Soil Morphological Properties

What is morphology?

a. The branch of biology that deals with the form and structure of organisms without consideration of function.

b. The form and structure of an organism or one of its parts: the morphology of a cell; the morphology of vertebrates

or in a simple word : physical properties.

Why measure the physical properties?

Introduction to Soil (SST 5201)

What is soil?

The UNCONSOLIDATED mineral or organic material on the immediate surface or the earth that serves as as natural medium for the growth of land plants.

Soil is a thin layer of material on the Earth's surface in which plants have their roots. It is made up of many things, such as weathered rock and decayed plant and animal matter. Soil is formed over a long period of time.

Soil Formation takes place when many things interact, such as air, water, plant life, animal life, rocks, and chemicals.

Soil Formation

The formation of soil happens over a very long period of time. It can take 1000 years or more. Soil is formed from the weathering of rocks and minerals. The surface rocks break down into smaller pieces through a process of weathering and is then mixed with moss and organic matter. Over time this creates a thin layer of soil. Plants help the development of the soil. How? The plants attract animals, and when the animals die, their bodies decay. Decaying matter makes the soil thick and rich. This continues until the soil is fully formed. The soil then supports many different plants.

Weathering:

Weathering is the process of the breaking down rocks. There are two different types of weathering. Physical weathering and chemical weathering.
In physical weathering it breaks down the rocks, but what it's made of stays the same. In chemical weathering it still breaks down the rocks, but it may change what it's made of. For instance, a hard material may change to a soft material after chemical weathering.

Soil Pedon or Soil Profile




Soil formation begins first with the break down of rock into regolith. Continued weathering and soil horizon development process leads to the development of a soil profile, the vertical display of soil horizons

Watch a typical progression of soil profile development (courtesy of University of Wisconsin)

http://courses.soil.ncsu.edu/resources/soil_classification_genesis/soil_formation/soil_transform.swf


 Soil Horizons

 A Typical Soil Profile (after Oberlander & Muller, 1987)

 

O Horizon

At the top of the profile is the O horizon. The O horizon is primarily composed of organic matter. Fresh litter is found at the surface, while at depth all signs of vegetation structure has been destroyed by decomposition. The decomposed organic matter, or humus, enriches the soil with nutrients (nitrogen, potassium, etc.), aids soil structure (acts to bind particles), and enhances soil moisture retention.

A Horizon

Beneath the O horizon is the A horizon. The A horizon marks the beginning of the true mineral soil. In this horizon organic material mixes with inorganic products of weathering. The A horizon typically is dark colored horizon due to the presence organic matter. Eluviation, the removal of inorganic and organic substances from a horizon by leaching occurs in the A horizon. Eluviation is driven by the downward movement of soil water.

E Horizon

The E horizon generally is a light-colored horizon with eluviation being the dominant process. Leaching, or the removal of clay particles, organic matter, and/or oxides of iron and aluminum is active in this horizon. Under coniferous forests, the E horizon often has a high concentration of quartz giving the horizon an ashy-gray appearance.

B Horizon

Beneath the E horizon lies the B horizon. The B horizon is a zone of illuviation where downward moving, especially fine material, is accumulated. The accumulation of fine material leads to the creation of a dense layer in the soil. In some soils the B horizon is enriched with calcium carbonate in the form of nodules or as a layer. This occurs when the carbonate precipitates out of downward moving soil water or from capillary action. The diagram below illustrates the effect of climate on eluviation and illuviation. Eluviation is significant in humid climates where ample precipitation exists and a surplus in the water balance occurs. Illuvial layers are found low in the soil profile. Illuvial zones are found closer to the surface in semiarid and arid climates where precipitation is scarce. Capillary action brings cations like calcium and sodium dissolved in soil water upwards where they precipitate from the water.

C Horizon

The C horizon represents the soil parent material, either created in situ or transported into its present location. Beneath the C horizon lies bedrock.The preceding paragraphs describe a generic soil profile, yet not all soils have each one of the horizons, nor are they all the same with respect to thickness composition and structure. Newly formed "immature" soils may only have an O-A-C sequence while older more "mature" soils display the full profile of horizons as described above. The particular compositional, structural and chemical composition of the soil depends on the various factors that influence soil formation.

Another different view and description of soil horizon:



The Nature of Land (SST 5201)

In the context of land evaluation, land is much more than the solid surface of the earth. It includes:

1. soils;
2. rocks beneath;
3. atmosphere with its climates;
4. cyclic interchange of water between the sky;
5. ground;
6. rivers;
7. sea; and
8. whole mantle of living things, both plant and animal

DEFINITION OF LAND:

 "An [area of the earth surface], including [all reasonably stable or predictably cyclic], attributes of the [biosphere vertically above and below] this area, including those of the [atmosphere], the [soil and underlying geology], the [hydrology], the [plant and animal populations] and the [results of past and present human activity], to the extent that these attributes exert a significant influence on present and future uses of the land by humans"

"A geographic concept. Each land area is unique located in space and is defined by that location"

KZ Notes:

1. There are different interpretation and meaning of land. As for this course, land can be defined as an area of the earth surface, which means that anything lies below and above earth surface is called LAND!
2. There are 8 points need to be stated in land defination: (1) surface (2) stable + predictably cyclic (3) biosphere above + below (4) atmosphere (5) soil + geology (6) hydrology (7) plant + animal (8) past + present activity

Introduction to Land Evaluation (SST 5201)

The need for land evaluation: why we need to evaluate land?

Sabah

Land evaluation is formally defined as 'the assessment of land performance when used for a specified purpose, involving the execution and interpretation of surveys and studies of land forms, soils, vegetation, climate and other aspects of land in order to identify and make a comparison of promising kinds of land use in terms applicable to the objectives of the evaluation' (FAO, 1976).

How people or nations use their land depends on complex, interrelated factors which include:

1. the characteristics of the land itself
2. economic factors
3. social, legal and political constraints
4. the needs and objectives of the land user

In order to make rational decisions, it is necessary to collect the right information about the physical, social and economic aspects of the land area in question and assess the land's relative suitability for different uses in the light of the needs and objectives of the land user and the community.

This process is known technically as land suitability evaluation (penilaian kesesuaian tanah) or simply as land evaluation. The basic methodology was set out in the 1976 FAO Publication: A Framework for Land Evaluation (Soil Bulletin 32).

http://www.fao.org/docrep/X5310E/X5310E00.htm

"The essence of land evaluation is to compare or match the requirements of each potential land use with the characteristics of each kind of land'

KZ Notes:

• Land evaluation is a basic necessity for all planners/developers/government agencies to look upon before they start doing any development project in any piece of land.
• A good evaluation will help main objectives of land development can be achieved in a sustainable way, thus will eventually reduce cost in a long term.
• Land use planning ensures the use of land resources in an organized fashion so that the needs of the present and future generations can be best addressed.
• Land use planning has as its basic purpose to ensure that each area of land will be used so as to provide maximum social benefits, especially including food production, without degradation of the land resource. 

LECTURE NOTES:

https://skydrive.live.com/redir.aspx?cid=940a19cb8b9d01a2&resid=940A19CB8B9D01A2!104&authkey=5uqoobCre*g%24

Land Evaluation (SST 5201)

Land Evaluation (SST 5201) subject is taught by Prof. Madya Dr. Siti. She is also the course coordinator for LARM Program.

Introduction to Land and Soil Characteristics:

• Morphology and Physical Characteristics - Soil Profiles, Horizons, Texture, Colour, Drainage
• Chemical Soil Characteristics: pH, CEC, Organic Carbon
• Rock Types: Igneous, metamorphic, sedimentary
• Land Characteristics: Climate, Topography, Wetness
• Slope Measurements
• GPS Measurements

Master in Land Resource Management

Master in Land Resource Management or popular known as LARM in UPM is one of the master degree course offered under Agriculture Faculty, Putra University of Malaysia.