AC-Ch. 3 Soil Science

Question 1

Group of soil bacteria resembling fungi. They play a role in the decomposition of organic matter and the release of mineral elements

Answer 1

Actinomycetes

Question 2

Close cluster or mix of small particles of soil and/or organic matter of varying sizes that are bonded together; sand, gravel or small rocks in soil and/or sand, gravel, or small rocks used under paved surfaces

Answer 2

Aggregate

Question 3

Clusters of flowers or fruits that appear as a single unit

Answer 3

Aggregate

Question 4

Individual tree crowns that form a canopy

Answer 4

Aggregate

Question 5

Ion that carries a negative charge

Answer 5

Anion

Question 6

Ability of a soil to maintain its pH

Answer 6

Buffering capacity

Question 7

Mass of soil per unit volume. Often used as a measure of compaction

Answer 7

Bulk density

Question 8

Water held in the capillary pores of the soil much of this water can move in any direction and is readily available to plant roots

Answer 8

Capillary water

Question 9

Positively charged ion.

Answer 9

Cation

Question 10

What are the most abundant cations in soil

Answer 10

Calcium. Magnesium. Potassium. Sodium. Aluminum.

Question 11

Ability of a soil to absorb and hold cations. Affected by soil pH. Measures soil fertility, clay composition, and enginnering characteristics.

Answer 11

Cation exchanged capacity CEC

Question 12

Soil particles with a typical grain size less than .004 mm.

Answer 12

Clay

Question 13

Substance or solution that oozes out of injured plant cells or is secreted through membrane pores

Answer 13

Exudate

Question 14

Maximum soil moisture content following the drainage of water due to the force of gravity.

Answer 14

Field capacity

Question 15

Water that drains from the larger soil macropores due to the force of gravity.

Answer 15

Gravitational water

Question 16

Layer of soil within the soil profile

Answer 16

Horizon

Question 17

Dark colored, stable form of organic matter that remains after most of the plant or animal residues have decomposed

Answer 17

Humus

Question 18

Atom or a group of atoms with a positive or negative charge

Answer 18

Ion

Question 19

Tendency for elements or compounds to wash down through or into the soil

Answer 19

Leach (leaching)

Question 20

Soil texture classification based on a certain ratio of sand, silt, and clay. Considered ideal for plant growth.

Answer 20

Loam

Question 21

Relatively large space between soil particles that is usually air filled and allows for water movement and root penetration

Answer 21

Macropore

Question 22

Space between soil particles that is relatively small and likely to be water filled

Answer 22

Micropore

Question 23

Process in which an organic substance is converted to or trapped in inorganic substance

Answer 23

Mineralization

Question 24

Microscopic roundworm. Many are beneficial organisms, but some feed on plant tissues and may cause disease or damage

Answer 24

Nematode

Question 25

Movement of mineral elements within an ecosystem as organic matter decomposes, releasing bound nutrients back to plants

Answer 25

Nutrient cycling

Question 26

Layer of organic at the soil surface

Answer 26

Organic layer

Question 27

Soil bedrock or base material from which a soil profile develops

Answer 27

Parent material

Question 28

Point at which a plant cannot pull any more water from the soil and suffers permanent damage.

Answer 28

Permanent wilting point

Question 29

Unit of measure that describes the alkalinity or acidity of a solution. Negative log of the hydrogen ion concentration.

Answer 29

pH

Question 30

Soil area immediately adjacent to and affected by plant roots. Typically has a high level of microbial activity

Answer 30

Rhizosphere

Question 31

Soil with a high concentration of soluble salts. Can cause poor plant growth

Answer 31

Saline soil

Question 32

Soil particles with a size between.06 and 2.0 mm in diameter

Answer 32

Sand

Question 33

Soil particles with a grain size between .004 and .062 mm

Answer 33

Silt

Question 34

Soil with relatively low levels of soluble salts and a concentration of sodium high enough to adversely affect soil structure

Answer 34

Sodic soil

Question 35

Symptoms include waterlogging erosion soil surface crusting and poor plant growth

Answer 35

Sodic soil

Question 36

Compression of the soil often as a result of vehicle or heavy equipment traffic that breaks down soil aggregates and reduces soil volume and total pore space especially macropore space

Answer 36

Soil compaction

Question 37

Complex network of interconnected food chains in an ecosystem in this case in the soil.

Answer 37

Soil food web

Question 38

Vertical section through the soil and all of the soil horizons

Answer 38

Soil profile

Question 39

Arrangement of soil particles into aggregates

Answer 39

Soil structure

Question 40

Relative fineness or coarseness of a soil due to particles size

Answer 40

Soil texture

Question 41

Modular system consisting of units of soil and integrated support structures that serves as both a foundation for paved surfaces and a hospitable environment for tree root growth.

Answer 41

Structural cells

Question 42

Pavement substrate that can be compacted to meet engineering specifications yet remains penetrable by tree roots in the urban environment.

Answer 42

Structural soil

Question 43

Composed of angular crushed stone clay loam and hydrogel mixed in a weight ratio of 100:20:0.03

Answer 43

Structural soil

Question 44

Sidewalk that is reinforced and supported with piers or other structures so that it does not rely on compacted subgrade or soil for support

Answer 44

Suspended sidewalk