ICSE Geography Solutions : Soil Resources (Part II)

    ICSE Geography

  Soil Resources (Part II)

 Exercise

 I. Answer the following question:

Q.1 (a) How were the alluvial soils formed?

  ans.> Alluvial soils are formed by the sediments brought down by rivers. They are also rich in chemicals ingredients. The rivers deposit very fine particles of soil called alluvium in their plains during their long journey.

    (b) Mention any two advantages of alluvial soil.

  ans.> The two advantages of alluvial soil are:

      * It is light and porous, therefore easily tillable.

      * It is a fertile soil as it is rich in minerals, especially potash and lime.

    (c)  (i) Why is soil a valuable resource for India?

    ans.> Soil is a valuable resource for India supports all forests, grassland and crops from which all living creatures on earth derive their food.

        (ii) Why is black soil is considered productive soil?

  ans.> Black soil is considered a productive soil because of its fine texture and clayey in nature.

    (d) 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 of their changing temperature, running water, and wind affect.

       (ii) Alluvial soils vary in texture.

  ans.> Alluvial soils vary in texture because it is mainly found in the river basins.

      (iii) Nearly all types of crops grow well in riverine soils.

  ans.> Nearly all types of crops grow well in riverine soils since, it is a mixture of sand, clay, and silt, called loam.

Q.2 (a) Give two characteristic features of the soil found most suitable for growing cotton and sugarcane in Maharashtra.

  ans.> The two characteristic features of the soil found most suitable for growing cotton and sugarcane in Maharashtra are:

      * It is fine textured and clayey in nature.

      * In any season it has moisture stored in its subsoil.

    (b) Name one soil of volcanic origin commonly found in India. Name one crop widely grown on this soil.

  ans.> Black soil is the soil of volcanic origin commonly found in India. The crop which is widely grown on this soil is cotton.

    (c) (i) Name the process by which Laterite soil is formed.

  ans.> The process by which Laterite soil is formed by atmospheric weathering of rocks under conditions of high rainfall and temperature with alternate wet and dry periods. It is a residual soil formed by leaching due to tropical rains. Leaching is the process in which the nutrients get percolated down below the soil due to heavy rainfall; thus leaving the topsoil infertile. This is also called desalination.

       (ii) Mention one disadvantage of Laterite soil.

  ans.>  The disadvantage of Laterite soil is:

      * It is acidic in nature.

    (d) Give a geographical reason for each of the following:

        (i) Deltaic alluvium is more fertile than the costal alluvium.

  ans.> Deltaic alluvium is more fertile than the coastal alluvium because deltaic alluvium deposited a new layer year after year during monsoonal floods.

       (ii) Black soil is largely found in the Deccan Trap region.

  ans.> Black soil is largely found in the Deccan Trap region because this region is formed due to denudation of volcanic rocks, therefore it is also known as lava soil.

      (iii) Black soil is often referred to as Cotton soil or Regur soil.

  ans.> This soil is black in colour therefore, it is also known as Regur soil or Black cotton soil. It is dark in colour and suitable for cotton cultivation.

Q.3 (a) State the two sub-categories into which alluvium soil is generally divided. Which one of them is superior to the other? Why?

  ans.> The two sub-categories in which alluvium soil is generally divided are:

      * Bhangar soil and

      * Khadar soil.

        Khadar soil is more superior than Bhangar soil. Because khadar soil is more fertile than bhangar soil, new layers are deposited year after year during monsoon floods.

    (b) What are the characteristics of alluvium soil?

  ans.> The characteristics of alluvium soil are:

       * It is formed by the deposition of the river load as it flows from its upper to its lower course.

       * It is light and porous, therefore easily tillable.

       * It is fertile soil as it is rich in minerals, especially potash and lime.

       * It is deficient in nitrogen and humus, except the alluvium of the Ganga deltaic region which is rich in humus.

       * It is suitable for the growth of a large variety of rabi and kharif crops.

       * Soil in the drier areas is more alkaline.

    (c) (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.> The two main characteristics of this soil are:

       * It does not retain moisture and hence is not fertile. It suits only special crops like coffee, tea, etc.

       * It is of a coarse texture, soft and friable.

    (d) Give a geographical reason for each of the following:

       (i) Laterite soil is useful for construction purposes.

  ans.> Laterite soil is useful for construction purposes since it becomes hard when exposed to air. It is red due to the presence of iron oxide and also it is acidic in nature as alkalis are leached.

      (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 an extreme form of soil degradation due to aridity.

     (iii) The foothills of the Himalayas as prone to excessive soil erosion.

  ans.> The foothills of the Himalayas as 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. 

Q.4 (a) Name two States in India where Regur soil is found.

  ans.> The states in India are:

       * Maharashtra,

       * Gujarat, etc.

    (b) Give two points of difference between Regur and Alluvial soil.

Regur soil	Alluvial soil
It is fine textured and clayey in nature.	It is light and porous, therefore easily tillable.
The soil is very fertile in most places.	It is fertile soil as it is rich in minerals, especially potash and lime.

    (c) (i) Besides cotton, name the crops which grow well in Regur soil.

  ans.> Beside cotton, the crops which grow well in regur soil is cereals, oilseeds, citrus fruits and vegetables, tobacco and sugarcane.

       (ii) In what way does Regur soil help agriculture?

  ans.> Regur soil helps agriculture as it is very clayey and highly retentive of water. Because of high clay content, this soil expands when wet and become difficult to plough. During the dry season, black soil shrinks and develops big cracks which help in air circulation.

    (d) Give a geographical reason for each of the following:

        (i) Jowar is grown in Maharashtra.

ans.> Jowar is grown in Maharashtra because of black (Regur) soil which is rich in calcium, lime, magnesium and iron.

       (ii) Bajra is grown in Rajasthan.

  ans.> Bajra is grown in Rajasthan because of the sandy soil found in this region.

      (iii) Sugarcane is grown in Uttar Pradesh.

  ans.> Sugarcane is grown in Uttar Pradesh because of its fine-textured and clayey in nature which makes the soil very fertile and suitable for cultivation.

Q.5 (a) Name two states where Red soil is found. Mention two important crops are grown in this soil.

  ans.> The two states, where Red soil is found, is:

      * Tamil Nadu,

      * Jharkhand, etc.

    The two crops that grow in this soil is:

      * Rice,

      * Ragi,  etc.

    (b) State two advantage of this type of soil.

  ans.> The two advantage are:

       * It is ideal for dry farming as it is formed in poor rainfall areas.

       * It contains soluble salts in small quantities.

    (c) (i) How is Red soil formed?

  ans.> This soil is formed by the development of old crystalline rocks. Which differ from place to place based on the parental rock material and climatic condition.

       (ii) How is this soil suitable for dry farming?

  ans.> It is suitable for dry farming as it is formed in poor rainfall areas.

    (d) Give geographical reason for each of the following:

       (i) Black soil is also called lava soil.

  ans.> Black soil is also called lava soil since; it is formed by the denudation of volcanic rocks. Therefore it is also known as lava soil.

      (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 of iron oxide. At several places, its colour slightly changes and appears brown or grey. It looks yellow when it occurs in a hydrated form.

     (iii) Jute is cultivated in West Bengal.

  and.> Jute is cultivated in West Bengal as it formed by the deposition of the river load as it flows from upper to its lower course and in lower course Ganga-Brahmaputra valley useful for jute cultivation.

Q.6 (a) What is soil erosion? Name the areas of soil erosion in India: (i) for wind erosion. (ii) for running water erosion.

  ans.> The removal of the topsoil cover by water, wind and human activities are called soil erosion.

        (i) for wind erosion:

       (ii) for running water erosion:

    (b) Give two methods used to prevent soil erosion.

  ans.> The two methods used to prevent soil erosion are:

       * Terrace Farming, and

       * Planting Trees.

    (c) (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 usage, acidification, salinization or other types of soil contamination.

       (ii) State two measures to conserve soil in hilly areas.

  ans.> The two measures to conserve soil in hilly areas:

        (i) Terrace Farming, and

       (ii) Contour Ploughing.

    (d) 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 as farmers plant trees in several rows to check wind erosion.

      (ii) Rural development will influence soil conservation.

  ans.> Rural development will influence soil conservation by making people aware of planting trees and crops with new and advanced techniques of farming especially in hilly areas.

      (iii) Water harvesting aids in soil conservation.  

  ans.> Water harvesting aids in soil conservation because it helps to reduce soil erosion and control flood while collecting rainwater which removes the topsoil and makes the soil fertile.

 Q.7 (a) How does deforestation leads to soil erosion?

  ans.> Forest are destroyed so that more land can be used for cultivation. Cutting trees exposes the soil to water and wind, which leads to soil erosion.

     (b) State two methods of controlling erosion of soil caused by running water.

  and.>  The two methods are:-

      i) Terrace Farming: On hilly slopes, terraces act as bunds and prevent the soil from being washed away by running water.

     ii) Construction of Dams: Rivers caused soil erosion. Dams are built in the upper course of rivers to control erosion of soil.

     (c) What are the constituents of the soil?

  ans.> Soils are derived from parent rock material through a process of breakup or wear and tear. A decomposed vegetal and animal remains, referred to as humus is an important constituent of soil and adds to the fertility of the soil. Besides humus, silica, clay and sand are the other constituents of soil.