Monday, 1 December 2014

Smart Notes on Indian (Agro) Geography Part - 22

1.       Soil is the mixture of rock debris and organic materials which develop on the earth’s surface.
2.       The major factors affecting the formation of soil are relief, parent material, climate, vegetation and other life-forms and time
3.       Components of the soil are mineral particles, humus, water and air.
4.       ‘Horizon A’ is the topmost zone, where organic materials have got incorporated with the mineral matter, nutrients and water,
5.       ‘Horizon B’ is a transition zone between the ‘horizon A’ and ‘horizon C’, and contains matter derived from below as well as from above. It has some organic matter in it,
6.       ‘Horizon C’ is composed of the loose parent material. This layer is the first stage in the soil formation process and eventually forms the above two layers
7.       This arrangement of layers is known as the soil profile
8.       Underneath these three horizons is the rock which is also known as the parent rock or the bedrock
1.       In ancient times, soils used to be classified into two main groups – Urvara and Usara
2.       Fertile and sterile
3.       In the 16th century A.D., soils were classified on the basis of their inherent characteristics and external features such as texture, colour, slope of land and moisture content in the soil
4.       In the 16th century A.D., soils were classified on the basis of their inherent characteristics and external features such as texture, colour, slope of land and moisture content in the soil
5.       Sandy, clayey, silty and loam, etc.
6.       On the basis of colour -Red, yellow, black, ET
Soil Survey of India
1.       Established in 1956, The National Bureau of Soil Survey and the Land Use Planning an Institute under the control of the Indian Council of Agricultural Research (ICAR)
2.       The ICAR has classified the Indian soils on the basis of their nature and character as per the United States Department of Agriculture (USDA) Soil Taxonomy

(i) Inceptisols
(ii) Entisols
(iii) Alfisols
(iii) Alfisols
(iv) Vertisols
(vi) Ultisols
(vi) Mollisols
ICAR classification on the basis of genesis, colour, composition and location,
(i) Alluvial soils
(ii) Black soils
(ii) Black soils
(iv) Laterite soils
(v) Arid soils
(vi) Saline soils
(vii) Peaty soils
(viii) Forest soils
Alluvial Soils
1.       Widespread in the northern plains and the river valleys
2.       40 per cent of the total area of the country
3.       Depositional soils
4.       Transported and deposited by rivers and streams
5.       Transported and deposited by rivers and streams
6.       Peninsular region, they are found in deltas of the east coast and in the river valleys
7.       Vary in nature from sandy loam to clay
8.       Rich in potash but poor in phosphorous
9.       Upper and Middle Ganga plain, two different types of alluvial soils have developed
 Khadarand Bhangar.
1.       Khadar is the new alluvium and is deposited by floods annually, which enriches the soil by depositing fine silts
2.       Bhangar represents a system of older alluvium, deposited away from the flood plains
3.       Khadarand Bhangarsoils contain calcareous concretions (Kankars
4.       More loamy and clayey in the lower and middle Ganga plain and the Brahamaputra valley
5.       More loamy and clayey in the lower and middle Ganga plain and the Brahamaputra valley
6.       Colour of the alluvial soils varies from the light grey to ash grey
7.       Shades depend on the depth of the deposition, the texture of the materials, time taken for attaining maturity
8.       Alluvial soils are intensively cultivated.
Black Soil
1.       Includes parts of Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh and some parts of Tamil Nadu.
2.       Western part of the Deccan Plateau
3.       And the north western part of the Deccan Plateau,
4.       Western part of the Deccan Plateau,
5.       Also known as the ‘Regur Soil’ or the ‘Black Cotton Soil
6.       Generally clayey, deep and impermeable.
7.       Generally clayey, deep and impermeable.
8.       There occurs a kind of ‘self-ploughing’
9.       The black soil retains the moisture for a very long time
10.   Helps the crops, especially, the rain fed ones, to sustain even during the dry season
11.   Chemically, the black soils are rich in lime and also contain potash
12.   Lack in phosphorous, nitrogen and organic matter.
13.   Soil ranges from deep black to grey
Red and Yellow Soil
1.       Red soil develops on crystalline igneous rocks in areas of low rainfall in the eastern and southern part of the Deccan Plateau
2.       Along the piedmont zone of the Western Ghat, long stretch of area is occupied by red loamy soil
3.       Yellow and red soils are also found in parts of Orissa and Chhattisgarh and in the southern parts of the middle Ganga plain
4.       Develops a reddish colour due to a wide diffusion of iron in crystalline and metamorphic rocks
5.       Fine-grained red and yellow soils are normally fertile
6.       Coarse-grained soils found in dry upland areas are poor in fertility
7.       Generally poor in nitrogen, phosphorous and humus

Laterite Soil
1.       Derived from the Latin word ‘Later ‘which means brick
2.       Develop in areas with high temperature and high rainfall
3.       Result of intense leaching due to tropical rains
4.       With rain, lime and silica are leached away, and soils rich in iron oxide and aluminium compound are left behind
5.       Humus content of the soil is removed fast by bacteria that thrives well in high temperature.
6.       While iron oxide and potash are in excess
7.       Not suitable for cultivation
8.       Application of manures and fertilisers are required for making the soils fertile for cultivation
9.       Red laterite soils in Tamil Nadu, Andhra Pradesh and Kerala are more suitable for tree crops like cashewnut
10.   Laterite soils are widely cut as bricks for use in house construction
11.   Mainly developed in the higher areas of the peninsular plateau
12.   Commonly found in Karnataka, Kerala, Tamil Nadu, Madhya Pradesh and the hilly areas of Orissa and Assam
Arid Soils
1.       Arid soils range from red to brown in colour
2.       Generally sandy in structure and saline in nature.
3.       The salt content is so high that common salt is obtained by evaporating the saline water
4.       Due to the dry climate, high temperature and accelerated evaporation, they lack moisture and humus
5.       Nitrogen is insufficient and the phosphate
6.       Content is normal
7.       Lower horizons of the soil are occupied by ‘kankar’ layers because of the increasing calcium content downwards
8.       The ‘Kankar ’layer formation in the bottom horizons restricts the infiltration of water,
9.       The soil moisture is readily available for a sustainable plant growth
10.   Characteristically developed in western Rajasthan, which exhibit characteristic arid topography
11.   Soils are poor and contain little humus and organic matter
Saline Soils
1.       Also known as Usara soils
2.       Saline soils contain a larger proportion of sodium
3.       Potassium and magnesium, and thus, they are infertile,
4.       Do not support any vegetative growth
5.       More salts, largely because of dry climate and poor drainage
6.       Occur in arid and semi-arid regions, and in waterlogged and swampy areas
7.       Structure ranges from sandy to loamy
8.       Lack in nitrogen and calcium
9.       Saline soils are more widespread in western Gujarat, deltas of the eastern coast and in Sunderban areas of West Bengal
10.   Rann of Kuchchh, the Southwest Monsoon brings salt particles and deposits there as a crust
11.   Seawater intrusions in the deltas promote the occurrence of saline soils.
12.   Areas of intensive cultivation with excessive use of irrigation, especially in areas of green revolution, the fertile alluvial soils are becoming saline
13.   Excessive irrigation with dry climatic conditions promotes capillary action, which results in the deposition of salt on the top layer of the soil.
14.   Punjab and Haryana, farmers are advised to add gypsum to solve the problem of salinity in the soil
Peaty Soils
1.       Found in the areas of heavy rainfall and high humidity
2.       Organic matter in these soils may go even up to 40-50 per cent
3.       Soils are normally heavy and black in colour
4.       Occurs widely in the northern part of Bihar, southern part of Uttaranchal and the coastal areas of West Bengal, Orissa and Tamil Nadu
Forest Soils
1.       Formed in the forest areas where sufficient rainfall is available
2.       They are loamy and silty on valley sides
3.       Coarse-grained in the upper slopes
4.       In the snow-bound areas of the Himalayas, they experience denudation
5.       Acidic with low humus content
6.       Soils found in the lower valleys are fertile
1.       Decline in soil fertility, when the nutritional status declines and depth of the soil goes down due to erosion and misuse
2.       Soil degradation is the main factor leading to the depleting soil resource base in India
3.       In the soil. Peaty Soils they are found in the areas of heavy rainfall and high humidity,
4.        Where there is a good growth of vegetation. Thus, large quantity of dead organic matter accumulates in these areas, and this gives a rich humus and organic content to the soil.
5.        Organic matter in these soils may go even up to 40-50 per cent. These soils are normally heavy and black in colour. At many places, they are alkaline also.
6.        It occurs widely in the northern part of Bihar, southern part of Uttaranchal and the coastal areas of West Bengal, Orissa and Tamil Nadu.
7.        Forest Soils As the name suggests, forest soils are formed in the forest areas where sufficient rainfall is available. The soils vary in structure and texture depending on the mountain environment where they are formed.
8.       They are loamy and silty on valley sides and coarse-grained in the upper slopes. In the snow-bound areas of the Himalayas, they experience denudation, and are acidic with low humus content.
9.        The soils found in the lower valleys are fertile. It is evident from the foregoing discussions that soils, their texture, quality and nature are vital for the germination and growth of plant and vegetation including crops.
10.   Soils are living systems. Like any other organism, they too develop and decay, get degraded, respond to proper treatment if administered in time.
11.   These have serious repercussions on other components of the system of which they themselves are important parts.
1.       In a broad sense, soil degradation can be defined as the decline in soil fertility,
2.       When the nutritional status declines and depth of the soil goes down due to erosion and misuse.
3.       Soil degradation is the main factor leading to the depleting soil resource base in India. The degree of soil degradation varies from place to place according to the topography, wind velocity and amount of the rainfall. Destruction of the soil cover is described as soil erosion.

4.       The soil forming processes and the erosional processes of running water and wind go on simultaneously
5.       There is a balance between these two processes.
6.       Sometimes, such a balance is disturbed by natural or human factors, leading to a greater rate of removal of soil
Wind erosion
1.       Wind erosion is significant in arid and semi-arid regions
2.       In regions with heavy rainfall and steep slopes, erosion by running water is more significant
3.       Sheet erosion takes place on level lands after a heavy shower and the soil removal is not easily noticeable.
4.       Harmful since it removes the finer and more fertile top soil.
Gully erosion
1.       Gully erosion is common on steep slopes. Gullies deepen with rainfall, cut the agricultural lands into small fragments and make them unfit for cultivation
2.       A region with a large number of deep gullies or ravines is called a badland topography
1.       Ravines are widespread, in the Chambal basin.
2.       The country is losing about 8,000 hectares of land to ravines every year
1.       Eroded materials are carried down to rivers and they lower down their carrying capacity, and cause frequent floods and damage to agricultural lands
2.       Deforestation is one of the major causes of soil erosion
3.       Plants keep soils bound in locks of roots
4.       They also add humus to the soil by shedding leaves and twigs
5.       Their effect on soil erosion are more in hilly parts of the country
6.       A fairly large area of arable land in the irrigated zones of India is becoming saline because of over irrigation
7.       The salt lodged in the lower profiles of the soil comes up to the surface and destroys its fertility
8.       This problem is common in all the command areas of the river valley projects, which were the first beneficiaries of the Green Revolution
9.       About half of the total land of India is under some degree of degradation.
Ways to curb soil erosion
1.       The first step in any rational solution is to check open cultivable lands on slopes from farming
2.       And with a slope gradient of 15 - 25 per cent should not be used
3.       Terraces should carefully be made.
4.       Should be regulated and controlled by educating villagers about the consequences. Contour bonding, Contour terracing
5.       Prevent gully erosion and control their formation
6.       Constructing a series of check dams.
7.       Special attention should be made to control headward extension of gullies
8.       In arid and semi-arid areas, protect cultivable lands from encroachment by sand dunes through developing shelter belts of trees and agro-forestry.
9.       Lands not suitable for cultivation should be converted into pastures for grazing.
10.   Central Soil Conservation Board, set up by the Government of India, has prepared a number of plans for soil conservation in different parts of the country
11.   Land use maps should be prepared and lands should be put to right uses

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