Science Study Guide

Earth Science Test Ch 7 Study Guide
Soil is a mixture of weathered rock, mineral fragments, water, air and what?
The layer of soil that contains the most organic material is called the ___ horizon.
What factors cause mechanical weathering?
Litter often covers which horizon?
Chemical weathering is more rapid in what kind of climate?
Mechanical weathering is more rapid in what kind of climate?
Soil erosion can be slowed by what?
What is the organic matter in humus made of?
The rate of weathering depends upon an area’s what?
The rock and mineral fragments in soil come from rock that has been ___.
On steep slopes and mountains, what helps reduce erosion by creating level areas for crops? (Don’t say farmers, what do we call what the farmers do?

What is the difference between mechanical and chemical weathering?
Soils in what kind of area contain little organic material and are thin?
Plants cannot grow without what?
What regions are especially vulnerable to erosion because their soils are useful to farmers for only a few years before their nutrients are gone?

Ice wedging is brought about by what?
Minerals found in the B horizon were dissolved in water and carried there by a process called what?
Oxidation occurs when materials containing what are exposed to oxygen and water?
In bottomlands where water is plentiful, soil is often what?
Describe the B horizon.
Plants don’t grow as well when what has been lost?
Name the factors that affect soil development.
What horizon has smaller rocks and mineral particles than the other layers?
How does mechanical weathering work?
How does chemical weathering work?
In areas where freezing and thawing occur frequently, rocks weather because of the ___ of freezing water.

When water mixes with carbon dioxide gas in the air or soil, what forms?
Because desert soils contain little organic material, their soil profiles have ___ horizons.
What turns and loosens soil, improving it for crops, but leaving soil vulnerable to erosion?
What factors contribute to soil erosion?
What is it called when farmers leave plant stalks in the field to reduce soil erosion?
Label a diagram of the soil horizons.
What do we call all of the soil horizons together for an area?
Which horizon contains the most humus?
Which horizon is most like the parent material?
The most leaching occurs from which horizon to which horizon?
Topsoil is which horizon?
Which horizon has the least organic material?
Most plant roots grow in which horizon?
What do we call leaves, twigs, and other organic matter on the A horizon?
What do we call small pieces of rock such as sand, silt, and clay?
What do we call the pattern of weather that occurs in a particular area of many years?
Because plants do not grow well when topsoil has been removed ___ is harmful.
When farm animals eat the grass on land until there is almost no ground cover, it is called what?
What is made of dead plant and animal matter that has decayed due to bacteria and fungi?
Planting along the natural slope of the land to reduce soil erosion is called what?
Eroded soil can enter what, causing them to fill up with sediment?
Be able to identify which picture shows ice wedging.
Be able to identify which picture shows weathering involving carbonic acid?
Are animal burrows an example of chemical or mechanical weathering?
Describe the factors that influence the development and type of soil in a certain area.
What human activities lead to soil erosion?
Name three things farmers can do to reduce soil erosion.