Science Chapter 8-2&3 Soil

Front 1

What is soil?

Back 1

- Soil- loose, weathered material on Earth’s surface in which plants can grow
-

Front 2

Bedrock

Back 2

- the solid layer of rock beneath the soil
- Once exposed at the surface it gradually weathers into smaller particles that are the basic material of soil

Front 3

Soil Composition

Back 3

Mixture of rock particles, minerals, decayed organic material, water, an air
-1.Sand, silt, and clay- come from weathered rock
2.Humus-

Front 4

Humus

Back 4

a dark colored substance that forms as plant and animal remains decay
a. Creates space for air and water (plants need)
b. Contains nutrients- nitrogen, sulfur, phosphorus, and potassium

Front 5

Fertile

Back 5

- a measure of how well the soil supports plant growth
a. Sandy soil has low humus- low fertility
b. Soil that is rich in humus- high fertility

Front 6

Soil Texture

Back 6

i.Differences in texture depend on size of soil particles
1.Sand- coarse and grainy
2.Clay- smooth and silky
3.Smallest to largest- clay, silt, sand, and gravel

Front 7

Loam-

Back 7

made up of equal parts of clay, sand, and silt- best for growing
- so includes organic material, water, and air

Front 8

The Process of Soil Formation

Back 8

wiat

Front 9

what makeks Prairie soil very fertile ?

Back 9

because of saw grass

Front 10

Sod

Back 10

the thick mass of tough roots at the surface of the soil

Front 11

what is the Value of Soil

Back 11

•Soil is one of the Earth’s most valuable natural resources because everything that lives on land
i.Plants depend on soil to grow
1.Humans depend on plants and animals for food
•Fertile soil is valuable because there is not much of it.

Front 12

Natural resource-

Back 12

•anything in the environment that humans use.

Front 13

How fertile is the typical soil found?

Back 13

i.Only 20 % of land has fertile soil

Front 14

What things affect soil?

Back 14

• The value of soil is reduced when soil loses its fertility and when topsoil is lost due to erosion

Front 15

why does Loss of Top Soil occur?

Back 15

soil is exposed water or wind and they erode it

Front 16

what happened in the Dust bowl in Oklahoma?

Back 16

In the drought the topsoil quickly dried out and turned to dust and ended up blowing away
the Dustbowl- an area of soil that was blown away like dust

Front 17

the Dustbowl-
- what? where? Impact on people?

Back 17

an area of soil that was blown away like dust
-In Oklahoma
-It influenced people to appreciate soil and see how valuable it is

Front 18

Soil Conversation
- what and how?

Back 18

the management of soil to prevent its destruction
- Soil can be conversed through contour plowing, conversation plowing, and crop rotation.

Front 19

Contour Plowing

Back 19

- when farmers carve their fields along the curves of a slop

Front 20

Conversation Plowing

Back 20

when farmers barley disturb the soil and its plant cover.

Front 21

Crop Rotation

Back 21

- when a farmer plants different crops every year and different plants absorbs different amounts of nutrients.

Front 22

Weathering-

Back 22

the process that breaks down rock and other substances at Earth's surface
i. Ex: Heat, cold, water, and ice

Front 23

Erosion-

Back 23

the removal of rock particles by wind, water, ice, or gravity.

Front 24

what 2 actions work together to wear own rocks?

Back 24

• Weathering and erosion work together continuously to wear down and carry away the rocks at Earth's surface.

Front 25

Uniformitarianism-

Back 25

- the geologic principle that the same geologic processes that operate today operated in the past to change Earth’s surface.

Front 26

Mechanical weathering

Back 26

- a type of weathering in which rock is physically broken into smaller pieces.

Front 27

what causes mechanical weathering?

Back 27

The causes of mechanical weathering include freezing and thawing, release of pressure, plant growth, actions of animals, and abrasion

Front 28

Abrasion-

Back 28

the grinding away of rock particles carried by water, ice, wind, or gravity

Front 29

Ice wedging-

Back 29

the process of wedges of ice in rocks widening and deepening cracks.

Front 30

Chemical weathering-

Back 30

the process that breaks down rocks through chemical changes.

Front 31

The causes of chemical weathering

Back 31

The causes of chemical weathering: are action of water, oxygen, carbon dioxide, living organisms, and acid rain

Front 32

Biggest cause of Chemical weathering

Back 32

Water- most important cause of weather, it dissolves the rock.

Front 33

how des oxygen cause chemical weathering?

Back 33

b. Oxygen- makes oxidation when it combines with iron in the rain.
a. Oxidation- the process of oxygen combining with iron in the presence of water.

Front 34

how does carbon dioxide cause chemical weathering?

Back 34

Carbon dioxide- dissolves rain water that sinks through air pockets of soil.

Front 35

how do living organisms cause chemical weathering?

Back 35

Living Organisms- when plants grow they cause rocks to grow in between them.

Front 36

how does acid rain cause chemical weathering?

Back 36

Acid Rain- it is caused by coals and oil and gas being burned into the air.

Front 37

what does permeble mean?

Back 37

• Permeable- means that a material is full of tiny, connected air spaces that allow water to seep through it

Front 38

How does soil form and what is it made of?

Back 38

Soils forms as roock is broken down by weathering and mixtes with other materials on the surface. Soil is constantly being formed where ever bed rock is exposed.

Front 39

soil horizon

Back 39

a layer of soil that differs in color and texture from the layers above or below it.

Front 40

Top soil

Back 40

crumbly, dark brown soil that is a mixture of humus, clay, and other materials. It is the first soil from the top.

Front 41

Subsoil

Back 41

a soil that has clay and a little bit of humus. The bottom section of soil.

Front 42

What are the three horizons?

Back 42

A horizon- the top horizon with the most humus
B- horizon with a little bnit of humus and in the middle
C- horizon the bottom part with only weathered rock and a little bit of soil.

Front 43

What controls the rate of which soil forms?

Back 43

the climate- in cosld and dry areas it is slow (thin soil) in moist and warm areas it is faster.(thick soil)

Front 44

How do scientist classify the different types of soil?

Back 44

on climates, plants, and soil composition- (rock, sandy, or if it is rich in clay) .

Front 45

What are the major soil types?

Back 45

forest, prarie (most fertile), desert, mountain, tundra, and tropical soils.

Front 46

What is the role of plants and animals in soil formation?

Back 46

SOme soil organisms make humus, the material that makes soil fertile. Other soil organisms mix the soil and make space in it for air and water

Front 47

Litter

Back 47

a loose layer above the soil with sheded leaves.

Front 48

Decomposers

Back 48

are the organisms that break the remains of dead organisms into smaller pieces and digest them with chemicals.

Front 49

What helps mix humus around the soil?

Back 49

earthworms

Front 50

How can rock weather fast?

Back 50

- being permeable
-dissolving by water
- wet climate
- hot weather/temp.