A science topic about soil.

2. •Soils are complex mixtures of minerals, water, air,
organic matter, and countless organisms that are
the decaying remains of once-living things.
•It forms at the surface of land – it is the “skin of
the earth.”
•Soil is capable of supporting plant life and is vital
to life on earth.

4. •There are different types of soil on the
planet, as every soil has different
compositions of minerals and organics,
and every soil has been formed in different
ways.
•There are four basic types of soil. These are
sand, clay, silt, and loam.

5. •Sand is used to provide bulk,
strength, and other properties to
construction materials like asphalt
and concrete.
•It is also used as a decorative
material in landscaping. Specific
types of sand are used in the
manufacture of glass and as a
molding material for metal casting.

6. •Clay soil has incredibly small particles.
This means that clay has very little air
spaces, allowing almost no drainage. This
is the reason why clay soil becomes very
sticky and heavy when wet.
•Clay soil can be bad for growing some
plants. Water cannot escape clay soil
when it is wet, causing the plant roots to
rot.

7. •Clay soil has been used for construction
since ancient times. It can be sun-dried or
fired to make adobe bricks and then be
used to assemble a house.
•Clay is used in ceramics, turning it into
pots, vases, pipes, and other useful
objects. It is also used in making
sculptures or antique jars, which are
usually expensive when bought.

8. •Silt is one of the most fertile of the many
types of soil, with rich nutrients and good
drainage. It is slightly smaller in size than
sandy soil, but otherwise is very similar in
composition.
•Silt soil is generally quite dark in color,
and is excellent for planting almost any
plant.

9. •Loam soil is actually made up of different
soil types, with varying amounts of clay,
silt, and sand mixed together.
•Loam holds water well because of the
heavy grittiness given from the sand. It
also has exceptional drainage so that the
water do not build up too much and is
also nutrient-rich.
•Loamy soil is the ideal soil for gardening.

11. •Soil covers much of the
land on Earth. It is made
up of minerals (rock, sand,
clay, silt), air, water, and
organic material (matter
from dead plants and
animals).
•Soil provides a substrate
for plants (roots anchor in
soil), a source of food for
plants, and a home for
many animals (insects,
spiders, centipedes,
worms, burrowing animals,
bacteria, and many others).

12. Soil Horizons (layers)
•Soil is made up of
distinct horizontal layers;
these layers are called
horizons.
•They range from rich,
organic upper layers
(humus and topsoil) to
underlying rocky layers
(subsoil, and bedrock).

13. ORGANIC
•The organic layer (also
called the humus
layer) is a thick layer
of plant remains such
as leaves and twigs.

14. TOPSOIL
•Topsoil is considered
the "A" horizon. It is a
fairly thin layer (5 to 10
inches thick) composed
of organic matter and
minerals.
•This layer is the primary
layer where plants and
organisms live.
• The topsoil has sand
and clay but is mostly
made up of loam.

15. SUBSOIL
•Subsoil is considered
the "B" horizon.This
layer is made primarily
of clay, iron, and organic
matter.
• Its color is usually light
because there is more
sand and clay in this
layer.
• The roots of most trees
grow downward into
the subsoil.
.

16. BEDROCKS
•The bottom layer is
several feet below the
surface. The bedrock is
made up of a large solid
mass of rock.
• Plants and animals
cannot live in this layer.
• This layer is a source of
materials for
constructing buildings
and making roads and
bridges.
.

17. HOW DO PEOPLE
USE SOIL?

18. AGRICULTURE
Soil has vital nutrients for plants. As a
result, it is used in agriculture to nourish
plants.
The roots of a plant receive nutrients
from the soil to help it grow.

19. BUILDINGS
Soil is an important part of the building process. Soil
compaction, which increases the density of the soil, is
done as part of the building process.
The purpose of the compaction is to improve the load
support. If not done, structural failure can result.
Soil can also be used as building materials such as
adobe and red bricks.

20. POTTERY
Clay soil is used in making ceramics, or pottery.
When water is added to clay soil, it can be used
to create the ceramics. Once formed, you can
leave it to dry and it will retain its shape.
Any type of ceramic can be created with the clay
soil, such as a vase, bowl, cup or sculpture.

21. MEDICINE
Soil is commonly used in antibiotics. Microbes
created in the soil are harmful to bacteria, which
is why soil is used in medicine.
Medicines created by soil include skin ointments,
tuberculosis drugs and anti-tumor drugs.

22. BEAUTY
PRODUCTS
Some beauty products are made with soil.
Commonly used beauty products where used
soil is used in the production include blush and
foundation.
Soil rich in clay can also be used in facial masks
and toothpastes.

23. CARE AND CONCERN
FOR SOIL

24. CARE AND CONCERN
FOR SOIL
Chemicals like oil, detergent
and acid affect the minerals
in soil that help plants grow.
Polluted soil affects the
health of plants; it can even
make plants die.

25. SOIL
EROSION
Soil erosion is a gradual process of movement
and transport of the upper layer of soil (topsoil)
by different agents – particularly water, wind,
and mass movement – causing its deterioration
in the long term.

26. SOIL
EROSION
Planting many trees and plants may prevent
this from happening especially when there are
heavy rains.
Sweeping the garbage carefully from the
ground would also prevent the topsoil from
being eroded.