Show:
mechanical weathering
chemical weathering
soil horizons
soil formation
soil conservation
100
weathering
What is the breaking down of rocks on the Earth's surface?
100
rust
What is a type of chemical weathering when oxygen reacts with iron?
100
layer of litter found on soil
What is the O horizon?
100
earthworms
What is the way humus gets into subsoil?
100
Dust Bowl
What is an area of the U.S. in the 1930's which lost all of its topsoil due to farming practices and drought.
200
root action
What is a type of mechanical weathering caused by tree roots cracking rocks apart?
200
chemical weathering
What is weathering that changes the chemical make-up of rocks.
200
subsoil including clay
What is the B horizon?
200
C horizon
What is the layer of soil that forms first?
200
crop rotation
What is planting different crops each year on the same land?
300
mechanical weathering
What are physical changes of rocks affecting size and shape?
300
acid rain
What is rain mixed with air pollution (carbon dioxide) ?
300
humus
What are decaying plant and animal remains?
300
humus, silt, sand, clay
What is found in the A horizon?
300
contour plowing
What is the plowing along the curve or slope of the land to prevent runoff of water.
400
ice wedging
What is the repeated freezing and melting of water in between cracks in rocks?
400
oxygen, water and acids
What is the main things that cause chemical weathering?
400
bedrock
What is the layer of solid rock under the soil?
400
soil fertility
What is the measure of how good soil is for growing plants?
400
conservation plowing
What is leaving the weeds and remains of last years crop in the soil to decompose.
500
warm
What is the climate where mechanical weathering occurs fastest?
500
copper reacting with oxygen
What is the reason why the Statue of Liberty has a green coating?
500
B horizon
What is the last layer of soil to form?
500
decomposers
What is responsible for breaking down dead organisms in the soil?
500
fire
What is the way the prairie soil remains fertile.