Organic Soils

References:

Criteria:
Soils mainly composed of organic peat materials with Of, Om or Oh horizons, or, upland organic forests materials with L, F or H horizons > 40cm thick.

Soils of the Organic order are composed largely of organic materials. They include most of the soils commonly known as peat, muck, or bog and fen soils. Most Organic soils are saturated with water for prolonged periods. These soils occur widely in poorly and very poorly drained depressions and level areas in regions of subhumid to perhumid climate and are derived from vegetation that grows in such sites. However, one group of Organic soils (Folisols) consists of upland (folic) organic materials, generally of forest origin. These Folisols are well to imperfectly drained, although they may become saturated after rainfall or snowmelt.

Organic soils contain more than 17% organic C (30% or more organic matter) by weight.

The control section (160 cm) for Fibrisol, Mesisol, and Humisol great groups is divided into three tiers: surface (0-40 cm); middle (40-120 cm); and bottom (120-160 cm).

For a detailed description see the source CSSC

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Regosolic Soils

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Criteria:

Soils with a Bm, Btj or Bfj horizon < 5cm thick and no Bg horizon

Regosolic soils do not contain a recognizable B horizon at least 5 cm thick and are therefore referred to as weakly developed. The lack of a developed pedogenic B horizon may result from any of a number of factors: youthfulness of the material, recent alluvium; instability of the material, colluvium on slopes subject to mass wasting; nature of the material, nearly pure quartz sand; climate, dry cold conditions. Regosolic soils are generally rapidly to imperfectly drained. They occur under a wide range of vegetation and climates.
They may have L, F and H or O horizons. Also they may have an Ah or Ap horizon less than 10 cm thick or of any thickness if there is no underlying B horizon at least 5 cm thick and characteristics of the Ah or Ap do not satisfy the criteria of a chernozemic A horizon.

For a detailed description see the source CSSC

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Brunisolic Soils

References:

Criteria:

Soils with either a Bm, Bmgj, Btj or Bfj horizon > 5cm thick.

Soils of the Brunisolic order have sufficient development to exclude them from the Regosolic order, but they lack the degree or kind of horizon development specified for soils of other orders.


The central concept of the order is that of soils formed under forest and having brownish-colored Bm horizons, but the order also includes soils of various colors with both Ae horizons and B horizons having slight accumulations of either clay (Btj), or amorphous Al and Fe compounds (Bfj), or both. Soils having a Bf horizon less than 10 cm thick are a part of this order.

A Bm horizon may have any or all of the following: stronger chroma and redder hue than the underlying material, partial or complete removal of carbonates, slight illuviation based mainly on the occurrence of an overlying Ae horizon, a change in structure from that of the original material.

A Bm horizon may develop in materials of any color, such as gray, brown, black or red, and which vary in texture from gravel to clay.

To a degree the Brunisolic order can be considered as an intergrade order between Regosolic soils and soils of several other orders. The distinctions are based more upon the degree than the kind of development.

Distinguish Brunisolic soils from Luvisolic, Podsolic and Regosolic:

Luvisolic
Luvisolic soils must have a Bt horizon, but Brunisolic soils do not. However, it is difficult to distinguish a Bt from a Btj horizon and micromorphological examination may be required.

Podzolic
Podzolic soils must have a Podzolic B horizon and Brunisolic soils do not. However, the colors of some Bm and Bfj horizons are within the range of that of Podzolic B horizons, and some of these horizons contain concentrations of amorphous complexes of Al and Fe with organic matter close to the minimum concentration diagnostic for Bf horizons. Therefore, chemical analysis is required to differentiate some Brunisolic soils from Podzolic soils. Soils having a Bf horizon thinner than 10 cm are classified as Brunisolic.

Regosolic
Brunisolic soils must have a Bm, Bfj, thin Bf, or a Btj horizon at least 5 cm thick; Regosolic soils do not.

For a detailed description see the source CSSC

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Podzolic Soils

References:

Criteria:

Soils with a podzolic B horizon and no Bt horizon within 50cm of the mineral surface

Soils of the Podzolic order have B horizons in which the dominant accumulation product is amorphous material composed mainly of humified organic matter combined in varying degrees with Al and Fe. Typically Podzolic soils occur in coarse- to medium-textured, acid parent materials, under forest or heath vegetation in cool to very cold humid to perhumid climates.>

Podzolic soils can usually be recognized readily in the field. Generally they have organic surface horizons that are commonly L, F, and H but may be Of or Om and have a light-colored eluvial horizon, Ae, which may be absent. Most Podzolic soils have a reddish brown to black B horizon with an abrupt upper boundary and lower B or BC horizons with colors that become progressively yellower in hue and lower in chroma with depth, except in reddish-colored parent materials.

The podzolic B horizon is at least 10 cm thick, accumulation of amorphous material in the podzolic B horizon is indicated by brown to black coatings on some mineral grains or brown to black microaggregates.

The texture of the podzolic B horizon is coarser than clay.

For a detailed description see the source CSSC

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Luvisolic Soils

References:

Criteria:

Soils with a Bt horizon and no Bg horizon or podzolic B horizon if the Bt is > 50cm below mineral surface.

Soils of the Luvisolic order generally have light-colored, eluvial horizons and have illuvial B horizons in which silicate clay has accumulated. These soils develop characteristically in well to imperfectly drained sites, in sandy loam to clay, base-saturated parent materials under forest vegetation.

The Bt horizon must have increase in clay over that in the eluvial horizon, clay skins indicative of translocated clay accounting for 1% or more of the area of a section through the horizon, and be at least 5 cm thick. Luvisolic soils may have Ah, Ahe, or dark-colored Ap horizons.

The genesis of Luvisolic soils is thought to involve the suspension of clay in the soil solution near the soil surface, downward movement of that clay with the soil solution, and the deposition of the translocated clay at a depth where downward movement of the soil solution ceases or becomes very slow.

The eluvial horizon (Ahe, Ae) commonly has platy structure due perhaps to the periodic formation of ice lenses.

For a detailed description see the source CSSC

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Gleysolic Soils

References:

Criteria:

Soils with a g horizon within 50cm of the mineral surface.

Gleysolic soils are defined on the basis of color and mottling, which are considered to indicate the influence of periodic or sustained reducing conditions during their genesis.

Gleysolic soils have a horizon or subhorizon, at least 10 cm thick (the upper boundary of which occurs within 50 cm of the mineral surface), with moist colors.

Soils of the Gleysolic order have properties that indicate prolonged periods of intermittent or continuous saturation with water and reducing conditions during their genesis. Saturation with water may result from either a high groundwater table or temporary accumulation of water above a relatively impermeable layer, or both.

In contrast, soils saturated periodically with aerated water or saturated for prolonged cold periods, which restricts biological activity without developing properties associated with reducing conditions, are not classified as Gleysols.

Those that are rarely saturated now presumably had aquic moisture regimes in the past and were once under reducing conditions. Drainage, isostatic uplift, or other factors have resulted in a changed moisture regime in these soils.

For a detailed description see the source CSSC

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Organic --> Fibrisol Great Group

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Criteria:

Soils composed mainly of undecomposed fibric materials.

Soils of this great group are composed largely of relatively undecomposed fibric organic material.
Fibric material is usually classified on the von Post scale of decomposition as classes 1-4.
Fibrisols occur extensively in Canada, particularly in peat deposits dominated by sphagnum mosses.
Fibrisols have a dominantly fibric middle tier, or middle and surface tiers if a terric, lithic, or hydric contact occurs in the middle tier (40cm - 120cm).
Fibric (f) material undecomposed to weakly decomposed, plant species identifiable, when squeezed no peat escapes through fingers. (vP1 to 4)

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Organic --> Mesisol Great Group

References:

Criteria:

Soils composed mainly of decomposed mesic materials.

Fibric material is usually classified on the von Post scale of decomposition as classes 1-4.


Fibrisols occur extensively in Canada, particularly in peat deposits dominated by sphagnum mosses.

Fibrisols have a dominantly fibric middle tier, or middle and surface tiers if a terric, lithic, or hydric contact occurs in the middle tier (40cm - 120cm).

Fibric (f) material undecomposed to weakly decomposed, plant species identifiable, when squeezed no peat escapes through fingers.  (vP1 to 4)

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Organic --> Humisol Great Group

References:

Criteria:

Soils composed mainly of decomposed humic materials.

Soils of this great group are at the most advanced stage of decomposition of the great groups of Organic soils. Most of the material is humified with few recognizable fibers. Humisols have a dominantly humic middle tier or middle and surface tiers if a terric, lithic, or hydric contact occurs in the middle tier.


Humic (h) material, strongly to completely decomposed, plant structure indistinct to unrecognizable; when squeezed at least half of the peat escapes through fingers, water released is dark. (vP7 to vP10)

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Organic --> Folisol Great Group

References:

Criteria:

Soils composed of upland (folic) materials, generally of forest origin.

Soils of the Folisol great group are composed of upland organic (folic) materials, generally of forest origin, that are either 40 cm or more in thickness, or are at least 10 cm thick if overlying bedrock or fragmental material.

Deep Folisols (greater than 40 cm of folic material) occur frequently in cool, moist, and humid forest ecosystems, particularly on the West Coast of Canada.

They also develop in northern regions where soil temperatures are low, but the soil is without permafrost. Shallow Folisols are found throughout Canada and commonly occur on upper slope shedding positions over bedrock and on, or incorporated in, fragmental or skeletal material.


Folic materials: L, F, and H - These organic horizons developed primarily from the accumulation of leaves, twigs, and woody materials with or without a minor component of mosses. They are normally associated with upland forested soils with imperfect drainage or drier.

For a detailed description see the source CSSC

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Regosolic --> Humic Regosol Great Group

References:

Criteria:

Soils with an Ah horizon >10cm thick.

These Regosolic soils have an Ah or dark colored Ap horizon at least 10 cm thick at the mineral surface. They may have organic surface horizons and buried mineral-organic horizons. They do not have a B horizon at least 5 cm thick.

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Regosolic -->Regosol Great Group

References:

Criteria:

Other soils

These Regosolic soils do not have an Ah or dark-colored Ap horizon at least 10 cm thick at the mineral soil surface. They may have buried mineral-organic layers and organic surface horizons, but no B horizon at least 5 cm thick.

For a detailed description see the source CSSC

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Brunisolic --> Melanic Brunisol Great Group

References:

Criteria:

Soils with an Ah horizon >10cm thick and a pH >5.5 on the B horizon.
These soils generally contain carbonates within 1m of the soil surface.

These are Brunisolic soils having a dark-colored Ah horizon and a relatively high degree of base saturation as indicated by their pH. They occur typically under deciduous or mixed forest vegetation on materials of high base status in areas of boreal to mesic temperature class and humid moisture subclass, but they are not restricted to such environments.

Many uncultivated Melanic Brunisols have a forest mull Ah horizon associated with the activity of soil fauna, especially earthworms.

For a detailed description see the source CSSC

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Brunisolic --> Sombric Brunisol Great Group

References:

Criteria:

Other soils with an Ah >10cm thick.

These are acid Brunisolic soils having a dark-colored Ah horizon and a relatively low base saturation as indicated by their pH. Minor areas of soils of this great group occur in association with the more widely spread Podzolic soils.

Sombric Brunisols have an Ah 10 cm or more in thickness or an Ap horizon 10 cm or more in thickness with a moist color value of less than 4, and a Bm, Bfj, thin Bf, or Btj horizon at least 5 cm thick.

The pH (0.01 M CaCl2) is less than 5.5 throughout the uppermost 25 cm of the B horizon, or throughout the B horizon and the underlying material to a total depth of at least 25 cm or to a lithic contact above that depth.

Sombric Brunisols may have L, F, and H horizons and Ae or Aej horizons, but they do not have solonetzic or podzolic B horizons or Bt horizons.

For a detailed description see the source CSSC

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Brunisolic --> Eutric Brunisol Great Group

References:

Criteria:

Other soils with a pH >5.5 in the B horizon.
These soils generally contain carbonates within 1m of the soil surface.

These are Brunisolic soils that have a relatively high degree of base saturation as indicated by their pH and lack a well-developed mineral-organic surface horizon. They occur mainly on parent material of high base status under forest or shrub vegetation in a wide range of climates.

Eutric Brunisols have either a Bm, Bfj, or Btj horizon at least 5 cm thick, and a pH (0.01 M CaCl2) of 5.5 or more in some part or all of the uppermost 25 cm of the B horizon, or some part or all of the B horizon and the underlying material either to a total depth of 25 cm or to a lithic contact above that depth.

For a detailed description see the source CSSC

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Brunisolic --> Dystric Brunisol Great Group

References:

Criteria:

Other soils.

These are acid Brunisolic soils that lack a well-developed mineral-organic surface horizon. They occur widely, usually on parent materials of low base status and typically under forest vegetation.

Dystric Brunisols have a Bm,Bfj, thin Bf, or Btj horizon at least 5 cm thick, and a pH (0.01 M CaCl2) of less than 5.5 throughout the upper 25 cm of the B horizon, or throughout the B horizon and the underlying material to a total depth of at least 25 cm or to a lithic contact above this depth.

Dystric Brunisols may have L, F, and H horizons; an Ae or Aej horizon, and an Ah horizon less than 10cm thick, but they do not have either a Bt or a podzolic B horizon.

For a detailed description see the source CSSC

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Podzolic --> Humic Podzol Great Group

References:

Criteria:

Soils with an Bh horizon >10cm thick.

These soils have a dark-colored podzolic B horizon that contains very little extractable Fe.

They occur typically in wet sites so that they are saturated with water during some periods of the year.

Characteristically they occur under heath (shrubland habitat), forest and heath, sphagnum.

Under virgin conditions Humic Podzols usually have thick L, F, and H or O horizons underlain by a light-colored eluvial horizon (Ae), an eluvial horizon darkened by humic material, or by a podzolic B horizon, which is usually a Bh.

The B horizon may include several kinds of podzolic B subhorizons: Bh, Bhf, and Bf, which may be cemented (ortstein, placic) or friable. The material below the podzolic B horizon may be cemented (duric), compact and brittle (fragipan), or friable.

For a detailed description see the source CSSC

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Podzolic --> Ferro Humic Podsol Great Group

References:

Criteria:

Other soils with a Bhf horizon > 10cm thick.

These soils have a dark-colored podzolic B horizon with a high content of organic C and an appreciable amount of extractable Fe and Al. They occur typically in the more humid part of the region of Podzolic soils under forest vegetation, or forest with heath or moss undercover. Under virgin conditions these soils usually have thick L, F, and H or O horizons; they may have an Ah horizon and usually have a light-colored Ae horizon. The podzolic B horizon is usually thick and dark reddish brown in the upper part and grades to lighter colors of higher chroma with depth.

The material below the podzolic B horizon may be cemented (duric), compact and brittle (fragipan), or friable.

Ferro-Humic Podzols have a Bhf horizon at least 10 cm thick and lack a Bh horizon at least 10 cm thick. The Bhf horizon contains 5% or more organic C and 0.6% or more pyrophosphate-extractable Fe+Al (0.4% for sands). It has a ratio of organic C to pyrophosphate-extractable Fe of less than 20, or has 0.3% or more pyrophosphate-extractable Fe, or both.

Ferro-Humic Podzols are generally both strongly acid and less than 50% base saturated (neutral salt). The pH-dependent CEC of the Bhf horizon is usually well above 8 cmol kg-1 and is commonly 25 cmol kg-1 or more. The Bhf horizon of these soils usually has a markedly silty feel when rubbed moist, which is presumably because of its high content of amorphous material.

For a detailed description see the source CSSC

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Podzolic --> Humo Ferric Podsol Great Group

References:

Criteria:

Other podzolic soils.

These soils have a brownish-colored podzolic B horizon with less organic matter than the B horizon of Ferro-Humic Podzols. They occur widely both in less humid sites of the region of Podzolic soils and in humid sites.

Typically they occur under coniferous, mixed, and deciduous forest vegetation but may occur under shrub and grass vegetation. Under virgin conditions these soils usually have L, F, and H horizons and may have an Ah horizon.

Usually they have a light-colored Ae horizon with an abrupt lower boundary to a podzolic B horizon in which the reddest hues or highest chromas and lowest color values usually occur near the top of the horizon and fade with depth.

Humo-Ferric Podzols have a podzolic B horizon at least 10 cm thick but do not have Bh or Bhf horizons at least 10 cm thick. The podzolic B horizon of Humo-Ferric Podzols may include a thin Bhf subhorizon, but usually it is a Bf horizon only.

For a detailed description see the source CSSC

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Luvisolic --> Gray Brown Luvisol Great Group

References:

Criteria:

Soils with an Ah horizon and mean annual soil temperature >8° C.

Soils of this great group have a forest mull Ah horizon and eluvial and Bt horizons as indicated for the order. They occur typically under deciduous or mixed forest vegetation on calcareous materials in areas of mild, humid climate. They occur mainly in the St. Lawrence Lowland.

Under undisturbed conditions the soils may have thin L, F, and H horizons, but, because of high biological activity and the abundance of earthworms, the leaf litter is usually quickly incorporated into the soil and humified.

Gray Brown Luvisols have either a forest-mull Ah horizon more than 5 cm thick or a dark-colored Ap horizon, an eluvial horizon, and a Bt horizon. The mean annual soil temperature is 8°C or higher and the soil moisture regime is humid or wetter.

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Luvisolic --> Gray Luvisol Great Group

References:

Criteria:

Other soils.

Soils of this great group have eluvial and Bt horizons as specified for the Luvisolic order. They usually have L, F, and H horizons and may have a degraded Ah or Abe horizon that resembles the upper A horizon of Dark Gray Chernozemic soils.

Commonly below the Ae horizon they have an AB or BA horizon in which the ped surfaces are grayer than the interiors of peds.

The solum of Gray Luvisols is generally slightly to moderately acid but may be strongly acid. The degree of base saturation (neutral salt extraction) is generally high. The parent materials are usually base saturated and commonly calcareous, but some Gray Luvisols have developed in acid materials.

Gray Luvisols have eluvial and Bt horizons. Their mean annual soil temperature is usually less than 8°C.

The dark colored A horizon is underlain by a thicker Ae horizon that extends to a depth greater than 15 cm below the mineral surface. It shows evidence of degradation (Ahe) and is underlain by an Ae horizon at least 5 cm thick below the Ahe or Ap horizon.

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Gleysolic --> Luvic Gleysol Great Group

References:

Criteria:

Soils with a Btg horizon.

Soils of this great group have the general properties specified for the Gleysolic order and a horizon of clay accumulation (Btg).

They are similar to Luvisolic soils except that they have dull colors or prominent mottling, or both, which indicates strong gleying.

They may have organic surface horizons and an Ah horizon. Luvic Gleysols occur commonly on poorly drained sites in association with Luvisolic soils.

Luvic Gleysols usually have an eluvial horizon (Ah, Aeg) and a Btg horizon. A Btg horizon is defined based on an increase in silicate clay over that present in the A horizon.

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Gleysolic --> Humic Gleysol Great Group

References:

Criteria:

Soils with a Ah horizon > 10cm thick.

Soils of this great group have a dark-colored A horizon in addition to the general properties of soils of the Gleysolic order.

They occur commonly in poorly drained positions in association with some Chernozemic, Luvisolic, Podzolic, and Brunisolic soils.

These soils may have organic surface horizons derived from grass and sedge, moss, or forest vegetation.

Humic Gleysols have no Bt horizon. They have either an Ah horizon at least 10 cm thick or a mixed surface horizon (Ap) at least 15 cm thick

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Gleysolic --> Gleysol Great Group

References:

Criteria:

Other soils.

Soils of this great group have the general properties specified for soils of the Gleysolic order, but they lack a well-developed, mineral-organic surface horizon. They occur commonly in poorly drained positions in association with soils of several other orders.

Gleysols lack an Ah or Ap horizon as specified for Humic Gleysols. They also lack a Bt horizon. They may have either an Ah horizon thinner than 10 cm or an Ap horizon

These soils have a gleyed B or C horizon, and they may have an organic surface horizon.

For a detailed description see the source CSSC

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