Field Analysis:How Composition

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Contents 1 Soil Composition 1.1 Organic matter 1.2 Mineral matter 1.3 Field moisture content

[edit] Soil Composition

This is a description of how organic or mineral a soil or sediment is, and if appropriate the nature of any organic matter present.

Organic	More than 30% organic matter
Organo-mineral	Between 2-30% organic matter, often intimately mixed with the mineral fraction
Mineral	Less than 2% organic matter

[edit] Organic matter

Description of organic matter in non-peaty deposits.

• Fresh/unaltered non woody clearly identifiable structures larger than 2 cm.
• Woody lignified structures larger than 2 cm.
• Humified Degraded no identifiable structure. Organic component mixed with the fine mineral fraction.

In peaty soils or sediments where there is no appreciable mineral content, following terms can also be used to describe the organic matter.

• Fibrous peat Contains large amounts of well preserved readily identifiable plant remains less than 2 cm.
• Semi-fibrous peat Partly decomposed peat in which plant structures are visible, but break down when rubbed between the fingers.
• Amorphous peat Contains virtually no identifiable plant structures.

[edit] Mineral matter

Where there are clear differences in the composition of a soil in terms of the types and mix of rocks and sand grains, this should also be noted in general comments.

[edit] Field moisture content

The moisture content of the soil at the time it was recorded may also be recorded in general comments.

Dry	Soil feels completely dry and when wetted will show a distinct colour change (unless entirely quartz sand).
Moist	Soil feels damp though no water is visible on grain or aggregate surfaces.
Wet	A film of water is visible on grains and aggregate surfaces but there is no free water.
Saturated	The sample contains easily visible free water, working or squeezing the soil liberates the water.