Soil

bedrock
igneous, metamorphic, and sedimentary rock of the lithosphere that may exist as mountains, cliffs, or low-lying plains
parent rock
an area of bedrock that is the source of an area of soil
soil
a mixture of mineral particles, air, water, and living and decaying organisms
soil profile
a vertical cross section of soil from the ground surface down to the bedrock
soil mismanagement
overgrazing and deforestation are results of poor agricultural practices
The land management technique of __________ helps limit topsoil loss.
contour farming
Overgrazing, poor irrigation, and poor soil management all contribute to which environmental problem?
soil erosion
Why is it important for farmers to switch to less destructive agricultural methods?
Less destructive agricultural methods reduce soil erosion. Preventing soil erosion will help stop the desertification of landmasses and protect the ecosystem.
Fertilizers and pesticides can lead to soil mismanagement by ____________.
poisoning soil organisms
Which is a reason that tundra and desert both have shallow soil profiles?
There is little precipitation.
Characteristics of soil profiles may be closely related to __________.
moisture
In soil profile, which is the most fertile layer?
top soil
How is soil formed?
Soil is formed by the weathering of rocks, mechanically or chemically. Waves pounding on a sea cliff are a form of mechanical weathering. Rusting of iron-containing minerals, such as biotite, is an example of chemical weathering.
Which is not a common cause of soil mismanagement?
Crop rotaion
Overgrazing, deforestation, and poor irrigation and cultivation all contribute significantly to __________.
soil erosion
How might irrigation harm soil and soil organisms?
It can water log topsoil.
Best for growing most plants, which soil has good drainage and sufficient moisture?
loam
Scientists who study soil divide it into layers called_________.
horizons
Which term describes the area of bedrock from which soil forms?
parent rock
Depending on climate and other factors, which is a reasonable length of time for soil to form from bedrock to fertile soil?
1,000 years
In the United States, unwise land-use practice lead to annual losses of topsoil by wind and water totaling ______________.
1.5 billion metrc tons
Overgrazing and poor cultivation can led to _______________.
desertification
Which is a characteristic of soil with a high percentage of clay?
able to hold water
Shelter belts prevent topsoil because __________.
trees act as windbreakers
Nearly one billion dollars a year are spent on clearing sediment from streams and lakes in the United States. Which is the most common source of this sediment?
hilly areas where protected by vegetation has been moved