Exam 1 Flashcards
What does soil provide as a plant growth media?
- nutrients
- water
- physical support
- oxygen
- temperature buffer
Name 6 roles or services that soil provide?
- Media for plant growth
- Recycling system for nutrients and waste
- Water supply and purification
- Habitat for soil microorganisms
- Engineering media (build things)
- Climate modification
What is a macro nutrient? Name the 6 essential elements?
Nutrients needed in large quantities •nitrogen (n) •phosphorous (p) •potassium (k) •calcium (ca) •Magnesium (mg) •sulfur (s)
What is a micro nutrient? Name 6?
Nutrients needed in small quantities/ needed in only specific plants. •Boron (b) •Copper (cu) •Iron (fe) •Manganese (mn) •Molybdenum (mo) •zinc (zn) Maybe-chlorine, cobalt Some-sodium,vanadium,chromium
How does soil influence climate?
- carbon sequestration(holds carbon)
- evaporation ie clouds
- particulate matter(dust prevent sun)
What is the soils role in the ecology of the plant?
Soil is the interface between
- biosphere
- hydrosphere (water)
- lithosphere (not alive)
- atmosphere (air)
What is the difference between soil an soils?
Soil is 4 components
-mineral, water, air, biomass (living and previously living)
Soils is the soil and the rest of everything on the planet
Describe the oversimplified process for the formation of soil.
- Rock exposed at earths surface is degraded.
- Creates a rubble = regolith
- Particles tend to move (water and rain)
- Regolith is further modified by living organisms
- Eventually “soil” is created.
Define “soil profile”?
Verticals section of the soil.
Name the 3 primary soil horizons?
A horizon- top soil
B horizon- in general lighter in color
C horizon- almost rock
What is a plow layer?
Is various layers of soil mixed together as a result of plowing
Why is the soil near bedrock less developed than near the surface?
**Less weathering and chemical reactions taking place
How might lower horizons be modified?
**Chemical reactions and large root systems
Name the constitutes and %
Inorganic particles (45%) Organic particles (5%) Air/ water (50%) controlled by climate
Define soil texture?
The relative quantities of 3 particle sizes
What is sand silt and clay?
Sand- large particle sizes (2mm-.05)
Silt - less than (.05mm-.002)
Clay- less than (.002)
How does one determine a texture class?
Use a textural triangle
Texture classifications determine what?
Water holding capacity
Nutrient holding capacity
Tilth- the farmability of the soil(ease of plowing)
Engineering properties