What’s in Soil?
Types of Soil
Soil Sizes
Weathering
Erosion
100
This natural material is a mix of water, air, tiny bits of rock, and humus.
What is soil
100
This soil has the largest grains, feels rough, and water passes through it easily.
Sand.
100
This common soil has the largest grains and feels rough.
Sand.
100
__________ is the breaking down of rocks into smaller pieces.
Weathering.
100
__________ is the movement of soil by wind or water.
Erosion.
200
Humus is made from broken-down, dead ______ and ______.
What are plants and animals?
200
This soil has the smallest grains, feels sticky when wet, and crumbly when dry.
Clay.
200
The way soil feels — like grainy, crumbly, rough, or silky — is called a soil’s what?
Texture.
200
When water freezes in small cracks of rocks, it expands and breaks the rock. Is that weathering or erosion?
Weathering.
200
Flowing water can create ditches, canyons, or river deltas because of this process.
Erosion.
300
This is the layer of soil where most plants grow because it is the most fertile.
Topsoil.
300
This soil is a mixture of sand, silt, and clay and is the best for growing most plants.
Loam.
300
Clay has the __________ grains of the common soils.
Smallest.
300
Jagged mountain peaks can become rounded over a long time because of this process.
Weathering.
300
In a desert, which is most likely the main source of erosion — wind or water?
Wind.
400
Tiny pieces of rock in the soil can make soils different __________.
Colors.
400
Why is clay not the ideal soil for most plants?
It holds too much water and roots have trouble pushing through.
400
The pieces of tiny rocks in soil determine this, so soils can look different.
Color.
400
Name two forces of weathering from the notes.
Plants, animals, water, wind, or ice (any two).
400
Many tree roots in an area can help stop this from happening. What is “this”?
Erosion.
500
This is the layer of soil where most plants grow because it is the most fertile.
Topsoil.
500
Loam is best for plants mainly because it is __________.
Fertile / has a good mix.
500
If a soil has big spaces between its grains, will water move through it quickly or slowly?
Quickly. (like sand)
500
How does weathering help make soil?
It breaks rocks into tiny pieces that can mix with water, air, and humus to form soil.
500
Glaciers move very slowly, but as they move they can wear away mountains and leave valleys behind. Is that an example of weathering or erosion?
Erosion. (movement)