Natural resources play an important role for the sustenance of human habitation. One of the most important of them is Soil. Apart from being an important natural resource, it is the top covering of the earth’s surface. The formation of soil takes place due to wear and tear of rocks by natural and human-made forces.
How is soil formed?– Formation of soil is related to the parent rock material, relief, climatic conditions, natural vegetation, and animal and human activities. Fine vegetable and animal remains, called humus add to the fertility of the soil. The importance of the soil lies in its fertility. The formation of soil is a slow process. It takes thousands of years to from a very thin layer of it. Thickness of soil is usually one to three metres. The reason being beyond this depth, rocks do not have the elements necessary for plant growth. Right mix of minerals and organic matter are important requisites to make the soil fertile. Soil formation takes place under specific natural conditions. The quality of soil varies from place to place. Soil also differs in colour, texture and fertility. Various factors influence the formation of soil. These are as follows:
- Parent rock material- Underlying rocks which contain minerals and make up the bulk of the soil are called parent rocks. Parent rocks influence the colour, texture, chemical properties, mineral content and permeability of the soil so formed.
- Relief- Elevation and the nature of slope influence the rate of weathering and drainage of water. Thus, flat areas have thicker layer of soil as compared to steep slopes.
- Climatic conditions- Climatic conditions exert both direct and indirect influences on soil formation. Seasonal distribution of temperature and rainfall determine the type and effectiveness of weathering of rocks and humus formation.
- Plant and Animal remains- Plants and micro-organisms help converting young soil into mature soil. Dead plants provide humus which is consumed by other forms of life, like bacteria. The dark brown colour of the soil is due to the humus.
- Time- A body of soil is considered mature if the soil forming processes have acted over a sufficient period of time and the soil has developed a distinct soil profile. Soil develops more quickly in humid regions than the dry ones.
Soil profile – A vertical section of soil from the surface to the parent rock is the soil profile. The process of formation of soil gives rise to well- marked horizontal layers in the soil profile. These horizontal layers are called soil horizons. The soil horizons are usually named A.B.C, and D from the uppermost layer of the soil to the parent rock below.
Soil erosion– Soil erosion has become really common and it is alarming. More trees must be planted for the soil to remain intact. Soil erosion can lead to death of microorganisms that help fix and convert various gases of atmosphere and aid humans in farming and agriculture. Also, soil erosion in areas where soil is present in large quantities can lead to landslides and loss of human lives. Hence, we must be considerate towards the environment and do our best to save it.
Sources- Google, Quora, Newspaper Articles