In this article, we will learn about What is soil made of, soil definition, soil profile, horizons and properties of soil.
What is Soil (Definition)?
Soil is a mixture of many solid, liquid and gaseous substances.
It is the topmost layer of the earth’s crust.
It is a mixture of living and non-living matters like minerals, plants, bacteria, water, air, etc.
Soil contains carbon dioxide, oxygen and nitrogen.
It holds the water which is absorbed by the roots of plants.
Soil formed in its original position is called as in-situ soil.
It supports life on earth.
Soil is the most valuable resource of earth.
Soil is formed when rocks are broken down into small pieces by the action of wind, water, and climate. This process is called weathering.
The characteristics feature of the Soils of India depends on the plant that grows in it and the type of rock from which it has been formed.
What is Soil made of?
There are 5 main factors responsible for Soil formation. Which are as follows:-
- Parent Material
- Plant and Animal Organism
Parent Material:- It is basically a rock from which soil is derived by the process of weathering.
Climate:- It is one of the major factors in soil formation.
- Two different parent material can produce the same soil in the same climate.
- However, one parent material may produce different soil in a different climate.
Plant and Animal Organism:- Plants and animals plays a major role in soil formation. As the Plants die they are eaten away by millions of insects and earthworms. The nutrients re-enter the soil and are used by the living plants.
Topography:- It is the local factors of the area that results in soil formation. Like deposition of soil, degree of its erosion and the speed of flow of water.
Time:- The longer the time a soil gets undisturbed, it produces a good quality of mature soil.
What does Soil Profile mean?
Soil Profile Definition
A vertical section that shows different layers of soil is called a Soil Profile. Each layer is called a Horizon.
As mentioned above a good soil profile is developed when soil is left undisturbed for a long time.
Soil Profile Horizons
A Soil Profile consists of four horizons. Which are as follows:-
- A – True soil. It also contains humus.
- B – It has weathered rock material like sand, silt, and clay.
- C – It has weathered material but it is coarse and of large grains.
- R – It is unweathered parent material.
List of Physical Properties of Soil
- Each type of Soil has features like colour, texture, and structure.
- The Colour of soil reflects the process and mechanism of soil formation.
- The texture of the soil shows its material constituent. It also shows the size of the pores.
- The soil with coarse material is sandy.
- Soil with finer material is clayey.
- The soils of India also have chemical properties. These can be acid, neutral, or alkaline.
- Soil with low lime content is called acid whereas those with high lime content are called alkaline.