Soil is created through the process of absent weathering. Weathering is the break down of rocks into smaller particles when in call with water (flowing with rocks), waiting or living organisms. Weathering can occur physically, biologically or chemically.

Physical weathering: This is the disintegration of rocks right into smaller particles through no change in your molecular structure. Air and also water space agents of physics weathering. Windblown ~ above rocks, heavy downpour of rain, water waves from the sea have the right to facilitate a gradual fragmentation of absent particles come sediments i m sorry eventually end up being soil.

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Chemical weathering: In chemistry weathering chemistry reactions in ~ rocks create transforms in their mineral composition. Examples of chemistry reactions causing weathering are hydrolysis, carbonation, oxidation and hydration.

•Hydrolysis: hydrolysis occurs together rain water seeps through rocks and also the hydrogen ion (H+) in water reacts with metallic ion in rocks leading to dissolution of rock minerals.

•Carbonation: throughout carbonation carbon dioxide indigenous the air and from life organisms dissolve in water to kind carbonic acid. This acidifies water in rocks top to further chemical reaction through rock minerals.

•Oxidation: in oxidation oxygen native the air reacts through iron in rocks to type iron oxides. This reaction create a rusty brown colouration on rocks.

Biological weathering: In this procedure biological biology facilitate absent fragmentation. Tree roots and also mosses prosper or pass through through rocks and create spicy spaces which progressively pull rocks apart. Pets burrow through rocks and also create disintegration. Micro organisms favor lichen (a symbiotic relationship in between fungi and algae) relax chemicals which malfunction rock minerals.

Table 1: The Eight most abundant elements present in igneous, sedimentary and metamorphic rocks

Source: Harpstead et al. 2001

Factors affecting soil formation

Factors affect soil development are: climate, topography, living organisms, parent material and also time.

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Climate contributes mostly to soil formation. Rainfall and also temperature pattern in a location influence the form of soils formed in that area. Rain gives water i m sorry facilitates chemical and also physical weathering. Different climates approximately the civilization create diversity in floor nature and property. For example, floor is much more exposed to erosion, weathering and leaching in locations of high or heavy rainfall. Acidic soils space also more prevalent in together places because minerals such as calcium, magnesium, potassium are regularly replaced by H+ indigenous rain water. Alternatively, locations of short rainfall space less delicate to leaching. Soils in these areas tend towards high alkalinity since in the lack of leaching calcium carbonates build up in the upper soil layers1. Warmer temperatures encourage quick weathering together plants and microbial tasks flourish while chillier climates encourage gradual rock weathering.


Topography can be identified as the shape of the earth’s surface area. The steepness of a land increases its vulnerability to water and wind erosion; bring about the movement of rock sediments and washing downwards of absent minerals come valleys.


Soils in the valleys of these areas are darker coloured, rich in organic matter and more fertile because that plant development while soils on hilltops space eroded, much less fertile and unfavourable because that plant growth.

Living organisms

Living biology play a key role in soil formation. One area through high vegetation is usually rich in humus. Humus build up together fallen leaves and dead plant components are decomposed by floor micro biology to become organic matter. The micro organisms feeding on sugars and also carbohydrates in organic issue leaving behind fats and also waxes in the soil. This is what accounts for the humus.

Parent material

Soil parent material is largely weathered rock. Parent material deserve to be sedimentary rocks, igneous rocks or geologically young sediments that overlie the bedrocks. Soil kind depends on the parent material from which it to be formed. Soil created from weathering granite rocks i do not care sand. Granite consists of quartz a silicate mineral really resistant come weathering. As quartz is extremely resistant come weathering granite disintegrates into gritty sand particles. Likewise rocks include feldspar (a mineral silicate through low resistance to weathering is broken down right into fine clay particles.


Time is a vital factor that holds and relates with all various other soil developing factors. Soil formation will occur an ext rapidly wherein the climatic, topographic or biological conditions room favourable because that weathering. Time likewise shows exactly how long various other soil forming factors have been in play. Areas with young parent product are usually more fertile because they have not undergone much weathering and also therefore have a large quantity the mineral materials still present. In the same method places through older parent material subjected come a lot an ext weathering would have less lot of mineral composition. These species of soils depend an ext on organic issue for your nutrients.

Bibliography and Websites for additional Reading

1.Miller RW, Gardiner DT (1998) Soils in our Environment, 8 hours Edition. Prentice Hall, brand-new Jersey.2.Gerrard J (2000) Fundamentals of soils. Routledge, London3.Harpstead M, Sauer TJ, Bennett WF (2001) Soil scientific research Simplified. 4th Edition. Iowa State Press, Iowa.4.