S3-U6L3 - What is Soil?

What is Soil?

S3-U6L3

What is humus?

• Humus is found in the uppermost part of the soil and is made of the decayed remains of once-living things.

What are nutrients?

• Nutrients are substances that plants need to grow.

Why do plants grow so well in soil with a lot of humus?

• Plants use the nutrients found in humus to grow.

Multiple Choice

What could you add to help the plants grow better?

• sand

• fertilizer

• pebbles

• seed

Multiple Choice

What can you do with vegetable scraps to make nutrients for your garden?

• make a compost pile

• throw away

• hide in a plastic bag and dispose it

• do nothing with it

What can you put in a compost pile besides vegetable peelings?

• Dried leaves, coffee grounds, and earthworms can all go into a compost pile to make nice, rich compost.

What things have you come across today that have relied on soil?

• Your pencil is made from wood that grew from the soil.

• Your wooden desk and the wooden classroom door also came from trees that grew in soil.

• Some breakfast cereal comes from wheat or other grains that grow in soil.

• Cotton in your clothes comes from cotton plants that rely on soil to grow.

Multiple Choice

What type of soil holds the most water?

• sand

• pebbles

• clay

• mush

What type of soil holds the most water?

• Clay soil has tiny particles that allow it to hold the most water of the different soil types.

• Because of this, clay soil feels stickier than sandy soils.

Why might sandy soil not be good for growing crops?

• Sandy soil might not be good for growing some crops because soil with lots of larger particles of sand does not retain water well.

Multiple Choice

Where might sandy soil be found?

• near the beach

• around the backyard

• near the city

• in the highway

Multiple Choice

_____ is the layer of soil with the most nutrients and decaying materials.

• subsoil

• topsoil

• solid bedrock

• weathered bedrock

Why would weathered bedrock not be great for plants to grow in?

• Weathered bedrock has very few nutrients for plants.

What else might you find in topsoil besides plants?

• Earthworms, dried leaves, and ants can all be found in topsoil.

Which is the best layer of soil for growing plants?

• Topsoil is the best layer of soil for growing plants.

• It has lots of nutrients from decaying matter that was once living.

If clay has a smaller particle size than silt, why might you be more likely to find silt blowing in air than clay?

• Even though clay has a smaller particle size, clay is more likely to be trapped by moisture than silt is.

Other than providing plants for people and animals to eat, how is soil important for life on Earth?

• Small plants that grow in soil provide homes and shelter for insects.

• Soil also keeps trees rooted in place.

• Trees then provide shade and help cool the surface of Earth.

• Trees also provide habitats for animals like squirrels, birds, and some snakes.

Describe how sandy soil might be formed.

• Sandy soil might be formed from solid bedrock that slowly breaks down into smaller pieces of rock, forming weathered bedrock and then subsoil.

• Further weathering and the addition of decaying plant and animal matter help to form sandy soil.

• If you were to look closely at sand from a beach, you might see that the sand particles are different colors because of the rocks the particles came from.

• You might even see little bits of shell.

End of Lesson

Third Quarter Complete