Properties Of Soil | Chemistry | Environmental Chemistry | Presentation | By: Faizan Tanoli
Post on 13-Apr-2017
The various properties of soil include
4. Soil structures
Color is the foremost physical
property that can be seen with
naked eye and is useful in
interpretation of valuable insight
into the soil environment, thus it
can be very important in
assessment and classification of
DIFFERENT SOIL COLORS
The most influential colours in a well drained soil are white, red, brown and black.
White indicates the predominance of silica (quartz), or the presence of salts.
Red indicates the accumulation of iron oxides.
Brown and black indicate the level and type of organic matter. A colour triangle can be used to show the names and relationships between the influential colours.
FACTORS DETERMINING SOIL
Four main factors influence the colour
of a soil:
1. Mineral matter derived from the
constituents of the parent material
2. Organic matter
3. The nature and abundance of iron
4. Moisture content
If we understand what determines soil colour,
then we can use colour to make some
inferences about, history, chemistry and
For example, an obvious change in colour
between horizons is a real indication of
changes in soil properties which are the result
of biological activity, water movement and
Soil colour should be determined on moist surfaces of freshly broken (not sliced) soil samples.
Like any other soil property, colour must always be observed throughout soil profile, paying special attention to the differences between soil horizons. Colour characteristics such as mottle size, percentage and contrast should be observed and recorded.
A system that uses specially printed colour charts (Munsell Soil Colour Charts) gives an international standard. It divides colour into wavelength, lightness, and colour saturation.
Where a Munsell Chart is not available, simple names as listed in the triangle can be used.
Munsell Color ChartsHue = dominant spectral or rainbow color Red,
Yellow, Blue, Green
Number increases and the color is more brilliant as
Color Determination in the
ALWAYS USE MOIST SOIL
Munsells color charts values:-
1. Absolute black = 0
2. Absolute white = 10
3. Light soils hue value = 7 or more
4. Medium soils hue value = 5 6
5. Dark soils hue value = 4 or less
Spots of different colors in the soil
Generally indicate that the soil has periods
of inadequate aeration each year
Usually rust colored
Bluish, grayish, & greenish subsoils with or
w/o mottles = indicate longer periods each
year of waterlogged conditions &
The term was coined in17901800; (< Latin: earth, ground)
Dark brown or black organic
substance made up of decayed plant
or animal organic matter, that
provides nutrients for plants and
increases ability of soil to retain water
In soil science, humus refers to any organic matter that has reached a point of stability, where it will break down no further and might, if conditions do not change, remain as it is for centuries. Humus significantly improves the structure of soil and contributes to moisture and nutrient retention.
In agriculture, humus is sometimes also used to describe mature compost, or natural compost extracted from a forest or other spontaneous source for use to amend soil. It is also used to describe a topsoil horizon that contains organic matter
Humus also controls the colour of soil higher the humus
content darker is the soil colour
Refers to the size of
Three types are:
The soil structures commonly
Particles cling together in angular aggregates.
Typical of soils with high clay content.
Typical of B horizons.
beds are large about 5 to 50 millimeters.
Soil has no visible
Hard to break
apart & appears
in very large
4. PRISMATIC Prismatic structure are
bounded by flat to
rounded vertical faces.
Units are longer vertically
and top of the prisms are
It is commonly found in B
5. GRANULAR Is the best for most
Particles cling together
to form rounded
It is commonly found in
Beds are small usually
between 1 to 10