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Soil And Its Formation
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This lesson deals with soil and its formation.


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hey Charu, you mentioned about grouping of different particles like sand, silt, clay. I want to what exactly is that 2.0-0.06 mm is that diameter or circumference or what
Good video but the speaker must improve on the pronunciation.
Just reading the text.. not helpful
Good content. But the narration can be better and accurate.
you are just reading the text....????
  1. SOIL AND ITS FORMATION Presented by Charu Meena


  2. SOIL Soil is natural part of earth's surface. Being characterised by layers parallel to the surface resulting by physical, chemical and biological processes, Contains four basic components-minerals 45%, water 25%, sorganicmatter 5% !humus, atmospheric gases 25% & organic matter 5% {humus, roots & living organisms! Study of soil is known as pedology. The process of soil formation is called pedogenesis


  3. Soil texture: Refers to size distribution of mineral particles. Particles are normally grouped into three main classes-sand 2.0- o.o6 millimetres, silt o.o6 - o.002 millimetres & clay less than o.oo2 millimetres. - Soil pH: Soil fertility is influenced by pHs. Best pH for plants growth is between 5.5 to 6.5 Soil colour: Variations in colours both horizontally & vertically. For e.g. In humid tropics colour varies from red or yellow, in temperate grassland soil colour varies black to grey


  4. Soil Profile " Soil profile refers to the display of horizons on a cross section through the soil Soil horizons are distinctive layers found in soils. " Up to five layers can be present in a typical soil: O, A, B, C, and R horizons The 10, horizon is the topmost layer of most soils. It is composed mainly of plants decompose and humus


  5. A' horizon is found below the O layer. It is a zone of translocation. Rich in organic matter. Dark in colour and usually light in texture and porous The B' horizon is a mineral soil layer. Receives material eluviated from the A horizon. Dense and though due to illuviation of clay and oxides . The horizon is composed of weathered parent material. Texture varies from clay to boulders. The final layer in a typical soil profile is called the 'R' horizon. This soil layer simply consists of unweathered bedrock


  6. Typical layers found in a soil profile 0 30 BedrockI


  7. Soil formation Soil formation process is slow & time consuming There are 4 classes of soil formation which are as follow: - Enrichment: Mineral enrichment of silt by river floods or through weathering, organic enrichment as water carries humus. 1. Removal: Loss of soil compounds & minerals by solution in water flowing to lower level (Leaching). 2. Translocation: Movement of materials between soil horizons. Downward movement process from a horizon known as Eluviation and accumulation process in a horizon known as Illuviation 3. 4. Transformation: Alters soil material within horizons, for e.g. decomposition of organic matter to produce humus [humification]


  8. Factors affecting soil formation Five factors effect soil formation an Parent material: The breakdown of underlying rocks which by agencies of weathering. It determines the chemical composition of soil. a. Weathering: Landform & its configuration, relief & its features are determined by weathering b. Climate: Acts through moisture conditions, temperature & winds, controls type & effectiveness of weathering of the parent material c. Natural vegetation: It enriches the soil by providing the decayed leaf material adds much needed content humuS e. Time: The length of time that the pedologic process have been operating.