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