X Land and Soil

Less than 30 percent of the area on this planet is covered by land, all are familiar with the fact that more than 70 percent of our earth is covered by water. but how much of this earth is covered by soil.

before it is estimated, it is pertinent to differentiate between land and soil

Earth has a three-layer structure - crust, mantle, and core, the upper layer is known as the crust.

the crust is further divided into the continental and oceanic crust, the solid part (crust without water) of the continental crust is known as land. the solid crust has all physical features -like mountains, plateau, plains, islands, etc these are the part of the land, and the loose grainy layer on the land(uppermost layer)  is known as the soil.

Land is a very important resource It supports natural vegetation, wildlife, human life, economic activities, transport, and communication systems. many human activities such as deforestation, overgrazing, mining, and quarrying have contributed to land degradation. 

on another hand soil is a living system and it is made up of organic matter, minerals, and weathered rocks. it has many layers - parent rock, weathered rock material, subsoil with sand silt and clay, and topsoil with hummus and vegetation. It takes millions of years to form soil up to a few cm in depth. The soil is classified on the basis of the proportion of particles of various sizes as .-sandy soil, clayey soil, and loamy soil(with silt).

Soil can also be classified on basis of its chemical composition, various types of soil are found in India 

1-Alluvial soil ( rich in potash, phosphoric acid and lime )

2- Black soil-(rich in calcium carbonate, magnesium, potash, and lime)

3-Red and Yellow Soils-

4-Laterite Soil (acidic in nature )

5- Arid soil (sandy and saline - having more salt)

6- forest soil 

the soil in the rainy areas is generally more acidic (pH is less than 7) than in dryer areas. (Find the causes of acidification of soil)