Soils Archives

11. Which one of the following soils is ideal for growing cotton ?

Which one of the following soils is ideal for growing cotton ?

[amp_mcq option1=”Regur soil” option2=”Laterite soil” option3=”Desert soil” option4=”Mountainous soil” correct=”option1″]

This question was previously asked in

UPSC NDA-2 – 2023

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Regur soil, also known as Black soil or Black Cotton Soil, is highly suitable for growing cotton. This soil type is derived from volcanic rocks and is rich in clay minerals, giving it a high capacity to retain moisture, which is crucial for cotton cultivation, especially in rain-fed areas. Laterite soil is generally not fertile enough for cotton and is better suited for crops like tea and coffee. Desert soil lacks moisture and organic matter, making it unsuitable for cotton without significant irrigation. Mountainous soil varies greatly but is generally not the ideal soil type for widespread cotton cultivation compared to black soil plains.

Regur soil (Black soil) is the most ideal soil for growing cotton due to its fertility and moisture retention capacity.

Black soils are found extensively in the Deccan Trap region of India, covering parts of Maharashtra, Madhya Pradesh, Gujarat, Andhra Pradesh, and Tamil Nadu, which are major cotton-growing areas.

12. The term ‘Regur’ is used to mean:

The term ‘Regur’ is used to mean:

[amp_mcq option1=”Laterite soil” option2=”Deltaic soil” option3=”Red soil” option4=”Black cotton soil” correct=”option4″]

This question was previously asked in

UPSC NDA-2 – 2015

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The correct answer is D) Black cotton soil.

‘Regur’ is the local name for the black soils found extensively in the Deccan trap region of India. These soils are dark grey to black, rich in clay, and known for their high water retention capacity, making them suitable for cotton cultivation, hence the name ‘Black Cotton Soil’.

Laterite soils are typically red and found in areas with high rainfall and temperature. Deltaic soils are alluvial soils found in river deltas. Red soils are generally formed from the weathering of crystalline and metamorphic rocks.

13. Consider the following statements regarding soils: 1. Soils having a

Consider the following statements regarding soils:

1. Soils having a very high content of sodium and calcium and pH of more than 7.0 are alkaline soils.
2. Black cotton soil had developed on the Deccan basaltic lava under hot and humid conditions.
3. Laterite soils are characterised by a deep weathered layer from which silica has been leached.

Which of the statements given above is/are correct ?

[amp_mcq option1=”1 only” option2=”1 and 2 only” option3=”2 and 3 only” option4=”1, 2 and 3″ correct=”option4″]

This question was previously asked in

UPSC NDA-1 – 2024

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Statement 1 is correct. Alkaline soils are defined as soils having a pH greater than 7. High content of base cations like sodium and calcium contribute to a higher pH, leading to alkaline conditions. Sodic soils (high sodium) and calcareous soils (high calcium carbonate) are common types of alkaline soils. Statement 2 is correct. Black cotton soil (Regur soil) is characteristic of the Deccan Trap region in India and is formed from the weathering of basaltic lava rocks under conditions including high temperatures and distinct wet and dry seasons, which facilitates the formation of expansive clays and cracking. Statement 3 is correct. Laterite soils are formed through intense weathering and leaching in hot, humid climates with distinct wet and dry seasons. This process, called laterization or desilication, involves the removal of silica and bases, leaving behind a concentration of iron and aluminum oxides in a deep weathered layer.

Soil classification and properties are influenced by parent material, climate, topography, organisms, and time. Different soil types exhibit distinct physical, chemical, and biological characteristics.

Alkaline soils can pose challenges for agriculture due to potential nutrient deficiencies or toxicities at high pH levels. Black soils are known for their high clay content and moisture retention but can be difficult to cultivate when wet or dry. Laterite soils are often poor in nutrients due to intense leaching but can be used for crops like cashew, tapioca, and groundnut after appropriate management.

14. Which of the following statements regarding Regur soil is/are correct

Which of the following statements regarding Regur soil is/are correct ?

1. It is a light coloured, clayey and fertile soil.
2. It is developed on Deccan basaltic lava under hot and humid conditions.
3. Cotton is extensively cultivated in this soil.

Select the answer using the code given below :

[amp_mcq option1=”1 and 2″ option2=”2 and 3″ option3=”2 only” option4=”3 only” correct=”option2″]

This question was previously asked in

UPSC NDA-1 – 2024

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Statement 3 is correct. Regur soil, also known as Black Cotton soil, is famous for its suitability for cotton cultivation due to its high clay content which allows it to retain moisture effectively. Statement 2 is also correct. Black soils are predominantly found in the Deccan Trap region and are formed by the weathering of basaltic lava rocks. While not exclusively under consistently humid conditions (alternating wet and dry periods are key for their cracking property), they develop under hot temperatures and seasonal rainfall characteristic of the region. Statement 1 is incorrect; Regur soils are dark grey to black in colour, not light-coloured.

Regur soils are characterized by their dark color, clayey texture, high moisture retention capacity, and tendency to develop deep cracks during dry periods. They are rich in minerals but can be deficient in nitrogen, phosphorus, and organic matter.

The parent material for Regur soils in the Deccan region is primarily basalt. The black color is attributed to compounds like titaniferous magnetite and often associated with humus accumulation in the presence of clays. While cotton is the most famous crop grown in these soils, they are also used for cultivating crops like jowar, wheat, sugarcane, and groundnuts.

15. ‘Zafran’ is cultivated in which type of soil?

‘Zafran’ is cultivated in which type of soil?

[amp_mcq option1=”Black soil” option2=”Red soil” option3=”Karewa soil” option4=”Laterite soil” correct=”option3″]

This question was previously asked in

UPSC Geoscientist – 2021

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‘Zafran’, which is Saffron, is primarily cultivated in the Karewa soil of Kashmir.

Karewa soils are lacustrine deposits found in the Kashmir Valley, known for their fertility and suitability for specific crops like saffron, almond, and apple.

These soils are composed of fine-grained silts, sands, and clay, along with boulders and gravel. They were formed during the Pleistocene period when the Kashmir Valley was a large lake.

16. Identify the type of soil on the basis of given characteristics : 1.

Identify the type of soil on the basis of given characteristics :

1. They contain a large proportion of sodium, potassium and magnesium, and thus, they are infertile.
2. Their structure ranges from sandy to loamy.
3. They are more widespread in western Gujarat, deltas of the eastern coast and in Sunderban areas of West Bengal.

[amp_mcq option1=”Peaty soil” option2=”Laterite soil” option3=”Arid soil” option4=”Saline soil” correct=”option4″]

This question was previously asked in

UPSC CDS-2 – 2023

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The characteristics describe Saline soil.

The key characteristics point towards Saline soil:
1. High proportion of sodium, potassium, and magnesium salts makes them infertile for most crops.
2. Their texture can vary from sandy to loamy.
3. They are typically found in arid and semi-arid regions, areas with poor drainage, and coastal areas or deltas where seawater intrusion occurs or where salts accumulate due to capillary action and evaporation. Western Gujarat, deltas of the eastern coast (like Godavari, Krishna, Cauvery deltas), and the Sunderban areas of West Bengal are all regions known to have issues with soil salinity.

Saline soils are also known as Solonchaks or “Usar” soils in some local Indian contexts. They are often formed due to factors like arid climate, poor irrigation management (leading to salt accumulation from irrigation water), poor drainage, and tidal influences in coastal areas. Reclamation of saline soils often involves improving drainage and leaching out the salts.

17. S had witnessed contour bunding and contour ploughing while visiting o

S had witnessed contour bunding and contour ploughing while visiting one of the States in India. Identify the State from the options given below.

[amp_mcq option1=”Punjab” option2=”Haryana” option3=”Himachal Pradesh” option4=”Rajasthan” correct=”option3″]

This question was previously asked in

UPSC CDS-2 – 2021

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Contour bunding and contour ploughing are soil and water conservation techniques primarily employed in hilly or sloping agricultural areas to prevent soil erosion and retain moisture. Himachal Pradesh is a mountainous state where such practices are commonly adopted due to the terrain.

– Contour bunding involves constructing small bunds or embankments along the contours of the land to check the flow of water.
– Contour ploughing involves tilling the land along the contours rather than up and down the slopes, which creates ridges and furrows that help trap water and soil.

– These techniques are most effective on moderate slopes and are part of sustainable agriculture practices in hilly regions.
– States like Punjab and Haryana are predominantly plains, while Rajasthan is largely arid/semi-arid, making contouring practices less widespread compared to a mountainous state like Himachal Pradesh, where water erosion on slopes is a major concern.

18. The largest geographical area of India is covered by which one of the

The largest geographical area of India is covered by which one of the following types of soils?

[amp_mcq option1=”Inceptisols” option2=”Entisols” option3=”Alfisols” option4=”Vertisols” correct=”option1″]

This question was previously asked in

UPSC CDS-2 – 2020

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According to the USDA soil taxonomy, Inceptisols cover the largest geographical area of India.

Inceptisols are young soils with minimal profile development, but they show the beginning of horizon formation. In India, these soils are widespread, particularly in the vast alluvial plains (like the Ganges and Brahmaputra plains) where fresh sediments are deposited and young soils develop, and also in parts of plateaus and hills.

Entisols are even younger soils with little to no horizon development, found in areas of very recent deposition (e.g., floodplains, dunes). While significant, they cover a smaller area than Inceptisols. Alfisols (typically found in areas with red soils) and Vertisols (black cotton soils) are also important soil orders in India but cover smaller total areas compared to Inceptisols. Estimates vary slightly, but Inceptisols are generally cited as covering the largest percentage of India’s land area.

19. Which of the following statements regarding soil is/are correct? 1.

Which of the following statements regarding soil is/are correct?

1. Alluvial soils are rich in nitrogen content.
2. Black soils are rich in iron and lime but deficient in nitrogen.
3. Laterite soils are rich in iron and aluminium but deficient in nitrogen and potassium.

Select the correct answer using the code given below.

[amp_mcq option1=”1 and 2 only” option2=”3 only” option3=”2 and 3 only” option4=”1, 2 and 3″ correct=”option3″]

This question was previously asked in

UPSC CDS-2 – 2016

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Statements 2 and 3 are correct, while statement 1 is incorrect.

– Alluvial soils are generally deficient in nitrogen and phosphorus, though rich in potash and lime.
– Black soils are rich in iron, lime, magnesium, and alumina, but are deficient in nitrogen, phosphorus, and humus.
– Laterite soils, formed by intense leaching, are rich in iron oxides and aluminium, but poor in nitrogen, potassium, phosphorus, lime, and magnesium.

Different soil types have varying nutrient profiles depending on the parent rock, climate, vegetation, and processes like weathering and leaching. Understanding these profiles is crucial for agriculture and land use planning.

20. Consider the following characteristics of a soil type: These soils c

Consider the following characteristics of a soil type:

These soils consist of various proportions of sand, silt and clay.
These soils contain adequate proportions of potash, phosphoric acid and lime.
These soils can be further classified on the basis of their age.

Identify the type of soil on the basis of the given characteristics.

[amp_mcq option1=”Alluvial” option2=”Laterite” option3=”Arid” option4=”Black” correct=”option1″]

This question was previously asked in

UPSC CDS-1 – 2023

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Alluvial soils are formed by the deposition of sediment carried by rivers. These soils are typically a mixture of sand, silt, and clay in varying proportions, known as loam. They are generally rich in potash, phosphoric acid, and lime, making them very fertile. A key characteristic of alluvial soils, particularly in the Indo-Gangetic plains, is their classification based on age: Khadar (newer alluvium, renewed yearly by floods) and Bhangar (older alluvium, above flood level). This classification is a strong indicator for alluvial soils.

Alluvial soils are the most widespread and fertile soils in India, covering large parts of the northern plains and coastal regions. Their texture varies from sandy loam to clay.

Laterite soils are formed under conditions of high temperature and rainfall with alternating wet and dry periods, often deficient in nitrogen, potash, and lime. Arid soils are found in dry areas, characterized by sandy texture and often high salt content, poor in organic matter. Black soils (Regur) are rich in calcium carbonate, magnesia, potash, and lime but generally poor in nitrogen, phosphoric acid, and organic matter.