Soil Forming Processes

The soil-forming is a complex process along with a lot of factors and processing ways. It takes a long period of time to develop even an inch of soil.

In this article, the basic processes of soil formation are discussed briefly.

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• Soil Forming Factors

Soil Forming processes

There are so many processes which collectively give rise to soil. These processes are:

Pedogenesis

The term “pedogenesis” originates from the Greek words “pedo/pedon,” meaning soil/earth, and “genesis,” meaning origin.. So, Pedogenesis means ‘the origin of soil’. It is also termed as soil formation or soil genesis.

Pedogenesis is the process of soil formation that is regulated by the effects of environment,  place  and history. In pedogenesis, the parent material of soil transforms into soil through several steps.

Step-1

Parent material in converted into regolith by weathering.

Regolith: The layer of unconsolidated solid material covering the parent material (bed-rock).

Weathering: The physical disintegration and decomposition of rocks and minerals under natural condition.

Step-2

In this step, the regolith transforms into soil through the influence of soil-forming factors.

Eluviation

It is the removal and translocation of certain constituent’s viz. Clay, Fe2O3, Al2O3, SiO2, humus, CaCO3, other salts etc. by the percolating water from the upper to lower layers.

Illuviation

Illuviation is the process of deposition of soil materials in the lower layers.

Calcification

It is the process of precipitation and accumulation of calcium carbonate (CaCO3) at the base of B- horizon.

Decalcification

It is the reverse of calcification that is the process of removal of CaCO3 or calcium ions from the soil by leaching.

Podzolization/Podsolization

It is a collection of processes that includes eluviation of base cations, weathering transformation of Fe and Al compounds, mobilization of Fe and Al from surface horizons, and transport of these compounds to the B horizon as Fe and Al complexes.

Laterization

It is the process that removes silica, instead of sesquioxides from the upper layers and thereby leaving sesquioxides to concentrate in the solum.

Melanization

Melanization is the development of dark, humus-rich coatings on ped faces and mineral grains, rendering the horizon a dark brown or black.

Gleization

The term glei is of Russian origin means blue, grey or green clay. It causes the development of a glei/gley horizon in the lower part of the soil profile above the parent material due to poor drainage
condition (lack of oxygen).

Humification

It is the process of transformation of raw organic matter into humus. It is extremely a complex process involving various organisms.

Immobilization

This process denotes the conversion of inorganic matter into organic matter.

Mineralization

It is the process of transformation of organic matter into inorganic matter.

Salinization

It is the process of accumulation of salts, such as sulphates and chlorides of calcium, magnesium, sodium and potassium, in soils in the form of a salty (salic) horizon.

Desalinization

It is the removal of excess soluble salts by leaching from horizons or soil.

Source:

1. Wikipedia

2. Class lecture