Soil Type Of India.docx

REPORT ON DIFFERENT SOIL TYPE OF INDIA

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SUBMITTED BY: DEEPTI CHAUHAN I SEM – I YEAR M.LANDSCAPE

GANGA INSTITUTE OF ARCH AND TOWN PLANNING KABLANA, H.R., INDIA.

DEFINITION OF SOIL Soil can be simply defined as a mixture of small rock particles/debris and organic materials/ humus which develop on the earth surface and support growth of plants.

MAJOR CLASSIFICATION OF INDIAN SOILS

1. Alluvial soil [43%] 2. Red soil [18.5%] 3. Black / regur soil [15%] 4. Arid / desert soil 5. Laterite soil 6. Saline soil & Alkaline soil 7. Peaty / marshy soil 8. Forest soil 9. Sub-mountain soil 10. Snowfields .

1. Alluvial Soils: These are formed by the deposition of sediments by rivers. They are rich in humus and very fertile. They are found in Great Northern plain, lower valleys of Narmada and Tapti and Northern Gujarat. These soils are renewed every year. 

Mostly available soil in India (about 43%) which covers an area of 143 sq.km.

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Widespread in northern plains and river valleys.

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In peninsular-India, they are mostly found in deltas and estuaries.

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Humus, lime and organic matters are present.

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Highly fertile.

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Indus-Ganga-Brahmaputhra plain, Narmada-Tapi plain etc are examples.

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They are depositional soil – transported and deposited by rivers, streams etc.

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Sand content decreases from west to east of the country.

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New alluvium is termed as Khadar and old alluvium is termed as Bhangar.

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Colour: Light Grey to Ash Grey.

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Texture: Sandy to silty loam or clay.

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Rich in: potash

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Poor in: phosphorous.

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Wheat, rice, maize, sugarcane, pulses, oilseed etc are cultivated mainly

2.Red Soils: .These are derived from weathering of ancient metamorphic rocks of Deccan Plateau. Its redness is due to iron composition. When iron content is lower it is yellow or brown. They cover almost the whole of Tamil Nadu, Andhra Pradesh, Chhattisgarh, Karnataka, Maharashtra and parts of Orissa. 

Seen mainly in low rainfall area.

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Also known as Omnibus group.

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Porous, friable structure.

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Absence of lime, kankar (impure calcium carbonate).

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Deficient in: lime, phosphate, manganese, nitrogen, humus and potash.

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Colour: Red because of Ferric oxide. The lower layer is reddish yellow or yellow.

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Texture: Sandy to clay and loamy.

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Wheat, cotton, pulses, tobacco, oilseeds, potato etc are cultivated.

3. Black Soils: These soils are made up of volcanic rocks and lavaflow. It is concentrated over Deccan Lava Tract which includes parts of Maharashtra, Chhattisgarh, Madhya Pradesh, Gujarat, Andhra Pradesh and Tamil Nadu. It consists of Lime, Iron, Magnesium and also Potash but lacks in Phosphorus, Nitrogen and Organic matter. 

cultivation.

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Most of the Deccan is occupied by Black soil.

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Mature soil.

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High water retaining capacity.

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Swells and will become sticky when wet and shrink when dried.

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Self-ploughing is a characteristic of the black soil as it develops wide cracks when dried.

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Rich in: Iron, lime, calcium, potassium, aluminum and magnesium.

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Deficient in: Nitrogen, Phosphorous and organic matter.

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Colour: Deep black to light black.

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Texture: Clayey.

4. Desert Soils: In the desert regions of Rajasthan, soils are not well developed. As evaporation is in excess of rainfall, the soil has a high salt content and saline layer forms a hard crust. These soils are generally sandy and deficient in organic matter. 

Seen under Arid and Semi-Arid conditions.

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Deposited mainly by wind activities.

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High salt content.

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Lack of moisture and Humus.

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Kankar or Impure Calcium carbonate content is high which restricts the infiltration of water.

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Nitrogen is insufficient and Phosphate is normal.

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Texture: Sandy

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Colour: Red to Brown.

5. Laterite Soils: These soils are formed due to intense leaching and are well developed on the summits of hills and uplands. They are commonly found in Kerala, Tamil Nadu, Maharashtra, Chhattisgarh and hilly areas of Orissa and Assam. 

Name from Latin word ‘Later’ which means Brick.

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Become so soft when wet and so hard when dried.

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In the areas of high temperature and high rainfall.

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Formed as a result of high leaching.

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Lime and silica will be leached away from the soil.

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Organic matters of the soil will be removed fast by the bacteria as it is high temperature and humus will be taken quickly by the trees and other plants. Thus, humus content is low.

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Rich in: Iron and Aluminum

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Deficient in: Nitrogen, Potash, Potassium, Lime, Humus

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Colour: Red colour due to iron oxide.

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Rice, Ragi, Sugarcane and Cashew nuts are cultivated mainly.

6. Saline and Alkaline Soils They are also known as Usara soils. Various local names for saline soils are Reh, Kallar, and Chopan, Rakar, Thur, Karl etc.These soils have developed in areas with dry climatic conditions (in areas having a little more rainfall than the areas of desert soils) accompanied by lack of proper drainage. In this situation, salts of sodium, calcium and magnesium are deposited on the upper layer of the soil by capillary action. 

In the Rann of Kuchchh, the Southwest Monsoon brings salt particles and deposits there as a crust.

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These soils are also formed when saline water spreads on the land at the time of high tide in coastal areas. Also, seawater intrusions in the deltas promote the occurrence of saline soils.

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Salinization also occurs because of over-irrigation (canal irrigation/groundwater use) and in areas of high water table (as in the coastal areas of Maharashtra and Tamil Nadu).Salinity from irrigation can occur over time wherever irrigation occurs. This is because almost all water (even natural rainfall) contains some dissolved salts. When the plants use the water, the salts are left behind in the soil and eventually begin to accumulate. Also, excessive irrigation with dry climatic conditions promotes capillary action, which results in the deposition of salt on the top layer of the soil (See the following figure).

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Areas: They occur in arid and semi-arid regions, and in waterlogged and swampy areas. These are more

widespread in western Gujarat, deltas of the eastern coast and in Sunderban areas of West

Bengal. 

Soil Texture: Their texture ranges from sandy to loamy.

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Other characteristic features:

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Because of capillary action, the salts are sucked up in solution to the surface and form white encrustations on the surface (See the picture below).

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The salt efflorescence of calcium, magnesium and sodium makes these soils infertile.

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Saline soils contain an excess of neutral soluble salts of chlorides and sulphates whereas sodic or alkali soils contain sodium carbonates/ sodium bicarbonates.

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They lack in nitrogen and calcium and have low water bearing capacity.

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These soils can be reclaimed by improving drainage, by applying gypsum and/or lime, and by cultivating salt resistant crops like barseem, dhaincha and other leguminous crops.

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The saline and alkaline soils may occur in any group of soils.

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Crops grown: In coastal areas, coconut trees are found in plenty in these soils. As discussed above, cultivating salt resistant crops like barseem, dhaincha and other leguminous crops can help in reclaiming these soils.

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Note: In the areas of intensive cultivation with excessive use of irrigation, especially in areas of green revolution, the fertile alluvial soils are becoming saline. In such areas, especially in Punjab and Haryana, farmers are advised to add gypsum to solve the problem of salinity in the soil.

7. PEATY SOILS 

These soils are locally called Kari in Kottayam and Alleppey districts of Kerala.

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Formation: These are marshy soils and are a result of water logging and anaerobic conditions (which leads to partial decomposition of organic matter).

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Areas: They are found in the areas of heavy rainfall and high humidity, where there is a good growth of vegetation. It occurs widely in the northern part of Bihar, the southern part of Uttaranchal and the coastal areas of West Bengal, Orissa and Tamil Nadu.

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Soil Colour and Texture: These soils are normally heavy and black in colour

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Other characteristic features: 

These soils are characterised by a rich humus and organic content.

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There is a presence of iron and varying amounts of organic matter (10-40%). The organic matter in these soils may go even up to 40-50 per cent.

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These soils are generally acidic in nature. But at many places, they are alkaline also.

Suitable crops: These are generally submerged during the rainy season and utilised for the cultivation of rice.

8. Forest Soils 

Formation: As the name suggests, forest soils are formed in the forest areas where sufficient rainfall is available.

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Areas: These are found in the forest areas of Himalayas, Sahyadris, Eastern Ghats and terai region.

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Soil colour and texture: The soils vary in structure and texture depending on the mountain environment where they are formed. They are loamy and silty on valley sides and coarse-grained in the upper slopes. Their colour is dark brown.

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Other Characteristics: 

In the snow-bound areas of the Himalayas, they are acidic with low humus content. This is because humus is rawer at higher levels. Also, these soils are subjected to denudation due to landslides and snowfall.

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The soils found in the lower valleys are fertile and rich in organic content.

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Owing to sharp differences of hill slopes and climates, these soils may differ greatly even when in proximity. [Recall here the discussion on the impact of topography on soils!]

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Also, these soils exist in thin layers because of their development on the mountain slopes.

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These soils are poor in potash, phosphorus and lime.

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Soil erosion is a major problem in these areas.

Crops grown: The slopes are used for horticulture and plantations crops like tea, coffee, spices, apple, peach etc. Rice and wheat are grown in valleys. Potatoes are grown in mostly all areas.

9. Mountain Soils: These soils are formed as a result of the accumulation of organic matter derived from forest growth. They are found in Himalayan region and vary in different regions according to altitude. Tea is grown in those areas which receive sufficient rainfall. 

In the mountain regions of the country.

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Immature soil with low humus and acidic.

10. Snowfield 

The area under snow and glaciers is about 4 million hectares. The high peaks of the Greater Himalayas, Karakoram, Ladakh, and Zaskar {Zanskar} are covered by ice and glaciers.

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The soils in these areas is immature, generally without soil erosion, It remains frozen and is unsuitable for the cultivation of crops.