Layers of
soil
Teacher Jessica López Mejía
Goal
Identify the layers of the soil and their composition
Bedrock
• Hard, solid rock beneath
surface materials such as soil
and gravel
• Underlies sand and other
sediments on the ocean floor.
• Consolidated rock, meaning
it is solid and tightly bound
Bedrock
Weathered parent material
• No organic matter here
at all. We’re out of reach
of all living and dead
organisms down here.
• It’s all rock particles that
are full of minerals.
Subsoil
• Tree roots and
earthworms live here.
• Mix of mineral particles
and some humus near the
top.
• Very low in organic matter
compared to the topsoil.
Subsoil
• A lot of soil nutrients are found in this layer.
• Deep plant roots come here looking for water.
Topsoil
• Organic layer. In this layer, plants grow and
animals live on top of the soil. The plants keep the
soil cool and from drying out.
• It has decomposers that recycle the dead plants
and animals.
• Consists fine textured mineral particles and
organic material known as humus.
Topsoil
Organic layer
• Where the plants and animals grow and live.
This layer helps keep the soil healthy.
• The plants help keep the soil cool and moist.
Decomposers such as bugs, bacteria, and
fungi break down dead plants and animals.
Organic layer
What did we learn?
• Layers of the soil (organic layer, top soil,
subsoil, weathering parent rock, bedrock)
• Composition of each layer changes