1
Horticulture Exam 3 Questions with Answers (100%
Correct Answers)
Horizons A, B, and C are collectively referred to as the ____________--
Answer: subsoil
Subsoil is _______ in organic matter Answer: low
T or F: subsoil is relatively infertile Answer: true
Roots may extend into the _____horizon, but rarely (except for large
woody plants) extend into the ____ horizon Answer: B horizon, C
Horizon
For a gardener, what are the two most important layers of soil? Answer:
Topsoil and subsoil
Explain hardpan/ claypan Answer: A layer of compacted soil that slows
or stops movement of water & air and the growth of roots into lower
layers
Where is hardpan/ claypan located? Answer: in subsoil, below topsoil,
below plow pan
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,2
Where is plow pan? Answer: Near top of topsoil
What causes hardpans Answer: sometimes happen naturally or as a
result of heavy equipment moving over soil
A basic understanding of soils can be obtained by considering mainly
the properties of ____________ and ______- Answer: clay and sand
Mineral soils are classified primarily by the size and quantity of
___________-- particles present in the soil Answer: mineral
Mineral soils are less than _______ % of OM Answer: 20
Organic soils (including muck and peat) are predominately
______________ organic matter Answer: decaying
Organic soils are greater than ______% OM Answer: 20
Organic soils are very ___________, but do not respond,in many respects,
the same as mineral soils Answer: fertile
if a soil contains mostly clay particles, but also a small amount of sand,
it will be classified a _________ _____________ Answer: clay soil.
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,3
When the percentage of sand increases to nearly equal the percentage
of clay, the soil is classified as a ___________ Answer: loam
When sand further increases to greatly surpassthe clay percentage, it
designated as a ________ _________ Answer: sandy soil
Clay soils are often referred to as _________ ____________, composed
primarily of plate like clay particles Answer: heavy soils
_________ particles might be likened to pennies being stacked in a jar,as
compared to marbles (sand particles) Answer: Clay
The property of clay responsible for its being sticky & moldable when
wet, and hard & cloddy when dry is called Answer: plasticity
________________- expands when its wet and contracts when it's dry,
results in surface cracking of the soil and is most evident when it
becomes dry Answer: clay
Nutrients tend to be stored in clay soils rather than washed away by
rainfall or irrigation. what is this called? Answer: Cation-Exchange
capacity
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, 4
T or F: Sandy soils or light soils, can be thought of as possessing the
opposite properties of clay soils Answer: true
_________ soils do not retain moisture well; nor do they expand &
contract, become sticky or cloddy, or compact readily. Answer: sandy
Cation-exchange capacity of sandy soils is very _______, so nutrients
wash away readily when water drains through. Answer: low
________ soils possess qualities of both clay and sand proportional to
the amount of clay and sand particles in the _____ soil Answer: loam (x2)
Which soil type is considered ideal for most plants due to not having
extreme properties Answer: loam soil
What 5 things make loam soils so great Answer: -absorb large
quantities of water
-don't require frequent irrigation
-Dry enough to be workable faster than clay
-holds more nutrients than sandy soil
-Not as prone to becoming cloddy or compacted as clay soils
© 2025 All rights reserved
Horticulture Exam 3 Questions with Answers (100%
Correct Answers)
Horizons A, B, and C are collectively referred to as the ____________--
Answer: subsoil
Subsoil is _______ in organic matter Answer: low
T or F: subsoil is relatively infertile Answer: true
Roots may extend into the _____horizon, but rarely (except for large
woody plants) extend into the ____ horizon Answer: B horizon, C
Horizon
For a gardener, what are the two most important layers of soil? Answer:
Topsoil and subsoil
Explain hardpan/ claypan Answer: A layer of compacted soil that slows
or stops movement of water & air and the growth of roots into lower
layers
Where is hardpan/ claypan located? Answer: in subsoil, below topsoil,
below plow pan
© 2025 All rights reserved
,2
Where is plow pan? Answer: Near top of topsoil
What causes hardpans Answer: sometimes happen naturally or as a
result of heavy equipment moving over soil
A basic understanding of soils can be obtained by considering mainly
the properties of ____________ and ______- Answer: clay and sand
Mineral soils are classified primarily by the size and quantity of
___________-- particles present in the soil Answer: mineral
Mineral soils are less than _______ % of OM Answer: 20
Organic soils (including muck and peat) are predominately
______________ organic matter Answer: decaying
Organic soils are greater than ______% OM Answer: 20
Organic soils are very ___________, but do not respond,in many respects,
the same as mineral soils Answer: fertile
if a soil contains mostly clay particles, but also a small amount of sand,
it will be classified a _________ _____________ Answer: clay soil.
© 2025 All rights reserved
,3
When the percentage of sand increases to nearly equal the percentage
of clay, the soil is classified as a ___________ Answer: loam
When sand further increases to greatly surpassthe clay percentage, it
designated as a ________ _________ Answer: sandy soil
Clay soils are often referred to as _________ ____________, composed
primarily of plate like clay particles Answer: heavy soils
_________ particles might be likened to pennies being stacked in a jar,as
compared to marbles (sand particles) Answer: Clay
The property of clay responsible for its being sticky & moldable when
wet, and hard & cloddy when dry is called Answer: plasticity
________________- expands when its wet and contracts when it's dry,
results in surface cracking of the soil and is most evident when it
becomes dry Answer: clay
Nutrients tend to be stored in clay soils rather than washed away by
rainfall or irrigation. what is this called? Answer: Cation-Exchange
capacity
© 2025 All rights reserved
, 4
T or F: Sandy soils or light soils, can be thought of as possessing the
opposite properties of clay soils Answer: true
_________ soils do not retain moisture well; nor do they expand &
contract, become sticky or cloddy, or compact readily. Answer: sandy
Cation-exchange capacity of sandy soils is very _______, so nutrients
wash away readily when water drains through. Answer: low
________ soils possess qualities of both clay and sand proportional to
the amount of clay and sand particles in the _____ soil Answer: loam (x2)
Which soil type is considered ideal for most plants due to not having
extreme properties Answer: loam soil
What 5 things make loam soils so great Answer: -absorb large
quantities of water
-don't require frequent irrigation
-Dry enough to be workable faster than clay
-holds more nutrients than sandy soil
-Not as prone to becoming cloddy or compacted as clay soils
© 2025 All rights reserved
