Q100. Statement 1: Black soil supports rainfed crops.
Statement 2: It stores moisture for extended periods.
Which relationship is correct?
[UPSC CAPF AC Paper I (4 August 2024)]
- (A) Both correct; statement 2 explains statement 1
- (B) Both correct; statement 2 does not explain statement 1
- (C) Statement 1 correct, statement 2 incorrect
- (D) Statement 1 incorrect, statement 2 correct
Answer: (A) Both correct; statement 2 explains statement 1
Explanation: The clay minerals of black soils absorb and retain considerable water, supplying crops after rainfall has stopped. This directly explains why they can be productive under rainfed cultivation. Their swelling and shrinking behavior is another familiar characteristic.
Q99. Which soil group occupies approximately forty percent of India’s area?
[SSC CHSL Tier I (2 July 2024, Shift 4)]
- (A) Red and yellow
- (B) Black
- (C) Alluvial
- (D) Laterite
Answer: (C) Alluvial
Explanation: Alluvial soils constitute the most extensive broad geographical soil group in India. They are laid down by streams and rivers, especially across the northern plains and major deltas. Different estimates vary with classification methods and mapped area.
Q98. Which physiographic division has extensive alluvial soil?
[SSC CPO Paper I (29 June 2024, Shift 1)]
- (A) Himalayan Range
- (B) North Indian Plain
- (C) Island Groups
- (D) Great Indian Desert
Answer: (B) North Indian Plain
Explanation: Rivers emerging from the Himalayas transport eroded sediment onto the broad North Indian Plain. Repeated deposition forms thick alluvial soils. By contrast, mountains are dominated by slope and forest soils, and the desert has predominantly arid sandy material.
Q97. Which statements are correct? 1. Every soil with sodium and calcium and pH above seven is termed alkaline. 2. Black soil developed over Deccan basalt. 3. Laterite has undergone deep silica leaching.
[UPSC NDA I, General Ability Test (21 April 2024)]
- (A) 1 only
- (B) 1 and 2 only
- (C) 2 and 3 only
- (D) 1, 2 and 3
Answer: (C) 2 and 3 only
Explanation: Black cotton soil is associated with basaltic lava, and laterite develops when prolonged tropical weathering removes silica. The first statement incorrectly uses a broad pH and composition test as a sufficient definition of problematic alkaline soils.
Q96. Which soil is especially associated with coffee plantations in the given options?
[Kolkata Police SI Preliminary (28 January 2024)]
- (A) Red soil
- (B) Alluvial soil
- (C) Black soil
- (D) Laterite soil
Answer: (D) Laterite soil
Explanation: Well-drained lateritic uplands in parts of southern India support coffee plantations under suitable rainfall and management. The soils are often acidic and leached, so organic matter and nutrients need attention. Climate, slope and shade also influence coffee cultivation.
Q95. Which state was selected as having the greatest laterite-soil extent among Uttar Pradesh, Bihar and Meghalaya?
[Bihar TRE 2.0, Social Science (9 December 2023)]
- (A) Uttar Pradesh
- (B) Bihar
- (C) Meghalaya
- (D) None of these
Answer: (C) Meghalaya
Explanation: Meghalaya has high-rainfall uplands where intense chemical weathering and leaching produce lateritic material. Uttar Pradesh and Bihar are more strongly associated with alluvial plains. The answer refers to the comparison of the particular states offered in the examination.
Q94. Which nutrient is notably deficient in black soil of the Deccan Plateau?
[SSC CPO Paper I (4 October 2023, Shift 3)]
- (A) Phosphorus
- (B) Potash
- (C) Iron
- (D) Lime
Answer: (A) Phosphorus
Explanation: Deccan black soils commonly contain lime, magnesia and several mineral bases but are relatively deficient in phosphorus and nitrogen. Their strong moisture retention does not imply balanced plant nutrition. Appropriate fertilizers and crop management may therefore be necessary.
Q93. Which crop is especially appropriate for cultivation on black soil?
[SSC MTS (11 September 2023, Shift 1)]
- (A) Soybean
- (B) Maize
- (C) Cotton
- (D) Barley
Answer: (C) Cotton
Explanation: Cotton is widely associated with black regur soils because their clay particles retain moisture during dry intervals. These soils developed largely from weathered basalt across the Deccan. Although soybean and maize can also be grown, cotton is the characteristic textbook association.
Q92. The Deccan Trap black-soil tract belongs to which Indian physiographic division?
[SSC MTS (6 September 2023, Shift 3)]
- (A) Northern Plains
- (B) Peninsular Plateau
- (C) Coastal Plains
- (D) Himalayan Mountains
Answer: (B) Peninsular Plateau
Explanation: The Deccan Trap is a basaltic volcanic province within the Peninsular Plateau. Its weathered lava supports extensive regur soil. This contrasts with the river-built Northern Plains, whose principal soil is alluvium rather than residual volcanic clay.
Q91. Which division of India was largely formed by the accumulation of alluvial deposits?
[SSC MTS (5 September 2023, Shift 2)]
- (A) Peninsular Plateau
- (B) Himalayan Mountains
- (C) Island Groups
- (D) Northern Plains
Answer: (D) Northern Plains
Explanation: The Northern Plains are a major depositional landscape receiving alluvium from Himalayan rivers. Fine material spread by streams and floods created deep fertile soils and flat surfaces. These conditions support extensive agriculture and dense settlements.
