Soils

1. Assertion (A): Black soils are suitable for cotton cultivation. [U.P.P.C.S.(Pre) 2013]

Reason (R): They are rich in humus.
Select the correct answer from the code given below:

(a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
(b) Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(c) (A) is true but (R) is false.
(d) (A) is false but (R) is true.

Correct Answer: (c) (A) is true but (R) is false.

Solution:'Black Soil' or 'Regur Soil' or 'Black Cotton Soil' are generally clayey, deep and impermeable. They swell and become sticky when wet, and shrink when dried. So, during the dry season, these soil develop wide cracks. Thus, there occurs a kind of 'Self-ploughing'. Because of this character the black soil retains the moisture for as very long time, which helps the crops, especially the rainfed ones, to sustain even during the dry season. Due to these characteristics, black soils are suitable for cotton cultivation. This soil lacks in Phosphorus, Nitrogen, and Humus.

2. Assertion (A) : Black soil are suitable for cotton cultivation. [U.P.P.C.S. (Spl) (MAINS) 2004]

Reason (R) : They are rich in nitrogen and organic matter.
In the context of the above, which one of the following is correct:

(a) Both (A) and (R) are true, and (R) is the correct explanation of (A)
(b) Both (A) and (R) are true, and (R) is not the correct explanation of (A)
(c) (A) is true, but (R) is false
(d) (A) is false, but (R) is true

Correct Answer: (c) (A) is true, but (R) is false

Solution:'Black Soil' or 'Regur Soil' or 'Black Cotton Soil' are generally clayey, deep and impermeable. They swell and become sticky when wet, and shrink when dried. So, during the dry season, these soil develop wide cracks. Thus, there occurs a kind of 'Self-ploughing'. Because of this character the black soil retains the moisture for as very long time, which helps the crops, especially the rainfed ones, to sustain even during the dry season. Due to these characteristics, black soils are suitable for cotton cultivation. This soil lacks in Phosphorus, Nitrogen, and Humus.

3. Which of the following is known as "self-ploughed" soil in the country? [U.P. Lower Sub.(Pre) 2009]

(a) Alluvial soil
(b) Lateritic soil
(c) Black cotton soils
(d) Desert soils

Correct Answer: (c) Black cotton soils

Solution:'Black Soil' or 'Regur Soil' or 'Black Cotton Soil' are generally clayey, deep and impermeable. They swell and become sticky when wet, and shrink when dried. So, during the dry season, these soil develop wide cracks. Thus, there occurs a kind of 'Self-ploughing'. Because of this character the black soil retains the moisture for as very long time, which helps the crops, especially the rainfed ones, to sustain even during the dry season. Due to these characteristics, black soils are suitable for cotton cultivation. This soil lacks in Phosphorus, Nitrogen, and Humus.

4. Which soil is best suited for cotton cultivation? [M.P.P.C.S.(PRE) 2004]

(a) Black
(b) Red
(c) Alluvial
(d) Laterite

Correct Answer: (a) Black

Solution:'Black Soil' or 'Regur Soil' or 'Black Cotton Soil' are generally clayey, deep and impermeable. They swell and become sticky when wet, and shrink when dried. So, during the dry season, these soil develop wide cracks. Thus, there occurs a kind of 'Self-ploughing'. Because of this character the black soil retains the moisture for as very long time, which helps the crops, especially the rainfed ones, to sustain even during the dry season. Due to these characteristics, black soils are suitable for cotton cultivation. This soil lacks in Phosphorus, Nitrogen, and Humus.

5. Lava soils are found in: [U.P.P.C.S.(Pre) 1998]

(a) Chhattisgarh plains
(b) Trans Saryu plains
(c) Malwa plateau
(d) Malwa plateau

Correct Answer: (c) Malwa plateau

Solution:The black soil of western India is made up of lava. Hence it is also known as Lava soil. The Malwa Plateau comes under this black soil region of Deccan trap. The Malwa Plateau roughly forms a triangle based on the Vindhyan Hills, bounded by the Aravali Range in the west and Madhya Bharat Pathar to the north and Bundelkhand to the east. This plateau has two systems of drainage; one towards the Arabian sea (The Narmada, the Tapi and the Mahi), and the other towards the Bay of Bengal (Chambal and Betwa, joining the Yamuna). In the north it is drained by the Chambal and many of its right bank tributaries like the Kali, the Sindh and the Parbati. It also includes the upper courses of the Sindh, the Ken and the Betwa. It is composed of extensive lava flow and is covered with black soils. The general slope is towards the north [decreases from 600 m in the south to less than 500 m in the north]. This is a rolling plateau dissected by rivers. In the north, the plateau is marked by the Chambal ravines.

6. The predominant soil of Malwa Plateau is [U.P.P.S.C.(GIC) 2010]

(a) Black soil
(b) Alluvial soil
(c) Red soil
(d) Laterite

Correct Answer: (a) Black soil

Solution:The black soil of western India is made up of lava. Hence it is also known as Lava soil. The Malwa Plateau comes under this black soil region of Deccan trap. The Malwa Plateau roughly forms a triangle based on the Vindhyan Hills, bounded by the Aravali Range in the west and Madhya Bharat Pathar to the north and Bundelkhand to the east. This plateau has two systems of drainage; one towards the Arabian sea (The Narmada, the Tapi and the Mahi), and the other towards the Bay of Bengal (Chambal and Betwa, joining the Yamuna). In the north it is drained by the Chambal and many of its right bank tributaries like the Kali, the Sindh and the Parbati. It also includes the upper courses of the Sindh, the Ken and the Betwa. It is composed of extensive lava flow and is covered with black soils. The general slope is towards the north [decreases from 600 m in the south to less than 500 m in the north]. This is a rolling plateau dissected by rivers. In the north, the plateau is marked by the Chambal ravines.

7. Which soil needs little irrigation as it retains soil water?

(a) Red
(b) Black
(c) Laterite
(d) Alluvial

Correct Answer: (b) Black

Solution:The black soil has a high moisture retention level. Remarkably "self ploughed" by loosened particles fallen from the ground into the cracks, the soil retains moisture The black soil needs little irrigation as it retains soil water. Hence, option (b) is correct.

8. Where is black soil found in Jharkhand? [Jharkhand P.C.S.(Mains) 2016]

(a) Damodar valley region
(b) Subarnrekha river valley region
(c) Rajmahal hill region
(d) Palamu region

Correct Answer: (c) Rajmahal hill region

Solution:According to National Institute of Disaster Management (NIDM) Report, black soil in Jharkhand is found in Rajmahal area. A typical black soil is highly argillaceous [Geology (of rocks or sediment) consisting of or containing clay] with a large clay factor, 62 per cent or more. In general, black soils of uplands are of low fertility while those in the valleys are very fertile. The black soil is highly retentive of moisture. It swells greatly on accumulating moisture. Strenuous effort is required to work on such soil in rainy season as it gets very sticky. In summer, the moisture evaporates, the soil shrinks and is seamed with broad and deep cracks. The lower layers can still retain moisture. The cracks permits oxygenation of the soil to sufficient depths and the soil has extraordinary fertility.

9. Which of the following statements is NOT correct? [U.P. P.C.S. (Pre) 2018]

(a) Black soil is locally called 'regur'
(b) According to Krabs, the regur soil is essentially a 112 mature soil
(c) Black soils are highly retentive to moisture
(d) Black soil is found in the Himalayan region

Correct Answer: (d) Black soil is found in the Himalayan region

Solution:The Black soil is locally called regur which is good for growing cotton. It is found mainly in the states of Maharashtra, Gujarat, Karnataka and Madhya Pradesh. Due to high clayey content and high iron content, the regur soil responds well to irrigation and retains moisture.

10. Which of the following soils of India has been formed due to weathering of basaltic lava? [U.P.P.C.S.(Pre) (RE.EXAM) 2015, U.P. Lower Sub.(Pre) 2015]

(a) Alluvial Soils
(b) Lateritr Soils
(c) Red Soils
(d) Regular Soils

Correct Answer: (d) Regular Soils

Solution:Regur Soils are formed by the weathering and erosional work of Basaltic lava. The Regur soil is also known as Black Soil or the Black Cotton Soil or the Tropical Black Earth or the Tropical Chernozem.