Soil Fundamentals Flashcards
What is a Pedosphere?
is the skin of the Earth and interfaces with the
atmosphere, biosphere, lithosphere, and hydrosphere
the outermost layer of the Earth that is composed of
soil and subject to soil formation processes.
It exists at the interface of
the lithosphere, atmosphere, hydrosphere and biosphere.
What factors affect the profile of a pedosphere?
the dynamic interaction between the
atmosphere, biosphere, lithosphere, and hydrosphere
lithosphere (minerals), biosphere (life), atmosphere
(air), and hydrosphere (water)
What does the lithosphere refer to?
minerals
What does the biosphere refer to?
life
What does the atmosphere refer to?
air
What does the hydrosphere refer to?
water
Why is the Pedosphere: a unique
medium
An arrangement of solids and pores in soil.
The pores are filled with air and/or water,
while the solids are composed of minerals, living and non living organic matter.
What is the relationship between the Pedosphere and Life
- The soil biota consists of microorganisms, soil fauna, and plants
- They form a food web in the soil
- Control decomposition of plant and animal
residue
**What is a Pedon?
A soil pedon is a 3D body in a landscape that can be divided into 4 main components:
1. air
2. organics
3. minerals
4, water
***Define Pedon
is the smallest volume that can be called a soil (1-10m2)
Define Polypedon
consists of more than 1 pedon
***Define Solum
The upper layer in soil, modified parent material, contain most plant roots
the upper horizon in a soil in which the parent material has been modified and in which most plants roots are contained
Define Aggregate
a group of soil particles cohering in such a way that they mechanically behave as a unit
Define Soilscape
a pedological portion of the landscape
Define Soil Ped
a unit of soil structure such as prism, block, or granule, which is
formed by natural processes
***Define Soil Horizon
a layer of soil or material approximately parallel to the land
surface (cm in thickness)
***Define Soil Profile
Vertical section of soil extending to the parent material
a vertical section of soil through all its horizons and extending into
the parent material (1-2 m)
How many interactions of spheres creates a pedon?
4 (ABHL)
A – Atmosphere
B – Biosphere
H – Hydrosphere
L – Lithosphere
***How many interactions of spheres create a pedosphere?
2 (any combo)
A – Atmosphere
B – Biosphere
H – Hydrosphere
L – Lithosphere
Why is the pedosphere important (2)?
The pedosphere is an integral component of many cycles: water, carbon, nitrogen
The pedosphere is a complex life support system for the plant
What are the soil forming factors (5)?
- Parent Material
- Climate
- Biota
- Time
- Topography
The process of Decay
Over time Plant Material decreases, and through Humification (decay), Humus increases
What are the soil process (3)?
- Physical (leaching, heat transport)
- Chemical (weathering of minerals)
- Biological (decomposition, mineralization)
What are the major components of soil (4)?
- Minerals
- Organic matter
- Water
- Air
List the soil profile
O - organics (humus)
A - Topsoil (minerals with humus)
B - Subsoil (deposited minerals and metals)
C - Parent Rock (partially weathered rock)
R - Bedrock (un-weathered rock)
Profile of the O horizon
L - leaf litter
F - Fermenting leaf litter
H - Humus
Define Rocks
naturally occurring combinations or coherent
aggregates of minerals, fossils or other hard materials
Metamorphic -> Igneous
Melting
Metamorphic -> Sedimentary
weathering, transportation,
lithification
Igneous -> Metamorphic
heat, pressure, ions
Igneous -> Sedimentary
weathering, transportation
lithification
Sedimentary -> Metamorphic
heat, pressure, ions
Sedimentary -> Igneous
Melting
Igneous Rocks
They were once molten and
upon cooling, the magma
(molten rock) crystallized
into solid rock.
Igneous rocks may form deep
inside the Earth or at the
Earth’s surface when a
volcano erupts
How do Igneous Rocks Form?
Intrusive vs Extrusive
Also known as primary rocks (first to be formed)
Intrusive - Slow cooling (of magma)
- Deep beneath the earth’s surface
- large crystals
Extrusive - Rapid cooling (of lava)
- Earths surface
- small crystals (not easily seen with the naked eye)
- cooling can be so rapid that glass forms instead of crystal
Examples of Extrusive igneous rocks
Pumice (the rapid cooling causes voids)
obsidian
Rhyolite
Andesite
Basalt
Perlite
Tuff
Volcanic Breccia
Examples of intrusive igneous rocks
Granite
Diorite
Gabbro
Peridotite
(think of granite and diorite counter tops, they have crystals)
SEDIMENTARY ROCKS
composed of particles derived from pre-existing rocks or by the crystallization of minerals that were held in solutions
What is a general characteristic of sedimentary rocks?
layering or stratification