Envirothon: Soil Flashcards
1
Q
What is soil?
A
A complex, self-renewing, living system; Soil is a resource that most terrestrial life depends on directly or indirectly for survival
2
Q
What is soil composed of?
A
Inorganic minerals, organic humus, living organisms, moisture, and air.
3
Q
Soils are the product of what?
A
Interactions between abiotic and biotic processes
4
Q
What is the study of soils called?
A
Pedology
5
Q
What two Greek words make the English word “pedology”?
A
pedon and logos; Pedon meaning soil and logos meaning logic
6
Q
In the early years of soil study, how was it thought that soil types were determined?
A
By the parent material
7
Q
Who changed how people thought soil types were determined?
A
V.V. Dokuchaev
8
Q
What did V.V. Dokuchaev discover?
A
In the late 1800s, he discovered that different soils develop over identical bedrock exposed to various climates.
9
Q
Which man in 1920 had the idea that climate plays a large role in soil formation?
A
C.F. Marbut; Chief of the United States Soil Survey
10
Q
What are the 5 categories for factors that influence soil development?
A
- The type of parent(source) material
- The climate under which the soil components have existed since accumulation
- The plant and animal life in and on the soil
- The relief of the land
- The length of time the other factors have interacted
11
Q
The five categories of factors are what?
A
Interdependent
12
Q
How does soil formation begin?
A
The degradation of parent material
13
Q
What is parent material?
A
Unconsolidated, chemically weathered mineral, rock, or organic matter
14
Q
What are the climate forces that act on parent material to form soil?
A
Precipitation, temperature, humidity, and
wind
15
Q
What greatly influences the way wind and water acts on the parent soil?
A
The relief of the land and the types of plants and animals that inhabit the area
16
Q
What things furnish organic matter?
A
Animals, insects, bacteria, fungi, and other plants
17
Q
Plant and animal actions cause differences in what?
A
Differences in the amount of organic matter, nutrients, structure, and porosity of soil
18
Q
What is an important factor in soil formation?
A
Time
19
Q
Finish the quote: “The physical and chemical changes
brought about by climate, living organisms, and relief are”
A
Slow
20
Q
Why does the length of time needed to convert raw geologic materials into soils vary?
A
It depends on the nature of the material and the interaction of other factors
21
Q
How are soils deposited?
A
In layers
22
Q
What is the difference between a mature soil and an immature soil?
A
A mature soil has defined layers, while an immature soil does not
23
Q
What is a soil profile?
A
A vertical column of soil
24
Q
What are the soil layers called?
A
Soil horizons
25
O Horizon
The O horizon is dominated by organic material. It contains fresh and decaying plant matter from leaves, needles, twigs, moss, lichens, and other organic accumulations
26
A Horizon
The A horizon is formed at the surface or below the O horizon. It is an accumulation of organic matter and
minerals. It is generally darker than the lower horizons because of the decaying organic matter. This horizon is where most plant root activity occurs. It may
be referred to as the surface layer in a soil survey.
27
E Horizon
The main feature of the E horizon is the loss of silicate clay, iron, or aluminum, or some combination of these, leaving a concentration of sand and silt-sized particles.
28
B Horizon
The B horizon lies directly below an A, E, or O horizon. It is
referred to as the subsoil. It is usually lighter colored, denser, and lower in organic matter than upper horizons. As the recipient of material from upper and lower soil layers, the B horizon is often called the “zone of accumulation.”
29
Leaching
When water percolates through soil and wash soil particles through A and B Horizons
30
What is the "zone of leaching" layer?
A Horizon
31
Fragipan
A dense, nearly impermeable subsurface layer
32
Hardpan (in Florida)
When a fragipan is made up of extremely compacted soil particles
33
Caliche
Layers cemented by calcium carbonate
34
Ironpan
Layers cemented by iron oxide
35
C Horizon
Also called the substratum; This layer may consist of less clay or other less-weathered sediments than the layers above. Partially disintegrated parent material and mineral particles are in this horizon.
36
R Horizon
Bedrock; It can be withing several inches of the surface or many feet below.
37
Master horizons are divided into what?
Specific layers
38
Suffix Symbol A
Highly decomposed organic materials
39
Suffix Symbol B
Buried soil horizon
40
Suffix Symbol C
Concretions — grains, pellets, or nodules of various sizes, shapes, and colors consisting of concentrated compounds or cemented soil grains
41
Suffix Symbol D
Physical root restriction
42
Suffix Symbol E
Organic material of intermediate decomposition
43
Suffix Symbol F
Frozen soil
44
Suffix Symbol G
Strong gleying — soil that is formed under poor drainage, resulting in the reduction of iron and other elements and in gray colors and mottles
45
Suffix Symbol H
Alluvial accumulation of organic matter
46
Suffix Symbol I
Slightly decomposed organic matter
47
Suffix Symbol K
Accumulation of carbonates
48
Suffix Symbol M
Cementation
49
Suffix Symbol N
Accumulation of sodium
50
Suffix Symbol O
Residual accumulation of sesquioxides
51
Suffix Symbol P
Tillage or other disturbance
52
Suffix Symbol Q
Accumulation of silica
53
Suffix Symbol R
Weathered or soft rock
54
Suffix Symbol S
Alluvial accumulation of sesquioxides and organic matter
55
Suffix Symbol T
Accumulation of alluvial clay
56
Suffix Symbol V
Plinthite: an iron-rich, humus-poor mixture of clay with quartz and other minerals; redoximorphic feature in highly weathered soil.
57
Suffix Symbol W
Development of color or structure
58
Suffix Symbol X
Fragipan character
59
Suffix Symbol Y
Accumulation of gypsum
60
Suffix Symbol Z
Accumulation of salts more soluble than gypsum
61
What varies with location?
The thickness of each layer
62
When will not all horizons be present?
When under disturbed conditions, such as intense agricultural development or where erosion is severe
63
What is used to define soil types?
Soil characteristics
64
What are the most common soil characteristics?
Texture, color, porosity, compaction, and permeability
65
Soil texture only refers to what?
Mineral particles smaller than 2 millimeters (mm)
66
How is the term "soil texture" used by the USDA?
To designate the percentages of sand, silt, and clay in a sample of soil
67
Soil Seperate
Each grouping of particle sizes
68
How many soil seperates are there?
8
69
What are the soil seperates?
```
Very coarse sand: 2.00–1.00 mm
Coarse sand: 1.00–0.50 mm
Medium sand: 0.50–0.25 mm
Fine sand: 0.25–0.10 mm
Very fine sand: 0.10–0.05 mm
Coarse silt: 0.05–0.005 mm
Fine: silt 0.005–0.002 mm
Clay: less than 0.002 mm
```
70
The texture of a soil gives an indication of what?
* The relative water-holding capacity
* Mineralogy
* Susceptibility to being transported by wind or water
* Chemical properties
71
Mechanical Analysis
The process by which soil separates are obtained
72
How many major texture class names are there?
12
73
What are the major texture class names?
```
Sand
Loamy sand
Sandy loam
Sandy clay loam
Sandy clay
Clay
Clay loam
Loam
Silt loam
Silty clay loam
Silty clay
Silt
```
74
How is the texture of a soil done in the field?
By feel
75
How is the soil felt, to determine its texture?
The soil is rubbed between the thumb and fingers and an estimate of the amount of the various separates
present is made on the basis of the degree to which the characteristic properties are expressed.
76
How are silts different from silt loams?
Silts have less sand and clay
77
How do you read a soil triangle?
Sand, silt, clay
78
What order do these go in (smallest to largest): sand, clay, silt?
Clay, silt, sand
79
What are soil colors produced by?
Organic matter, iron compounds, silica, lime, manganese
| compounds, aluminum hydroxide, and various salts
80
How are soil colors measured?
By comparison with a chart known as the Munsell Soil Color charts
81
How many different color chips are in the Munsell Soil Color charts?
322
82
How are the color chips in the Munsell Soil Color arranged?
By hue, value, and chroma
83
Hue
Indicates the color’s relation to spectral colors such as red, yellow, green, blue, and purple.
84
Value
(Sometimes called brilliance) indicates the relative lightness or darkness of the chip
85
"Vertically, the chip becomes lighter as the column progresses from the _______ to the ________."
Bottom; Top
86
The value for each chip is noted by the vertical scale on which side of the chart?
Far left
87
What symbol is in the top right corner of the chart?
The hue. R for red, YR for yellow-red, etc.
88
What do the numbers stand for on the far left side of the chart?
0 for absolute black; 10 for absolute white
89
Chroma
The chip color’s relative purity or the degree of vividness in contrast to grayness
90
"Horizontally, the chips increase in chroma from _____ to ____"
Left; Right
91
Where is the chroma located on the card?
The bottom of the chart
92
The notation for chroma consists of numbers beginning with what for neutral grays and increasing at equal intervals
to a maximum of about what?
0;20
93
Soils are classed as what two things?
Achromatic and chromatic
94
Achromatic Colors
White, all shades of gray, and black. They have a neutral hue and a zero chroma, but differ in value.
95
Chromatic Colors
Represent various combinations of hue, value, and chroma.
96
Soil Color Notations
The color name is written first, followed by the Munsell notation in parentheses. In writing Munsell color notation, the order is hue, value, and chroma, with a space, hue letter, and succeeding value number, and a diagonal line between the two numbers for value and chroma.
Thus the notation for a yellowish-red colored soil of hue 5YR, value 5, and chroma 6 is yellowish-red (5YR5/6)
97
How is an accurate comparison of a soil sample to the Munsell Soil Color charts accomplished?
By holding the specimen behind the openings next to the closest matching color chip. Rarely will the soil sample be perfectly matched by any color in the charts.
98
Porosity
Porosity refers to the amount and size of spaces between soil or rock particles. Porosity determines the amount of water that a soil can hold. Sands and gravels have
high porosity. Clays are very porous. Some can hold up to 60 percent of their total volume. High porosity does not always indicate good permeability. Porosity is an
important factor in the choice of plants or crops to be grown and in the design and management of irrigation systems.
99
Permeability
Permeability refers to the rate of water and air movement through soil or bedrock, if present. It is an indication of downward movement of water when the soil is
saturated. This may be considered internal drainage. Permeability can be estimated from texture, compaction, and arrangement of soil particles (structure). The drawing
illustrates the common ways particles may affect the soil’s internal drainage by either providing a pathway for water to drain or by retarding water movement.
100
How is permeability measured?
In the number of inches per hour (in/hr) that water moves
| downward through a saturated soil
101
What are the terms that describe permeability and respective flow rates of soil?
```
Very slow less than 0.06 in/hr
Slow 0.06–0.20 in/hr
Moderately slow 0.20–0.6 in/hr
Moderate 0.6–2.0 in/hr
Moderately rapid 2.0–6.0 in/hr
Rapid 6.0–20 in/hr
Very rapid more than 20 in/hr
```
102
A healthy topsoil has about what percent of pore space?
50%
103
Soil Compaction
Destruction by tillage, intense agricultural operations, or heavy vehicle and foot traffic.
104
Largest pores
Macropores
105
Macropores are the most vulnerable to what?
Soil compaction
106
The loss of macropores inhibits what?
Inhibits the movement of gases, including oxygen, into and out of the soil.
107
Small pores
Micropores
108
The loss of micropores lowers what?
The permeability of the soil, thereby restricting
| percolation and increasing runoff, erosion, and flooding.
109
How do porosity and permeability influence the classification of soils?
By drainage patterns
110
Drainage classes refer to what?
The periods of saturation or partial saturation during soil
| formation, as opposed to altered drainage.
111
What drainage is a result of human interaction?
Partial saturation during soil formation
112
How many classes of soil drainage are there?
7
113
Excessively Drained
Water is removed from the soil very rapidly. Excessively drained soils are commonly very coarse-textured, rocky, or shallow. Some are steep. All are free of mottling related to wetness
114
Somewhat Excessively Drained
Water is removed from the soil rapidly. Many
somewhat excessively drained soils are sandy and rapidly pervious. Some are shallow. Some are so steep that much of the water they receive is lost to runoff. All are free of the
mottling related to wetness
115
Well-Drained
Water is removed from the soil readily, but not rapidly. It is available to plants throughout most of the growing season, and wetness does not inhibit growth of roots for significant periods during the growing seasons. Well-drained soils are commonly medium textured. They are mainly free of mottling.
116
Moderately Well-Drained
Water is removed from the soil somewhat slowly during
some periods. Moderately well drained soils are wet for only a short time during the growing season, but periodically they are wet long enough that most mesophytic crops are affected. They commonly have a slowly pervious layer within or directly below the solum or periodically receive high rainfall, or both.
117
Somewhat Poorly Drained
Water is removed slowly enough that the soil is wet for
significant periods during the growing season. Wetness markedly restricts the growth of mesophytic crops unless artificial drainage is provided. Somewhat poorly drained
soils commonly have a slowly pervious layer, a higher water table, additional water from seepage, nearly continuous rainfall, or a combination of these.
118
Poorly Drained
Water is removed so slowly that the soil is saturated periodically during the growing season or remains wet for long periods. Free water is commonly at or near the surface for long enough during the growing season that most mesophytic crops cannot be grown unless the soil is artificially drained. The soil is not continuously saturated directly below the plow depth. Poor drainage results from a high water table, a slowly pervious layer within the profile, seepage, nearly continuous rainfall, or a combination of these.
119
Very Poorly Drained
Water is removed so slowly that free water remains at or on the surface during the growing season. Unless the soil is artificially drained, most crops cannot be grown. Very poorly drained soils are commonly level or depressed, are
frequently ponded, or have impermeable layers close to the surface. Yet where rainfall is high and nearly continuous, they can have moderate or high slope gradients.
120
Wetlands
A general term used for areas where the soil is covered or saturated with fresh or salty water for at least one month per year and where special vegetation has grown because of the wet conditions.
121
"Wetlands are usually at a _____ elevation compared
| to the surrounding land, but may be at a ______ level with impermeable soil."
Low; Higher
122
What are several benefits of wetlands?
• They can store rain and slow runoff, which helps to control flooding and erosion.
• They are valuable for recreation and beauty.
• They filter and absorb pollutants and purify water.
• They provide habitat for a wide variety of plants and animals, including 90 percent of the plants, 30 percent of the birds, 15 percent of the mammals, and 50 percent of
the fish on the United States endangered species list.
• They help stabilize shorelines and reduce coastal storm damage.
• They provide important spawning and nursery grounds for approximately two thirds of the nation’s shellfish and important commercial and sport species of marine fish.
• They provide important rest areas for the millions of migrating birds every year.
123
It is estimated that Florida has lost around what percent of its original 20 million acres of wetlands?
60%
124
Florida contains what percent of the wetlands in the United States?
20%
125
In 1951, what soil taxonomy classification was created to help create a more accurate and universally understandable classification of soils?
No specific name; Soil Taxonomy Classification
126
The soil taxonomy group recognizes how many categories?
6
127
What are the 6 taxonomic classification categories?
```
Order
Suborder
Great Group
Subgroup
Family
Series
```
128
Soil orders reflect what?
The dominant soil-forming processes and the degree of soil formation
129
Each soil is identified by a word with what suffix?
sol
130
How many soil orders are there?
12 soil orders
131
How many soil orders are found in Florida?
7 soil orders
| Soil orders found in Florida will be marked with an asterisk.
132
Alfisols*
Well-developed soils with a relatively fine-textured subsoil horizon that has a base saturation of 35 percent or more.
133
Andisols
Soils of volcanic origin
134
Aridisols
Dry soils that occur in arid or semi-arid regions.
135
Entisols*
Soils with little or no horizon development.
136
Gelosols
Soils of cold climates influenced by permafrost.
137
Inceptisols*
Soils of humid regions with profile development sufficient to exclude them from the Entisols, but insufficient to include them in Spodosols, Ultisols, or other well developed
soils. Soils that appear to be like Mollisols but have less than 50 percent or more base saturation may also be Inceptisols.
138
Mollisols*
Soils with thick (usually 10 inches or more), dark surfaces that have a base saturation of 50 percent or more in the surface soil.
139
Oxisols*
Highly weathered soils of the tropics.
140
Spodosols*
Soils with a spodic horizon (a dark-colored subhorizon with a mixture of organic matter and aluminum, with or without iron).
141
Ultisols*
Well-developed soils with a relatively fine-textured subsoil horizon that has less than 35 percent base saturation.
142
Vertisols
Soils with more than 30 percent clay which appreciably expand upon wetting and contract upon drying.
143
HIstosols*
Soils composed of relatively thick (usually 16 inches or more) organic materials (muck and peats).
144
How are soils further differentiated?
* Suborders
* Great groups
* Subgroups
* Families
* Series
145
What kind of soil does the Everglades have?
Histosols
146
What kind of soil does Union County have?
Ultisols
147
Knowledge of soil characteristics helps determine?
The land’s capability for farming and ranching, proper agricultural and urban use, and conservation practices necessary.
148
What are some examples of land uses?
```
Crop and pasture lands
Rangeland
Forestry
Recreation
Wildlife
Habitat,
Engineering uses
Building sites
Sanitary facilities
Water management
Construction materials
```
149
How does knowing soil characteristics help farming?
Identification of soil types helps to analyze potential erosion problems, soil drainage, soil fertility, and soil tilth, all of which are important factors in determining which crops are best suited to an area and the productivity potential for those crops
150
How does knowing soil characteristics help ranching?
Rangeland is land on which the natural vegetation is predominately native grasses, grasslike plants, and shrubs, suitable for grazing by domestic livestock and
wildlife. In addition to livestock forage and wildlife habitat, rangeland provides wood, water, recreation, and scenic beauty. Rangeland includes grassland, open forest, wetlands, and shrubland.
151
How does knowing soil characteristics help forestry?
Knowledge of soils can be used by forest managers to increase the productivity of forest lands. Some soils respond better to fertilization than others, and
some are more susceptible to erosion after roads are built and timber is harvested. Some soils require special efforts to reforest. Soils vary in their ability to produce trees.
152
How does knowing soil characteristics help recreation?
Recreational uses include camping areas; picnic areas, playgrounds, paths and trails for hiking, horseback riding, and bicycling; and golf courses. Provision of camping areas requires the consideration of a number of factors, including preparation of tent or RV sites, parking areas, sanitary facilities, roads, and the installation of utility lines.
153
How does knowing soil characteristics help wildlife habitat?
Numerous elements provide for good wildlife habitat. They include grain and seed crops, grasses, and legumes, wild herbaceous plants, hardwood trees coniferous plants, wetland plants, shallow water areas, and open land. A primary factor in evaluating wildlife habitat is the plant diversity in the area. Increasing dominance by
a few plant species is commonly accompanied by a corresponding decrease in wildlife. Soils affect the kind and amount of vegetation that is available to wildlife as food and
cover.
154
How does knowing soil characteristics help engineering uses?
Engineering uses require a careful examination of soil characteristics and properties. Soil strength, shrink-swell potential, permeability, drainage, and erosion potential are all important factors to consider for building sites, roads, and sanitary facilities. Florida’s five water management districts pay careful attention to soils as a part of their management plans and regulatory requirements.
155
Erosion
The wearing away of the land surface by water, wind, ice, or other geologic agents and by such processes as gravitational creep.
156
Geologic erosion is caused by what?
Geologic processes acting over long geologic periods and resulting in the wearing away of mountains and the building up of such landscape features as floodplains and coastal systems.
157
Geologic erosion is another name for?
Natural erosion
158
Accelerated erosion is the result of?
The activities of humans or other animals or of a natural catastrophe such as a hurricane or a wildfire.
159
What is the first principle in wind erosion control?
Cover the soil
160
What is one of the most permanent methods of wind erosion control?
A wind barrier
161
What are other agricultural practices that control wind erosion?
Crop residue management, crop rotation,
| planting cover crops, strip cropping, and planting buffer strips that protect soil from erosion.
162
Crop Residue Management
Leaving crop remains in the field as mulch
163
IFAS
University of Florida’s Institute of Food and Agricultural Science
164
FFB
Florida Farm Bureau
165
FDACS
Florida Department of Agriculture and Consumer Services
166
FDEP
Florida Department of Environmental Protection
167
FAESS
Florida Association of Environmental Soil Scientists
168
FACD
Florida Association of Conservation Districts
169
NRCS
Natural Resources Conservation Service
170
Nitrogen-fixing bacteria have what kind of relationships with legumes and trees?
Symbiotic
171
What are examples of the symbiotic relationships with nitrogen-fixing bacteria?
Roots of legumes such as clover and lupine and trees such as alder and locus
172
How does the nitrogen-fixing bacteria work?
The plant supplies simple carbon compounds to the
bacteria, and the bacteria convert nitrogen (N2) from air into a form the plant host can use. When leaves or roots from the host plant decompose, soil nitrogen increases in the surrounding area.
173
What is the preferred form of nitrogen by grasses and most row crops?
NO-3
174
Nitrifying bacteria change _______ (NO+4) to ______ (NO-2) to ______ (NO-3)
Ammonium; Nitrate; Nitrate
175
Denitrifying bacteria change ______ to ______ (N2) or to ______ (N2O)
Nitrate; Nitrogen; Nitrous Oxide
176
Denitrifyers are what?
Anaerobic; They thrive where oxygen isn't; Saturated soils or inside soil aggregates
177
Actinomycetes
A large group of bacteria that grow as hyphae-like fungi. They are responsible for the characteristically “earthy” smell of freshly turned, healthy soil.
178
Actinomycetes decompose many substrates, but what are they most important for decomposing?
Degrading recalcitrant (hard to decompose) compounds, such as chitin and cellulose, and are active at high pH levels.
179
What is more important at degrading recalcitrant compounds at low pH levels?
Fungi
180
Streptomyces
A number of antibiotics are produced by actinomycetes,
181
Bacteria are especially concentrated in the what?
Rhizosphere, the narrow region next to and in the root
182
What is an example of a single-celled fungi?
Yeast
183
How large is a hyphae's diameter?
Several thousandths of an inch/a few micrometers in diameter
184
"Hyphae group into masses called _______."
Mycelium or thick, cord-like “rhizomorphs” that look like roots.
185
Fungal fruiting structures
Mushrooms
186
What actions do fungi perform that helps move along the ecosystem?
Along with bacteria, fungi are important as decomposers in the soil food web:
- They convert hard-to-digest organic material into forms that other organisms can use.
- Fungal hyphae physically bind soil particles together, creating stable aggregates that help increase water infiltration and soil water-holding capacity.
187
How many soil fungi groups are there?
3
188
Soil Fungi-Decomposers
Convert dead organic material into fungal biomass, carbon dioxide (CO2), and small molecules, such as organic acids. These fungi generally use complex substrates, such as the cellulose and lignin, in wood, and are essential in decomposing the carbon ring structures in some pollutants.
189
"Sugar Fungi"
Very few fungi are called this; Sugar fungi use the same simple substrates as do many bacteria.
190
What is another name for the soil fungi-decomposers?
Saprophytic fungi
191
Soil Fungi-Mutualists
Colonize plant roots. In exchange for carbon from the plant, mycorrhizal fungi help solubolize phosphorus and bring soil nutrients (phosphorus, nitrogen, micronutrients, and perhaps water) to the plant
192
What is one major group of mycorrhizae?
Ectomycorrhizae
193
Where do ectomycorrhizae grow?
On the surface layers of the roots and are commonly associated with trees
194
What is the second major group of micorrhizae and where do they grow?
Ectomycorrhizae; Within the root cells and are commonly associated with grasses, row crops, vegetables, and shrub
195
What is another type of endomycorrizal fungi?
Arbuscular mycorrhizal (AM) fungi
196
"Ericoid mycorrhizal fungi can by either _____ or
| _________."
Ectomycorrhizal; Endomycorrhizal
197
Soil Fungi-Pathogens or Parasites
Cause reduced production or death when they colonize roots and other organisms
198
What are some examples of root pathogenic fungi?
Verticillium, Pythium, and Rhizoctonia
199
What do root pathogenic fungi do?
Cause major economic losses in agriculture each year.
200
What is an example of a fungi that helps control diseases?
Nematode-trapping fungi that parasitize disease-causing nematodes and fungi that feed on insects may be useful as
biocontrol agents.
201
Where are saprophytic fungi active?
Around woody plant residue. Fungal hyphae have advantages over bacteria in some soil environments
202
What kind of organisms are fungi?
Aerobic; They work with oxygen, they cannot work without
