soil science exam one
due to high pressure differences (saturated flow)
mass flow
which of the following methods does not promote good soil structure
maximize tillage
when all soil pores are filled with water
maximum retentive capacity
6 ecological roles of soil
medium for plant growth recycles nutrients and wastes controls the flow and purity of water provides home for billions of soil organisms building material/base for homes and roads influences the composition of the atmosphere detoxifies organic contaminants
an inorganic material derived from rocks, or a distinct mineral found in nature
mineral
soil has four components
minerals organic matter water air
pollution from scattered, diffuse sources of pollutant
nonpoint source pollution
organic horizon on the soil surface
o horizon
which of the following components of soil form the soil solids?
organic matter and mineral
high salt concentration, reduces water availability
osmotic potential
which potential energy deals with salt levels
osmotic potential
loss - gain of electrons due to presence of o2/h
oxidation-reduction reactions
geological or organic precursors to the soil (lithosequence)
parent materials
the 3d body of soil with lateral dimension large enough to permit the study of horizon shapes and relations
pedon
soil is interface of air, water, organic, rock
pedosphere
downward movement of water through the soil
percolation
the moisture content of a soil, on an oven dry basis at which plants wilt and fail to recover their turgidity
permanent wilting percentage/wilting coefficient
water retained by the soil between the field capacity and wilting coefficient
plant available water
plant roots crack rocks, animals burrow or stumble on rocks
plants and animals
highly concentrated pollution originating from a specific location
point source pollution
the volume of soil not occupied by particles, expressed relative to total volume
porosity
which of the following is not a major factor influencing soil bulk density
precipitation
what is the name of the characteristic of soil that makes it follow the largest open area
preferential flow
opportunistic flow of water in nonuniform manner through macropores
preferential/macropore/bypass flow
not altered chemically since deposition and crystallization from molten lava
primary mineral
determining optimum water content for maximum bulk density
proctor test
bedrock
r horizon
loose earth materials above solid rock
regolith
a material that forms the essential part of the earth's solid crust
rock
plants get their essential elements by
root interception, mass flow, diffusion
the process of salt accumulation in soil
salinization
mass movement due to saturated hydraulic conductivity
saturated flow
resulting from decomposition of primary mineral
secondary mineral
which of the following is not one of the essential elements of plant growth?
silver
deep rooted plants can explore more water, and hardpan layers can limit rate of water flow and root exploration
soil depth and layering
a layer of soil that differs in properties and characteristics from adjacent layers, approximately parallel to the surface
soil horizon
a vertical section of the soil through all its horizons
soil profile
the arrangement of soil particles into groups called aggregates or peds
soil structure
the relative proportions of the various soil separates
soil texture
the measure of the difference between the free energy state of soil water and that of a pure water
soil water potential
the upper and most weathered part of the soil profile, oa, a, b, and e horizons
solum
which of the following subsurface horizons has an accumulation of illuvial humus with low base saturation without Al and Na
sombric
part of the soil below the plow layer
subsoil
expansion and contraction of rock due to heat results in exfoliation
temperature
physical manipulation soil for crop production
tillage
the period of time since the parent materials became exposed to soil formation (chronosequence)
time
slope, aspect, and landscape position (topsequence)
topography
surface soil
topsoil
soils are chemically or physically modified
transformations
movement of inorganic and organic materials
translocations
soil air is both spatially and temporally variable
true
soil water is considered a solution
true
topography of the land is one of the five major factors that influence soil formation
true
Diffusion of water due to matric potential
unsaturated flow
physical weathering is dominant in what type of environments
very cold or very dry
which of the following is not a method of measuring the content of water in a soil
water density method
all physical and biochemical changes produced in rocks at earth's surface by atmospheric agents
weathering
soil provides most of the
17 essential nutrients
molecular weight of water
18g
if your soil is 100% saturated, what is the volume percentage of the mineral component?
45%
what are the molecules that water split into when undergoing hydrolysis?
H and OH
surface horizon high in organic matter, but composed of mineral soil
a horizon
component of soil changes with soil management season climatic conditions
a transitory
water creates gorgers, windblown sands wear down rocks, and ice grind down rocks
abrasion by water, ice and wind
inputs from outside sources to developing soil profile
additions
attract to other molecules
adhesion
what is the type of the soil that has been deposited into a stream or river
alluvial
which of the following is not a major transporter of soil
animals
subsurface horizon, illuviation from soil forming processes of the above horizon, colored
b horizon
dominant under hot and wet conditions where water, oxygen, and biological agents are prevalent
biochemical weathering
living organisms (microbes, soil animals, and human beings) (biosequence)
biota
which of the following is not a characteristic to look for in the munsel color chart
brightness
least weathered (and deepest) of all the soil horizons
c horizon
water and carbon dioxide form carbonic acid that accelerates weathering
carbonation and acid reactions
which soil separate is the smallest in size
clay
temperature and precipitation (climosequence)
climate
attraction to each other
cohesion
what type of climate is physical weathering more predominant
cold
organic complex (chelates)
complexation
which of the following zones/layers is a defined portion of the soil profile used in determining the soil's classification
control section
water dissolves many minerals
dissolution
who are the two fathers of modern soil classification
dokuchaev and marbut
subsurface horizon light in color due to leaching (eluviation)
e horizon
three most special zones/layers are used for soil classification
epipedon, subsurface, control section
according to the USDA classification used for appropriate land utilization, the letter W stands for wildlife present
false
the application of fertilizer with irrigation water
fertigation
the percentage of water remaining in a soil two or three days after it has been saturated and after free drainage has practically ceased.
field capacity
soil is a ___________ system (both vertically and horizontally)
heterogeneous
addition of water
hydration
water molecules split into H and OH and the H replaces a cation from the mineral
hydrolosis
water level below the wilting point
hygroscopic coefficient
which of the following is not component of soil water potential energy
inert potential
the downward entry of water into the soil
infiltration
when performing a hand feeling texture test and the soil does form a ball but does not form a ribbon, what kind of soil do you have
loamy sand
materials are lost from the soil profile
losses