We will discuss here about the soil and its distinct layers. Soil is the portion of landmass on which plants can grow naturally.
In fact soil is the outer most layer of the Earth’s crust. Heat, rain and wind play important roles for the formation of soil. The primary rock is broken into finer particles by prolonged weathering. These particles contain several minerals. Wind carries these particles from one place to another while mixing of many other materials undergoes. Organic remains of plants and animals are called humus which also get mixed with it. In this process soil is formed as a soft and heterogeneous mixture on the Earth’s surface.
Soil is a moist mixture of various-sized rock particles and minerals together with partly decomposed organic matters as well as remains of dead plants and animals.
Soil has three distinct layers, referred to as soil profile. They are; topsoil, subsoil and bed rock.
1. Topsoil: It is the top most part of soil profile. It contains fine sand, clay, water and air. It supplies all necessary nutrients to the plants, which grow on it. It is usually rich in humus and minerals.
2. Subsoil: It is the second layer of soil profile. It contains larger particles. This portion contains little organic matters, water and minerals.
Tap roots of bigger plants can reach this layer.
3. Bed rock: It is the base of soil profile, which is made of large pieces of parent rocks. This layer has very little water. Roots of plants never reach this layer.
When we collect soil samples anywhere from the topsoil we find five basic components in it. Those are minerals, humus, water, air and a few living organisms.