The content includes the Physical and Chemical Properties of Soil, Particle Density, Bulk Density and Soil Porosity.

1. RABEKA SULTANA SHILPI
STUDENT ID : ER-18017
SESSION :2017-2018
DEPARTMENT OF ENVIRONMENTAL SCIENCE
AND RESOURCE MANAGEMENT
WELCOME TO MY
PRESENTATION

2. My Presentation On
• Soil Properties
• Soil Density
• Soil Porosity
• Soil Structure

3. SOIL
The collection of natural bodies
occupying parts of the Earth‟s
surface that is capable of
supporting plant growth and
that has properties resulting
from the integrated effects of
climate and living organisms
,acting upon parent material, as
conditioned by topography over
period of time is known as soil.

4. • Mineral = 45%
• Air = 25%
• Water =25%
• Organic Matter = 5%
(i)Organisms = 10%
(ii)Roots = 10%
(iii)Humus = 80%
COMPOSITION OF SOIL

5. Soil properties are of two types . They are:
1.Physical properties of soil
2. Chemical properties of soil
SOIL PROPERTIES

6. Horizon
Soil color
Soil texture
Soil structure
Soil consistence
PHYSICAL PROPERTIES OF SOIL

7. Cation Exchange Capacity
Soil Reaction (pH)

8. PHYSICAL PROPERTIES OF SOIL
*Soil “horizons” are discrete
layers that make up a soil
profile.
Horizon
Soil “horizons” are discrete layers
that make up a soil profile. Mainly
soil horizon are of six types.
(a) O horizon
• Dominated by organic material
• Dark colour
• More than 20% organic matter
• Layer 0-2 feet thick

9. (b) A horizon
• Referred to as „top soil‟ or „biomantle‟ horizon
• Largly consists of minerals (sant, silt and clay)
• Topmost layer of mineral soil, at depths of 2-10 feet
• Darker in color than layers below
(c) E horizon
• The leaching layer horizon
• At depths of 10-15 feet
• Light in color (sant and silt present)
PHYSICAL PROPERTIES OF SOIL

10. (d)B horizon
• The sub soil horizon
• At depths of 10-30 feet
• Rich in clay and mineral like Fe & Al
• Red/Brown color due to oxides of Fe and Clay
(e)C horizon
• The “Saprolite” horizon
• At depths of 30-48 feet
(f) R horizon
• Bedrock horizon
• At depths of 48+ feet
PHYSICAL PROPERTIES OF SOIL

11. PHYSICAL PROPERTIES OF SOIL
COLOR
Soil color is usually due to 3 main
pigments
• Black-from organic matter
• Red-from iron and aluminium
oxides
• White – from silicates and salt
Color can be a useful indicator of the
general properties of soil , as well as
some of the chemical processes that
are occurring beneath the surface .

12. PHYSICAL PROPERTIES OF SOIL
SOIL TEXTURE
The relative proportion (percentage ) of
sand silt clay in soil is known as soil texture.
These soil particles (sand, silt and clay)
have the following size ranges:
• Sand = 2 to 0.05 mm
• Silt = 0.05 to 0.002 mm
• Clay = <0.002 mm
For all mineral soils, the proportion of sand,
silt, and clay always adds up to 100
percent. These percentages are grouped
into soil texture “classes”, which have been
organized into mentioned “textural
triangle”.

13. PHYSICAL PROPERTIES OF SOIL
SOIL SRUCTURE
The arrangement of sand silt and
clay in soil is known as soil
structure.
Soil structures are of different type
. Some of them are mention in the
picture.

14. SOIL CONSISTENCY
Soil consistency is the strength with which soil
materials are held together .
Soil consistency measured for -
• Wet soil
• Moist soil
• Dry soil
PHYSICAL PROPERTIES OF SOIL

15. CATION EXCHANGE CAPACITY (CEC)
Some plant nutrients and metals exist as positively charged
ions, or “cations”, in the soil environment. Among the more
common cations found in soils are hydrogen (H+), aluminum
(Al+3), calcium (Ca+2), magnesium (Mg+2), and potassium
(K+). Most heavy metals also exist as cations in the soil
environment. Clay and organic matter particles are
predominantly negatively charged (anions), and have the
ability to hold cations from being “leached” or washed away.
The adsorbed cations are subject to replacement by other
cations in a rapid, reversible process called “cation
exchange”.
CHEMICAL PROPERTIES OF SOIL

16. SOIL REACTION (pH)
By definition, “pH” is a measure of the active hydrogen ion (H+)
concentration. It is an indication of the acidity or alkalinity of a soil,
and also known as “soil reaction”.
The most important effect of pH in the soil is on ion solubility, which
in turn affects microbial and plant growth. A pH range of 6.0 to 6.8 is
ideal for most crops because it coincides with optimum solubility of
the most important plant nutrients. Some minor elements (e.g., iron)
and most heavy metals are more soluble at lower pH. This makes pH
management important in controlling movement of heavy metals (and
potential groundwater contamination) in soil.
CHEMICAL PROPERTIES OF SOIL

17. Bulk density can be define as the ratio of oven dry
weight of soil to total volume of the soil.
It can be expressed mathematically as,
Bulk density = Oven dry soil weight/ Total volume of the
soil

18. Particle density can be define as the ratio of oven
dry weight of soil to total volume of the soil particle.
It can be expressed mathematically as,
Bulk density = Oven dry soil weight/ Total volume of
the soil particle
PARTICLE DENSITY

19. Soil porosity is the percentage of a soil that is pore
space or voids . The average soil porosity is about
50% and the pores are filled with air or water
depending on the moisture content.Sands have larger
pores , but less total pore space than clays.
If bulk density and particle density are known , the
total porosity can be calculated using these values
Porosity (%)= (1- Bulk density/particle density )*100