Show:
Mechanical Weathering
Chemical Weathering
Soil Formation
Living Organisms in Soil
Soil Conservation
100
The freezing and thawing of water causes mechanical weathering of rock in a process called what?
ice wedging
100
The process that breaks down rock and other substances at Earth's surface is called what?
weathering
100
The type of soil called loam is made up of what?
equal parts of silt, sand, and clay
100
Living organisms in soil help to do what two things?
mix the soil and make humus
100
The management of soil to prevent its destruction is known as what?
soil conservation
200
The most important factors in determining the rate of weathering are what?
type of rock and climate
200
Weathering takes place more quickly in what type of climate?
hot and wet
200
The layer of soil in which topsoil is found is known as what?
The A Horizon
200
Soil organisms that break down and digest the remains of dead organisms are called what?
decomposers
200
Water and wind can ________________ soil, or carry it away.
erode
300
The growth of plant roots and animal activity may result in what type of weathering?
mechanical weathering
300
Some plants produce acids that result in what type of weathering?
chemical
300
Soil begins to form when the solid layer known as what begins to weather?
bedrock
300
Why is soil a very valuable resource?
Because all living things on Earth depend directly or indirectly on soil.
300
In the 1930s, an area in the southern Plains states was named what because the topsoil turned to dust?
The Dust Bowl
400
The burrowing action of animals most commonly causes the type of weathering known as what?
mechanical weathering
400
One agent of chemical weathering is ___________________, which combines with water to form carbonic acid.
carbon dioxide
400
The loose layer of plant remains that accumulates on the ground is called what?
litter
400
Humus makes soil more _____________, or rich in nutrients that plants need to grow.
fertile
400
What type of plowing helps conserve soil by disturbing it as little as possible?
Conservation Plowing
500
One cause of mechanical weathering is the wearing away of rock by grinding rock particles, known as what?
abrasion
500
Rapid chemical weathering can be caused by rain that is combined with pollutants, known as what?
acid rain
500
The thick mass of grass roots that helps hold prairie soil in place is called what?
sod
500
Bacteria and fungi in soil break down dead plants and animals and are examples of what?
decomposers
500
The practice of plowing fields along the curves of a slope is called what?
Contour plowing