Soil As A Medium For Plant Growth Flashcards
____ compose ______ of dry matter of plants
CHO
90%
List the three phases of soil
Air 25%
Water 25%
Solids 50%
What is Mass Flow
List the nutrients involved
Water soluble nutrients are carried with the flow of water
Nitrogen, Mg, S, Ca
What is Diffusion
List the nutrients involved
Nutrients move as a result of concentration (Root interception)
K, P
List the soil 6 forming factors
- Parent material
- Climate
- Temperature
- Organisms
- Topography
- Time
List the four important factors that the soil provides plants for growth
- Support
- Oxygen
- Ions
- Liquid
What are the 6 types of soil transportation
- Colluvial
- Alluvial
- Marine
- Lacutrine
- Eolian
- Glacial
___ of soil develops from _____
99%
Parent material
Other _____ developed in ______
1%
Organic materials
South/west slopes have…..
Thinner profiles
North/East slopes have….
Deeper profiles
What are the 4 Soil Forming Processes
(Pedegenic)
- Additions
- Losses
- Translocations
- Transformation
What is the difference between Muck & Peat
Muck- OM residues altered beyond recognition
Peat- Undecomposed or slightly decomposed OM; still recognizable
What is the difference between humus & crop residue
Humus- fully decomposed
Crop residue- in process of decomposing
What are the primary nutrients
N, P, K
What are the secondary nutrients
Ca, Mg, S
Saturation can best be described as…
Water filled MACROpores, air filled MICROpores
Glacial till parent material is….
Heterogenous
Other materials pushed into it
Name the different soil horizons in order and their characteristics
O- organic material
A- accumulation of OM (dark surface horizon)
E- Eluviation; process of removal
B- Illuviation
C- slightly altered parent material
R- Not for hand digging (hard bedrock)
Sand settles after ______
40 sec
Silt settles after _____
8 hrs
Clay settles after _____
Never
What is Stokes law
If particles are in Water the LARGEST particles will fall out at the fastest rate
What determines soil structure
Size and shape of PEDS
____ spaces allow ____ textured soils to ____ & allow ______
Large
Finer
Drain rapidly
Root penetration
What is the most important part of soil texture
Pore spaces between particles
What is the most important property for use interpretation
Pore spaces between particles
As bulk density _____ porosity _____
Increases
Decreases
What is the difference between Bulk density and Particle density
Bulk density includes voids and spaces
Particle density focuses on particles only
What is Histosol
Organic soil
When soil compacts, bulk density _____, which _____ MICROpore space
Increases
Increases
What is Inceptisol
Very young soil
Why does Porosity decrease when Bulk density Increase
When soil is compacted, the pore spaces get smaller
How does compaction affect Bulk Density
Why?
Bulk density increases
Since the soil is being pushed together it’s more dense
How can you increase Bulk Density
Compact soil
How can you decrease Bulk Density
Why?
Cultivation
It breaks up the particles and it loses it’s compaction so there are more spaces
How does structure and texture affect Porosity
Texture has different sized particles
Ex. Finer soils have smaller pore spaces but they have a lot so they have more porosity
