantity of Redoximorphic
Features (few, common, many)
The following amountscorrelate with specific
percentages:
Few -- less than 2% (20%)
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Determination of the
quantity of Redox Features
Use the Charts for EstimatingProportions of Mottles andCoarse Fragments found inthe Munsell Soil Color Charts.These will quantify the amountof redox features.
Abundance and Size of Color
Contrasting Areas Size of mottles
Fine < 5 mmMedium 5 to 15 mmCoarse > 15 mm
Note that the size ofthe mottles do notmatter, only theamount.
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QUESTIONS???
Which procedure is
performed first?
Texturing the soil?
Coloring the soil?
Coloring
Why? Glad you asked!
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The first thing normally observed aboutthe soil is how it looks. The same soilsample should be used to both colorand texture. This increases accuracy of
the profile. Redoximorphic features could be
overlooked if the soil was textured firstdue to the physical manipulation of thesoil. All colors in the sample arerecorded before being combined fortexturing, especially in loamy/clayeysoils, where multiple colors blend.
See what happens?
AT LEAST 4 COLORS EXIST IN SAMPLE
BEFORE MIXING
AFTER MIXING
Where is the best place to get
the soil sample?
The sample to be colored (and textured)should come from an area that has not been
disturbed or contaminated from the process
of taking the sample (e.g. turning of the soilauger). For example, in heavier textured
soils, the outside of the sample is often
marred by the turning of the auger and is
contaminated by soil above it. The true color
(or texture) of the soil is not on the outside of
the sample.
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Heavy textured soils
(loams and clays)
The sample must be obtained from the
area of least disturbance, normally themiddle of the sample.
The soil sample should be brokenlongitudinally to observe the colors and
to collect the sample for texturing.
EXAMPLE IN AUGER BUCKET
Inside of sample
Outside of sample
INSIDE THE
AUGER BUCKET
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Sandy soils Sandy soils are not easily removed
from the bucket in one or two large
pieces. The sample still must come from an
unadulterated area. Make sure that
what you are looking at is from the
horizon in question, not debris from a
different source (soil falling into hole or
onto sample).
SANDY SOIL WITH REDOX
Careful observation is required. Redoxfeatures can be missed when using a
bucket auger. Take the time necessary
to make proper observations.
Use a shovel to remove a plug of soil to
determine the depth to the uppermostSHWT feature. The larger soil sample
size makes it easier to see soil features.
Some redox features are harder to see
in an auger.
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Approximate
comparisonbetween
samples
found in
auger and
sharpshooter
shovel
Soil Formation -
Horizons
What is a Soil Horizon?
Soil Horizon Basics A soil horizon is a layer of soil, approximately
parallel to the surface, having distinctcharacteristics produced by the soil-formingprocess.
Soil has natural organization and is
biologically active. This is a result of severalfactors that will be discussed in a laterpresentation.
Individual kinds of soils are distinguished bytheir specific sequence of horizons, or soilprofile. The characteristics and verticalsequence of these horizons vary in naturalpatterns across the landscape.
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SOIL TEXTURES
Why is Soil Texture Important?
Soil texture controls whichredoximorphic features are used to
determine the seasonal high water
table.
Soil texture controls the size of thedrainfield/unobstructed area once the
estimated daily sewage flow rate is
known.
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COMPONENTS OF THE SOIL
There are 4 basic components of
soil.
Minerals
Organic Matter
Water
Gases
Soil Minerals: Particle Size
For DOH purposes, only mineralparticle size is considered, as
opposed to the material from
which the particle is made.
Mineral size is broken down intothree main categories.
Three Mineral Sizes
Sand
Silt
Clay
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Soil Particle Size
Comparison
.Sand Silt Clay Sand: 2.00-0.5 mm
Silt: 0.5-0.002 mm
Clay:
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SAND Size Subdivisions
Fine Sand and MediumSand (medium sand is
referred to as sand) are
the most common of the
sand sizes that are found
in Florida.
Sand is the only
particle size that is
subdivided into
smaller categories for
texturing purposes.
SAND Size Subdivisions Very Coarse Sand: 2.00 - 1.00 mm;
thickness of nickel to just under a dime
Coarse Sand: 1.00 0.50 mm; about 4sheets of standard paper thickness
(smallest)
Medium Sand (Sand): 0.50 0.25 mm;sugar grain size
Fine Sand: 0.25 0.10 mmpen point orstrand of hair, thickness of business card
Very Fine Sand: 0.10 0.05 mm usemagnifying glass to see
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Silt
SILT facts Intermediate in diameter between sand
and clay
Size is 0.05mm to 0.002mm in diameter
Difficult to see without magnification
When moist or dry, feels smooth andfloury; silky
Primarily found on floodplains of riversand areas in the southern part ofFlorida (rare in Florida, but moreabundant in SW Florida)
Clay
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CLAY facts Smallest mineral particle
Size is
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Loam Is not a soil particle size.
Loam is a soil texture composed ofspecific percentages of sand, silt andclay.
When texturing, a loam feels like equalparts of sand, silt and clay (feelssomewhat gritty, yet fairly smooth andslightly plastic. When moist, it forms acast that may be handled quite freelywithout breaking ), but it does not haveequal parts of each separate.
NOTE:
Review 64E-6.016 for soil
texture classification,
including divisions
between
sand particle sizes
The Textural Triangle
Used to simplify description of particlesize mixtures (i.e. texture)
USDA NRCS Soil Textural Classification
is required by rule. Only schemeacceptable by regulation.
12 classes of soil texture are depictedon a 3-axis graph
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Lab soil sample analysis:
All the individual particle sizes (SAND,
SILT, CLAY) must equal 100 % (or very
close, a little might be lost on the sieves)
So, if we have a soil sample of 300 grams,
once the soil fractions have been divided
by size, the weights are as follows: Sand
275g, Silt 20g and Clay is 5g, the
percentages are:
Sand = 275/300 = 91.67%(92%)
Silt = 20/300 = 6.67% (7%)
Clay = 5/300 = 1.67% (1%) Sample size adds up to
300 g (275+20+5=300), the
original sample weight)
The soil texture is:
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92% S; 7% Si; 1% C
So this is SAND (size of sand
particle unknown. FS/S/COS?)
Texture Example 2
80% sand
15% silt
5% clay
100 percent total
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80% S
5%C
15% Si
So this is a LOAMY SAND (LS)(Dont know size of sand particles)
What happens if the
percentages fall on adividing line??
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Texture Example
80% Sand
10% Silt
10% Clay
100 percent total
Close-up of intersection of 3
lines
Is this aloamysand or asandyloam?Why?
Whenever the point falls on a
line, the evaluator MUST go with
the more stringent soil texture
according to NRCS
methodology. So, the answer is SANDY LOAM(SL)
Note that we still dont know theactual size of the sand particles, it
could be COSL, SL, FSL, VFSL.
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CAUTIONS ON LAB ANALYSIS
MAKE SURE THAT THE RESULTS ARE
UNDERSTOOD! WHAT METHODS WERE USED?
SIEVE ANALYSIS?
THE RESULTS MUST ACCOUNT FORSAND GRADATION AS WELL AS
SILT/CLAY CONTENT
Example CHD sends a sample to an agricultural lab and
asks for a texture determination
Sample comes back as percent Sand/Silt/Clayso that the result can be read on the Textural
Triangle. Result was given as Sandy Loam.
The size of the sand had not been determined,so it is unknown if sample is COSL, SL, FSL or
VFSL.
The actual sand fragments would determineproper sizing of system.
For DOH purposes, accepting this lab report at
face value would be a mistake.
The result in this case? CHD ACCEPTED THE SOIL AS SANDY
LOAM
THIS HAS NO AFFECT ON REDOXFEATURES
THE SOIL TYPE WAS ACTUALLY FINESANDY LOAM
DRAINFIELD WAS UNDERSIZED BY
OVER 23 PERCENT
UNOBSTRUCTED AREA TOO SMALL
PERMITTING ISSUES???
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When supplying soils
samples to a lab alwaysensure a complete texture
determination is made.
This must include a sieve
analysis to determine the
sand size.
Common Soil Textures in Florida
*Fine Sand (FS)
*Sand (S)
Loamy Fine Sand (LFS)
Loamy Sand (LS)
Fine Sandy Loam (FSL)
Sandy Loam (SL)
Sandy Clay Loam (SCL)
Sandy Clay (SC)
*most common
**NOTE THAT THE
TEXTURE OF LVFS IS
CONSIDERED TO BE A
LOAMY TEXTURED SOIL
FOR PURPOSES OF
REDOX FEATURE
IDENTIFICATION.**
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QUESTIONS???
PROPER TEXTURING
METHODOLOGY FOR
MINERAL SOILS
Touch Texture Method
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First, a note on WHAT
to texture
MAKE SURE THE
SAMPLE HAS NOT
BEEN
CONTAMINATED!!
The soil to be textured must notbe
contaminated from anyother source
material. For example:
Soil falling in from above the sample
Soil translocated from above, such asthe outside of the sample having soil
material from above adhering to the
auger
Soil material covering your hands fromprevious texturing.
The sample mustbe from the horizon inquestion.
For loamy and clayey soils, it is
normally best to get the sample
from the interior of the auger
sample (fortexturing and coloring).
Break the soil sample along the
long axis and retrieve the sample
from the middle.
And dont forget------
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VCOS very coarse sand COS c oarse sand S sand
FS fine sand VFS very fine sand LCOS loamy coarse
sand
LS loamy sand LFS loamy fine sand LVFS loamy very fine
sand
COSL coarse sandyloam
SL sandy loam FSL fine sandy loam
VFSL very fine sandy
loam
L loam SIL silt loam
SI silt SCL sandy clay loam CL clay loam
SICL silty clay loam SC sandy clay SIC silty clay
C clay MARL is written out MK mucky
PT peaty GR gravelly or gravels MUCK is written out
PEAT is written out Hard Rock is wri tten
out
Soft Rock is written out
What is Mineral Texture? Mineral texture is the soil texture due
to the particle size of the minerals thatare present.
This DOES NOTinclude any organicportions that may be in the soilsample.
If there is enough organic material inthe soil, it may form a ribbon, but itreally does not qualify as a soil ribbonfrom mineral soil, therefore it isunusable for texturing.
How much soil? Really need enough towork with, depends on your hand size.
Try a tablespoon or so. Dont get too
much/little.
Ribbon needs to be uniform thickness
and width. Thickness of ribbon shouldbe approximately 2 mm. The thickness
of a nickel is 1.95 mm. A quarter is 1.75
mm thick and a dime is about 1.35 mm
thick.
Ribbon width will vary between people
due to width of the thumb.
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Texture-by-Feel
MethodologyMineral Soil Only
Due to soil
texture, not
water or
organic
matter.
Poke it to
see if it
falls apart.
Must remove organics
from mineral texture
consideration
Ribbon is 1 inch
to
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SANDY SOILS DO NOT
FORM RIBBONS!!!!
(Loamy Very Fine Sand
will act more like silt
and be somewhat gritty
and malleable, but
wont ribbon.)
Loamy and Clayey Soils
All loamy and clayey soils form
ribbons, the length being thedetermining factor.
Loams form shorter ribbons
Clays form longer ones.
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What about texturing Silt???
Silt lacks grittiness and feels
extremely floury or silky whenmoist or dry. It will not ribbonand forms a weak ball that bearscareful handling withoutbreaking. Is malleable (able tobe shaped/formed).
Organic Matter (OM) and
Texturing Mineral Texture does not include OM
Must remove OM from considerationof mineral portion
If enough OM in sample, the texture ofmineral material would be modified
Do not confuse a FS soil with enoughorganics to make it form a ball with aLFS THEY ARE NOT THE SAME.
Organic soils/components Organic material in mineral soils add
difficulty in texturing.
For example, soil from a spodic layer mayform a ribbon, but it is not due to the
content of mineral particles (sand, silt and
clay). It is due to the cohesiveness of theorganic particles.
The Near Saturated Rub Test is used todetermine muck, mucky peat, or peat. This
information is then added to the mineral
component, if any. This procedure will be
discussed in the Hydric Soils Presentation.
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Soil Texturing
Pictures
Sand
Clayey soil
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Clayey soil starting to
ribbon
Clayey soil >2 ribbon
Ribbon
Comparison
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Soil Texture
Names
The major fraction is the LASTpart of the name.
So, a sandy soil includes:
All things with SAND as the
dominant particle size (e.g.loamy sand or LS).
The texture of Sand can alsobe broken down to VeryCoarse, Coarse, Medium, Fineand Very Fine.
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As stated earlier, the only soil particlesize that is divided into smaller
subgroups is SAND.
This means that when naming soils, the
same information is used.
For example: Fine Sandy Loam (FSL)
means the soil is mostly loam, and the
sand portion is fine sand. Compare to
Fine loamy sand there is NOtexture
recognized with this name. Loam is not
further divided, so one cannot have a
fine loamy anything.
Organic modified textures:
When organic soils are found in
combination with mineral soils, the
organic soil is the modifier, not the
prominent portion.
Muck, mucky peat or peat would be
added to any soil texture BEFORE the
texture is named.
This means that while a Mucky Sand
is allowed as a name, Sandy Muck is
not.
Comparison of Particle Size Classes in
Different Systems
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QUESTIONS???
Class Ex erc iseon
Textur ing Get your hands
dir ty! ! !
TEXTUREMODIFIERS
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Particle sizes 2mm are soil particles,i.e. FINE EARTH FRACTION,
(including shell fragments). This is
what is used to determine the mineraltexture.
As long as fragments that are >2 mmoccupy
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NON-SOIL PARTICLES
(Coarse Fragments)
Particles larger than 2 mm are not
soil particles (i.e. the fine-earth
fraction), they are Coarse Fragments
and have several names. They do
figure into the overall texture of a
soil by modifying the soil texture.
When the particle size exceeds 2mm,it moves out of the very coarse sand
texture and is no longer a soil
particle. These items can include
shells, rocks, or other non-soil (non-
fine earth) items. The modifier
gravellyor "GR" is used when the
fragment content by volume is 15%
to
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Soil Texture Determination Must remove the gravels (non-soil
particles) from consideration of the soil-
size particles in order to get actual soil
texture (if 15% by volume of the soil
horizon). (See next slide for example)
This is done by running the soil samplethrough a nest of sieves.
After the non-soil particles are removed,the remaining sample is the entire soil
sample and will be used to determine the
texture of the mineral soil (fine-earth)
fraction.
VCOS GRAVELSCOS
SANDFINE SAND
Mineral Texture
Remove gravels from consideration asthey are >2mm in size and do not countas part of the mineral texture.
The remaining sieves with the VCOS,COS, S, FS, and VFS (plus the pan)comprise 100% of the mineral soilsample.
The gravel portion will modify the mineraltexture name only if it occupied at least15% of the volume of the soil horizon.
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Soil Texture Determination
Once soil texture is determined, willadd the proper adjective (e.g. gravelly,
very gravelly, etc.) to soil texture toproperly name the soil.
Example:Gravelly Loamy Fine Sand indicates
that 15% and
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Fragments 15% Once the fragments (including
shell) reach at least 15%, the soil
texture is now modified.
For fragments 2 mm to 75 mm (3in.) the modifier used is
GRAVELLY.
For fragments 75 - 250 mm (10 in.)the modifier used is COBBLY.
For fragments 250 600 mm (23.75in.) the modifier used ofSTONY.
Organic Matter (OM)
The second solid component
of soils and consists
primarily of pieces and parts
of plants that are in various
states of decay. Sometimes
called humus.
Organic Matter (OM) Effects of Organic Matter on
Mineral Soils-increasing water holding capacity-adds tilth, less compacted or loosen
-DARKENS THE SOIL COLOR
Organic Matter in Dry vs. WetSoilsWhich has more?? (Wet has more)
Kinds of Organic Material- Muck (Sapric); Peat (Fibric); MuckyPeat (Hemic)
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NOTE REDDISH
COLORATION
The third component of soils. Water movesover and between soil particles in the pore
spaces.
Pore spaces - most soils containapproximately 50% pore space and they are
filled with air or water. Porosityis the amount
of pores in a given area.
The movement of liquids (and air) through thesoil is VERYimportant for OSTDS
considerations.
Permeability the rate at which water moves
through the soil.
Water: The Mobile Soil Component
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Gases
The fourth basiccomponent of soil.
Occupies the pore spacethat does not have liquid
in them.
Compaction Compaction decreases the
permeability and porosityof the soil, therebyreducingthe ability of thesoil to transfer liquidsbetween soil particles.
Compaction?
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The previous
picture was froma MOUND
SYSTEM.
Low Chroma Colors
Throughout this courseyou will hear the term
low chroma colors-
What does it mean?
Low Chroma means:
CHROMA 2 OR LESS
All hues have chroma 2 or less on thepages, therefore all hues have low
chroma colors. All Gley chart colors are totally
comprised of low chroma colors.
Specificlow chroma colors havemeaning regarding the SHWT
determination (more on this later)
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QUESTIONS???
End of presentation