Land, Soil, Water

LAND


Land Use

Land is used for various purposes; like agriculture, forestry, mining, building houses, roads, industries, etc. Factors which affect the use of land are topography, soil, climate, minerals and availability of water. Human factors also determine the land use pattern. Ownership of land also determines the land use pattern.

Increasing population means there is an ever growing demand for land. But the availability of land is limited. Land degradation, landslides, soil erosion, desertification are the major threats to the environment.

Human encroachment has led to large scale destruction of forest cover and arable land. This is creating a danger for quality of land. Land degradation can be prevented by afforestation, land reclamation, regulated use of chemical pesticide and fertilizers, and by checking overgrazing.

SOIL

The topmost layer of land which is composed of grainy substance is called soil. Soil is made up of organic matter, minerals and weathered rocks. Soil formation takes place because of weathering of rocks. The soil becomes fertile because of the right combination of minerals and organic matter.

Soil Profile

The arrangement of different layers of soil at a place is called soil profile. The typical soil profile is composed of following layers:

  1. Topsoil: Topsoil is composed of humus and fine particles of clay and sand.
  2. Subsoil: This is the second layer of soil. It is composed of sand, silt and clay.
  3. Weathered Rock Material: The third layer is composed of large pieces of rocks.
  4. Bedrock: The last layer of soil profile is composed of huge rocks.

Factors of Soil Formation:

Following are the factors of soil formation:

Soil Erosion

Removal of topsoil is called soil erosion. Deforestation, overgrazing, overuse of chemical fertilisers or pesticides, rain-wash, landslides and floods are the factors which lead to soil erosion.

Methods of Soil Conservation:



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