Term
| 3 controls of plant growth |
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Definition
temperature
aeration
moisture content |
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Term
| 6 physical properties of soil |
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Definition
drainage
compaction
consistency
strength
tilth
terroir |
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Term
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Definition
particle coating (OM , Oxides)
moisture content
minerology |
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Term
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Definition
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Term
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Definition
indicates mineral composition
(what color it is) |
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Term
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Definition
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Term
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Definition
intensity (gray - pure color)
indicates hydrologic regime. |
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Term
| Depletion of redox features |
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Definition
value > 3
Chroma < 2
OM can stain and mask |
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Term
| With High value / chroma = |
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Definition
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Term
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Definition
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Term
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Definition
saturated or reduced conditions
less color |
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Term
| Gleying soil characteristics |
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Definition
reduced / depleted iron = color!!!
WET FOR LOng periods of time |
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Term
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Definition
| gets color from parent material |
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Term
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Definition
V/c > 4/4
< 25 cm thick
base saturation < 50% |
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Term
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Definition
v/c < 4/4
>25 cm
base saturation >50% |
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Term
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Definition
v/c < 4/4
> 25 cm
base saturation <50% |
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Term
|
Definition
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Term
| texture classification does not include |
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Definition
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Term
| Surface area for texture classes (1g) |
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Definition
Sand = .1 m^2
silt = 1 m^2
clay = 10-10000 m^2 |
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Term
| higher surface area increases 4 things |
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Definition
net charge
water
nutrients
weathering |
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Term
| available moisture by texture |
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Definition
sand = low
silt = medium
clay = high |
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Term
|
Definition
sand = good
silt = moderate
clay = poor |
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Term
|
Definition
sand = rapid
silt = slow
clay = supper dooper very slow |
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Term
| nutrient retention by texture |
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Definition
sand = low
silt = medium
clay = high |
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Term
| relationship between infiltration, drainage, and aeration |
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Definition
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Term
| relationship between pore volume, nutrient supply, and plasticity |
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Definition
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Term
| chemical formula for aerobic microbes |
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Definition
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Term
| chemical reaction for anaerobic microbes |
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Definition
| CH2O + FeOOH = CO2 + H2O Fe+2 + H+ |
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Term
|
Definition
(mass of dry soil)/(volume of particles)
= 2.65 g/cm^3 |
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Term
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Definition
| (mass of dry soil)/(volume of soil + pores) |
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Term
|
Definition
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Term
| relationship between texture class and porosity |
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Definition
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Term
| organic matter increases or decreases bulk density? |
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Definition
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Term
| compaction increases or decreases bulk density? |
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Definition
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Term
| if bulk density is increased, what is decreased? |
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Definition
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Term
| bulk density is higher or lower in coarse texture soils? |
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Definition
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Term
| affect of cultivation on change in bulk density by texture |
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Definition
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Term
| compaction yields lower or higher hydraulic conductivity? |
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Definition
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Term
|
Definition
| ability of soil to be ruptured |
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Term
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Definition
| ability for soil to be penetrated |
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Term
| does particle density change with compaction? |
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Definition
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Term
| relationship between porosity and bulk density |
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Definition
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Term
| large pores contain air or water? |
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Definition
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Term
| small pores contain air or water? |
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Definition
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Term
| relationship between clay content and bulk density |
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Definition
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Term
|
Definition
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Term
|
Definition
primary particles
sub micro aggregates
micro aggregates |
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Term
| factors that promote aggregates |
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Definition
Clay content
OM (root abundance and fungal biomass)
low disturbance |
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Term
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Definition
| spacial arrangement of primary particles |
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Term
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Definition
| binding agents provided by plant roots |
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Term
| What is most important for soil structure |
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Definition
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Term
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Definition
| used to improve soil structure |
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Term
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Definition
| how easily peds fall apart |
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Term
| 3 characterizations of structure |
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Definition
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Term
| 4 types of soil structure and horizon location |
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Definition
Platy = E-horizon
blocky = B-horizon
granular = A-horizon
Prismatic = B-horizon |
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Term
|
Definition
| water attraction to solid surfaces |
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Term
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Definition
| water attraction to water |
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Term
|
Definition
| contact angle, which measures the attractive force |
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Term
does water potential increase or decrease as you move from the soil surface
(micro scale) |
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Definition
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Term
|
Definition
| rate of lateral movement of water in soil |
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Term
|
Definition
pore size
structure
particle packing |
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Term
| 3 types of potential energy |
|
Definition
gravity
osmotic
matric
(hydrostatic) |
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Term
|
Definition
fully saturated = gravity
Field capacity = capillary
wilting point = hygroscopic |
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Term
|
Definition
vertical = gravity (saturated flow)
from thick to thin films = unsaturated flow
vapor water = hygroscopic conditions |
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Term
| if infiltration is constant |
|
Definition
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Term
| 5 influences on infiltration |
|
Definition
surface texture
bulk density
OM
subsurface composition
initial water content |
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Term
| when pore conductivity is high |
|
Definition
rapid water movement
low chemical weathering |
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Term
| define gravimetric moisture content |
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Definition
| mass of water in the soil |
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Term
| volumetric moisture content |
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Definition
gravimetric moisture content x bulkdensity
(theta v) |
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Term
|
Definition
| organic and inorganic particles with high surface areas |
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Term
|
Definition
crystalline silicate / phylo silicate
none crystalline silicate (amorphus)
Fe and Al oxides
OM (humus) |
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Term
| what is the chemical formation of clay |
|
Definition
primary particle + H3O = secondary particle + cation + OH
Hydrolysis |
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Term
|
Definition
silicate tetrahedron
aluminum octahedron |
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Term
| 5 ions exchanged in tetrahedron |
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Definition
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Term
|
Definition
AL+3
Fe+3
Mg+2
Zn+2
Na+
O-2
OH- |
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Term
|
Definition
Al+3
Fe+3
Mg+2
Zn+2
Na+
Ca+2
K+ |
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Term
| Classification of clay types |
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Definition
# and combination of structural units
size and location/layer of charge
presents or absence of inter layer cations |
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Term
|
Definition
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Term
|
Definition
Semectite
vermiculite
micas
chlorate |
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Term
| What are characteristics of kaolinite |
|
Definition
inter layer H bonding
does not allow expansion
stable at low pH
most weathered
no isomorphic substitution
no internal charge |
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Term
| semectite characteristics |
|
Definition
montmorillonites
switch Mg with Al = permanent -1 charge
most swelling (because of van de walls)
water and cations in the inter layer space |
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Term
|
Definition
product when mica looses K layer
most nutrient rich
substitute Al for Si in tetrahedral
Substitute Fe for Al in octrahedral |
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Term
|
Definition
covalently bonded K inner layer
exchange Al for Si in tetrahedral
water causes dissolution and leaching to produce vermiculite |
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Term
|
Definition
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Term
| clay differentiations due to |
|
Definition
weathering conditions
ions present and their concentration |
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Term
|
Definition
permanent from isomorphic substitution
pH dependent charge (edge phonomina) |
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Term
|
Definition
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Term
| clay types in entisols and inceptisols |
|
Definition
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Term
| clay type in vertisol alfisol and mollisol |
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Definition
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Term
|
Definition
| kaolonite ( highest weathering) |
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Term
| define cation exchange capacity |
|
Definition
| total number of positive charges that a mineral can absorb at a given pH |
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Term
|
Definition
strength of adsorption
relative concentration of ions |
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Term
|
Definition
| H+ > Al+3 > Ca+2 > Mg +2 > NH4+ = K+ > Na+ |
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
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Term
|
Definition
proportion of base cations occupying exchange sites
Ca NH4 K |
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Term
|
Definition
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Term
| chemical formula for source of acidity |
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Definition
| Al+3 + 3H2O = Al(OH)3 + 3H+ |
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Term
| Chemical formula for how lime raises pH |
|
Definition
| CaCO3 + 2H+ = H2O + CO2 + Ca+2 |
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Term
|
Definition
| exchange K+ for H+ then measure the pH |
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Term
|
Definition
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