PSC 3000- Final Exam Study Guide
well answered to pass
The horizon considered a zone of illuviation - correct answer ✔✔B horizon
The two active soil forming factors are - correct answer ✔✔vegetation and climate
The subhorizon indicating a layer high in calcium carbonate. - correct answer ✔✔k
An organic horizon containing no mineral matter. - correct answer ✔✔O horizon
This horizon consists of parent material only. - correct answer ✔✔C horizon
Which master horizon is a zone of maximum leaching (eluviation)? - correct answer ✔✔E
horizon
The sub horizon distinction indicating a cemented layer of soil. - correct answer ✔✔m
This sub horizon indicates a zone containing an accumulation of illuviated silicate clays. - correct
answer ✔✔t
In which region would you expect to find a soil with an abundance of calcium carbonate in the A
horizon - correct answer ✔✔Arizona desert
Which of the following horizons or sub horizons does not contain illuviated material? - correct
answer ✔✔o
,In which environment would you expect to find an O horizon? - correct answer ✔✔cool
temperature forest
This soil horizon is typically the most biologically active in grassland soils. - correct answer ✔✔A
horizon
This soil horizon typically has the highest clay content relative to the other horizons. - correct
answer ✔✔B horizon
This sub horizon indicates a zone containing an accumulation of illuviated organic matter. -
correct answer ✔✔h
Which of the following horizons or sub horizons does not contain illuviated material? - correct
answer ✔✔o
An ideal soil for growing plants consists of - correct answer ✔✔50% solids, 50% pore space
Hydrometer method: Six to seven hours (depending on temperature) after stirring which soil
separates are still in suspension at the depth of the hydrometer? - correct answer ✔✔clay
A soil contains 50% clay and 30% sand. What is its texture? - correct answer ✔✔clay
Hydrometer method: Forty seconds after stirring which soil separates are still suspended in the
water at the depth of the hydrometer? - correct answer ✔✔clay and silt
Hydrometer method: Six to seven hours (depending on temperature) after stirring which soil
separates are still in suspension at the depth of the hydrometer? - correct answer ✔✔clay
, 100 grams of dispersed soil was added to a sedimentation cylinder and a hydrometer reading
was taken after 40 seconds. The measured reading was 60 grams. What is the percentage of
sand in the soil? - correct answer ✔✔40
Hydrometer method: 50 grams soil total. 40 second reading = 30 grams. Seven hour reading =
18 grams. What is the texture of this soil? - correct answer ✔✔clay loam
The smallest amount of clay that a soil can contain and still be in the clay textural class is -
correct answer ✔✔40
The amount of sand, silt, and clay in 50 grams of soil was determined using the hydrometer
method. The readings indicated that 20 grams were present in the 0.05 to 0.002 mm fraction,
and 10 grams were present in the less than 0.002 mm fraction. What is the texture of this soil? -
correct answer ✔✔loam
Fifty grams of dry soil was subjected to the hydrometer method. The reading after 40 seconds
was 30 grams and after seven hours the reading was 15 grams. How much silt is in this soil? -
correct answer ✔✔15 grams
Why is a dispersing agent, such as Calgon or sodium hexametaphosphate, added to the sample
before it is shaken for 24h? - correct answer ✔✔disperses soil particles
The texture of a soil that makes a ribbon greater than two inches and has a smooth feeling that
predominates is a - correct answer ✔✔silty clay
Which pedogenic processes are mostly responsible for O horizon development? - correct
answer ✔✔additions and transformations
The pedogenic process most responsible for the formation of secondary minerals - correct
answer ✔✔transformation
well answered to pass
The horizon considered a zone of illuviation - correct answer ✔✔B horizon
The two active soil forming factors are - correct answer ✔✔vegetation and climate
The subhorizon indicating a layer high in calcium carbonate. - correct answer ✔✔k
An organic horizon containing no mineral matter. - correct answer ✔✔O horizon
This horizon consists of parent material only. - correct answer ✔✔C horizon
Which master horizon is a zone of maximum leaching (eluviation)? - correct answer ✔✔E
horizon
The sub horizon distinction indicating a cemented layer of soil. - correct answer ✔✔m
This sub horizon indicates a zone containing an accumulation of illuviated silicate clays. - correct
answer ✔✔t
In which region would you expect to find a soil with an abundance of calcium carbonate in the A
horizon - correct answer ✔✔Arizona desert
Which of the following horizons or sub horizons does not contain illuviated material? - correct
answer ✔✔o
,In which environment would you expect to find an O horizon? - correct answer ✔✔cool
temperature forest
This soil horizon is typically the most biologically active in grassland soils. - correct answer ✔✔A
horizon
This soil horizon typically has the highest clay content relative to the other horizons. - correct
answer ✔✔B horizon
This sub horizon indicates a zone containing an accumulation of illuviated organic matter. -
correct answer ✔✔h
Which of the following horizons or sub horizons does not contain illuviated material? - correct
answer ✔✔o
An ideal soil for growing plants consists of - correct answer ✔✔50% solids, 50% pore space
Hydrometer method: Six to seven hours (depending on temperature) after stirring which soil
separates are still in suspension at the depth of the hydrometer? - correct answer ✔✔clay
A soil contains 50% clay and 30% sand. What is its texture? - correct answer ✔✔clay
Hydrometer method: Forty seconds after stirring which soil separates are still suspended in the
water at the depth of the hydrometer? - correct answer ✔✔clay and silt
Hydrometer method: Six to seven hours (depending on temperature) after stirring which soil
separates are still in suspension at the depth of the hydrometer? - correct answer ✔✔clay
, 100 grams of dispersed soil was added to a sedimentation cylinder and a hydrometer reading
was taken after 40 seconds. The measured reading was 60 grams. What is the percentage of
sand in the soil? - correct answer ✔✔40
Hydrometer method: 50 grams soil total. 40 second reading = 30 grams. Seven hour reading =
18 grams. What is the texture of this soil? - correct answer ✔✔clay loam
The smallest amount of clay that a soil can contain and still be in the clay textural class is -
correct answer ✔✔40
The amount of sand, silt, and clay in 50 grams of soil was determined using the hydrometer
method. The readings indicated that 20 grams were present in the 0.05 to 0.002 mm fraction,
and 10 grams were present in the less than 0.002 mm fraction. What is the texture of this soil? -
correct answer ✔✔loam
Fifty grams of dry soil was subjected to the hydrometer method. The reading after 40 seconds
was 30 grams and after seven hours the reading was 15 grams. How much silt is in this soil? -
correct answer ✔✔15 grams
Why is a dispersing agent, such as Calgon or sodium hexametaphosphate, added to the sample
before it is shaken for 24h? - correct answer ✔✔disperses soil particles
The texture of a soil that makes a ribbon greater than two inches and has a smooth feeling that
predominates is a - correct answer ✔✔silty clay
Which pedogenic processes are mostly responsible for O horizon development? - correct
answer ✔✔additions and transformations
The pedogenic process most responsible for the formation of secondary minerals - correct
answer ✔✔transformation
