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Soils in India Soil is the uppermost layer of Earth s crust. Soil is the medium in which plants grow and thus it supports the lives on earth. How soils are formed? Soils are formed due to the weathering of rocks. WHAT IS SOIL? Soil is the thin layer of loose mixture of small rock particles and rotting organic matter that covers much of the world s land surface. SOIL FORMATION Soil formation is a very long process. It begins with the weathering of rocks into small fragments. The rocks are also worn away by the agents of erosion like river, wind, sea and glacier. The sediments and tiny rock particles are then deposited by the agents of erosion. The accumulation of such sediments over the ages forms soil. Eventually, the plants that grow on the soil, shed their leaves which decay to form the topmost layer of soil called 'humus'. India is primarily an agricultural country. The success of agriculture depends upon the fertility of soils. The soils of India are classified into the following main groups depending upon the rock cover and climatic conditions. The most two important factors that determine the types of soil found in India are : i. The climate ii. The topography The soils of India on the basis of their formation are divided in the following two broad catagories. 1.Residual Soil 2.Transported Soil The major soil groups are: Black Soil Black soils are mainly found over the Deccan lava tract (Deccan Trap) including Maharashtra, Madhya Pradesh, Gujarat and Andhra Pradesh. These soils are found in river valley of Narmada, Tapi, Godavari and Krishna. These soils have been formed due to the weathering of the lava rocks. This is also known as the Regur soil and Cotton soil. These soils are rich in lime. iron, magnesia and alumina butlack in the phosphorus, nitrogen and organic matter. It is formed by the weathering of igneous rocks and the cooling of lava after a volcanic eruption. In India, extensive deposits of black soil are found in the Deccan Plateau which includes parts of Maharashtra, Madhya Pradesh, Gujrarath, Andhra Pradesh, parts of Tamil Nadu. In the upper parts of Godavari and Krishna, the north western part of Deccan Plateau, black soil is very deep. BLACK SOIL IS:Clayey, deep and impermeable They swell and become sticky when wet and shrink when dried During dry season, these soils develop wide cracks. Rich in lime and iron, magnesia and alumina Also contain potash Lack phosporus, nitrogen and organic matter Colour of the soil ranges from deep black of grey. Known as Black Cotton Soils. Dark in colour, suitable for cotton cultivation Are residual soils, i.e. they are formed at the place of their origin over the underlying rocks. Are formed in situ, i.e. formed where they are found. Therefore, they are essentially formed by weathering of Deccan Trap. Spread over an area of 5.4 sq. km., i.e. 16.6 % of the total land area of the country. CHARACTERISTICS: * Fine textured and clayey in nature . * Has high qualities of lime, iron, mangnesium, and generally poor percentage of phosphorous, nitrogen and organic matter. * Black in colour as it is formed from weathered lava rocks Soil s colour also varies from Black to Chestnut brown Very clayey and therefore highly retentive of water. Because of high clay content, these soils expand when wet and become difficult to plough. During dry season, black soils shrink and develop big cracks which help in air circulation . Soil is very fertile in most of places. Poor in nitrogen, phosphorous, potassium, and organic matter and rich in potash and lime. Needs irrigation support for cultivation Contains soluble salts in small quantities. Cultivation is done with the help of fertilizers . Suited for dry farming as it does not require much moisture. CROPS: Cotton cultivation Suitable for growing cereals, rice, wheat, jowar, oilseeds, citrus fruits and vegetables, tobacco and sugarcane. Their moisture retentiveness makes them suitable for dry farming. Shall we revise black soils? BLACK SOIL (SUMMARY) Black soil is made from lava-solidified rocks and is also called as Black Cotton Soil or Regur Soil . The black colour of regur soil is due to its iron content, deriving from plutonic lava materials. Mainly found in the Deccan region which includes the major part of Maharashtra, Gujarat and part of Tamil Nadu, Andhra Pradesh and Madhya Pradesh. Cotton is most important crop RED SOIL These soils are found in Chhotanagpur plateau, Telangana, Nilgiris, Tamil Nadu, Karnataka, Andhra Pradesh and periphery areas of Deccan Plateau. These soils have been formed due to decomposition fo underlying igneous rocks under heavy rainfall. These are suitable for the cultivation of millets, pulses. Lin-seed, tobacco etc. These soils are poor in Lime, Nitrogen and humus. CHARACTERISTICS: Red soils are reddish in colour due to the presence of iron. This type of soil is found in south India as well as in the Chota Nagpur Plateau. Formed due to weathering of ancient crystalline and metamorphic rocks. Parent rocks are acid granites and gneisses. Occupy an whi area of about 3.5 lakh sq km 10.6% of the total land area of the country . These are transported type soils. Found to a depth of 500 meters. Coarsest in the upper section of the valley, medium in the middle and finest in the delta region. Are mostly light to dark colour depending on new or old alluvium. Rich in potash and become fertile with the proper use of fertilizers and irrigation. Deficient in nitrogen,lime, magnesia, humus and phosphate Found mainly on the plateau regionof peninsular India, the Malwa Plateau and the Chotanagpur Plateau. It covers almost the whole of Tamil Nadu, Karnataka, Andhra Pradesh, south-eastern Maharashtra, eastern parts of Madhya Pradesh, parts of Orissa, Jharkhand and Bundelkhand. They practically encircle the entire black soil region on all sides.They extend northwards in the west along with the Konkan Coast of Maharashtra. Red due to its very high iron content. Colour varies from red to brown, chocolate and yellow. Are porous, friable in nature . Loose and aerated. Contains soluble salts in small quantities. LATERITE SOIL laterite = brick (Latin word) These soils are formed under conditions of high temperature and heavy rainfall with alternate wet and dry periods. Thus its formation takes place strictly under monsoon conditions. Residual soils formed by leaching in areas of heavy rain. Leaching is a process in which the nutrients get percolated down below the soil due to heavy rainfall; thus leaving the top soil inFertile. Also called DESILICATION. Laterite soils are found in elevated areas which receive very high rainfall As a result, top soil gets washed away. This process is called leaching. The soil, therefore, loses its fertility to a great extent. It covers an area of about 2.4 lakh sq km. These soils are found in the north- eastern state of Meghalaya in India. Is of coarse texture, soft and friable. Is red due to the presence of iron oxide which is formed by leaching. The soluble plant foods like potash are removed from the top soil leaving alumina and iron oxide. Is a porus soil, silica is removed from it by chemical action. Is poor in lime and magnesium, and deficient in nitrogen. Laterite soil is formed by weathering of lateritic rocks, low temperature and heavy rainfall with alternating dry and wet periods. Laterite soil does not retain moisture and hence is not fertile. It suits only special crops like Tapioca, Cashewnuts, etc.It is acidic in nature as alkalis are leached. Laterite soils are found on the highland areas of the plateau. These are found in Karnataka, Kerala, Tamil Nadu and hilly regions of Assam, Rajmahal hills and Chhotanagpur plateau. These are shallow, acidic and less fertile soils. These soils are poor in lime but rich in iron. So these are suitable for plantation of crops like tea, rubber, coffee etc. Since low fertility because of high acidity and low moisture retention, manuring and other activities are required to make them suitable for growing crops such as ragi, rice and sugarcane. Paddy is grown on lower elevations whereas tea, cinchona, rubber, and coffee are grown on higher elevations. It is also suitable for building purpose. ALLUVIAL SOILS Alluvial Soil (Riverine soil) It covers about 40 percent of land area of the country. They are depositional soils, transported and deposited by rivers and streams. Through a narrow corridor in Rajasthan, they extend into the plains of Gujarath. These soils are formed by the deposition of fine sediments and silt by the rivers along their banks. In India, alluvial soils are mostly found in the Great Northern Plains, the coastal plains and river deltas In Peninsular region, they are found in deltas of the east coast and in the river valleys. These soils originate from the transported alluvium brought by the rivers. They can be divided into two types: 1. Young Khadar soils: these are newer alluvium of sandy, pale brown composition, found in lower areas of valley bottom which are flooded almost every year. It is non phorous, clayey and loamy. 2. Old Bhangar soils: these consist of older alluvium of clayey composition and are dark in colour. They are coarse in nature, contain kankar (lime nodules), pebbles, gravels. They are found 30 m above flood level of the rivers. nThey represent the riverine alluvium brought down by Sutlej, Yamuna, Ghagra and other rivers of Indo-Gangetic Plains. These soils are the most widespread soils covering an area of 8 lakh sq. km from Punjab to Assam. These are found in the river basin, flood plains and coastal areas. These soils are deep soils rich in potash but poor in nitrogen. These soils are covering 22.16 per cent of total area of India. The major rivers which are contributing in the formation of the alluvial soils are :Ganga river,Brahmaputra river, Sutlej river, Mahanadi river ,Godavari river , Krishna river Alluvial soils though differ greatly in texture, are very fertile on whole. They: Respond well to irrigation and manuring. Good for both rabi and kharif crops. Suitable for wheat, sugarcane, rice, cotton and oilseeds. In delta region, they are ideal for jute cultivation. AREA/STATES Alluvial soils of two types: deltaic coastal and inland alluviul. Found in Uttaranchal, U.P., Bihar, W. Bengal, Punjab, Haryana & Assam.In south,found in the plains and deltas in Andhra Pradesh, Orissa, Tamil Nadu. Useful for agriculture since it is fertile. Soil is rich in potash and lime but poor in nitrogen and humus. Important crops wheat, rice, sugarcane, cotton and jute. It is very suitable for jute. SUMMARY - ALLUVIAL SOIL Alluvial soils are most extensive soil most part It is formed due to deposition of the rivers brought down from the upper course of the river. It is found on the combined plain land of the Indus and the Ganga-Brahmaputra rivers which includes Punjab, Haryana, U.P., Bihar and West Bengal. The Deltaic alluvium is found in deltas of the Ganga-Brahmaputra, Godavari, Mahanadhi and Kaveri rivers. The Coastal alluvium is found in coastal sides of Peninsular India. Called Riverine Soils it is originally found in river basins . Rice and wheat 2 main crops being cultivated in the alluvial soil. Deltaic alluvium is more fertile than the coastal alluvium because as the coastal alluvium being mixed with sands, has been lacked the meagre power of water-preserving than its counter parts. The deltaic alluvium has been riched with newly river-deposited alluvial components. The economics of India, Pakistan and Bangladesh are dependent on alluvial soils. The India, Bangladesh & Pakistan, i.e. combinedly the Indian sub-continent have been sectorising the agriculture into its primary occupation since a considerable period; and occasionally the accumulated river basin of Indus-Ganga-Brahmaputra, one of the riches source of fertile alluvial soil of the world, has occupied the region s foremost areas. Thus, this type of agro friendly soil inhabitance consequently favours the economic upsurging among the totalwards. Inland alluvium and Coastal Alluvium Inland Alluvium soil is found in Indus river plains and the Ganga-Brahmaputra river plains whereas Coastal alluvium is found on the coastal regions of peninsular India Inland Alluvium soil is found in Punjab, Haryana, U.P. Bihar, W. Bengal and Coastal Alluvium is found in Gujarath plains Other Soils: The other soils in the category of the Indian soils are as follows: DESERT SOIL These soils cover 2 lakh sq. km areas in dry areas of Rajasthan, Gujarat, Punjab, and Haryana. These coarse soils are suitable for cultivation of jowar, bajara, cotton etc. Saline and Alkaline Soils: These soils are found in the dry and marshy areas. These are locally known as Bhur, Rehu, Kallar. The accumulation of salts makes these soils infertile. Mountain Soils: Mountain soils are found in, as the name suggests, in mountainous regions. They are quite prone to soil erosion as a result of the top soil getting washed away due to the steep slopes of the mountains after a period of heavy rainfall. These soils are mostly thin and infertile. These include peat, meadow and forest hill soils. The major characteristics of this soil are: *they are rich in humus * are coarse and infertile. They are deficient in potash, phosphorous and lime. *Tea, coffee, spices and tropical fruits The states of Jammu and Kashmir, Himachal Pradesh and Uttaranchal, Assam, Sikkim as well as higher reaches of Arunachal Pradesh have mountain soil. ARID AND DESERT SOILS Large part of arid and semi-arid region of Rajasthan and adjoining areas of Punjab and Haryana Desert soils are found in arid regions which receive very little rainfall. *Low rainfall and high temperature are reasons for the formation of this soil . *Having less than 50 cm rainfall . The high temperature adds to the loss of any remaining moisture in the soil. The soil is therefore sandy in nature. Thar Desert in Rajasthan has sandy soil. *Covers an area of about 1.4 lakh sq km * Originated from the mechanical disintegration of the ground rock of by deposition by wind * Desert soil contain 90% of sand and 5% of clay. It contains rich percentage of soluble salts, but lack in organic matter. * Are porus and coarse . * They respond well to irrigation and manuring , especially phosphate and nitrate.- it can improve the soil fertility as it is seen in the case of Indira Gandhi Canal in Rajasthan. * Only suitable for drought resistance crops like millets, barley, cotton, maize and pulses. C opyrigh t www.www.examrace.co m Soil Wealth The Indian council of Agricultural Research has indentified eight main types of soil in the country. Soil cover in India (%) Alluvial Soil 43.4 RedSoil 18.6 BlackSoil 15.2 Lateritic Soil 12.2 OtherSoil 17.9 Soil Types The main soil types are: The Indian council of Agricultural Research has indentified eight main types of soil in the country. Soil cover in India (%) Alluvial Soil 43.4 RedSoil 18.6 BlackSoil 15.2 Lateritic Soil 12.2 OtherSoil 17.9 The main soil types are: Alluvial Soil It covers 15 lakh km2 Greater parts of Rajasthan, Punjab, Haryana, U. P, parts of Assam, Orissa, W. Bengal, valleys of Narmada and Tapi Depth of soil exceeds 600m below the ground surface Divided into newer and older; finer and newer alluvium is called Khadar-Khadar is light coloured and is less kankary Bhangar: Older alluvium more clayey in composition and generally of dark colours; also becomes Alkaline and is called Bhurs Khadar soils are more sandy in composition that Bhangar soils Characteristics The fertility of the soil is because of the following reasons: Lit is due to more mixing up the debris from the rocks of the Himalayas rather that the prevalence of nitrogenous matters or humus. These soils are composed of material drawn from different rocks and therefore contain a great variety of salts. These soils are very fine grained, highly porous and light so that they are easily tilled and are therefore the best agricultural soils of the country. Crops: Rice, sugarcane, tobacco, banana, cotton, wheat, jute, maize, oilseeds and vegetables. Red And Yellow Soil It covers about 6.1 lakh km2 of area. Western Tamil Nadu, Karnataka, Southern Maharashtra, Chhattisgarh, Andhra Pradesh, Orissa and Chotanagpur plateau of Jharkhand. Scattered patches can be found in Birbhum (W. Bengal), Mirzapur, Jhansi, Banda, Hamirpur (U. P), Udaipur, Chiltisgarh, Dungarpur, Banswara and Bhilwara dist (Rajasthan). The colour is mainly due to ferric oxides occuring as thin coatings on the soil particles while the iron oxide occurs as haematite or as hydrous ferric oxide, the colour is red and when it occurs in the hydrate form as limonite the soil gets a yellow colour These soils are poor in phosphorus, nitrogen and lime contents and are acidic like laterite. Red soils develop generally on metamorphic rocks It is sandier and less clayey It is rich in potash Black Or Regur Soils It covers an area of 5, 46, 000 km2 Tracts in A. P, Maharashtra (Tapi, Godavri, Bhima and Krishna), Karnataka (Bijapur, Gulbarga, Bidar, Belgaum, Dharwar and Raichur), Gujarat (Surat, Bharuch, Vadodra), M P (Narmada, Vindhya and Satpura plateau), Tamil Nadu, Rajasthan (Kota, Bundi, Jhalawar); U. P (Jalawn, Hamirpur, Banda and Jhansi) -The black colour is due to the presence of titaniferous magnetite compound of iron and aluminum silicate. It is also believed that black colour is due to admixture with humus on cultivation. These are rich in iron, lime, calcium and magnesium carbonate and alumina. Black soils are poor phosphorous and nitrogen The soil is clayey and fine texture with dark colour Crops: Cotton, wheat, chilies, linseed, jawar, Virginia tobacco, castor, millets It develop cracks in hot weather Black soils are ideal for dry farming due to their moisture retentive quality. It becomes sticky due to high percentage of clay and so difficult to plough. Lateritic Soils It covers an area about 1.26 lakh km2 Laterite is a typical soil of the tropical regions which receives heavy seasonal rainfall. Iron and aluminum compounds dominate in its composition It is found in W. Bengal (Midnapur, Burdwan, Birbhum and Bankura), Orissa (Cuttack and Ganjam), Maharashtra (Ratnagiri, Satara, Kolaba, Kanara dist.), Karnataka (Shimoga, Hasan, Kadur, Mysore), Kerala (Malabar) The soils are generally poor in nitrogen, potassium and organic matters Fertilizers are necessary Cannot retain moisture while in plains they consist of heavy loam and clay and easily retain moisture Crops: Rice, ragi, sugarcane, cashewnuts Saline Or Alkaline Salts It covers an area of 68, 000 km2 Tracts in Rann of Kutch, Sundarbanns, Bihar, UP, Haryana, Punjab, Rajasthan and Maharashtra It is known by different names: Thur, Reh, Kallar, Rakar, Usar, Kari and Chopan Texturally they are sandy to loamy sand Alkaline soils are deficient in calcium and nitrogen Peaty saline soils are called Kari in Kerala Main salts: Calcium, sodium and magnesium these soils can be reclaimed by providing good drainage applying lime or gypsum and cultivating salt resistant crops (like berseem, rice and sugarcane) -These soils are utilized in the cultivation of a wide variety of crops like rice, wheat, cotton, sugarcane and tobacco etc. Mountain Soils It is of three types Brown Forest Soils: Height 900 1800m; rich in humus and are fertile Podzol: 1800m (height); thick coniferous forest, maize, wheat and orchids: Phosphoric content Alpine Meadow Soil: Sandy loam These soils are silty loam to loam in texture and dark brown in colour These are found in hills of deccan, eastern ghats, western ghats, valley and hill slopes of Himalayas etc. These are deficient in potash, phosphoric acid and lime Desert Soils It covers an area of 14, 200km2 Tracts in Rajasthan, Haryana, south of Punjab, Thar desert occupies and area of 1, 06, 000 alone Clay content is poor and is less than 8% These are reddish brown Sandy soils are called Bhur-Rich in phosphates and poor in nitrogen Contains high content of soluble salts but low moisture content The soil is sandy to gravelly These soils may be reclaimed with the proper development of irrigation facilities For example, the Ganganagar district benefited by the Indira Gandhi Canal has become a leading producer of cereal and cotton. Crops: Millets, jawar bajra jowar and coarse grains
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