Short Question Answers: Soils | Geography for Grade 11 PDF Download

Q. 1. Name the four main elements found in soils.
Ans. Silica, clay, chalk and humus.

Q. 2. What is the function of clay in soils?
Ans. It absorbs water.

Q. 3. Name the three layers (horizons) of soils.
Ans. (i) A Horizon—Top soil (ii) B Horizon—Sub-soil (iii) C Horizon—Mantle.

Q. 4. Define the term Soil.
Ans. Soil is a thin layer of loose material.

Q. 5. State the factors on which the formation of soils depend.
Ans. (i) Parent material (ii) Topography (iii) Climate.

Q. 6. Name three broad regional divisions of soils in India.
Ans. (i) Soils of the Peninsula (ii) Soils of the Northern plains (iii) Soils of the Himalayas.

Q. 7. Which is the most widespread soil in India?
Ans. Alluvial soils.

Q. 8. Name two main types of alluvial soils found in Northern India.
Ans. Khadar and Bangar soils.

Q. 9. Which soil is spread over large area of northern plains?
Ans. Alluvial soils.

Q. 10. Which soils are found on the periphery of Deccan plateau?
Ans. Red soils.

Q. 11. Which soil is most widespread over Peninsular India?
Ans. Red soil.

Q. 12. Name two states where red soils are mostly found.
Ans. Tamil Nadu and Chhattisgarh.

Q. 13. Name two states where black soils are found.
Ans. Maharasthra and Madhya Pradesh.

Q. 14. Name the crop for which black soil is best suited.
Ans. Cotton.

Q. 15. In which type of climate, are laterite soils formed?
Ans. Tropical monsoon climate.

Q. 16. State the two types of laterite soils.
Ans. Upland laterites and lowland laterites.

Q. 17. Name an area in India where desert soils are found.
Ans. Thar Desert (Rajasthan and Sind).

Q. 18. What are Chos?
Ans. Chos are seasonal streams in foothills of Shiwaliks.

Q. 19. What is the process of Pedogenesis?
Ans. Soil formation is a complex process. Soil is formed under specific natural conditions. All the physical, chemical, biological and cultural elements of the environment act and react together to form the soils. Soil is the end product of these processes. The process of soil formation is known as process of pedogenesis.

Q. 20. What is Parent Material?
Ans. All the materials derived from the weathering and erosion of the exposed rocks are called parent material. Parent material is generally composed of minerals. Soils are formed by these parent materials.
The colour, texture, fertility of the soil depend upon parent material.

Q. 21. What is Soil? How is it formed?
Ans. The loose and unconsolidated material which forms the upper layer of the crust is called soil. It is found in layers or horizons. Its thickness varies from some cms. to metres. It consists of many mineral and organic particles, humus, bacteria, etc. Soil formation is a slow process. Soil is formed through the chemical and mechanical weathering of rock cover. Parent materials derived from rock cover and humus together lead to soil formation. Soil is the end product of the physical, chemical, biological and cultural factors which act and react together.

Q. 22. What are the major factors in the formation of Soil?
Ans. The formation of soil depends upon many factors.
The major factors are :  
(i) Parent Material.
(ii) Climate.
(iii) Surface features of relief.
(iv) Slope of the land.
(v) Natural vegetation.

Q. 23. Describe the formation of Laterite soils, giving two reasons in support of your answer. Name two areas where such soils may be found.
Ans. Laterite soils. Laterite soils are found on the highland areas of the plateau. These are found in Karnataka, Kerala, Tamil Nadu and hilly regions of Assam, Rajamahal hills and Chhota Nagpur plateau.Due to monsoonal climate (wet and dry seasons alternately occurring), there is the leaching of soils. It washes away the silica current in soils. These are shallow, acidic and less fertile soils. The lowland laterite soils are useful for cultivation of foodgrains and other crops. The upland laterites are thin, coarse and infertile. These soils are poor in nitrogen and lime, but rich in iron. So these are suitable for plantation of crops like tea, rubber, coffee, etc.

Q. 24. What are the characteristics of Alluvial Soils?
Ans. (i) Alluvial soils are deposited by rivers.
(ii) These soils are limited to river basins and plains.
(iii) These are very fertile soils.
(iv) It consists of fine grained clay and sand.
(v) These soils are rich in potash, but poor in phosphorus.
(vi) These are generally deep soils.

Q. 25. What is Contour Ploughing? How can we guard against the danger of  Soil Exhaustion?
Ans. Contour Ploughing. In hilly slopes, terraced farming is practised along the contour lines. These terraced fields break the flow of surface run off. Along steep slopes, small bunds are constructed on a contour to act as a barrier. Contour ploughing helps in protecting soil. The following methods are adopted to guard against soil  exhaustion :
(i) Afforestation and Reforestation.
(ii) Controlled grazing.
(iii) Terraced ploughing.
(iv) Contour bunding.
(v) Rotation of crops.

Q. 26. Which type of soils are formed as a result of wide diffusions of iron in the rocks? Explain two important characteristics of these soils of India.
Ans. Red Soils are formed as a result of wide diffusion of iron in the rocks.
Characteristics of Red Soils. These soils are found in Tamil Nadu, Karnataka, Andhra Pradesh and areas on periphery of Deccan Plateau. These soils have been formed due to decomposition of under-lying igneous rocks. The red colour of these soils is due to oxidation and diffusion of iron in hard crystalline rocks.
These are given to the cultivation of millets, pulses, linseed, tobacco etc. These soils cover the largest area in Peninsular India. These soils are poor in lime, nitrogen and humus. Fertilizers are added to make these fertile.

Q. 27. What methods should be used to improve the fertility of the soils?
Ans. The following methods should be used to improve the fertility of the soils :
(i) Methods should be adopted to check soil erosion.
(ii) Manures and chemical fertilizers should be used to maintain the fertility of soils.
(iii) Crop rotation should be practised.
(iv) Scientific methods of cultivation be used.
(v) Land should be kept fallow to retain its fertility.
(vi) Suitable combination of crops should be cultivated.

Q. 28. Explain the importance of soils.
Ans. Many human and economic activities depend upon soils. All our food comes directly or indirectly from soils. Livestock farming depends upon raising of grass on different soils. Soils have affected the march of civilisations. Ancient civilisations developed in fertile river valleys. Fertile soils attract human settlements. Density of population depends upon soil fertility and productivity.

Q. 29. Name any five methods to check Soil Erosion.
Ans. The following methods are adopted to guard against soil erosion :
(i) Afforestation and Re-afforestation.
(ii) Controlled grazing.
(iii) Terraced ploughing.
(iv) Contour bunding.
(v) Rotation of crops.

Q. 30. What are the characteristics of Laterite Soils? Name one region where it is found.
Ans. (i) The laterite soils are of brick colour.
(ii) These are shallow, acidic and less fertile.
(iii) These are less fertile due to leaching of soil.
(iv) These are poor in nitrogen, potash but rich in iron.
(v) These are found in Tamil Nadu.