ICSE CLASS 10 GEOGRAPHY //Important Previous Years Question of Soil
What
is the soil? Name the four types of soil.
Answer:
Soil is the thin mixture of small rock particles and rotting organic matter
that covers the surface of the earth. 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
(i) How can you say that soil has evolved over
millions of years?
Ans:
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.
(ii)
Name one important constituent of soil that adds fertility to the soil.
Ans:
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.
Ans:
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.
Ans:
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.
Ans:
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?
Ans: 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.
(i)
Why is soil a valuable resource for India?
Ans:
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.
(ii)
Why is black soil considered a productive soil?
Ans:-
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.
Ans:-
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.
Ans:
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.
(iii)
Nearly all types of crops grow well in riverine soils.
Ans:
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.
Ans: 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.
Ans:
One soil of volcanic origin commonly found in India is black soil. Cotton is
widely grown on this soil.
(i)
Name the process by which Laterite soil is formed.
Ans:
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.
(ii)
Mention one disadvantage of Laterite soil.
Ans:
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:
(i)
Deltaic alluvium is more fertile than the coastal alluvium.
Ans:
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
(ii)
Black soil is largely found in the Deccan Trap region.
Ans:
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.
(iii)
Black soil is often referred to as Cotton soil or Regur soil.
Ans:
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?
Ans’:
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?
Ans:
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.
(i) Which soil is suitable for growing coffee
in Karnataka?
Ans:
Laterite soil is suitable for growing coffee in Karnataka.
(ii)
Mention two main characteristics of this soil.
Ans:
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:
(i)
Laterite soil is useful for construction purpose.
Ans:
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.
Ans:
) 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.
Ans:
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.
Ans:
Regur soil is found in Maharashtra and Madhya Pradesh.
Give
two points of difference between Regur and Alluvial soil.
Ans:
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.
(i) Besides cotton, name the crops which grow
well in Regur soil.
Ans:
Besides cotton, jowar, wheat, linseed, gram, citrus fruits and vegetables,
tobacco and sugarcane grow well in Regur soil.
(ii)
In what way does Regur soil help agriculture?
Ans: 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:
(i)
Jowar is grown in Maharashtra.
Ans:
Jowar is grown in Maharashtra because of the black regur soil which is rich in
lime, potash-magnesium, carbonates, allumina and calcium.
(ii)
Bajra is grown in Rajasthan.
Ans:
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.
Ans:
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.
Ans:
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.
Ans:
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?
Ans:
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?
Ans:
This
soil suitable for dry farming as it is formed in areas with poor rainfall.
Give
a geographical reason for each of the following:
(i)
Black soil is also called lava soil.
Ans:
Black soil is also called lava soil because it is formed by the denudation of
volcanic rocks.
(ii)
Red soil is red in colour and its colour varies from yellow to brown.
Ans:
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.
Ans:
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
Ans:
Wind erosion affects the dry areas of Rajasthan, Gujarat and Haryana
(ii)
for running water erosion
Ans:
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.
Ans:
Two
methods used to prevent soil erosion are-
Terrace
farming
Shelter
belts
(i) What is meant by soil conservation?
Ans:
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.
Ans:
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.
Ans:
Shelter belts reduce soil erosion in arid areas because planting trees in
several rows checks wind erosion.
(ii)
Rural development will influence soil conservation.
Ans:
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.
Ans:
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?
Ans:
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.
Ans:
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.
Ans:
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.
Ans:
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
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