Soil formation and its significance
A] What is Soil?
Soil is the most important resource for us, because we get almost all our food directly or indirectly from it. Vegetables, fruits and animal products and much of our clothing, everything is obtained from soil. It has been derived from parent rock material through process of Weathering( breakdown / dissolving of rocks and minerals on the Earth's surface due changes in the temperatures). Nature and its elements also play important role in existence of soil. Changes in temperatures, running water and wind, contribute in evolution of soil. Chemical and organic changes in soil are also equally important. Whereas, these factors do not act on soil independently or in isolation, but in close association with each other. Fine vegetal and animal remains known as Humus add fertility to soil. It results in making soil fertile. Faulty agricultural practices, deforestation and overgrazing have led to soil erosion in many parts. As a result, soil conservation through improved agricultural practices, afforestation and decline in pressure of grazing has become very important.
B] Soil Formation:
- Soil is the thin layer of material covering the Earth' surface and is formed from weathering of rocks.
- It is mainly made up of mineral particles, organic materials, air, water and living organisms.
- Most plants get their nutrients from soil and they are main source of food for humans, animals and birds.
- Soil is a mixture of rock debris and organic material, developed on Earth's surface.
- The process of soil formation is known as "Pedogenesis".
C] Factors affecting Soil Formation:
- Parent Material:
- Minerals are the base of soil.
- They are produced from rocks (parent material) through process of weathering and natural erosion.
- Water, wind, temperature change, gravity, chemical interaction, living organisms and pressure differences all contribute in the break-down of parent material.
- For example: Soils formed from granite are often sandy and infertile, whereas basalt under moist conditions breaks down to form fertile, clay soils.
- Temperature affects rate of weathering and organic decomposition.
- With colder and drier climate, these processes can be slow but with heat and moisture, they are relatively faster.
- Climate is the most important single factor in soil formation.
- Climate controls type and effectiveness of weathering of parent material and type of micro-organisms present in soil.
- It affects the condition of soil formation in 2 ways:
- a) Amount of Rainfall and b) Variations in Temperature and rainfall.
- Process of soil formation is related to the growth of vegetation and micro-organisms that thrive on plants.
- The decayed leaf materials add to the fertility of soil.
- It enriches soil by providing with much needed content of humus.
- Soil formation is influenced by organisms (plants), micro-organisms (bacteria/ fungi), burrowing insects, animals and humans.
- Shape, length and grade of slope affects drainage patterns.
- Aspect of slope determines type of vegetation and indicates amount of rainfall received.
- These factors ultimately change the way soil forms.
- In areas of steep slope, with little vegetation cover the top layer of soil is heavily denuded as in Chambal valley, where ravines have been formed.
- Soil development takes place in an area with gentle slope.
- The process of soil formation is also affected by amount of water percolating below surface layers.
- The soils left on steep hills are usually shallower.
- Different methods of soil conservation help to mitigate erosion, keep fertility, avoid degradation, and minimize nature pollution due to chemicals by applying integrated weed and pest control techniques.
- Thus, soil conservation strategies greatly contribute to the sustainability of the environment and resources.