Soil Vocabulary Flashcards
(113 cards)
1
Q
ABC soil
A
A soil having an A, a b, and a C horizon
2
Q
Aggregate, soil
A
Many fine particles held in a single mass or cluster.
3
Q
Peds
A
natural soil aggregates such as granules, blocks or prisms.
4
Q
Clods
A
Aggregates produced by tillage or logging
5
Q
Alkali (Sodic) soil
A
A soil having so high a degree of alkalinity (pH 8.5 or higher) or so high a percentage of exchangeable sodium (15% or more of the total exchangeable bases), or both, that plant growth is restricted
6
Q
Alluvium
A
Material, such as sand, silt, or clay, deposited on land by streams
7
Q
Aquic conditions
A
Current soil wetness characterized by saturation, reduction, and redoximorphic features.
8
Q
Association, soil
A
A group of soils or miscellaneous areas geographically associated in a characteristic repeating pattern and defined and delineated as a single map unit
9
Q
Available water capacity
A
the capacity of soils to hold water available for use by most plants. It is commonly expressed as inches of water per inch of soil.
10
Q
Very low, low, moderate, high, very high, water capacities
A
0 to 3 3 to 6 6 to 9 9 to 12 more than 12
11
Q
Bedding planes
A
Fine strata, less than 5 millimeters thick, in consolidated alluvial, eolian, lacustrine, or marine sediment.
12
Q
Bedrock
A
the solid rock that underlies the soil and other unconsolidated material or that is exposed at the surface
13
Q
Bottomland
A
the normal floodplain of a stream , subject to flooding
14
Q
Calcareous soil
A
A soil containing enough calcium carbonate (commonly combined with magnesium carbonate) to bubble visibly when treated with cold, dilute hydrochloric acid
15
Q
Cation
A
An ion carrying a positive charge of electricity
16
Q
Clay
A
Mineral soil particles less than 0.002 millimeters in diameter. As soil textural classification, soil material that is 40% or more clay, less than 45% sand, and less than 40% silt
17
Q
clay film
A
A thin coating of oriented clay on the surface of a soil aggregate or lining pores or root channels. Synonyms: clay coating, clay skin
18
Q
Complex, soil
A
a map unit of two or more kinds of soil in so small an area that it is not practical to map them separately at the selected scale of mapping. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas.
19
Q
Concretions
A
Cemented bodies with crude internal symmetry organized around a point, a line, or a plane.
They typically take the form of concentric layers visible to the naked eye.
Calcium carbonate, iron oxide, and manganese oxide are common compounds making up concretions
20
Q
Conservation cropping system
A
growing crops in combination with needed agricultural and management practices
21
Q
Conservation tillage
A
a tillage system that does not invert the soil an that leaves a protective amount of crop residue on the surface throughout the year.
22
Q
Consistence, soil
A
Refers to the degree of cohesion and adhesion of soil material and its resistance to deformation when ruptured
23
Q
Contour strip cropping.
A
growing crops in strips that follow the contour. strips of grass or close-growing crops are alternated with strips of clean-tilled crops or summer fallow
24
Q
Control section
A
The part of the soil on which classification is based. For many soils, it is that part of the soil profile between depths of 10 inches and 40 or 80 inches.
25
Corrosion
Soil-induced electrochemical or chemical action that dissolves or weakens concrete or uncoated steel.
26
Cover crop
a crop grown primarily to improve and protect the soil between periods of regular crop production, or a crop grown between trees and vines in orchards and vineyards.
27
Cropping system
growing crops according to planned system of rotation and management practices
28
Crop residue management
Returning crop residue to the soil, which helps to maintain soil structure, organic matter content, and fertility and helps to control erosion.
29
Diversion terrace
a ridge of earth, generally a terrace, built to protect downslope areas by diverting runoff from its natural course
30
Drainage class
Refers to the frequency and duration of wet periods under conditions similar to those under which the soil formed
31
Seven classes of natural soil
excessively drained, somewhat excessively drained, well drained, moderately well drained, somewhat poorly drained, poorly drained, and very poorly drained.
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Drainage, surface
runoff or surface flow of water, from an area
33
Eluviation
The movement of material in true solution or colloidal suspension from one place to another within the soil. Soil horizons that have lost material through eluviation are eluvial; those that have received material are illuvial.
34
Endosaturation
A type of saturation of the soil in which all horizons between the upper boundary of saturation and a depth of 2 meters are saturated.
35
Episaturation
A type of saturation indicating a perched water table in a soil in which saturated layers are underlain by one or more unsaturated layers within 2 meters of the surface.
36
Erosion
The wearing away of the land surface by water, wind, ice, or other geologic agents and by such processes as gravitational creep.
37
Erosion (geologic)
erosion caused by 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 planes. Also called natural erosion.
38
Erosion (accelerated)
Erosion much more rapid than geologic erosion, mainly as a result of human or animal activities or of a catastrophe in nature, such as a fire, that exposes the surface.
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Excess fines (in tables)
Excess silt and clay in the soil.
40
Excess sodium (in tables)
Excess exchangeable sodium in the soil. The resulting poor physical properties restrict the growth of plants.
41
Fallow
Cropland left idle in order to restore productivity through accumulation of moisture. Summer fallow is common in regions of limited rainfall where cereal grain is grown.
42
Fast intake (in tables)
The rapid movement of water into the soil.
43
Fine textured soil
Sandy clay, silty clay, or clay.
44
Floodplain
A nearly level alluvial plain that borders a stream and is subject to flooding unless protected artificially.
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Fluvial
Of or pertaining to rivers; produced by river action, as a fluvial plain.
46
Fragipan
A loamy, brittle subsurface horizon low in porosity and content of organic matter and low or moderate in clay but high in silt or very fine sand. A fragipan appears cemented and restricts roots. When dry, it is hard or very hard and has a higher bulk density than the horizon or horizons above. When moist, it tends to rupture suddenly under pressure rather than to deform slowly.
47
Grassed waterway
A natural or constructed waterway, typically broad and shallow, seeded to grass as protection against erosion.
48
Gravel
Rounded or angular fragments of rock as much as 3 inches (2 millimeters to 7.6 centimeters) in diameter. An individual piece is a pebble.
49
Groundwater
Water filling all the unblocked pores of the material below the water table.
50
Gully
A miniature valley with steep sides cut by running water and through which water ordinarily runs after rainfall. The distinction between a gully and a rill is one of depth. A gully generally is an obstacle to farm machinery and is too deep to be obliterated by ordinary tillage; a rill is of lesser depth and can be smoothed over by ordinary tillage.
51
Hard bedrock
Bedrock that cannot be excavated except by blasting or by the use of special equipment that is not commonly used in construction.
52
High-residue crops
Such crops as small grain and corn used for grain. If properly managed, residue from these crops can be used to control erosion until the next crop in the rotation is established. These crops return large amounts of organic matter to the soil.
53
Horizon, soil
A layer of soil, approximately parallel to the surface, having distinct characteristics produced by soil-forming processes. In the identification of soil horizons, an uppercase letter represents the major horizons. Numbers or lowercase letters that follow represent subdivisions of the major horizons
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A horizon
The mineral horizon at or near the surface in which an accumulation of humified organic matter is mixed with the mineral material. Also, a plowed surface horizon, most of which was originally part of a B horizon.
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E horizon
The mineral horizon in which the main feature is loss of silicate clay, iron, aluminum, or some combination of these.
56
B horizon
The mineral horizon below an A horizon. The B horizon is in part a layer of transition from the overlying A to the underlying C horizon. The B horizon also has distinctive characteristics, such as (1) accumulation of clay, sesquioxides, humus, or a combination of these; (2) prismatic or blocky structure; (3) redder or browner colors than those in the A horizon; or (4) a combination of these.
57
C horizon
The mineral horizon or layer, excluding indurated bedrock, that is little affected by soil-forming processes and does not have the properties typical of the overlying soil material. The material of a C horizon may be either like or unlike that in which the solum formed. If the material is known to differ from that in the solum, an Arabic numeral, commonly a 2, precedes the letter C.
58
Cr horizon
Soft, consolidated bedrock beneath the soil
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R layer
Consolidated bedrock beneath the soil. The bedrock commonly underlies a C horizon, but it can be directly below an A or a B horizon.
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Hydrologic soil groups
Refers to soils grouped according to their runoff potential. Runoff potential is affected by depth to a seasonal high water table, the infiltration rate and permeability after prolonged wetting, and depth to a very slowly permeable layer.
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Illuviation
The movement of soil material from one horizon to another in the soil profile. Generally, material is removed from an upper horizon and deposited in a lower horizon.
62
Infiltration
The downward entry of water into the immediate surface of soil or other material, as contrasted with percolation, which is movement of water through soil layers or material.
63
Intake rate
The average rate of water entering the soil under irrigation. Most soils have a fast initial rate; the rate decreases with application time. Therefore, intake rate for design purposes is not a constant but is a variable depending on the net irrigation application
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rate of water intake, in inches per hour
Less than 0.2........................... very low
0.2 to 0.4........................................... low
0.4 to 0.75................... moderately low
0.75 to 1.25............................. moderate
1.25 to 1.75................ moderately high
1.75 to 2.5........................................ high
More than 2.5........................ very high
65
Intermittent stream
A stream that carries water only part of the time, generally in response to periods of heavy runoff either from snowmelt or storms.
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Irrigation
Application of water to soils
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Border Irrigation
Water is applied at the upper end of a strip in which the lateral flow of water is controlled by small earth ridges called border dikes, or borders.
68
Furrow Irrigation
Water is applied in small ditches made by cultivation implements. Furrows are used for tree and row crops.
69
Sprinkler Irrigation
Water is sprayed over the soil surface through pipes or nozzles from a pressure system.
70
Leaching
The removal of soluble material from soil or other material by percolating water.
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Loam
Soil material that is 7–27% clay particles, 28–50% silt particles, and less than 52% sand particles.
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Mineral soil
Soil that is mainly mineral material and low in organic material.
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Minimum tillage
Only the tillage essential to crop production and prevention of soil damage
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Morphology, soil
The physical makeup of the soil, including the texture, structure, porosity, consistence, color, and other physical, mineral, and biological properties of the various horizons, and the thickness and arrangement of those horizons in the soil profile.
75
Munsell notation.
A designation of color by degrees of three simple variables — hue, value, and chroma. For example, a notation of 10YR 6/4 is a color with hue of 10YR, value of 6, and chroma of 4.
76
Nodules
Cemented bodies lacking visible internal structure. Calcium carbonate, iron oxide, and manganese oxide are common compounds making up nodules.
77
Nutrient, plant
Any element taken in by a plant essential to its growth. Plant nutrients are mainly nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper, boron, and zinc obtained from the soil and carbon, hydrogen, and oxygen obtained from the air and water
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Organic matter
Plant and animal residue in the soil in various stages of decomposition
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content of organic matter in the surface layer
Very low........................ less than 0.5%
Low...................................... 0.5 to 1.0%
Moderately low.................. 1.0 to 2.0%
Moderate............................. 2.0 to 4.0%
High..................................... 4.0 to 8.0%
Very high.................... more than 8.0%
80
Parent material
The unconsolidated organic and mineral material in which soil forms.
81
Permeability
The quality of the soil that enables water or air to move downward through the profile. The rate at which a saturated soil transmits water is accepted as a measure of this quality. In line with conventional usage in the engineering profession and with traditional usage in published soil surveys, this rate of flow continues to be expressed as “permeability.”
82
Terms describing permeability, measured in inches per hour
Extremely slow..................... 0.0–0.01 inch
Very slow............................ 0.01–0.06 inch
Slow........................................ 0.06–0.2 inch
Moderately slow.................... 0.2–0.6 inch
Moderate..................... 0.6 inch–2.0 inches
Moderately rapid............... 2.0–6.0 inches
Rapid..................................... 6.0–20 inches
Very rapid................ more than 20 inches
83
pH value
A numerical designation of acidity and alkalinity in soil. (See Reaction, soil.)
84
Piping (in tables)
Formation of subsurface tunnels or pipe-like cavities by water moving through the soil.
85
Ponding
Standing water on soils in closed depressions. Unless the soils are artificially drained, the water can be removed only by percolation or evapotranspiration.
86
Reaction, soil
A measure of acidity or alkalinity of a soil, expressed in pH values. A soil that tests to pH 7.0 is described as precisely neutral in reaction because it is neither acid nor alkaline
87
The degrees of acidity or alkalinity, expressed as pH values
Ultra acidic................................... less than 3.5
Extremely acidic................................... 3.5–4.4
Very strongly acidic............................. 4.5–5.0
Strongly acidic....................................... 5.1–5.5
Moderately acidic................................. 5.6–6.0
Slightly acidic........................................ 6.1–6.5
Neutral................................................... 6.6–7.3
Slightly alkaline ................................... 7.4–7.8
Moderately alkaline............................. 7.9–8.4
Strongly alkaline................................... 8.5–9.0
Very strongly alkaline............ 9.1 and higher
88
Residuum (residual soil material)
Unconsolidated, weathered or partly weathered mineral material that accumulated as consolidated rock disintegrated in place.
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Root zone
The part of the soil that can be penetrated by plant roots.
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Runoff
The precipitation discharged into stream channels from an area. The water that flows off the surface of the land without sinking into the soil is called surface runoff. Water that enters the soil before reaching surface streams is called groundwater runoff or seepage flow from groundwater.
91
Sand
As a soil separate, individual rock or mineral fragments from 0.05–2.0 millimeters in diameter. Most sand grains consist of quartz. As a soil textural class, a soil that is 85% or more sand and not more than 10% clay.
92
Saturation
Wetness characterized by zero or positive pressure of the soil water. Under conditions of saturation, the water will flow from the soil matrix into an unlined auger hole.
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Series, soil
A group of soils that have profiles that are almost alike, except for differences in texture of the surface layer. All the soils of a series have horizons that are similar in composition, thickness, and arrangement.
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Sheet erosion
The removal of a fairly uniform layer of soil material from the land surface by the action of rainfall and surface runoff.
95
Silt
As a soil separate, individual mineral particles that range in diameter from the upper limit of clay (0.002 millimeter) to the lower limit of very fine sand (0.05 millimeter). As a soil textural class, soil that is 80% or more silt and less than 12% clay.
96
Slope
The inclination of the land surface from the horizontal. Percentage of slope is the vertical distance divided by horizontal distance, then multiplied by 100. Thus, a slope of 20% is a drop of 20 feet in 100 feet of horizontal distance
97
classes for simple slopes
Level.................................. 0–1%
Nearly level...................... 1–3%
Gently sloping................. 3–8%
98
Sodic (alkali) soil
A soil having so high a degree of alkalinity (pH 8.5 or higher) or so high a percentage of exchangeable sodium (15% or more of the total exchangeable bases), or both, that plant growth is restricted.
99
Soil
A natural three-dimensional body at the earth’s surface. It is capable of supporting plants and has properties resulting from the integrated effect of climate and living matter acting on earthy parent material, as conditioned by relief over periods of time.
100
Soil separates
Mineral particles less than 2 millimeters in equivalent diameter and ranging between specified size limits.
101
The names and sizes, in millimeters, of separates
Very coarse sand................. 2.0–1.0
Coarse sand......................... 1.0–0.5
Medium sand.................... 0.5–0.25
Fine sand.......................... 0.25–0.10
Very fine sand................. 0.10–0.05
Silt................................... 0.05–0.002
Clay......................... less than 0.002
102
Solum
The upper part of a soil profile, above the C horizon, in which the processes of soil formation are active. The solum in soil consists of the A, E, and B horizons. Generally, the characteristics of the material in these horizons are unlike those of the material below the solum. The living roots and the plant and animal activities are largely confined to the solum.
103
Stripcropping
Growing crops in a systematic arrangement of strips or bands that provide vegetative barriers to wind erosion and water erosion.
104
Structure, soil
The arrangement of primary soil particles into compound particles or aggregates.
105
Subsoil
Technically, the B horizon; roughly, the part of the solum below plow depth.
106
Substratum
The part of the soil below the solum
107
Surface layer
the soil ordinarily moved in tillage, or its equivalent in uncultivated soil, ranging in depth from 4 to 10 inches (10 to 25 centimeters). Frequently designated as the “plow layer” or the “Ap horizon.”
108
Terrace
An embankment, or ridge, constructed across sloping soils on the contour or at a slight angle to the contour. The terrace intercepts surface runoff so that water soaks into the soil or flows slowly to a prepared outlet. A terrace in a field generally is built so that the field can be farmed. A terrace intended mainly for drainage has a deep channel that is maintained in permanent sod.
109
Terrace (geologic)
An old alluvial plain, ordinarily flat or undulating, bordering a river, lake, or sea.
110
Texture, soil
The relative proportions of sand, silt, and clay particles in a mass of soil. The basic textural classes, in order of increasing proportion of fine particles, are sand, loamy sand, sandy loam, loam, silt loam, silt, sandy clay loam, clay loam, silty clay loam, sandy clay, silty clay, and clay. The sand, loamy sand, and sandy loam classes may be further divided by specifying “coarse,” “fine,” or “very fine.”
111
Tilth, soil
The physical condition of the soil as related to tillage, seedbed preparation, seedling emergence, and root penetration.
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Topsoil
The upper part of the soil, which is the most favorable material for plant growth. It is ordinarily rich in organic matter and is used to topdress roadbanks, lawns, and land affected by mining.
113
Weathering
All physical and chemical changes produced in rocks or other deposits at or near the earth’s surface by atmospheric agents. These changes result in disintegration and decomposition of the material.
