Introduction to Soil: Overview, Types, Uses, Conservation

Introduction to Soil: Soil is the Earth’s topmost layer that supports life. It is made up of organic matter, clay, and rock particles. It also has air and water in it. It is one of the most vital natural resources on the planet. Also, soil plays a major role in food production, fodder cultivation, and mineral and fuel mining.

Soil pollution reduces soil fertility and the quality of the soil. Soil erosion occurs in those areas of land which are not covered by vegetation or very little vegetation. In this article, we will look at the introduction of soil and its properties in detail.

­­Soil – An Important Natural Resource

One of the most important natural resources is soil. It is made up of various types of rock particles, and it continues to remain of dead plants and animals. Soil can be found in gardens, school playgrounds, parks, construction sites, and fields.

It lies beneath our feet and is often hidden by roads and buildings. Probably, this is the reason we often fail to realize how soil affects our lives.

Layers of the Soil

If you have ever looked closely at the deep pits dug at construction sites, you will know that soil is not like a uniform, solid substance. It has layers, and these layers look and feel different. Scientists call these layers horizons.

A horizon: This is the topmost layer of soil, often referred to as the topsoil. Its dark colour is due to the presence of humus. The particles of this layer are the finest, and the action of decomposers makes this layer porous. This layer supports most plants. Only the roots of very big trees manage to reach the next layer.

B-horizon: The B-horizon forms the subsoil. It is lighter in colour as it does not have much humus. The subsoil is rich in minerals due to deposits of minerals released from percolating water. Plant roots generally grow till this layer.

C horizon: This layer consists of large pieces of broken rock and coarse soil particles called gravel. It is also called substratum and is derived from the layer of hard rock that lies beneath. The topsoil is not always derived from this layer. It can be carried from distant places and deposited over this layer. Soil that forms from the substratum is called residual soil. On the other hand, soil that is deposited over the substratum is called transported soil.

The substratum lacks humus altogether and is infertile. Rainwater seeping through the topsoil collects in this layer as it cannot pass through the layer of hard rock underneath. The reservoir of rainwater in this layer is called groundwater. When there is sufficient rain, groundwater rises to the subsoil.

The reservoir of rainwater in this layer is called groundwater. When there is sufficient rain, groundwater rises to the subsoil.

Bedrock or R-Horizon

Below it is the hard-rocky base of unweathered rocks, which slowly undergoes weathering and form the C-horizon. Water cannot penetrate through this layer. This layer is also called the bedrock.

Introduction to Soil Pollution

When toxic substances, chemicals, salts, disease-causing germs, which may affect plant growth, get accumulated in the soil, we say that the soil gets polluted. Soil pollution may be caused in many ways like:

1. Excessive use of pesticides, fertilizers, herbicides, weedicides and insecticides.
2. Direct discharge of toxic industrial wastes into the soil.
3. Seeping of contaminated water into the soil.
4. Dumping of large quantities of solid waste into the soil.
5. Oil and petroleum leaks from vehicles get washed off on the road into the surrounding soil.
6. Septic tank leakage.

Soil Pollution Prevention Measures

Soil pollution leads to reduced soil fertility and its quality. As a result, crop yield is affected. Even the microorganisms and other organisms living in the soil get affected. Soil pollution can be controlled by:

1. Proper treatment of industrial wastes.
2. Adopting proper methods for the management of solid waste disposal.
3. Recycling of materials like glass, paper, plastic, etc.
4. Reusing materials like a plastic bag, cloth, paper, etc.
5. Reducing the use of fertilizers, pesticides, etc.

Introduction to Soil Erosion

The topsoil is very fertile. This topsoil is often carried away by strong winds or washed away by heavy rains. The removal of fertile topsoil from land by wind or water is called soil erosion. The loss of fertile topsoil exposes the infertile subsoil that cannot be used to grow plants and trees. And in the absence of plants and trees, the area becomes a desert. In the desert, soil erosion occurs mainly through the wind.

Soil erosion does not occur easily where the land is covered by vegetation (trees and other plants). Soil erosion occurs easily in those areas of land which are not covered by vegetation (trees and other plants) or have very little vegetation. Thus, soil erosion is more severe in areas such as bare land or deserts. We will now describe why the soil covered by vegetation is not eroded easily, but the soil not covered by vegetation (or bare soil) is eroded very easily.

1. If there is vegetation (trees and other plants) on land, then the roots of vegetation (trees and other plants) growing in the soil bind the particles of topsoil firmly. Since the roots of trees and plants bind soil particles, the blowing wind and flowing rainwater will be unable to carry away topsoil, and thus soil erosion does not occur. On the other hand, the soil not covered by vegetation (trees and other plants) is easily eroded because there are no roots of trees and plants in it which can bind the soil particles together and prevent them from being carried away by strong winds or flowing rainwater (Actually, in the absence of plant roots, the soil becomes loose).
2. If there is vegetation (trees and other plants) on the land, most of the rain falling is absorbed by the trees and plants before it reaches the soil. As a result, vegetation cover softens (or lessens) the impact of heavy rains on the soil. The soil is not easily loosened, and flowing rainwater cannot carry away top soil. Thus, soil erosion does not occur. However, if there is no vegetation (trees and other plants) on the land to soften the effect of heavy rains, the bare soil becomes loose rapidly and erodes easily due to the force of falling rainwater. This is due to its weak nature, which allows it to be easily carried away by flowing rainwater or strong winds.

Introduction to Soil Conservation

The judicious and economical use of natural resources is called conservation. Protection of soil against erosion and degradation is called soil conservation. Soil can be conserved in the following ways:

1. Afforestation: The growing of trees on a large scale is called afforestation. This helps in soil conservation as the roots of plants bind the soil particles together.
2. Avoiding Overgrazing and Overuse of Land: Overgrazing by cattle should be prevented so that the soils are not devoid of green cover and thus are not eroded easily.
3. Step Farming: In mountain regions, step farming helps slow down the downward flow of water, which reduces soil erosion.
4. Construction of River Embankments and Dams: The embankments of rocks and stones on the banks of rivers help prevent soil erosion caused by river flooding.
5. Crop rotation is another method that can be used for preventing soil degradation.

Summary

Soil is required for life to exist on Earth. Plants and trees can only thrive in soil. Soil aids plant (and tree) growth by holding roots in place and providing water and nutrients. There would be no grass, crop plants, or trees if there were no soil on the world, hence no sustenance for ourselves or other land creatures. As a result, the soil is essential for agriculture. Food, clothing, and shelter are all provided through agriculture. This article taught us about soil erosion, introduction to soil pollution, soil conservation, layers of soil, and the importance of soil natural resources.

FAQs on Introduction to Soil

Q.1. What is the introduction of soil?
Ans: The soil is an important component of the landscape, as it influences the distribution of natural vegetation, crops, and human settlements over the terrain. Minerals, organic matter, gases, liquids, and the numerous species that support life on Earth make up soil.

Q.2. What are soil and its importance?
Ans: Soil is a natural resource that contains a large number of minerals that help plants grow. It’s necessary for agriculture. It contains a variety of microorganisms that promote soil fertility by decomposing waste materials in the soil.

Q.3. What are the 5 layers of soil?
Ans: The five layers of soil are O- Horizon, A-Horizon, B-Horizon, C-Horizon, and Bedrock.

Q.4.What are the 10 uses of soil?
Ans: Soil is essential for the survival of organisms found on Earth. Its applications are as follows:
1. Plants can grow in soil. It provides all of the nutrients that plants require to grow.
2. Soil is also important as a habitat, providing a home for millions of soil organisms such as insects, earthworms, bacteria, fungi, and so on.
3. It serves as a foundation for trees and vegetation.
4. Soil is also necessary for the world’s forests. Forests provide us with a variety of useful products. Forests not only provide us with timber, but they also serve as the natural habitat for many plants and animals.
5. Soil is used in the agricultural production of crops required for human and animal food. Soil is used in making pottery and bricks.
6. Soil microorganisms assist in the recycling of nutrients from dead plants and animals.
7. Food is grown on soil (like grains, pulses, fruits and vegetables, etc.).
8. Soil is used to grow trees for the purpose of obtaining wood for building purposes (timber), burning as fuel (firewood), and making paper.
9. Soil is used to grow cotton plants, which produce cotton clothing.
10.  Soil is also used to grow mulberry trees for silkworm rearing, which provides silk for silk clothing.

Q.5. What are the three types of soil?
Ans: The three types of soil are sandy soil, clayey soil, loamy soil,

Q.6. What are the three benefits of soil?
Ans: It supports plant growth, retains and cleans water, recycles nutrients, and provides a home for a diverse range of species on Earth.

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