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SOILS > Diagnostic criteria > Flashcards

Diagnostic criteria Flashcards

1
Q

anthraquic horizon

A

paddy soils: The layer comprising the puddled layer and the plough pan, both showing a reduced matrix and oxidized root channels.

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2
Q

hortic horizon

A

It is dark, has a high content of organic matter and phosphorus (P), high animal activity, and high base saturation; resulting from long-term cultivation, fertilization, and application of organic residues.

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3
Q

hydragric horizon

A

paddy soils: The layer below the anthraquic horizon showing redoximorphic features and/or an accumulation of iron (Fe) and/or manganese (Mn).

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4
Q

irragric horizon

A

A uniformly textured layer with at least moderate content of organic matter and high animal activity, gradually built up by sediment-rich irrigation water.

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5
Q

plaggic horizon

A

A dark layer with at least moderate content of organic matter, sandy or loamy; resulting from the application of sods and excrements.

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6
Q

pretic horizon

A

A dark layer with at least moderate content of organic matter and phosphorus (P), high contents of exchangeable calcium (Ca) and magnesium (Mg), including Amazonian Dark Earths.

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7
Q

terric horizon

A

It shows evidence of the addition of substantially different material, with at least moderate content of organic matter and high base saturation; resulting from adding mineral material (with or without organic residues) and cultivation.

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8
Q

calcic horizon

A

A horizon with an accumulation of secondary carbonates that are not continuously cemented.

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9
Q

cryic horizon

A

A horizon that is perennially frozen, showing visible ice or temperatures below 0°C if water is insufficient.

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10
Q

salic horizon

A

A horizon with high amounts of readily soluble salts.

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11
Q

thionic horizon

A

A horizon with sulfuric acid and a very low pH value.

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12
Q

folic horizon

A

An organic layer that is not water-saturated and not drained.

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13
Q

histic horizon

A

An organic layer that is water-saturated or drained.

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14
Q

chernic horizon

A

A thick, very dark-coloured horizon with high base saturation, moderate to high content of organic matter, and well-developed soil structure or structural elements created by agricultural practices.

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15
Q

mollic horizon

A

A thick, dark-coloured horizon with high base saturation and moderate to high content of organic matter, with at least some soil structure or structural elements created by agricultural practices.

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16
Q

umbric horizon

A

A thick, dark-coloured horizon with low base saturation and moderate to high content of organic matter, with at least some soil structure or structural elements created by agricultural practices.

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17
Q

argic horizon

A

A subsurface layer with distinctly higher clay content than the overlying layer, without a lithic discontinuity and/or presence of illuvial clay minerals.

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18
Q

duric horizon

A

A horizon with concretions or nodules cemented by secondary silica, and/or remnants of a broken-up petroduric horizon.

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19
Q

ferric horizon

A

A horizon containing ≥ 5% reddish to blackish concretions and/or nodules and/or ≥ 15% reddish to blackish coarse masses, with accumulation of Fe (and Mn) oxides.

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20
Q

gypsic horizon

A

A horizon with an accumulation of secondary gypsum that is not continuously cemented.

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21
Q

limonic horizon

A

A horizon with accumulation of Fe and/or Mn oxides in a layer that has or had gleyic properties; at least partially cemented.

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22
Q

natric horizon

A

A subsurface layer with distinctly higher clay content than the overlying layer, without a lithic discontinuity and/or presence of illuvial clay minerals; high content of exchangeable sodium (Na).

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23
Q

petrocalcic

A

A horizon with an accumulation of secondary carbonates that are relatively continuously cemented.

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24
Q

petroduric horizon

A

A horizon with an accumulation of secondary silica that is relatively continuously cemented.

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25
Q

petrogypsic horizon

A

A horizon with an accumulation of secondary gypsum that is relatively continuously cemented.

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26
Q

petroplinthic horizon

A

A horizon consisting of oximorphic features inside (former) soil aggregates that are at least partially interconnected and have a yellowish, reddish and/or blackish colour; high contents of Fe oxides; relatively continuously cemented.

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27
Q

pisoplinthic horizon

A

A horizon with ≥ 40% at least moderately cemented yellowish, reddish, and/or blackish concretions and/or nodules, with accumulation of Fe oxides.

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28
Q

plinthic horizon

A

A horizon that has in ≥ 15% of its exposed area oximorphic features inside (former) soil aggregates that are black or have a redder hue and a higher chroma than the surrounding material; high contents of Fe oxides; not continuously cemented.

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29
Q

sombric horizon

A

A subsurface accumulation of organic matter other than in spodic or natric horizons; not a buried surface horizon.

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30
Q

spodic horizon

A

A subsurface accumulation of aluminum (Al) with iron (Fe) and/or organic matter.

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31
Q

tsitelic horizon

A

A horizon with lateral accumulation of Fe, usually derived from Planosols and Stagnosols further upslope.

32
Q

albic horizon

A

A light-coloured horizon with loss of coloured substances (e.g. oxides, organic matter) due to soil-forming processes.

33
Q

cambic horizon

A

A horizon showing evidence of soil-forming processes, not meeting the criteria of diagnostic horizons that indicate stronger alteration or accumulation processes.

34
Q

cohesic horizon

A

A horizon with massive or subangular blocky structure, restricted root penetration, normally free drainage, rich in kaolinite, and poor in organic matter.

35
Q

ferralic horizon

A

A strongly weathered horizon dominated by kaolinites and oxides.

36
Q

fragic horizon

A

A horizon with large soil aggregates where roots and percolating water penetrate the soil only in between these aggregates; not or only partially cemented.

37
Q

nitic horizon

A

A horizon rich in clay minerals and Fe oxides, with moderate to strong structure and shiny soil aggregate surfaces.

38
Q

panpaic horizon

A

A buried mineral surface horizon with a significant content of organic matter.

39
Q

protovertic horizon

A

A horizon influenced by swelling and shrinking clay minerals.

40
Q

vertic horizon

A

A horizon dominated by swelling and shrinking clay minerals.

41
Q

takyric properties

A

Fine-textured surface crust with a platy or massive structure; under arid conditions in periodically flooded soils.

42
Q

yermic properties

A

A combination of desert features: desert pavement, varnishing, ventifacts, vesicular pores, and platy structure.

43
Q

abrupt textural difference

A

A very sharp increase in clay content within a limited depth range.

44
Q

albeluvic glossae

A

Interfingering of coarser-textured and lighter-coloured material into an argic horizon forming vertically continuous tongues.

45
Q

lithic discontinuity

A

Differences in parent material.

46
Q

retic properties

A

Interfingering of coarser-textured and lighter-coloured material into an argic or natric horizon.

47
Q

andic properties

A

Short-range-order minerals and/or organo-metallic complexes.

48
Q

anthric properties

A

Applying to soils with mollic or umbric horizons, if the mollic or umbric horizon is created or substantially transformed by humans.

49
Q

continuous rock

A

Consolidated material excluding cemented pedogenic horizons.

50
Q

gleyic properties

A

Saturated with flowing or upwards moving groundwater (or upwards moving gases), permanently or long enough for reducing conditions to occur.

51
Q

protocalcic properties

A

Carbonates derived from the soil solution and precipitated in the soil, less pronounced than in calcic or petrocalcic horizons.

52
Q

protogypsic properties

A

Gypsum derived from the soil solution and precipitated in the soil, less pronounced than in gypsic or petrogypsic horizons.

53
Q

reducing conditions

A

Low redox potential (rH value) and/or presence of sulfide, methane, or reduced iron (Fe).

54
Q

shrink-swell cracks

A

Cracks that open and close due to the swelling and shrinking of clay minerals.

55
Q

sideralic properties

A

Properties indicating relatively low cation exchange capacity (CEC).

56
Q

stagnic properties

A

Saturated with surface water (or intruding liquids), at least temporarily, long enough for reducing conditions to occur.

57
Q

vitric properties

A

Properties indicating ≥ 5% (by grain count) of volcanic glasses and related materials, containing a limited amount of short-range-order minerals and/or organo-metallic complexes.

58
Q

mineral material

A

< 20% soil organic carbon and < 35% (by volume) organic artefacts.

59
Q

mulmic material

A

Material developed from water-saturated organic material after drainage; 8 - 20% soil organic carbon.

60
Q

organic material

A

Material with ≥ 20% soil organic carbon.

61
Q

organotechnic material

A

Material with < 20% soil organic carbon and ≥ 35% (by volume) organic artefacts.

62
Q

soil organic carbon

A

Organic carbon that does not meet the diagnostic criteria of artefacts.

63
Q

claric material

A

Light-coloured fine earth, expressed by high Munsell value and low chroma.

64
Q

artefacts

A

Materials created, substantially modified, or brought to the surface by humans; no subsequent substantial change of chemical or mineralogical properties.

65
Q

technic material

A

Hard material that is consolidated and relatively continuous, resulting from an industrial process.

66
Q

aeolic material

A

Material sedimented by wind.

67
Q

calcaric material

A

Material with ≥ 2% calcium carbonate equivalent, at least partially inherited from the parent material.

68
Q

dolomitic material

A

Material with ≥ 2% of a mineral that has a ratio of CaCO3/MgCO3 < 1.5.

69
Q

fluvic material

A

Material from fluviatile, marine, or lacustrine deposits with evident stratification.

70
Q

gypsiric material

A

Material with ≥ 5% gypsum, at least partially inherited from the parent material.

71
Q

hypersulfidic material

A

Material containing sulfides and capable of severe acidification.

72
Q

hyposulfidic material

A

Material containing sulfides and not capable of severe acidification.

73
Q

limnic material

A

Material deposited in water by precipitation (possibly with sedimentation), or derived from algae or aquatic plants with subsequent transport or modification by aquatic animals or microorganisms.

74
Q

ornithogenic material

A

Material from excrements or remnants of birds or bird activity.

75
Q

solimovic material

A

A heterogeneous mixture that has moved down a slope, suspended in water; dominated by material that underwent soil formation at its original place.

76
Q

tephric material

A

Material with ≥ 30% (by grain count) volcanic glass and related materials.

SOILS (7 decks)

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