Download Soil, an Essential Natural Resource

Soil, an Essential Natural
Resource
S6E5h. Describe soil as consisting of weathered
rocks and decomposed organic material
What is soil?
Key terms:
 Soil—the loose, weathered material on
Earth’s surface in which plants can grow.
What is soil?
Key terms:
 Soil—the loose, weathered material on
Earth’s surface in which plants can grow.
“soil” v. “dirt”—dirt gets on our clothes and
in our house, and we don’t want it there;
soil is what plants need to grow
What is soil?
Key terms:
 Soil—the loose, weathered material on
Earth’s surface in which plants can grow.
 Bedrock—the solid layer of rock beneath
the soil.
What is soil?
Key terms:
 Soil—the loose, weathered material on
Earth’s surface in which plants can grow.
 Bedrock—the solid layer of rock beneath
the soil.
 Soil horizon—a layer of soil that differs in
color and texture from the layers above or
below it.
What is soil made of?
Soil is a mixture of rock particles,
minerals, decayed organic material, water,
and air.
Humus—a dark-colored substance that
forms as plant and animal remains decay. It
has nutrients plants need, making the soil
fertile.
Fertility measures how well soil supports
plant growth.
What is soil made of?
Soil is a mixture of rock particles,
minerals, decayed organic material,
water, and air.
Loam—soil consisting of about equal
parts of clay, sand, and silt.
How is soil formed?
Three main soil horizons:
 Soil horizon A—topsoil—dark soil mixture
of humus, clay, and other minerals
 Soil horizon B—subsoil—the middle layer,
consisting of clay and other particles washed
down from the A horizon, but little humus
 Soil horizon C—weathered bedrock, bottom
layer, first layer to form
How is soil formed?
How is soil formed?
Order of formation: C
 A
 B
How do scientists classify
soil types?
 Soil is classified into groups based on
climate, plants and soil composition.
 List and describe five different soil
types
 What type of soil do we have in
Georgia?
What is the role of plants and
animals in soil formation?
Key terms
 Litter—loose layer of dead plant leaves and stems
on the surface of the soil
Plants provide most of the organic material found in
soil. Plant remains contain lots of stored nutrients,
which can help to make soil fertile.
What is the role of plants and
animals in soil formation?
Key terms
 Litter—loose layer of dead plant leaves and stems
on the surface of the soil
 Decomposers—organisms that break the remains of
dead organisms into smaller pieces and digest them
with chemicals
What is the role of plants and
animals in soil formation?
With your partner, describe how
different decomposers help to enrich
soil.
Classify soil organisms into two or more
groups. You can decide how you will
create your groups.
What is the role of plants and
animals in soil formation?
Some organisms make humus; other
organisms mix the soil and make spaces
in it for air and water.