Soil Morphology Characteristics

What does the term 'morphology' primarily refer to in the context of soil characteristics?

Which soil color can be indicative of high organic matter content?

What is the primary characteristic of Goethite?

In soil morphology, what is the significance of color 'value'?

What condition typically results in grey, olive, or blue soil colors?

What attribute of soil color describes its actual hue or shade?

Which of the following elements is associated with a white soil color?

Which mineral is responsible for the blue coloration in soils?

What does the term 'value' refer to in soil color determination?

Which of the following colors is NOT commonly found in soils?

How is chroma defined in relation to soil colors?

What color pages does the Munsell Soil Color Chart use to indicate combinations?

Which moisture condition is NOT one of the three reported for soil color determination?

What does the Munsell chart's vertical arrangement of value units indicate?

What is meant by soil color 'mottles'?

In the Munsell Soil Color Chart, what does a high chroma value indicate?

Soil Morphology

Soil morphology deals with the study of soil form, shape, and arrangement of soil particles.
It is divided into two categories: Profile morphology (study in situ) and Micromorphology (study with the aid of microscopes and computer-aided image processors).

Soil Morphological Properties

Commonly described soil morphological properties include:
- Colour
- Colour mottles
- Texture
- Structure
- Consistency

Soil Colour

Soil colour is the most obvious soil morphological characteristic.
It gives an indication of certain conditions, such as:
- Organic matter content (black, brown, or grey soil colour)
- Presence of iron oxides (goethite, lepidocrocite, hydrogoethite, limonite, and xanthosiderite, resulting in brownish-black, yellow, and brown colours)
- Presence of high amounts of potassium, sodium, aluminium, and manganese (resulting in unique soil colours such as white, black, and yellow)
- Drainage condition of the soil/water table fluctuation (grey, olive, and blue colours in anaerobic conditions)

Description of Soil Colour

Soil colour is described by three attributes:
- Hue (dominant spectral colour, related to wavelength of light reflected by soil particles)
- Value (lightness or darkness of the colour, affected by moisture)
- Chroma (strength or purity of colour, indicating degree of difference between white, black, or neutral colour)

Soil Colour Determination

Soil colour determinations are reported at three different moisture contents: wet, moist, and dry.
Internationally, soil colour is commonly reported using Munsell Soil Color Charts.
The Munsell book consists of 15 pages, each with a number followed by a letter or letters indicating the hue (e.g., 10 Y/R page contains yellow-red colours).

Colour Mottles

Colour mottles occur when a soil contains more than one colour, with a dominant background colour and differently coloured mottles.
Mottles form under alternative wet-dry soil moisture conditions.
Soil mottles are described by their abundance, size, and contrast to the background colour.

Explore the properties of soil that can be observed by sight or feel, including its form, shape, and arrangement of particles. Learn about profile morphology and more.