explain how soil is formed
Answers
Answer:
The formation of soil is a complex process. Before studying about the formation of soil let us first know about soil.
The outer layer or the uppermost layer of the earth is formed of soil. The soil is a mixture that contains minerals, organic matter, and living organisms. But broadly speaking, soil can refer to any loose sediment.
Explanation:
Formation of soil:
The soil is created by the process of weathering or disintegration of parent rocks by physical, chemical and biological agents. Soil formation is a slow process that takes thousands of years. Soil can be formed by three processes given below
Mechanical Weathering
This is usually observed near the surface of the earth. It is called physical weathering, as this method is influenced by physical forces such as wind, water and temperature.
Chemical Weathering
Chemical weathering occurs when rocks are broken down by chemical reactions. Such types of weathering can change the chemical composition of the soil.
Biological Weathering
The lichens growing on the rocks discharge certain chemicals that break down the rock into a fine powder and form a thin layer of soil. The mosses also develop on the rock surface and further break the rock. The roots of the trees get into the cracks of the rocks and push them to widen, thereby, breaking the rocks.
Answer
- Soil is the thin layer of material covering the earth’s surface and is formed from the weathering of rocks. It is made up mainly of mineral particles, organic materials, air, water and living organisms—all of which interact slowly yet constantly.
- As soils develop over time, layers form a soil profile.
- Most soil profiles cover the earth as 2 main layers—topsoil and subsoil.