Soil Texture in 14 minutes
Summary
TLDRIn this educational video, Sir Roger, the Dean, delves into the concept of soil texture, a fundamental and unchanging soil property. He explains that soil texture is determined by the relative proportions of sand, silt, and clay, which together form the soil's matrix. The lecture covers various methods for soil texture classification, including the USDA and ISSS systems, and discusses the technical aspects of determining soil texture through field and mechanical analysis. Sir Roger also touches on the significance of particle size, the hydrometer method, and the international pipette method. The video is designed to aid students in understanding soil texture for competitive exams, with a call to action for viewers to engage with the content by subscribing and asking questions.
Takeaways
- π± Soil texture refers to the relative proportion of sand, silt, and clay in the soil.
- π Soil texture is a basic and permanent property of soil, which does not change with management practices.
- π The size of soil particles (sand, silt, and clay) is crucial for determining soil texture.
- π The USDA classification and the International Society of Soil Science (ISSS) classification are major methods for classifying soil texture.
- π The USDA classifies soil into seven categories, while ISSS uses four categories, highlighting the distribution of soil separates.
- π§ͺ Soil texture can be determined by field methods and mechanical analysis, including hydrometer and pipette methods.
- π‘ The hydrometer method, developed by Boyd in 1927, is a relatively rapid technique compared to the pipette method.
- π¬ The pipette method, introduced by GW Robinson in 1922 and modified by HM Anderson in 1928, is considered more accurate for soil texture analysis.
- βοΈ Specific surface area is the ratio of the total surface area of soil particles to their mass or volume, with clay particles having a much higher specific area than sand.
- π The soil textural triangle is a useful tool for visually determining soil texture classes based on the proportions of sand, silt, and clay.
Q & A
What is soil texture?
-Soil texture refers to the relative proportion or percentage of three soil separates: sand, silt, and clay.
Why is soil texture considered a basic and permanent property of soil?
-Soil texture is considered a basic and permanent property because it does not change with soil management practices and is a fundamental characteristic that influences other physical properties.
What are the three soil separates and their roles in soil structure?
-Sand and silt form the skeleton of the soil, providing structure and support, while clay is referred to as the flesh of the soil, influencing water retention and nutrient availability.
What are the major classifications of soil texture?
-Major classifications include the USDA classification, the International Society of Soil Science (ISSS) classification, and the Pipette method classification.
How many categories does the USDA classification have for soil texture?
-The USDA classification has seven categories for soil texture.
What are the two methods used to determine soil texture?
-Soil texture can be determined by field methods and mechanical analysis, which includes particle size analysis.
What is the hydrometer method and who developed it?
-The hydrometer method is a relatively rapid method for soil texture determination developed by Boyd in 1927.
What is the international pipette method and who modified it?
-The international pipette method is a preferred method for soil texture determination, originally given by GW Robinson in 1922 and later modified by HM Anderson in 1928.
What is the significance of the specific surface area of soil particles?
-Specific surface area is the ratio of the total surface area of the material to its mass or volume, indicating the amount of surface area available for interaction with water and nutrients.
What are the assumptions and limitations of the hydrometer method?
-The hydrometer method assumes that soil particles are spherical, rigid, and smooth, and that there is no Brownian movement. Limitations include the requirement for uniform particle density, constant temperature, and still suspension during analysis.
How can one determine the soil texture class using the USDA soil textural triangle?
-By observing the proportions of sand, silt, and clay, one can plot these on the USDA soil textural triangle to determine the soil's textural class at the point of intersection of the plotted lines.
Outlines
π± Introduction to Soil Texture
This paragraph introduces the topic of soil texture, emphasizing its importance as a fundamental and permanent property of soil. Sir Roger, Dean explains that soil texture refers to the relative proportion of sand, silt, and clay in the soil. These components form the matrix of the soil, with sand and silt constituting the 'skeleton' and clay being the 'flesh'. The paragraph also discusses the criteria for classifying soil as sand, silt, or clay based on their respective percentages. Additionally, it touches on the major classifications of soil texture, including the USDA classification and the International Society of Soil Science classification, highlighting the seven categories recognized by the USDA and the four by the I Triple S.
π¬ Methods for Determining Soil Texture
The second paragraph delves into the methods for determining soil texture, which include field methods and mechanical analysis. The mechanical analysis is further divided into the hydrometer method and the international pipette method. The hydrometer method, introduced by Boyd in 1927, is a relatively rapid technique that involves using a Calgon solution to disperse soil particles before measuring them. On the other hand, the international pipette method, introduced by GW Robinson in 1922 and later modified by HM Anderson in 1928, is considered more accurate. The paragraph also mentions the need for removing organic matter and rocky constituents before analysis, and it briefly introduces Stokes law, which is relevant to the mechanical analysis of soil particles.
π Soil Texture Analysis and Specific Surface Area
The final paragraph discusses the assumptions and limitations of the textural analysis method, such as the requirement for soil particles to be spherical, rigid, and smooth, and the need for a uniform temperature and still suspension during analysis. It also introduces the concept of specific surface area, which is the ratio of the total surface area of the material to its mass or volume. The paragraph provides examples of specific surface area for different soil types and mentions the highest specific surface area found in vermiculite. It concludes with a brief explanation of how to determine soil texture using the soil textural pyramid or triangle, where the proportions of sand, silt, and clay are plotted to identify the soil's textural class.
Mindmap
Keywords
π‘Soil Texture
π‘Sand
π‘Silt
π‘Clay
π‘USDA Classification
π‘Hydrated Soil
π‘Hydrometer Method
π‘International Pipette Method
π‘Specific Surface Area
π‘Soil Textural Triangle
Highlights
Soil texture refers to the relative proportion of sand, silt, and clay.
Soil texture is a basic and permanent property of soil.
Sand and silt form the soil's skeleton, while clay is considered its flesh.
Soil texture is determined by the percentage of sand, silt, and clay present.
USDA classification categorizes soil into seven textural classes.
International Society of Soil Science (ISSS) classifies soil into four textural classes.
Soil particles are categorized based on their diameter.
Clay is defined as soil containing at least 40% clay particles.
Silt must contain at least 80% silt particles and less than 12% clay.
Sand is defined as soil with more than 70% sand and less than 15% clay.
Soil texture can be determined by field methods or mechanical analysis.
Hydrometer method and international pipette method are used for mechanical analysis.
Hydrometer method is a rapid technique developed by Boyd in 1927.
International pipette method is a preferred technique for clay soils, modified by HM Anderson in 1928.
Soil texture analysis involves removing organic matter and rocky constituents.
Stokes law is fundamental to understanding soil particle sedimentation.
Assumptions of the pipette method include spherical, rigid, and smooth particles.
Specific surface area is the ratio of total surface area to mass or volume.
Clay particles have a significantly higher specific surface area compared to other soil particles.
The USDA soil textural triangle is a tool for identifying soil textural classes.
Transcripts
hello dear students this is Sir Roger
Dean again with the second video and the
first lecture video the Pala video app
Sabini daily hoagie just like a man hope
Corral and in the first video we have
discussed about avi you know check your
competitive status to obser be up no
competitive status I actually John shook
a hangi kaypea hey so let us start with
the lecture video so today's topic is
soil texture so starting with the soil
texture definition we are very much
aware that soil texture refers to the
relative proportion or percentage of
three soil separates and which are sand
silt and clay so job ehim sand silt and
click a relative proportion Quora
forgotten that is designated as soil
texture the second Joe point at ahead
that soil texture is the basic and
permanent property of soil a basic you
kagayaki basic or permanent property of
soil here those horizon hey hey KJ Joe
property has oil key which comes under
physical properties Jacob he V
management practices Skiba JC Jana you
get all 10 aug 2013 14 million cubby
aapke soil texture change who sat there
otherwise yeh soil texture cubby changed
nahi hota as such
next Johan textual determination Curtin
to juvy soil particles are k - mm sasada
hangi diameter may they will not be
considered in the soil textural
determination minded dear then now out
of three soil separates your sand and
silt they form the skeleton of the soil
your clay is referred as the flesh of
the soil and all three of them all
together form the matrix of the soil now
AB Kia prerequisites Hank is disco harm
you no money or hunka hunka clay hunk of
clay cassock there so clay will only be
called as clay
when it must contain at least 40% of the
clay then silt must contain at least 80%
of the silk and 12 all less than 12% of
the clay and in case of sand if it
contains more than 70% of the sand but
with that it should you know contain
less than 15% of the clay so it now cook
clear Hojo Koga let us move on to the
next topic now let us talk about the
major classifications of the soil
texture there are a number of
classifications but comes if major
classifications by the ending icky most
of the question sub k in Edo
classification say pooja garden the
first classification is USDA
classification that means United States
Department of Agriculture or do rajo
classification and that was given by I
Triple S that means International
Society of soil science or easy
classification go home at a Burks
classification genome say be in John
Thain those subset Bella question aapke
is Samantha a key according to USDA
kidney categories soil separates could
agree so as you can see that according
to USDA there are seven categories but I
Triple S key agura but can item
oppressive four categories highlight
hood the distribution has a Jobin
Tehelka then quotient bantha up cocky
according to USDA Kiptyn e
categories miss and Cody white Kyogre so
according to SDA as you can see there
are five categories which have been
given to the sin but in case of I Triple
S only two categories have been
designated to the sin then or Kalakaua
question is urban sector kick click a
size kitna hota hai so you can easily
see that it is less than point zero zero
two mmm so in synthetic a say of course
sorry K sorry Jo diameter say yup Co
Yadkin a RP hopper apne video pause
querque in cone note down correct there
and then memorize them then acre barking
apples you Artyom mostly you see
that this silt
diameter in case of USDA ranges from
0.0 0.0 5mm by
you see cojo sighs hey i triple-s May
that ranges from point zero zero to two
point zero 2 mm to a half per point zero
five her USD MA or aapke Issa I triple s
my point zero two mmm then
yato bath hui Hammadi teen soil separate
ski but but in say oh but a
separate so then they have been
categorized to a guru round shape ke hum
yes uh Brown shaped Yong a so other
point to say 0.5 centimeter and key
diameter at Oh fine gravel smudging he
see tariqa say 0.5 say point 2
centimeter while a medium gravel me are
saying it and as I move on caretaker
they objects acting core Belkis I say
7.62 25 centimeter here is stone cop car
25 to 60 centimeter hair or bald Erica
it is more than 60 centimeter lake in a
guru up cacio soil separate her both
flat hair soju channa here
so channel Casa Hogar point to say Lake
a 15 centimeter then flagstone Kara I
engage open Drusilla K 38 centimeter
thick range carbon or stone 38 silicate
head up a 60 centimeter or boulders same
ragas sak acapella valley man more than
60 centimeter now let us talk about the
determination of soil texture so this
soil texture can be determined by two
methods one is field method and the
another one is mechanical analysis so
basically two question Arthur have a
mechanical analysis parts Arthur disco
hum particle size analysis can arm say
be John thing so under this category as
you can see that there are two methods
one is hydrometer method and the another
one is international pipette method the
direct question BIA sakta hai ki console
method out of these soil texture
determination Gilly use over to Aqua do
Newnham pathani sahih a Kogi aapke
hydrometer method and another one is
international pipette method a binky
Panama coach highlight some pilot gives
you hydrometer method that was given by
Boyd quest in the 19th in the year of
1927
then agar is a compare can a relatively
rapid method as compared to
international people method but it's my
kia cadenza from dispersion
carvanha hooter hammock Oh soil
particles car those colleges Felician
user there that is named as Calgon
solution originally question puja
bachata through Calgon solution Akiho
takea hey this is the five or ten
percent of sodium hexametaphosphate so
is comb Calgon solution cane am so
hunting or jovem hydrometer ki baat
karta nato is co calibrate k jata at 20
degree celsius
yeah fa 68 degrees celsius agar aapke
temperature about 20 degree celsius a
sixty degree Fahrenheit pending here
so then aku correction factor in our use
kinda bodega moving on again i'm
international piped method key bath
korean so that was given by GW robinson
in the year of 1922 like in so are some
present time international preferred
method for low curtain that was modified
by a HM Anderson in the year of 1928
so agar rapid method puja to hydrometer
of cancer hoga lake in most accurate
method pooja gotta high then
international payment method will be
your answer then couch cushions or
bantha hamper ki aapke Pataki soils my
different the rocky constituents pies
okay to aghanim textual analysis curtain
sep11 come a remove quite now with that
so again my organic matter go remove
kinda here then what is the way to deal
the hydrogen peroxide up you squaring a
six to thirty percent aqui range of U
square sector hang up then a good-sized
Q oxides have key so up sodium sulphide
and oxalic acid mixture you squaring it
and in case of carbonate or exchangeable
mid metal square the domination so Abu
say dilute hydrochloric acid say create
crying here then moving on you bought
the Rudy up a claw head that is the
Stokes law to sell a question how much
Abuja gotta aching mechanical analysis
ka khalsa lawful follow Jota here though
your answer is a Stokes low so the soil
texture analysis Kelly because low here
so this is Stokes law so Stokes loca
kehta hai ki jo aapke velocity have
falling particle ski would directly
proportional UT he was K square of
radius K so particle Caray D s of K
square K directly proportional Hootie
here not to its surface and moreover it
is inversely proportional to
viscosity of the liquid in which it is
traveling so up the exact thing the
pores cooking Harper no down curse
attack or of course if it na drachma v
is directly proportional to R square and
inversely proportional to Nita that
meter denotes the viscosity of water and
rest of the description is there in the
video so you can pause the video note
down this but safe it nanny Agatha the
beak abruptly assumptions Bipasha
limitations say be questions been there
so let us talk about some limitations
and office talk slow then first
assumption is that your particles must
be spherical rigid and smooth though up
to two particles have a spherical be
unity rigid beneath your smooth mmunity
the visa Caracas to explore so apply
hoga then Brownian movement in a human
acharya or generally they kageki Joe
particles is in casa is point zero zero
zero two MMC Nietzsche Jota they exhibit
this you know the Brownian movement or
who ski possesses a rate of falling have
aa very Curt ahead those talks Lama para
apply nano SATA or hoga be thoroughfare
error op geudaega then your particles
must be of uniform density on each
jianchi then your temperature should be
you know like constant throughout the
above is custom machine current and one
more thing that the suspension must be
still up was still rek ennopp cusco hill
on adoulin in a year or a me show you
the he up jump point 0 8 mm Cesare the
Joe but a particle so then they you know
settle very fast though wooden Kiva's is
a turbulence caused ho sakta a medium
may so these are the assumptions and the
limitations of this talk slow moving on
the another one is a specific surface
area it's a be a quotient a sec therapy
exams may so basically german is
specific surface area ki baat karta it
is the ratio of the total surface area
of the material divided by the mass of
it otherwise bulk volume so total
surface area per unit of mass or the
volume so easily juice key unit hand
that can be you know meter square per kg
meter square
per gram if it is like in terms of mass
then in terms of volume it can be meter
square per meter cube or generally per
meter then equation bought you know her
bark which I think a big about that clay
particles you know this clay particles
have 10,000 times more specific area
than the same talk we attract Nike cents
a clay particle catch a specific area
here surface area would thus hajar guna
hota
then here also you can pause the video
up put the kraaho became anecdote tables
there this may have course pacific area
their gags certain minerals car or
certain size fraction scar so RP has a
readout kar saktha and to just you know
dictate some of them you can see that
sand loam soil ranges 10 to 40 meter
square per gram loamy soils car fifty
two hundred meter squares per gram and
clay soil car 150 to 250 meter square
per gram then in case of clearly night
it ranges from 37 to 45 and so on and
vermiculite has got the highest with
specific area out of all the claim
endures that is 780 to 900 now in this
you can see that the there are twelve
textural classes of soils as per the
usda so up sub k they accept their nam
sandy soil low me sand sandy loam loam
cell phloem silt sandy clay loam clay
loam silty clay loam sandy clay silt
clay and clay so these are the textural
classes of the soils you can see then
agar aapko pata like an icky soil
texture aquakey ahead then observe
proportions nickel lynge then with the
help of this soil textual pyramid or
which is also known as soil textural
triangle up characteristic they're
plotting curse at them or chopper up
Cuttino point intersect korea that will
be royal textural classes so apne the
hug is your base a that is representing
sin then agar up apne right side the
king then it will be silt and then clay
so accordingly jitna be percentage outta
here you can draw the lines and where
these lines you know intersect that
point will be considered as the soil
textural plus this is all about soil
texture I hope it will be helpful for
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