It is basically the top layer of soil; if you’ve ever visited an area of riverbanks, you have probably seen that the soil’s top layer of the many layers is darker than the rest of the soil, and surprisingly lush too. When it comes to soil classification systems the top layer is referred to as the A Horizon.
This is the upper two to seven inches of soil. It contains the greatest amount of organic matter as well as microorganisms. The soil’s upper layer is mostly composed of nitrogen and carbon and the living creatures living in it. If soil is fertile It also has nutrients which can aid the growth of plants in it.
The most important function of topsoil is the provision of food for plants in it. The microorganisms diverse population found in topsoil are also involved in fostering the development of plants, which creates an environment conducive for the flourishing of living things in soil.
Topsoil has more other than simply having soil to look at. wnuttnbegn.