Exam 1 Flashcards
(151 cards)
What is the lithosphere primarily made up of?
Rocks
What is the pedosphere primarily made up of?
soil and its interactions with rocks, air, water, and living things
What are the six key roles of soil in the ecosystem?
- Supporting plant growth
- Recycling waste products of society and nature
- A modifier of the atmosphere (think carbon cycle)
- Providing habitat for an enormous diversity of organisms
- Functioning as construction material of support for buildings
- Controlling the flow of water through the hydrologic cycle
What is the Solum made of?
The O, A, E, and B horizons
What is the Regolith made of?
The Solum (O, A, E, B) and the C horizon
How long does it take for 1 inch of soil to form?
500 years
What is the ideal soil?
50% solid material (45% mineral and 5% organic) and 50% pore space (25% air and 25% water)
What are the different soil particle sizes?
Coarse fragments, Sand, Silt, Clay (CSSC)
How big is a coarse fragment?
> 2 mm
How big is a sand particle?
2-0.05mm
How big is a Silt fragment?
0.05-0.002mm
How big is a Clay fragment?
<0.002mm
What is Humus?
the portion of the soil organic matter that is well
decomposed, colloidal, and relatively
resistant to further microbial attack
How much of a soil’s dry weight is Soil Organic Matter?
1 to 6%
What greatly influences nearly all soil properties and uses?
Soil organic matter
Why is does water act differently in soil?
-the interactions with soil particles (Adhesion and cohesion)
-Water in soil has many substances dissolved in it
How many elements are considered to be essential to all plants?
17
How many of the essential elements to plants are supplied by soil water
14 of 17
How is soil air different from atmospheric air?
it is generally several times more concentrated in C)2 than normal air
How does soil support plant growth?
-deeper soils can allow for deep roots that stabilize a plant
-denser or compacted soils can limit root growth
-Aluminum is toxic to plants and can stunt growth
-soil texture can dictate water holding capacity, fertility, and treatability of conaminants
-porosity can allow for gas exchange
What is the law of the minimum?
if one growth factor is deficient a plant is limited to that growth factor even if all other factors are met.
What is Fauna?
Animal life
What is Flora?
plant life
What role do animals play in regards to soil?
They turn/plow the soil