10E6 - SOILS (Notes for class 9 and 10)ICSE

SOILS

1. a. Give a single word for the following: (2)
i) The organic matter present in the soil formed by the decomposition of plants and animals - Humus
ii) The soil which are carried down by agents of gradation such as river, wind – Transported soil.
iii) The loose rock material, together with humus, forming the uppermost layer of the earth’s crust and serving as a source of food and moisture for plants”.
soil
iv) The process of percolation by which valuable mineral nutrients are washed down from the top layer of the soil only to deposit them in the lower layers, making thereby the topsoil infertile.
Soil erosion

How does the soil of the Ganga Yamuna plain differ from that of central Maharashtra? (2)
* Soil found in Ganga-Yamuna plain is alluvial soil, whereas soil found near central Maharashtra is black soil.
* The soil of Ganga-Yamuna plain has been formed from the sediments deposited by rivers which are rich in potash but poor in nitrogen whereas soils of central Maharashtra have been formed due to the weathering of the lava which contains potassium, iron, magnesium and humus.
* The soil of Yamuna-Ganga plain is suitable for the cultivation of a wide varieties of crops, i.e. rice, wheat, sugarcane, oil seeds, etc whereas the soil of the central Maharashtra region is most suitable for cotton crop.

c. Give reasons: (3)
Alluvial soil can hold moisture and is very fertile: Since the soil is made up of fine particles, it can hold a lot of water.
Black soil needs to be tilled after the first rain: When wet, the soil becomes sticky and is difficult to work with. So the soil needs to be tilted after the first rains.
Red soil is ideal for dry farming: It is suited for dry farming as it does not require much moisture.

d. i) Name any two regions where coastal alluvium is found.
ii.) Why is deltic alluvium more fertile than coastal alluvium?(3)
Ans.c. i) The coastal alluvium occurs in the coastal strips of peninsular India and the plains of Gujarat.
ii. Deltic alluvium (Khaddar) is more fertile than coastal alluvium (Bhangar) as new layers are
deposited year after year during monsoonal floods.

e. State any three factors which affect the soil formation. (3)
Ans: i) WEATHERING: Extremes of temperature (as in the day and night temperatures in deserts), freezing and thawing of ice break down rocks, and favour soil formation.
ii) VEGETATION: The growth and decay of vegetation determines the humus content of the soil. Roots of plants penetrate the soil and make it porous.
iii. Bio-chemical processes taking place in the soil: Bacteria and fungi cause the decay of plants and animal remains. Some transform the atmospheric nitrogen into soil nitrogen.
iv. CLIMATE : Climate is the most important single factor in the soil formation. the amount of rainfall and range of temperature are the most important climatic factors affecting soil formation.
v. RELIEF: Low relief areas generally experience deposition and have deep layer of soil whereas the soils are generally shallow in the plateau areas.
vi) PARENT MATERIAL: Parent rock determines the composition of soil.



f. What is soil? How soil is important to man?
Soil is the thin top cover of earth’s crust composed of mineral particles, humus, water and air in which plant grows.
Most of our food items like cereals, pulses, fruits, vegetables, meat, eggs, milk, clothing, etc., are obtained directly or indirectly from the soil. A large number of human and economic activities depend on the soil. Fertile soil attracts a large number of people and human settlements.

g. State the two most important factors that determine the types of soils found in India.
Parent material, relief, climate and natural vegetation are some of the major factors determining the types of soils found in India.

h. What do you understand by humus?
It is the organic matter which is formed by the decomposition of plant remains, dead animals and manure. Humus content determines the fertility of the soil.

i. Give reason:
i) Alluvial soil can hold moisture and is very fertile:- Alluvial soil can hold moisture and is very fertile because the alluvial soil is made up of fine particles. The soil is very fertile because it is rich in mineral nutrients like potash and lime.
ii) Black soils needs to be tilled after the first rain: The soil is sticky and difficult to work unless tilled immediately after the first rain.
iii) Red soil is ideal for dry farming: Red soil is ideal for dry farming because it does not require much moisture.
iv) The percentage of organic matter in desert soil is very low:- The percentage of organic matter in desert soil is very low because of the dry climate and absence of vegetation.
v) Red soil is less fertile:- Red soil is less fertile because it is deficient in phosphorous, nitrogen, lime and humus.

j. Distinguish between ‘Khaddar’ and ‘Bhangar’. (3)
Bhangar (old)
Khaddar (new)
It is non-porous, clayey soil
It is porous and loamy soil.
It is found higher up in the plains at river terraces away from rivers
It is found in the lower level in the plains near the rivers.
It is less fertile as compared to khaddar
It is more fertile compared to bhangar. This is due to deposition of new layers by floods during monsoon
It belongs to old alluvium.
It belongs to new alluvium.

2. a. Read the feature of the soil carefully and identify the soil: (2)
i) It develops insitu as a result of leaching - Laterite soil
ii) It develops on crystalline igneous rocks. - Red soil
iii) It develops insitu from volcanic rocks. - Black soil
iv) It is a transported soil and is formed by river sediments. – Alluvial soil

Mention any four human factors responsible for soil erosion. (2)
Deforestation, faulty methods of agriculture, urbanisation and industrialisation.

Name any two crops association with following soils: (3)
i. Alluvial soil - Rice and sugarcane, wheat
ii. Red soil - Rice and wheat
iii. Black soil - Cotton and sugarcane
iv. Desert - Barley and ragi
v. Laterite - coffee and tea

d. With reference to the type of soil only, state why:
i, Jowar is grown in Maharashtra. – Jowar is grown in Maharshtra because of its black soil.
ii. Bajra is grown in Rajasthan – Bajra is grown in Rajasthan because of desert soil.
iii) Sugarcane is grown in Uttar Pradesh – Sugarcane is grown in Uttar Pradesh because of well drained alluvial soil.

e. Name four broad types of soils found in India. (2)
Red, black, alluvial and laterite soil.

f. Mention any three characteristics of the northern plains. (3)
* These are constituted by two large river basins i.e. the Indus river basin and the Ganga-Brahmaputra
basin.
* These are very fertile plains.
* These plains support some of the highest population densities.

g. What is the importance of Northern plains for the Indian economy?
* The plain supports some of the highest population densities depending upon purely agro-based economy in some of these areas. The extensive use of irrigation has made some parts of this plain, especially Punjab, Haryana and western part of Uttar Pradesh the granary of India.
* The entire plan except the Thar Desert has a close network of roads and railways which has led to large scale industrialization and urbanization.

h. Distinguish between Alluvial soil and Black soil keeping in mind texture, minerals and crops associated. (3)
ALLUVIAL SOIL
BLACK SOIL
1. TEXTURE: Coarse, in upper regions, medium in the middle and fine in the lower regions.
Fine grained, moisture retentive.
2. MINERALS: Rich in potash.
Rich in lime, iron and potash.
3. CROPS: Rice, wheat, and sugarcane.
Cotton, sugarcane and tobacco.
4. FORMATION: It is formed due to deposition of sediments by the river.
It is formed due to the weathering of the lava.
5. AREA: It covers more than 45% of the total land area of the country.
It covers only 16% of the total land area of India.
6. FERTILITY: The soil is very fertile.
The soil is less fertile as compared to alluvial soil..



i. Explain the formation of soil. Name three various forces of nature which contribute to the evolution of soil. (3)
Soils are derived from parent rock material through the process of break up or wear and tear.
Various forces of nature i) changing temperature, ii) running water, iii) wind contribute to the evolution of soil.

j. State two main differences between alluvial soil and red soil.
Alluvial soil
Red soil
Most of the alluvial soil is derived from the sediments deposited by the rivers.
Most of the red soil has been formed due to weathering of ancient crystalline and metamorphic rocks.
Alluvial soil is highly moisture retentive.
Red soil is not moisture retentive.
Alluvial soil is very fertile as it is rich in mineral nutrients like potash and lime.
It is less fertile as it is deficient in phosphorous, nitrogen, lime and humus.

k. Mention two ways by which soil can get nitrogen. (2)
Soil can get nitrogen by :
* By growing pulses as there are certain bacteria in the roots of pulses which have the ability to fix atmospheric nitrogen to form nitrogen compounds.
* By applying NPK fertilizer or by adding manure, by crop rotation.

l. Which minerals are found in regur soil?
Iron, lime, potash, calcium carbonate and magnesium carbonate are found in regur soil.

m. Distinguish between Transported and ‘in-situ’ soils:
Transported soils
In-situ soils
These soils are carried down by the natural agents like water and winds.
These soils are found where they are formed.
Example: Alluvial soil
Example: Black soil

n. Distinguish between soils of Northern Plains and Soils of the Deccan Plateau.
SOILS OF NORTHERN PLAINS
SOILS OF THE DECCAN PLATEAU
Soils of the Northern plains are alluvial soils.
Soils of the Deccan Plateau are Black soil or red soil.
They are very fertile, suitable for the cultivation of rice, wheat, sugar-cane, cotton, jute, oil seeds, etc
They are also fertile, suitable for the cultivation of cotton, sugarcane, rice, tobacco, etc

o.Distinguish between Inland alluvium and Coastal alluvium:
Inland Alluvium
Coastal Alluvium
Inland alluvial soils are found in the Indus river plains and the Ganga-Brahmaputra river plains.
Coastal alluvial soils are found on the coastal regions of peninsular India.
They are found in Punjab, Haryana, U.P. , Bihar, West Bengal.
They are found in the Gujarat plains.




p. Distinguish between Regur soils and Laterite Soils.

REGUR SOILS
LATERITE SOILS
Regur soils are black in colour.
Latertite soils are red in colour.
They are formed due to weathering of lava-flow rocks.
They are formed due to weathering lf laterite rocks.
They are of fine texture.
They are of coarse texture.
They are clayey in nature.
They are soft and friable.
They are rich in lime and magnesium.
They are deficient in lime and magnesium.
Retention of moisture is high.
They do not retain moisture.
Regur soils are very fertile.
Laterite soils are not fertile.
They are suitable for cultivation of cotton, sugarcane, wheat, jowar, gram and linseed.
They are suitable only for special crops like coffee, cashewnuts, tapioca , etc

q. Distinguish between red and laterite soil. (2)
Red soil
Laterite soil
Most of the red soil has been formed due to weathering of igneous and metamorphic rocks.

ii. Rice, wheat, sugarcane and cotton can be cultivated.
Most of the laterite soil has been formed due to leaching.

Coffee, rubber and cashew are some of the crops cultivated on this soil.

3.a. Write two differences between intensive and extensive farming. (2)
INTENSIVE AGRICULTURE
EXTENSIVE FARMING
1. Production is increased by using higher inputs and new techniques.
1. Production is increased by bringing more and more area under cultivation.
2. This is done in thickly populated areas where no more land is available.
2. This is done in thinly populated areas.

b. Give a single word for each of the following:
* The loose rock material , together with humus, forming the uppermost layer of the earth’s crust and serving as a source of food and moisture for plants. – Answer: Soil or Top soil
* The process of percolation by which valuable mineral nutrients are washed down from the top layer of the soil only to deposit them in the lower layers, thereby making the top soil infertile. – Ans: leaching.









c. Name the type of soil which is :
i) Useful for the cultivation of jute. - Alluvial soil
ii) Formed by decomposition of metamorphic rocks. – Red soil
iii) Covers 40% of the land area of India. - Alluvial Soil
iv) Develops on old crystalline rocks under moderate to heavy rainfall. - Red Soil
v) Alkaline in nature and contains a high proportionof salts. - Desert Soil.
vi) Agriculturally most significant - Alluvial Soil
vii) formed due to volcanic activity - Black/Regur soil
viii) Rich in iron but poor in silica – Laterite soil
ix) rich in humus - Alluvial soil of the Ganga Delta
x) Rich in potash but poor in phosphorus – Alluvial Soil
xi) Rich in lime and potash but deficient in phosphorous and nitrogen – Laterite Soil

d. What is dry farming?
Dry farming is the method of farming adopted in certain region having inadequate rainfall and devoid of irrigation facilities by conserving moisture in the soil and by raising drought-enduring crops.

e. Explain the following terms:
i) In situ : - The soils which are found where they are formed. They are also called residual soil. e.g. Black Soil.
b. Transported Soil: These are soils which are carried down by agents of gradation such as river, wind. e.g. Alluvial Soil
c. Badland: it is a region with a large number of deep gullies which cannot be put to any use till soil restoration takes place.
d. Soil profile: A soil profile is a section showing the successive layers of the soil which would appear if you cut straight down into the soil.
e. Humus: It is the organic matter present in the soil formed by the decomposition of plants and animals. Humus content determines the fertility of the soil.
f. Parent Rock: The weathered and partially broken rock from which a soil is formed is termed as parent rock.
g. Soil Texture: The proportion of the various particle sizes in a soil.
h) Deccan Trap: The word ‘trap’ is Swedish which means steps. The term describes the step-like rock formation that covers the north-western part of the Deccan Plateau.

f. Place two broad categories the soils of India on the basis of their formation.
i) RESIDUAL SOILS: These are found where they are formed, hence called ‘in situ’. Black soil, Red Soil, and Laterite soil are the examples of residual soils.
ii) TRANSPORTED SOILS: These are carried down by agents of gradation such as rivers, and wind. Alluvial soil and Loess are the examples of transported soils. The most important transported soil in India is alluvial soil. The states are West Bengal and Bihar.

g. Name the soils found abundantly in the following regions:
i) Hills of Assam and Meghalaya – Mountain Soil
ii) Coastra strip of Deccan Plateau – Coastal alluvium\
iii) South-Western parts of Punjab – Desert Soil
iv) Chhotanagpur Plateau – Laterite Soil
v) Delta of Krishna - Deltaic alluvium
vi) Sunderbans of West Bengal – Deltaic alluvium



EROSION AND CONSERVATION OF SOIL
4a) Explain the following terms: i) Soil Erosion ii) Conservation of Soil iii) Deforestation
iv) Contour Ploughing v) Strip Cropping vi) Crop Rotation
i) SOIL EROSION: It is the removal of topsoil by different agents of weathering such as running water, wind, over grazing and faulty methods of agriculture used by farmers.
ii) CONSERVATION OF SOIL: Conservation of soil is an effort made by humans to prevent soil erosion in order to retain fertility of soil.
iii) DEFORESTAION: The removal of trees of an area of land by felling or burning is called deforestation. The process of deforestation is deliberate in order to make the land available for other uses.
iv) CONTOUR PLOUGHING: It is the cultivation of soil according to contour lines, i.e. at the right angles to the hill slopes.
v) STRIP CROPPING: It is the cultivation of crops in strips to check the fast-blowing winds.
vi) CROP ROTATION: It is the cultivation of crops in a year in such a sequence that the fertility of the soil is not reduced.

b.. Explain the need for soil conservation in India. State two methods of soil conservation. (3)
i) Soil is the most precious asset of India. More than 60% of the population is dependent on agriculture.
ii) Protective soil alone ensures progress of agriculture, forests and industrial development.
METHODS: i) Afforestation ii) Proper farming technique iii) shelter belts iv) terraced cultivation

c. Name two important agents of erosion. For each, state one method of controlling the erosion caused. (3)
Two important agents of erosion are : i) Running water
ii) Faulty agricultural activities.
iii) wind
RUNNING WATER: Construction of dam, river embankment , terrace farming and afforestation can
control the soil erosion caused by running water.
FAULTY AGRICULTURAL ACTIVITIES: Scientific methods of cultivation like contour ploughing,
terrace farming and conservation of moisture is the important conservative measure
WIND: One method of controlling erosion caused by wind is planting of shelter belts alongside of desert.

d. ‘Proper farming techniques can help in soil conservation.’ Explain by giving three examples. (3)
* Terracing of hill slopes is effective in controlling soil erosion. Terracing is cutting into the hill slopes in a series of large steps made up of flat fields.
* Constructing bunds across hill slopes and filed boundaries is effective in reducing soil erosion. Bunds are low mud walls or embankments that help to obstruct the flow of water.
* Contour ploughing should be practised. It involves ploughing along the outline of the field in a circular manner. This prevents the soil from being washed away by running water.

e. Differentiate between sheet erosion and gully erosion. (2) (2005)
1. When top soil gets eroded from very large areas due to fast flowing rivers it is called sheet erosion.
Gully erosion occurs when running water etches out deep rivers creating a badland topography in an otherwise normal landscape.
2. The unprotected lands are most susceptible to sheet erosion. Sheet erosion is particularly harmful because it removes the top layer which is finer and fertile.
The main cause of gully erosion is the removal of vegetation, particularly of trees with their widespread binding roots. Gully erosion is also responsible for the formation of ravines.






f. Difference between Sheet erosion and wind erosion and sheet erosion and gully erosion.
SHEET EROSION
WIND EROSION
It is caused by running water or heavy rain .
It is caused by wind..
It is found in hilly regions.
It is found in desert and dry regions.
Due to high speed of water, a layer of the soil on the surface is removed over a large area.
Under this top fertile soil is blown away by high speed wind.

SHEET EROSION
GULLY EROSION
It is the first stage of water erosion.
It is the third stage of water erosion.
It is caused by running water or heavy rain in hill regions which lead to the removal of a large area by running rainwater through steep slopes.
Gully erosion is caused due to running down of water in distinct path which results in the removal of soil in the path.
Sheet erosion is also harmful since it removes fertile top soil of the land.
Gully erosion is harmful since it cut up agricultural land.

g. Man is largely responsible for soil erosion. How?
Soil erosion is the removal of soil by the forces of nature, particularly wind and water. Soil erosion mainly takes place due to man’s activities such as deforestation, overgrazing of cattle, faulty methods of cultivation.

h. What is conservation of soil? Why is it necessary? (3)
It is an effort made by man to prevent soil erosion, or at least to reduce the rate of soil erosion, to retain the fertility of the soil.
It is necessary because soil is our most important natural resource. It alone assures prosperous agriculture.

i. Explain the following terms:
i) Soil Erosion. ii) Conservation of Soil iii. Soil Texture iv. Contour Ploughing v. slip erosion vi. Strip cropping
SOIL EROSION: It is removal of topsoil by different agents of weathering such as running water, wind, over
grazing and faulty methods of agriculture used by farmers.
CONSERVATION OF SOIL: Conservation of soil is an effort made by humans to prevent soil erosion in order
to retain fertility of soil.
SOIL TEXTURE: soil texture refers to the size of particles in soil. The texture of soil ay be gravel, sand, silt or clay.
CONTOUR PLOUGHING: It is a farming technique which is used in hilly areas to prevent soil erosion. It involves ploughing along the outline of the fields in the circular manner.
SLIP EROSION: During heavy rains, water filters into the soil until it is unable to penetrate further by the underlying impervious rocks.
STRIP CROPPING:It is a farming technique in which different kinds of crops are grown in alternate rows instead of leaving strips of land uncultivated.

j. What are the different types of soil erosion?
The types of soil erosion by different agencies are as follows:
Soil erosion by running water:
i) GULLY EROSION: This type of erosion is occurred due to heavy rainfall in hilly regions and as a result deep gullies are formed on bare soils when water gushes down.
ii) SHEET EROSION: This type of erosion takes place due to slow removal of a thin layer of soil by running water on account of destruction of the vegetation.
iii) LEACHING: It occurs during the rainfall when the nutrients in the soil are washed away.
iv) RILL EROSION: In this type of erosion finger like rills appear on the surface of the land which are formed due to cutting of soil by flowing down of water.
v) STREAM BANK EROSION: It takes place on the banks of rivers and stream by the flowing water.
vi) SHORE EROSION: It occurs due to tidal water along the coast during the rainy season.



k. How does the soil of the Ganga-Yamuna plain differ from that of central Maharashtra?
Soil found in Ganga-Yamuna plain is alluvial soil, whereas soil found near central Maharashtra is black soil. Alluvial soil is transported soil. Black soil is formed in situ.

l. Define : Gully erosion ii) Sheet Erosion
GULLY EROSION: Gully erosion takes place when running water cuts deep ravines in the absence of vegetation. This type of erosion makes soil unfit for cultivation.
SHEET EROSION: When top soil gets eroded from very large areas due to fast flowing rivers or due to heavy monsoons, it is called sheet erosion..

Soil erosion by wind: Soil erosion by wind mainly occur in dry areas such as western Rajasthan and Southern Punjab where strong wind blows away the loose sand in the form of dust and as a result top soil is removed.

Soil erosion by Human activities:
Deforestation or indiscriminate cutting of the trees is one of the main reason of soil erosion.
overgrazing of pastures by animals.
improper method of cultivation.

m. What are the causes of soil erosion in:
i) Shiwaliks or the Outer Himalayas: Destruction of vegetation is the main cause of soil erosion in hilly areas because when vegetation is removed, the soil surface becomes loose and is more easily removed by running water.Due to this , a large amount of debris domes down the slopes of Shiwaliks and chokes up the rivers and causes floods. Hence, land slides and land slips are very frequent.
ii) North-Eastern parts of India: Heavy rainfall which leads to frequent floods is responsible for soil erosion in Assam, West Bengal and hilly regions of North-east.
iii) Arid regions of India: In deserts and dry regions like Rajasthan, Southern Punjab and south-western areas of Haryana, where there is little or no vegetation, wind is the most powerful agent of soil erosion, blowing away fine particles of sand depositing them in other areas making both areas unproductive.
iv) Hilly areas of the South: In this region, steep slopes, heavy rainfall and unscientific methods of cultivation are responsible for the soil erosion.

n. Name a part of India where:
a. Wind is the main agent of erosion - Rajasthan
b. Water is the main agent of erosion - Meghalaya

o. How is the migration of sand dunes from Thar desert checked?
By building shelter belts, the migration of sand dunes from Thar desert checked.

p. Name any four states which have been affected by gully erosion.
U.P. , M.P. , Bihar and Rajasthan.

q. What are the main causes of soil erosion?
Main causes of soil erosion are:
* Steep slopes * Deforestation * Torrential rainfall * Strong winds * Over grazing
* Unscientific methods of cultivation






r. What are the different methods of soil conservation?
AFFORESTATION: Afforestation or planting of trees in deforested areas saves the soil from erosion caused both by water and wind.
CONSTRUCTION OF CHECK DAMS: is an important method of checking soil erosion in the upper course of the rivers.
OVERGRAZING should be checked. Grazing should be limited according to the size of the pasture.
GULLIES should be plugged by stone dams, wire netting or by raising trees across gullies to check the flood water.
SHELTER BELTS of trees and shrubs should be planted to check wind velocity in arid regions.
PROPER FARMING TECHINIQUES, i.e. strip cropping, contour ploughing and terracing of hills should be adopted for soil conservation.

s. Discuss important soil conservation measures undertaken by the Govt of India.
* A scheme for reclamation and development of ravine areas was launched in 1987-88 in Madhya
Pradesh, Uttar Pradesh and Rajasthan.
The scheme for control of shifting cultivation is being implemented since 1994-95.
In urban area, rain water harvesting is a means of checking soil erosion besides recharging ground water.
The centrally sponsored scheme of Integrated Watershed Management in the catchments of flood-prove rivers was launched during Sixth Plan in eight flood-prove rivers of the Gangetic Basin covering seven States and one Union Territory.

t. Name two methods of soil conservation adopted in the mountainous areas.
i) Terrace cultivation ii) Contour ploughing

u. State how destruction of vegetation cover increases the soil erosion.
Vegetation cover protects the soil from erosion as the roots of the trees and plants hold the soil particles together and strengthen the soil. Therefore, the destruction of vegetation cover increases the soil erosion.

RED SOIL
5.a. How is Red Soil formed? Mention two important properties of Red Soil. (2)
Red soil is formed due to weathering of ancient crystalline and metamorphic rocks of the Peninsular
plateau. The properties of red soil are:
* Red soils are rich in iron contents , hence, they are red in colour.
* It is loamy in deep depressions and in uplands , it consists of loose gravel – a highly coarse material.
* It is deficient in lime, nitrogen, phosphorous and humus but fairly rich in potash.
* The productivity of the red soils increases with regular use of fertilizers.
* They are porous in nature but not retentive to moisture.
* They are suited for dry farming as it does not require much moisture.

b. Why are red soils not suitable for agriculture? or State two reasons for the low productivity of red soil.
Red soils are not suitable for agriculture because these are not retentive of moisture and are deficient in nitrogen, lime, phosphoric acid and humus. It is light in texture.

c. With reference to red soils in India,
i) Name two states where it found. ii. State two disadvantages of this soil.
It is found in Tamil Nadu/Karnataka, Orissa, Andhra Pradesh, Goa.
i. It is poor in humus, nitrogen, lime, phosphorus
ii. It is coarse, porous, crumbly and does not retain moisture . It needs irrigation support for
cultivation as it is loose and aerated.


d. Red soil is red in colour. Give reason.
Red soil is red in colour due to the presence of iron oxides.

e. Give three reasons for the low fertility of Red soils.
# Red soils are less fertile as they lack nitrogenous, phosphorous and organic matter.
# On uplands, they abound in loose gravels and are less fertile.
# Their coarse grains lack sustenances of fertility.

f. Where are Red soils found in India?
Red soils are found in the states of Kerala, Tamilnadu, Karnataka, Goa, eastern part of Andhra Pradesh, Orissa, and on the Chhota Nagpur Plateau of Jharkand.

g. Mention some properties of Red soils.
* Red soils are formed in situ by weathering of the ancient crystalline and metamorphic rocks.
* Red soils are rich in iron contents, hence, they are red in colour.
* The productivity of the red soils increases with regular use of fertilizers.
* These soils are deficient in nitrogen, lime, phosphoric acid and humus.
* They are rich in potash, porous, friable but not retentive of moisture.
* They are suited for dry farming as it does not require much moisture.

i. Name the state in India which mostly has red soil.
Tamilnadu and Karnataka

j. State two disadvantages of red soil.
* The soil lacks in nitrogen, organic and phosphoric acid contents and is less fertile.
* Red soils are porous in nature but not retentive to moisture.

k. Give three reasons for the low fertility of the Red soil.
* Red soils are less fertile as they lack nitrogenous, phosphorous and organic matter.
* On uplands, they abound in loose gravels and are less fertile.
* Their coarse grains lack sustenance of fertility.

BLACK SOIL

6.a. Mention two characteristics of black soil. Why is this soil agriculturally important?
# The black soils are made of extremely fine material.
# These soils are rich in nutrient.
# It develops cracks when dry which helps in aereation.
# It has a self-ploughing quality.
It is agriculturally important because it is rich in lime,iron and potash. Because of high clay content, these soils expand when wet and become difficult to plough. During the dry season, the black soils shrink and develop big cracks which help in air circulation. The moisture-retentiveness makes them suitable for dry farming.

Black soil is also called regur soil or cotton soil. Cotton is the most important crop grown in these soil. After alluvial soils it occupy largest areas in the country. It covers 16% area of the country.

b. Name an area of black soil in India. Mention two crops grown in this soil.(2)
Deccan Plateau is an area of black soil in India. Two crops grown in this soil are cotton and sugarcane.


c. Black soils are called ‘Black Cotton Soils’. Why?
Black soils are called ‘Black Cotton Soils’ because these soils are most suitable for the cultivation of cotton.

d. How black soils or Black cotton soils or Regur soils are formed? Which minerals are found in regur soil? Name the most important crop grown on it.
Black soils are formed in situ, that is , formed where they are found. These soils are formed from solidification of basic lava spread over large areas of Deccan Plateau during volcanic activity. Hence, these are formed by weathering of Deccan Trap.
Lime, iron, potash, alluminium, calcium and magnesium carbonate. It is deficient in phosphorous, nitrogen and organic matter.
The most important crop grown on it is cotton.

e. Name the soil known for its self-ploughing quality and capacity to hold moisture. Name one cash crop for which it is most suited?
Black soil. The cash crop that grows best is Cotton/sugarcane.

f. How is Regur soil formed? Mention four important properties of Regur Soil. Name two states where Regur soils are found. Name two cash crops grown best on these soils.
These soils have been formed due to the solidification of lava spread over large areas during volcanic activity in the Deccan Plateau.
Features:
* Black soils are well known for its capacity to hold moisture
* It is a deep fine grained soil
* They vary in colour from deep balck to chestnut brown.
* They are rich in lime, calcium, iron, magnesium and potash and deficient in phosphorous, nitrogen
and organic matter.
* They are made of extremely fine material i.e., clayey material.
* These soils are best-suited for cotton and sugarcane cultivation.
* Black soils are widely spread over the Deccan Plateau, comprising large areas of Maharashtra,
Gujarat, and Madhya Pradesh.
* They are also know as Regur soils in Maharashtra and Black Cotton soils in Peninsular India.

States – Maharshtra and Gujarat
Cash crops – cotton and sugarcane.

g. Large tracts in Mahatrashtra are covered with Black soil. Give reason.
Large tracts in Maharashtra are covered with Black soil because it is made up of lava tracts which after weathering is reduced to black soil.

h. Give two characteristic features of the soil found most suitable for growing cotton and sugarcane in Maharashtra.
The most suitable soil for growing cotton and sugarcane in Maharasthtra is black soil. Its characteristics are:
* It is rich in iron, potash, lime, calcium carbonate, aluminium and magnesium.
* Its self-ploughing characteristic helps in aeration due to deep and wide cracks during dry season.
* highly retentive of moisture
* Sticky when wet, dry when fine grained.
* It is volcanic in origin.



i. Name a rock from which black soils are formed? Write on characteristic of this soil? What is the advantage of ‘clay’ contents in Black soils.(2)
Igneous rock. The soil has a great capacity to retain moisture.

Clay contents increase the capacity of black soils to retain moisture. During dry period, they develop deep cracks which help in aeration or air circulation.

j) Name one crop & one mineral associated with B lack soil. Name two states in India where this type of soil is found. Crop: Cotton, Mineral: Iron State : Maharashtra and Madhya Pradesh

k. Name one soil of volcanic origin commonly found in India.
The black soils are of volcanic origin.

l. Mention an two advantages of the black soil. OR What is the advantage of ‘clay’ contents in black soils?
* The black soil has the ability to retain moisture which is due to its clay contents.
* During dry period, they develop deep cracks which help in aeration or air circulation.

m. Name the soil which occupies largest area after alluvial soil.
Black soil or Regur soil.

n. What are the advantages and disadvantages of black soil or clayey soil?
ADVATAGES: * As it has the ability to retain moisture, so the moisture is released to the plants during
dry spells
* During dry period, it develops deep cracks which help in aeration or air circulation..
DISADVANTAGES: Very difficult toplough when wet because it becomes sticky when wet.

ALLUVIAL SOIL

7.a. How is alluvial soil formed? Why is this soil agriculturally important? (3)
Alluvial soil is formed by the deposit of silt brought down by rivers. This soil is agriculturally important because it is very fertile.It is rich in potash, humus and lime and soil is renewed every year by rivers.

b. What type of soil is widely distributed over the Gangetic Plain?
Alluvial soil is widely distributed over the Gangetic Plain.

c. Name the transported soil most widely found in India. State the two sub cateogories into which it is generally divided. What are local names and which one of them is superior to the other?
Transported soil most widely found in India is Alluvial soil.
Sub-categories – Old alluvium/Bangar, New alluvium/Khadar.
Khadar is more superior to them, as the floods replenish it.

d. What are the differences between the alluvial soil found in the upper course of rivers and that found in the lower courses?
In the upper course of the river, the soil particles are somewhat bigger in size and are more coarse. Soil particles are large and not uniform. The soil in this region is less fertile.
In the lower course of the river, the soil particles are fine and less coarse. Silt and clay are found in abundance. the soil in this region is more fertile.


e. By what other name alluvial soil is known? Justify your answer.
Riverine; because it is mainly found in river basins.

f. How are the soils of Gangetic Plains formed?
Alluvial soil is formed by the deposit of silt brought down by the rivers Ganga and Brahamaputra. This soil is agriculturally important because it is very fertile.It is rich in potash, humus and lime and soil is renewed every year by rivers.

g. On regional level what are three different types of alluvium?
# Deltaic alluvium in West Bengal and Orissa
# Coastal alluvium in Peninsular India
# Inland alluvium in Punjab, Haryana, Delhi, Uttar Pradesh, Bihar, West Bengal, Assam and Orissa.

h. Mention the main characteristics of alluvial soils.
# Alluvial soils are transported soils as they have come into existence because of the silt deposition brought by rivers and wind.
# They are very fertile as they are rich in minerals like potash and lime.
# They are fine- grained.
# They are rich in humus contents.
# the soils of the Ganga valley are faint yellow and consist of a mixture of sand, clay and organic matter.
# The soils of the Godavari and Krishna valleys are clayey, non-porous and brown in colour as these rivers flow over black soil.

i. What is the difference between Inland alluvium and Coastal alluvium?
Inland alluvium is the soil found on the plains of the Indus, the Ganga and the Brahmaputra rivers.
Coastal alluvium is of tidal origin and is found in coastal strips of Peninsular India.

LATERITE SOIL

8.a. Name one area where laterite soils is found on large scale. (1991)
Laterite soil is found in parts of Kerala, Goa, Tamil Nadu, Karnataka, Andhra Pradesh, on the summits of the Western and Eastern Ghats.

b. Name the type of soil found on the summits of the Eastern Ghats.(1990, 2000)
Laterite soil.

c. Name the soil which is formed due to high temperature and heavy rainfall with alternating wet and dry periods. Name two states where this type of soil is found.
Laterite soil develops as a result of leaching in areas of heavy rain. The soil is found in Tamil Nadu and Orissa.

d. What is laterite soil? (1994)
Laterite soils are those formed under alternating wet and dry spells. They are composed of a mixture of hydrated oxides of aluminium and iron. They are poor in nitrogen, potash, lime. They are low in fertility but respond favourably to manuring and leaching of soil of its nutrients.


e. In which parts of India are laterite soils found? (1994)
They are found in Kerala, Karnataka, Maharashtra, A.P., Orissa and on the summits of Eastern and Western Ghats.


f. What is the meaning of leached soil? (1995)
It is the process by which soluble substances such as organic and mineral salts are washed out of the upper layer of soil into a lower layer by percolating rainwater

g. Name one Indian soil that has been formed by leaching. (1995)
Laterite soil.

h. Name the soil which is formed due to high temperatures and heavy rainfall with alternating wet and dry periods. Name two states where this type of soil is found. (1991)
Laterite soil. Found in the highland of Western Ghats, Andhra Pradesh, Tamil Nadu, Assam and Kerala.

i. With which type of soil is the term leaching associated? Name two regions in India where this type of soil is found.
Ans: Leaching is associated with laterite soil.
TWO REGIONS: 1. Assam Hills 2) Hill summit of Eastern and Western Ghats

j. How laterite soils formed? Why is it acidic in nature? Give one difference between laterite soil and regur soil.
Laterite soil is formed by weathering of rocks under monsoon climatic conditions.
It is acidic in nature because alkalis are leached out.
Laterite soil is of coarse texture while Regur soil is fine textured.

k. Give one difference between Laterite soil and Regur soil.
Laterite soil is of coarse texture while Regur soil is fine textured.

l. Mention two important characteristic of laterite soil. (2)
* Laterite soils are leached soils because alternating dry and wet spells cause the soluble silica to be
removed.
* Laterite soils are acidic in nature, coarse and crumbly in texture.
* Due to lack of nitrogen, potassium and organic elements, laterite soils lack fertility.
* They are poor in most minerals.
* They are porous in nature.
* These soils support pastures and scrub forests.
* With the use of manure, coffee, rubber, cashew, etc., can be grown on these soils.

m. Why is laterite soil unsuitable for agriculture or less fertile? Name an area in India where this soil is found. (2)
Laterite soil is unsuitable for agriculture due to its high content of acidity and inability to retain
moisture.
It is poor in nitrogen, phosphorous, potash and lime.
It is formed as a result of leaching which r enders the topsoil infertile. The soil becomes hard like a brick when it dries up.

n.Give two reasons responsible for low fertility in laterite soil. (2)
* It is formed due to leaching.
* It is poor in lime, phosphorous, nitrogen and potash which are fertile ingredients of a rich soil.

o. Name the type of soil found on the summit of the Eastern Ghats. How is it formed? (2)
Laterite soil. Laterite soil is formed by leaching.



p. Why is laterite soil found in the Western Coastal regions?
These regions receive very heavy rainfall which results in intense leaching and helps in the formation of laterite soil.

q. Define the term ‘leaching’. In which region, south of the Tropic of Cancer can one find soil formed by leaching? Name the soil which is formed as a result of leaching. Leached soils are red in colour. Why?
Leaching is the movement of the organic matter and mineral salts from the upper region of the soil into the lower region of the soil due to heavy rainfall.
On the highland areas of Western Ghats, one can find the laterite soil formed by leaching.
Laterite soil is formed as a result of leaching.
Red colour of leached soil is due to presence of iron oxide, which is reddish in colour.

r. Which soil is found suitable for growing coffee in Karnataka?
In Karnataka, laterite soil is suitable for growing coffee.

MOUNTAIN SOIL
9.a. State one feature of Mountain soil. Name two crops that can be grown on it.(1998)
One feature of mountain soil is-
n It is rich in Iron but poor in lime.
n It is coarse in texture, friable in nature.
n It is good for growing tea, coffee and fruits such as apples, plums, cherries.
n
b. State one advantage of Mountain soil.
* It is moisture retentive.
* It is rich in iron, potash, lime and humus.
* This soil does not undergo leaching.
DESERT SOIL

10.a. Why is the desert soil alkaline in nature? or ‘The desert soil contains high proportion of salts’. Why?
The desert soil is alkaline in nature as there is no rainfall to wash away and dissolve soluble salts.

b. Why are desert soils coarse? Why are they not suitable for agriculture? Name two places, in India, where this soil is found.
Because fine topsoil particles are removed by fast-blowing winds.
Because of low water retention power and very low humus content, desert soils are unsuitable for
farming. However, under irrigation they can yield rich crops.
Rajasthan, North Gujarat and Southern Punjab

c. Give one advantage and one disadvantage of sandy soil.
ADVANTAGE: Plant roots are well aerated since water and air easily penetrate through the soil.
DISADVANTAGE: The soil requires a lot of water as it dries up easily.

d. What are the characteristics of Desert soils?
# These soils are coarse in texture.
# They are most saline and alkaline.
# The content of organic matter is low in these soils because of dry climate and lack of vegetation.
# These sand and porous soils are not fertile but with irrigation crops like wheat, gram, jowar, bajra, etc.,
can be grown.

OTHER QUESTIONS

11.Which soil is found suitable for growing coffee in Karnataka? (1997, 2001)
n The soil found suitable for growing coffee is Mountain soil or Laterite soil.


12. Test yourself
a.Red soil is being formed as a result of decomposition of metamorphic rocks. True or false.
True

b.Alluvial soil occupies the largest area in the country. True or False
True

c.Alluvial soil is formed by the deposition being brought down by river. True or False
True

d. .Black soil is a transported soil. True or False
False

e. .Regur soil is red in colour. True or false.
False

f. Black soils need to be tilled after the first rains.
because it becomes sticky in presence of the rain water.

n Fill in the blanks

1. Alluvial soil is formed by the deposition being brought down by river.
2. Black soil is most suitable for the cultivation of cotton.
3. The black colour of regur soil is due to its iron content.
4. Laterite soil has been developed as a result of leaching.
5. Laterite soil is the typical soil causing for the monsoon type of climates.
6. Soil containing high proportion of salts and alkali is called saline soil.

n Name the soils

1. Rich in humus – Mountain soil
2. Rich in potash, poor in phosphorus – Alluvial soil
3. Rich in iron, poor in silica – Laterite soil
4. Rich in lime and potash but deficient in phos-phorus and nitrogen – Black soil
5. Contains high proportion of soluble salts – Desert soils

n SOIL EROSION: It is the removal of topsoil by different agents of weathering such as running water, wind, overgrazing, and faulty methods of agriculture used by farmers.
n CONSERVATION OF SOIL: is an effort made by humans to prevent soil erosion in order to retain fertility of soil.