SOIL Flashcards
What is soil
The upper most layer of earths crust
Made of minerals and organic matter
4 steps of how soil forms
1- organic matter–plants and bugs decompose
2- mineral particles - rocks and other minerals erode and weather
3- chem. weathering- changes in mineral causes it to change and maybe into other compound
s4- mech. weathering - physical/weathering type changes
Chemical vs. Mechanical
chem-changes the composition of the rick into new compoundsmech-physical/weathering related changes.
3 soil types
clay, sand, slit
how does some soil types change
increase/decrease in water amt.temp. chnagemicro-organismsmacro-organisms
soil profile
OAEBC
O-organic matter-fallen tree parts
A-some organic matter-small mineral sediments
E- lighter color, nutrient rich layer
B- accumulation of nutrients and minerals from top layers
C-partially weathered bedrock
Porosity
volume of space btwnn soil particles
permeability
how easily water moves through the pores
Groundwater
water flowing in the ground
zone of aeration
pores filled with air where water can infiltrate through
zone of saturation
when the pores are filled up/saturated with water. can be filtered out.
what is the water tab;e
The area that separates the zone or aeration and saturation
Soil erosion
natural decay (erosion) of soil
what is the mass movement
Sometimes, rock and soil will move on a larger scale
what is in soil
air, water, minerals and organics
3 factors that affect porosity
1-size
2-shape
3-number of pores
how is porosity measured
by pouring water into soil and seeing how much water stays in the soil
3 factors that affect permeability
1-size
2-shape
3-number of pores
how is permeability measured
measured by how much water comes out
what causes soil erosion
over saturated soil dried out soil overly steep slopes earthquakes no vegatation
what is the mass movement triggered by?
Triggered by: Saturation of soil Overly steep slopes of hillsides Removal of vegetation (trees, bushes, etc) Earthquakes
Describe how to use a soil triangle to identify the texture of a soil.
follow each percent on all three sides til they meet at/in the designated area for each soil texture
horizon
a distinct layer of soil
aquifer
underground layer of water-bearing permeable rock from which groundwater can be extracted using a water well.
