1 SoilColors Handout

7/31/2019 1 SoilColors Handout

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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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Color Interpretation, October 2012 1

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

1 SoilColors Handout

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