Test 1 Chapters 1-4
What value for soil water tension most likely refers to the permanent wilting point?
-1500kPa
Silt measurements
0.002-0.05 mm
Sand measurements
0.05-2mm
composition of ideal soil
25% water 45% mineral 25% air 5% organic
clay measurements
<0.002 mm
In a given soil, the ____ horizon has the highest organic matter content.
A horizon
If you wanted to see a Gelisol in the United States, you would need to travel to _______
Alaska
Entisol
Aquic Udifluvent
Illuviation most likely occurs in the _____ horizon
B horizon
Which soil horizon does not have a lot of soil development?
C horizon?
E horizon
Eluvial horizon
zone of maximum leaching
Eluvial horizon
Soil orders from lowest to highest
Entisols, Inceptisols, Mollisols, Alfisols, Ultisols, Oxisols, Vertisols, Aridisols, Spodosols, Histosols, Andisols, Gelisols
B horizon
Illuvial horizon
zone of accumulation
Illuvial horizon
B horizon
Illuvial horizon, zone of accumulation
To which soil type does Eutrudept belong to?
Inceptisols
The designation 10YR 8/1 is referred to as the ____________ for a soil.
Munsell Notation
color classification system
Munsell Notation
Soils that develop in-place from limestone bedrock have formed in ______ parent materials.
Residium
loss of water from surface instead of infiltrating
Runoff
Soil Taxonomy
Soil Order Sub-order Great Group Sub-Group Family Series Phase
West TN subordinate distinction: t
accumulation of silicate clays (Bt)
Benefits of soil drainage
aeration, easier to work fields, reduces heavy frosting, helps soil warm up faster
Cambic horizon
altered or changed by physical movement
soil structure____________
arrangement of soil separates into aggregates called peds
Fragipan horizon
brittle pan, dense loamy texture
dry mass of soil per unit volume
bulk density
adhesion and cohesion
capillary forces
If a dry soil high in certain types of _______ is moistened, it's likely to swell up with enough force to crack pavements and building foundations.
clay
What are the 5 soil forming factors?
climate, topography, parent material, time, native biota
physical characteristics that make soils different
color, texture, structure
chemical weathering
decomposition
Red soil indicates_______
dehydrated iron compounds, good drainage
Bulk density
density of soil as it exists in nature
Particle density
density of soil solids alone
physical weathering
disintegration
Soil crusting
dispersion of soil particles and sealing the pores
Hue is the ______
dominant color of the rainbow
Different iron compounds in the subsoil are indications of ________
drainage
E horizon
eluvial horizon, zone of loss.
Recent alluvium most likely would be a common parent in _________ soil order
entisols
Who is responsible for lab safety?
everyone
soil genesis
evolution of soil from its parent material
West TN subordinate distinction: x
fragipan, high bulk density (Bx)
Examples of physical weathering
freezing, thawing, plant roots splitting rocks, animals digging
Loess is deposited during periods of __________ and it is highly susceptible to ________
glaciation; erosion
______ is a type of soil structure
granular
Colluvium travels by _________ and an example is_______
gravity; piles, stony
another aggregate definition
groupings of soil separates
R horizon
hard bedrock like sandstone, limestone, or granite
Water in soil moves from areas of ______ (_____) potential to areas of ______(_______) potential.
high (wet); low (dry)
Surface soils are generally darker than subsoil due to _______.
higher organic matter contents
The layers of contrasting material found when one digs a hole in a soil are called ______
horizons
Soil colors are described using the Munsell system that includes designations for:
hue, value, and chroma
yellow soil indicates________
hydrated iron oxides, somewhat restricted drainage
Glacial travels by________ and an example is________
ice; glacial till
The 3 classes of rock are
igenous, sedimentary, metamorphic
The Smokey Mountains have the only ______ in the state
igneous rocks
Brown and red colors in subsurface horizons are caused by _______ in the soil
iron oxides
Albic horizon
light colored, clay, Fe and Al mostly removed
ochric horizon
light in color, low organic matter, hard and massive when dry
Value is the degree of _______
lightness or darkness
Highland rim soils have a lot of ______.
limestone
Soil textural class that represents equal properties of the soil separates
loam
wind-blown silt deposits
loess
Residual parent materials are best described as______
materials formed by weathering of rocks and minerals in place.
function of soils
medium for plant growth recycling system for nutrients and organic matter habitat for soil organisms system for water supply and purification engineering medium **pottery **mined for minerals
Primary minerals form from
molten magma
"O" layer
organic
Soil colors are produced primarily by _________.
organic matter, iron compounds, silica, and lime
C horizon
parent material, not affected by soil forming process
organic deposits
peat
study of soil as a natural body
pedology
What "world" refers to soil?
pedosphere
aggregates
peds
Difference in physical and chemical weathering?
physical changes size chemical changes composition
West TN subordinate distinction: p
plowing or other disturbance (Ap)
unequal distribution of charge in a molecule
polarity
Chroma is the degree of __________
purity of hue
Secondary minerals are
recrystallized products of the chemical breakdown of primary minerals
Coastal plains are ____ in color and ____ in fertility
red; low
Gray soil indicates________
reduced iron, poor drainage
soil texture
relative percentage of sand, silt and clay
What would best assure good aeration in a soil?
removing excess water
Cumberland Plateau has a lot of ________ and they are _____,_______ soils
sandstone monolith; shallow, acid
paralithic materials
saprolite
Argillic horizon
silicate clay accumulation
variations in color, texture, and structure are used to help identify ________
soil horizons
2 ways topography influences soil
soil moisture relationships and soil erosion
physical condition of soil in relation to plants
soil tilth
Minerals are_______
solid, inorganic elements or elemental compounds having definite atomic structures and chemical compositions which vary in a fixed range
West TN subordinate distinction: g
strong gleying, soil is mostly gray because of poor drainage (Cg)
type of soil structure
sub-angular blocky
A horizon
subsurface mineral horizon enriched with organic matter
The relative amount of the different soil separates defines the soil________
texture
Soil tilth
the physical condition of soil in relation to plant growth
A soil profile consists of
the set of layers (horizons) seen in a vertical cross section of a soil.
pedology is______
the study of soil as a natural body
edaphology is________
the study of soil from the standpoint of higher plants
Soil is______
the unconsolidated mineral and organic materials on the immediate surface of the earth that serves as a natural medium for the growth of plants.
Mollic horizons
thick, dark colored, high fertility strong structure
Umbric horizon
thick, dark colored, low fertility, strong structure
Why don't we find many free carbonates in West TN soils?
too much rain; free carbonates have been washed away
A horizon
topsoil
regolith
unconsolidated material overlying rock (engineering term)
parent material
upper part of the regolith which develops into a soil
histic horizon
very high organic matter, wetlands
Aggregation is very important to
water infiltration and absorption
Soil structure is important to
water movement, soil aeration, root penetration
Main chemical agents in weathering are
water, oxygen, and carbon dioxide
Alluivum, marine, and lacustrine travel by ________ and an example is________
water; floodplains, coastal plains, and lake beds
Aeolian travels by_______ and an example is________
wind; loess, sand