Several times while playing games in the fields our clothes get dirty. As kids we never thought how dirt is formed; never tried to know the composition of the earth. Dirt or dust is made up of soil. Now the question is what is soil?
The outer layer of the earth is formed of soil. So when we fall on the ground, our clothes get dirty because of soil. Its thickness varies from few millimeters to several meters. Soil formation occurs as a result of a gradual breakdown of rocks. Rocks are broken down into finer particles through many processes such as weathering and erosion. The geological components are mixed with organic materials to form soil. This implies that it is a mixture of rocks which are broken into smaller particles and the dead and decayed organic matter along with the little microbes.
Plants do not grow in the sand because pure sand is only rock particulate matter and it does not contain the minerals required for the proper growth of plants. Sand can be converted into soil by adding organic matter to it. There are two main components of soil, the rock particles and the organic matter. Soil also has a lifecycle of its own. Formation of soil starts with the disintegration of rocks under certain environmental conditions.
Rainwater sips in rocks and the fluctuation in temperature causes differential expansion and contraction of the rocks. Then the freezing and thawing of the water captured inside the rocks creates cracks inside the rocks and finally breaks them into finer particles.
In the pioneering vegetations, if rocks are kept still for some day, lichens start growing on the surface of the rocks. During their growing period, lichens release certain substances which convert the rocks into powder form and slowly convert the powdery material into the soil. Small plants like moss can grow on these surfaces and their growing roots further loosen the rock particles. The decaying plants produce organic acids that attack the rocks. Organic matter and the rock particles are mixed with the minerals and forms soil.
It is considered as our life support system, without which human life will be difficult on earth. It provides plants with a foothold for roots, and it consists of necessary nutrients for plants. In this article, we have discussed soil and its constituents. To know more about the components of soil and the factors affecting soil formation watch the video.