Soil

Soil is defined as the topmost layer of the earth’s crust. Plants get its food from the soil. It is formed by mineral particles, organic matter, water, air and living organisms. As soil formation is an extremely slow process, soil can be considered essentially as a non-renewable resource.

Process of formation of soil

1. Soil is formed by weathered rock or mineral that has been transported from various region.
2. Due to fluctuation in temperature during day and night, time rock gets divided into small pieces and forms soil.
3. When river-water or rain water gets into the small holes of rock, it is divided into small rocks. Small pieces of rocks are easily divided into the soil.
4. Thunderstorms break rock then plants grow on that rock which weakens the rock and helps to form soil.
5. Storms and tornado ruin the rocks and form soil

Soil Profile:

The soil profile is a vertical section of the soil that depicts all of its horizons. The soil profile extends from the soil surface to the parent rock material. By examining a soil profile, we can gain valuable insight into soil fertility. Infertile soil usually contains a light-colored layer in the subsurface soil from which nutrients have leached away. A highly fertile soil often has a deep surface layer that contains high amounts of organic matter.

Soil Erosion and Deposition

Soil erosion is the wearing of the topmost layer of the soil by various factors like water and wind. Soil erosion especially occurs in the rainy season. Soil that is eroded is deposited somewhere. The process by which transported materials are left in a new location is called deposition.

Wind, tornado and hurricane carry away the topsoil of the bare land. River, heavy rainfall and landslides also carry away the soil.

Methods of soil conservation

Soil is one of the most important factor of the earth which makes earth a living planet. It is very important to conserve the soil. Nepal is prone to soil erosion as its land topology is hilly. Unplanned development and unscientific agriculture make soil easily erodible.

Some major methods of preventing soil erosion are as follows:

1. Afforestation should be promoted and intensive grazing by domestic animals should be avoided.
2. Construction of roads and dams should be restricted to fragile areas.
3. People should be aware of the cause of soil erosion.
4. Terrace farming on the hills slows down the rate of soil erosion.
5. Bamboo-like plants which have strong roots should be planted near the rivers.
6. The Edge of rivers should be surrounded by walls of rocks.
7. Fruits, vegetables and grasses should not be grown in sloppy areas.

Things to remember

• Soil is defined as the topmost layer of the earth’s crust.
• The soil profile is a vertical section of the soil that depicts all of its horizons.
• Soil erosion is the wearing of the topmost layer of the soil by the various factors like water and wind.
• The process by which transported materials are left in the new location is called deposition.

• It includes every relationship which established among the people.
• There can be more than one community in a society. Community smaller than society.
• It is a network of social relationships which cannot see or touched.
• common interests and common objectives are not necessary for society.

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