ICSE CLASS 10 GEOGRAPHY//SOIL IN INDIA
What is the soil? Name the four types of soil.
Answer:- 'Soil' means the uppermost layer of the earth's crust, which contains the organic as well as mineral matter necessary for the growth of plants.
. The four types of soil are-
Alluvial soil
Black soil
Red soil
Laterite soil
State any two factors responsible for the formation of soil.
Answer:- Two factors responsible for the formation of soil are —
Weathering
Erosion
How can you say that soil has evolved over millions of years?
Answer;:-Soil changes with age - As a soil ages, it gradually starts to look different from its parent material. That is because soil is dynamic. Its components—minerals, water, air, organic matter, and organisms—constantly change.
Name one important constituent of soil that adds fertility to the soil.
AnsweR:- One important constituent of soil that adds fertility to the soil is humus.
Give a geographical reason for each of the following:
(i) The colour of alluvium soil varies in different areas.
Answer:- The colour of alluvium soil varies in different areas because its shades depend on the depth of deposition, the texture of the materials and the time taken for maturity.
(ii) Khadar is more fertile than bhangar soil.
Answer:- Khadar is more fertile than bhangar soil as new layers are deposited year after year during monsoon floods.
(iii) Black soil has a kind of self-ploughing characteristic.
Answer:- Black soil has a kind of self-ploughing characteristic because during dry season, it shrinks and develops big cracks which help in air circulation. This characteristic causes a kind of self-ploughing.
How are alluvial soils formed?
Answer:-Alluvial soil is formed by the sediments brought down by rivers. The rivers deposit very fine particles of soil called alluvium in their plains during the course of their long journey. The resultant alluvial soil is known as riverine soil.
Mention any two advantages of alluvial soil.
Answer:- Two advantages of alluvial soil are-
It is light and porous. So, it is easily tillable.
It is suitable for the growth of a large variety of rabi and kharif crops.
Why is soil a valuable resource for India?
Answer:- Soil is a valuable resource for India because agriculture is the main occupation in India. Soil supports agriculture and it is the source of nutrients for many forms of life.
Why is black soil considered a productive soil?
Answer:- Black soil is considered a productive soil because it has high moisture retention capacity and more clay content which responds well to irrigation. It is suitable for the cultivation of cotton, jowar, wheat, linseed, gram, citrus fruits and vegetables, tobacco and sugarcane.
Give a geographical reason for each of the following:
(i) Different regions in India have different kinds of soil for agriculture.
Answer:- Different regions in India have different kinds of soil for agriculture because India is a vast region with varied natural environment. Several physiographic regions and different types of climate lead to the formation of different types of soil in different regions.
(ii) Alluvial soils vary in texture.
Answer:- Alluvial soils vary in texture as in the upper reaches of the river valleys, the soil is dry, coarse, porous and sandy. Soil particles are large and non-uniform but as we move further down a river valley, the soil particles become smaller and more uniform. They are more compact and more moist.
Nearly all types of crops grow well in riverine soils.
Answer:- Nearly all types of crops grow well in riverine soils because alluvial soil is a mixture of sand, clay and silt. It is rich in mineral and easily tillable. Its composition makes it suitable for the growth of a variety of crops.
Give two characteristic features of the soil found most suitable for growing cotton and sugarcane in Maharashtra.
Answer:- Black soil is suitable for growing cotton and sugarcane in Maharashtra. Its characteristics are-
It is black in colour.
It has high quantities of lime, iron, magnesium and generally poor percentage of phosphorus, nitrogen and organic matter.
Name one soil of volcanic origin commonly found in India. Name one crop widely grown on this soil.
Answer:-One soil of volcanic origin commonly found in India is black soil. Cotton is widely grown on this soil.
Name the process by which Laterite soil is formed.
Answer:-Laterite soil is formed as a result of atmospheric weathering of rocks under the conditions of high rainfall and temperature with alternate wet and dry periods. It is the residual soil formed by leaching due to tropical rains.
Mention one disadvantage of Laterite soil.
AnsweR:- One disadvantage of Laterite soil is that it does not retain moisture and hence, is infertile.
Give a geographical reason for each of the following:
Deltaic alluvium is more fertile than the coastal alluvium.
Answer:-
Deltaic alluvium is more fertile than coastal alluvium as new layers are deposited year after year during monsoonal floods. Also, deltaic alluvium is composed of fine silt and clay whereas coastal alluvium is full of lime nodules.
Black soil is largely found in the Deccan Trap region.
Answer:-Black soil is found in the Deccan trap region because this region is formed due to the deposition of lava produced by the volcanic eruption. When lava rocks breaks down into finer particles due to weathering, it results in the formation of the black soil.
Black soil is often referred to as Cotton soil or Regur soil.
Answer:- Black soil is often referred to as Cotton soil or Regur soil because it is black in colour and is suitable for cotton cultivation.
State the two sub-categories into which alluvial soil is generally divided. Which one of them is superior to the other? Why?
Answer:-Two sub-categories into which alluvial soil is generally divided are khadar and bhangar.
Khadar is superior to bhangar because it is more fertile as new layers are deposited year after year during monsoon floods.
What are the characteristics of alluvial soil?
Answer:- The characteristics of alluvial soil are:
Colour — The colour of alluvial soil varies from light grey to deep black.
Texture — In the upper reaches of the valleys, the soil is dry, coarse, porous and sandy with large and non-unifrom soil particles. In the lower reaches of the river valley, the soil particles become smaller and more uniform and more moist.
Minerals — It varies in nature from sandy loam to clay. It is fertile with minerals like iron, magnesia, alumina, potash and lime but poor in phosphorus, nitrogen and organic matter.
Which soil is suitable for growing coffee in Karnataka?
Answer:-
Laterite soil is suitable for growing coffee in Karnataka.
Mention two main characteristics of this soil.
AnsweR:- Two main characteristics of this soil are-
It is red in colour due to the presence of iron oxide.
It is of a coarse texture, soft and friable.
Give a geographical reason for each of the following:
Laterite soil is useful for construction purpose.
Answer:-Laterite soils are used as a building material because they become hard like iron when exposed to air. So, they are used as a building material. Laterite soils are red in color due to the presence of iron oxide. These soils are generally coarse in texture and friable and porous in nature.
(ii) Soils of the Western Ghats are affected by wind erosion.
Answer:-Soils of the Western Ghats are affected by wind erosion because a large chunk of Western zone is arid or semi-arid and wind erosion is a result of extreme form of soil degradation due to aridity.
(iii) The foothills of the Himalayas are prone to excessive soil erosion.
Answer:- The foothills of the Himalayas are prone to excessive soil erosion because the vegetation over there is very less. There are not many plant or tree roots to hold the soil in place, which makes the foothills of the Himalayas prone to excessive soil erosion.
Name two States in India where Regur soil is found.
Answer:- Regur soil is found in Maharashtra and Madhya Pradesh.
Give two points of difference between Regur and Alluvial soil.
Answer
Regur Soil
Alluvial Soil
It is formed by the weathering of lava rocks. It is formed by deposition of sediments by rivers.
It is of black colour.
Its colour varies from light grey to deep black.
Besides cotton, name the crops which grow well in Regur soil.
Answer:- Besides cotton, jowar, wheat, linseed, gram, citrus fruits and vegetables, tobacco and sugarcane grow well in Regur soil.
In what way does Regur soil help agriculture?
Answer:-Regur soil helps agriculture as it is very fertile. In any season, it has moisture stored in its subsoil. This allows dry farming as well. In dry season, it forms big cracks which help in air circulation, and causes a kind of self ploughing.
Give a geographical reason for each of the following:
Jowar is grown in Maharashtra.
Answer:-Jowar is grown in Maharashtra because of the black regur soil which is rich in lime, potash-magnesium, carbonates, allumina and calcium.
Bajra is grown in Rajasthan.
Answer:-
Bajra is grown in Rajasthan because of the sandy soil found in this region. It is rich in soluble salts.
(iii) Sugarcane is grown in Uttar Pradesh.
Answer:-Sugarcane is grown in Uttar Pradesh because the climatic conditions and presence of alluvial soil support the cultivation of sugarcane.
Name two states where red soil is found. Mention two important crops grown in this soil.
Answer:- Two states where red soil is found are Tamil Nadu and Karnataka. Two important crops grown in this soil are rice and tobacco.
State two advantages of this type of soil.
Answer:- Two advantages of this type of soil are-
It is porous, loose and aerated.
It is ideal for dry farming.
How is red soil formed?
Answer:- Red soil develops on old crystalline rocks. Under prolonged weathering by rainfall, ancient crystalline and metamorphic rocks of the peninsular plateau break up to form this soil
(ii) How is this soil suitable for dry farming?
Answer:- This soil suitable for dry farming as it is formed in areas with poor rainfall.
Give a geographical reason for each of the following:
Black soil is also called lava soil.
Answer:-Black soil is also called lava soil because it is formed by the denudation of volcanic rocks.
Red soil is red in colour and its colour varies from yellow to brown.
Answer:-Red soil is red in colour as it contains large amounts f iron oxide. At several places, its colour changes and it appears brown or grey. It looks yellow when it occurs in a hydrated form
(iii) Jute is cultivated in West Bengal.
Answer:- Jute is cultivated in West Bengal because the alluvial soil found in West Bengal is very fertile and supports jute cultivation.
What is soil erosion? Name the areas of soil erosion in India-
(i) for wind erosion
(ii) for running water erosion
Answer
The removal of the top soil cover by water, wind and human activities is called soil erosion.
(i) Wind erosion affects the dry areas of Rajasthan, Gujarat and Haryana
(ii) Running water erosion affects the badlands of Chambal and Yamuna river, the piedmont zone of western Himalayas, the Chotanagpur plateau, the Tapi-Sabarmati valley and the regur soil area of Maharashtra.
Give two methods used to prevent soil erosion.
Answer:-Two methods used to prevent soil erosion are
Terrace farming
Shelter belts
What is meant by soil conservation?
Answer:- Soil conservation means prevention of soil loss from erosion or prevention of reduced fertility of soil caused by over-use, acidification, salinisation or other types of soil contamination.
(ii) State two measures to conserve soil in hilly areas.
Answer:-Two measures to conserve soil in hilly areas are-
1. Terrace farming- Terraces act as bunds and prevent soil erosion by running water.
2. Contour Ploughing- Ploughing along contours on a slope prevents soil erosion by running water.
Give a geographical reason for each of the following:
(i) Shelter belts reduce soil erosion in arid areas.
Answer:- Shelter belts reduce soil erosion in arid areas because planting trees in several rows checks wind erosion
(ii) Rural development will influence soil conservation.
Answer:- Rural development will influence soil conservation as in the programmes of rural development, villagers are provided with the techniques of how to improve vegetative cover and the steps required to be taken for preventing soil erosion. The farmers are briefed about the farming methods (such as strip cropping and shelter belts) to be followed to reduce soil erosion.
(iii) Water harvesting aids in soil conservation.
Answer:- Water harvesting aids in soil conservation as it reduces soil erosion and flood hazards by collecting rainwater and reducing the flow of water which causes the removal of fertile top soil
How does deforestation lead to soil erosion?
Answer:-Deforestation exposes the soil to water and wind, which leads to soil erosion.
State two methods of controlling erosion of soil caused by running water.
Answer
Two methods of controlling erosion of soil caused by running water are construction of dams and plugging gullies.
Name two important agents of erosion. For each, state one method of controlling the erosion caused.
Answer:-Two important agents of erosion are water and wind. Water erosion can be controlled by the construction of dams. Wind erosion can be controlled by making shelter belts.
Explain briefly the need for conservation of soil as a natural resource.
Answer:-There is an acute need for conservation of soil as a natural resource because of its adverse effects which include the following-
Loss of fertile topsoil with its mineral content
Lowering of the water table
Drying of vegetation and extension of arid lands leading to an increase in the frequency of drought and floods
Silting of river and canal beds
Recurrence of landslides
Adverse effect on economic prosperity and cultural development
Which two types of Soils are the most important Soils?
Answer: Alluvial Soil and Black Soil are the most important Soils.
What is meant by 'in Situ'?
Answer: 'In situ' are the Soils which are found where they are formed.
How is Soil formed?
Answer: Soil is formed by the Parent rock material through a process of break up or wear and tear. The decomposition of plant remains, animal manures and dead animals add to the fertility of the soil.
How we define Soil from agricultural point of view?
Answer: 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. It supports all forests, grasslands and crops from which all living creatures on earth derive their food.
What are the different types of Soil according to their Zones?
Answer: Zonal Soils:
Alluvial Soils are also called ‘Riverine Soils’. Why?
Answer: The chief region of Alluvial Soils in India is the Indo-Gangetic plain, where Alluvial Soils have been deposited mostly by rivers. The coastal belts are the areas of alluvium. The deltaic alluvium on the eastern coast has also been deposited by river-channels. Therefore, Alluvial Soils are rightly called Riverine Soils.
How is the Alluvial Soil found in the Ganga plain different from that found in the Godavari valley?
Answer: The Alluvial Soil of the Ganga plain is formed due to the deposition of alluvium which is brought from the Himalayan region. These are light in colour. The Alluvial Soil of the Godavari valley is formed due to the deposition of alluvium brought mainly from the Deccan trap region which is volcanic in origin. It is dark in colour.
How is Alluvial soil formed? Why is this soil agriculturally important?
Answer: Alluvial soils are formed by the sediments brought by the rivers. The rivers deposit very fine silt called ‘alluvium’ in their plains during the course of their journey starting from its source in the mountains and ending till its mouth.
This soil is agriculturally very important because it is a mixture of sand, clay and silt (loamy) which makes it very fertile. It is rich in potash and lime. It is light and porous therefore easily tillable. It is suitable for growing large variety of Rabi and Kharif crops.
(i) How is Black Soil formed?
Answer: Black Soil is formed as a result of denudation of lava-flow rocks. They contain large quantities of lime, potash, aluminium, magnesium. They are deficient in phosphorus, nitrogen and organic matter. Black Soil is highly retentive of moisture, and become sticky when wet.
What are the other names of Black Soil? Where are they found?
Answer: Black Soil is also known as ‘Regur Soil’ or ‘Black Cotton Soil’. Black Soil is found in Gujrat, Maharashtra, parts of Madhya Pradesh, South Uttar Pradesh, North-west Orissa and the western parts of Andhra Pradesh.
(i) Explain the origin of the Black Soil. Name two States in India, which have Black Soil.
(ii) Mention any two advantages of the Black Soil.
Answer: (i) Black Soil is formed by weathering of volcanic rocks. It is found in Maharashtra and M.P. (ii) It retains moisture for a long time, is rich in lime, potash and calcium.
Where is Red Soil found?
Answer: Red Soil is found in Tamil Nadu, Karnataka, South-eastern Maharashtra, parts of Andhra Pradesh and Orissa. They are also found in the southern districts of Uttar Pradesh, Madhya Pradesh and eastern Rajasthan.
What are mineral deficiencies of Red Soil? How can they be corrected?
Answer: The Red Soils are generally poor in nitrogen, phosphoric acid and humus. They become reasonably fertile when fertilizers are added to it.
How is Red Soil formed? State two reasons for the low productivity of Red Soil or . disadvantages.
Answer: Red Soil is formed by weathering of crystalline and metamorphic rocks.
Reasons for low productivity:
(i) Deficient in nitrogen, humus. (ii) Porous, friable.
How is Laterite Soil formed?
Answer: It is formed by the weathering of Soil or due to intense leaching during the periods of heavy rainfall. All the soluble materials are removed and a hard stony layer remains.
Where is Laterite Soil found?
Answer: It is found m Andhra Pradesh, Tamil Nadu, Karnataka, Assam, Bengal, Orissa and along the Western and Eastern Ghats.
State two disadvantages of Laterite Soil.
Answer: Disadvantages of Laterite Soils are:
(i) They contain high percentage of acidity.
(ii) It is generally coarse in texture and cannot retain moisture.
(i) Why is Laterite Soil unsuitable for cultivation? Name an area where this Soil is found.
(ii) Name the type of Soil found on the summit of the Eastern Ghats. Explain the causes of its formation.
Answer: (i) Laterites are intensively leached Soils of the monsoon climate. They lack in elements of fertility and thus are normally of low value for crop production. Laterite Soil is found in India in hill summits ot Eastern and Western Ghats and Assam Hills.
(ii) Laterite Soils are found on the summits of the Eastern Ghats. These are formed in the areas
which experience high temperature and heavy rainfall. They are formed by the process of leaching.
Mention the types of Soil erosion by water.
Answer: Soil erosioivby water can be of the following sub-types:
(i) Sheet erosion (ii) Rill erosion (iii) Gully erosion
(iv) Stream Bank erosion. (v) Sea-shore erosion. (vi) Slip erosion.
State the factors upon which the rate of Soil erosion depends.
Answer: The rate of Soil erosion depends upon:
(i) Character of the slope of land. (ii) The density of vegetation.
(iii) Rainfall—Heavy or Light.
Define ‘Leaching’? In which region South of the Tropic of Cancer, can one find Soil formed by ‘Leaching’?
Answer: Leaching Soil is the process by which soluble substances such as organic basic minerals and mineral salts are washed out of the upper layer of a Soil into a lower layer by percolating rain water, e.g., Laterite Soil.
Found in Karnataka which is south of Tropic of Cancer.
What is sheet erosion?
Answer: When the vegetation cover of an area is removed, the rain water instead of sinking into the ground, washes the Soil down the slope. Each succeeding rain-stream washes away a thin layer of absorbent top Soii. This is known as Sheet Erosion.
What is rill erosion?
Answer: In rill erosion small finger-like rills begin to appear on the landscape. These rills are usually smoothened out by working of the farm implements. But, slowly the rills increase not only in number but also in their shape and size. They get wider and deeper. This reduces the actual area under crop and results in declining crop yields.
What is stream bank erosion?
Answer: The banks of the streams or rivers get eroded every year by the flowing water. In certain areas, the streams and rivers often change their course bit by bit every year and their beds get widened.
(i) How does sea or shore erosion occur?
(ii) How is slip erosion caused?
(i) The tidal waters of sea cause considerable Soil erosion along the coast, particularly during the rainy season when the sea gets rough. The roaring waves rush and dash on the coast, swallowing every time bits of coastal lands.
(ii) Slip erosion is caused by hydraulic pressure exerted by moisture penetrating into the Soil
during heavy, raips. Sometimes the entire field on hill side may slide down because of slip erosion.
How does wind erose Soil?
Answer: When wind blows over barren land, there will be damage to the top Soil. In the areas of scanty rainfall wind erosion is predominant. When deaf-forestation due to over-grazing of cultivation makes the top Soil bare, wind erosion occurs.
Mention some measures to check Soil erosion.
Answer: Some measures to check Soil erosion are: Contour method of ploughing, terraced farming, plugging of gullies and ravine method, constructing dams across the streams, check on unrestricted grazing over the pastures, afforestation and legal binding on primitive method of Jhooming cultivation should be exercised.
Explain the need for Soil conservation in India. State two methods of Soil conservation.
Answer: A rich soil in plant food is the chief requirement of a successful agriculture. It is an essential as a support for plants.
Soil is a very important natural resource of India because agricultural production is basically dependent on the fertility of Soil. Food products like cereals, pulses, fruits and vegetables are obtained indirectly from the Soil.
Two methods:
(i) Contour ploughing. (ii) Afforestation.
How does the nature of the Soil affect Soil erosion?
Answer: Sandy and porous Soils are subjected to least erosion by water action because they absorb a good amount of water at the time of rainfall. Impervious Soils are subjected to gradual erosion by water because they are incapable of absorbing rainwater.
State any two methods of controlling soil erosion.
Answer: (i) Terrace farming.
(ii) Planting shelter belts to check the speed of wind.
What is soil conservation? How does reafforestation help in soil conservation?
Answer: Soil conservation refers to the methods of protecting the soil from erosion. Roots of the trees protect the soil by holding it in place against wind and water erosion. Re-afforestation means replanting trees which have been cut down. For every tree that is cut, two trees are grown. In this way forest cover is increased.
Mention two ways by which soil can get nitrogen.
Answer: (i) Use of fertilizer.
(ii) Crop rotation: Rotation ofxrpps is a system in which farmers grow pulses or leguminous crops after the harvest of a soil exhausting crop. Through this method the soil retains its fertility or gets back the nitrogen.
Name the factors responsible for the formation of Soil.
Answer:
Climate: The climate in which Soil develops is the most important factor. It is responsible for the following:
(a) Weathering: Extremes of temperature, freezing and thawing of ice break down rocks and favour Soil formation.
(b) Vegetation: The growth and decay of vegetation determines the humus content of the Soil. Roots of plants penetrate the Soil and make it porous.
(c) Bio-chemical processes taking place in Soil: Bacteria and fungi cause the decay of plants and animal remains. Some transform the atmospheric nitrogen into Soil nitrogen.
The Parent rock: The physical and chemical composition of the parent rock determines the relative proportion of different minerals in the Soil layers.
The Topography: The slope of the land surface is an important factor in the formation of Soil layer.
(a) Hills and slopes: Steep slopes usually have a thin Soil layer because weathered particles are easily carried downslope by running water and wind.
(b) Plains and Valleys: On flat plains and in valleys, thick fertile Soils are developed.
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