Basically soil is collection of natural bodies. However when applied to different segment its definition varies according to the nature of the particular thing. For farmer, it is the source of nourishing his crops while for civil engineer it is the basis through which building is constructed.

SOIL COMPOSITION

As far as composition of soil is concerned, it is made up of four basic components mainly minerals, organic matter, air and water. Although the perfect soil is one which comprises of 45% minerals, 25% water, 25% air and 5%organic matter. Readers would be surprised to know that in practical conditions the proportions of these components vary drastically.

SOIL FORMATION

According to Jenny(1941) five factors are key to soil formation which are following :Parent material,Organisms,Climate,Relief and Time.

Parent materials are mostly in the ocean, rivers or streams. Other important parent materials can be found in area which has high calcium carbonates.

Organisms basically affect the type of organism mixed in the soil.

Climate affects soils through the rate at which chemical reaction takes place. Moreover the affect climate change varies with geographical location.

Relief is the factor having a greatest effect on the soils of the ACE basin study area. It is also seen that changes of few feet can bring in major changes.

Time is also a key factor as soil processing occurs over time. For instance young soils show very slow development.

STAGES OF SOIL FORMATION

Soil formation begins with a process of gathering of parent material. After which the building of organic material takes place then what happens is organic thing is made up on the surface of the material .The A-horizon than starts to form as organic matter changes into humic material.Humicm materials coat the soil particles. Interesting thing is A-horizon even takes decades sometimes even centuries.

Now B horizon forms as suspended materials come downward in greater depths through rainwater. Now A horizon increases in thickness while B horizon begins to nurture. The creation E horizon occurs as top of B horizon goes deeper in the soil. It should be noted that E horizon is same in texture as A horizon .Clays in B horizon are less active minerals.

Finally Bases are leached from soil which we refer to as acids and bases in Ph. scale. In general soil is infertile matter.

Reference

Jenny, H. 1941. Factors of soil formation. McGraw-Hill, New York, NY.