Layers of the Earth

ObjectivesI will construct a model that depicts the layers of the earth.

I will identify characteristics of the earth’s layers.

I will select soil traits that best support plant growth.

Layers Of The Earth

The earth’s crust is made up of minerals and rocks. However to get to the rocks, you have to dig through layers.

At the bottom there is solid rock that has weathered into chunks. We call this layer bedrock.

Layers Of The Earth

The chunks weather into smaller pieces in the next layer and mix with soil. This is called C horizon.

This layer contains very little humus. What is humus?

Layers Of The Earth Gradually layers of soil, or soil horizons develop. Our next

layer, horizon B, is a layer of soil that may contain smaller rocks.

Our final layer is horizon A. This is the top layer. This is the layer that you got your dirt from for class today. This layer contains the most humus.

Horizon A can also be called topsoil. How are these horizons different?

Soil The top layer of soil, or topsoil, is the layer that

contains plant and animal material needed for plant growth.

Can you name a type of soil?

How about clay or sand?

Plants need many things to be able to grow. The soil can provide these things.

Can you name something that soil provides to plants to help them grow?

Soil and Plant Growth Soil must provide nutrients, water,

and air to help plants grow.

Can people ruin soil?

How?

Why is it important to protect our soil?