Q143. Which Peninsular Plateau region has black soil produced through the weathering of volcanic rock?
[DSSSB Court Attendant (2 June 2026, Shift 1)]
- (A) Western Ghats
- (B) Deccan Trap
- (C) Central Highlands
- (D) Chota Nagpur Plateau
Answer: (B) Deccan Trap
Explanation: The Deccan Trap developed from extensive basaltic lava flows. Weathering of these rocks produces the clay-rich black or regur soil. Its capacity to retain moisture helps agriculture, especially cotton cultivation across western and central parts of the peninsula.
Q142. Which Indian physiographic region combines extensive fertile alluvial deposits with a dense population?
[SSC GD Constable (20 May 2026, Shift 2)]
- (A) Peninsular Plateau
- (B) Northern Plains
- (C) Coastal Plains
- (D) Himalayas
Answer: (B) Northern Plains
Explanation: The Indus, Ganga and Brahmaputra river systems deposited enormous quantities of alluvium in the Northern Plains. Their flat terrain, fertile soils and accessible water favor intensive farming and settlements, helping explain the region’s unusually high population density.
Q141. Which crop-region association is characteristic of the regur-soil belt?
[SSC GD Constable (18 May 2026, Shift 1)]
- (A) Jute—upland desert
- (B) Cotton—black-soil basins
- (C) Tea—arid plains
- (D) Rice—dry sand dunes
Answer: (B) Cotton—black-soil basins
Explanation: Black cotton soil has high clay content and retains water for long periods. Such conditions support cotton in the basaltic Deccan region. Other crops also grow there, but the cotton–regur association remains a defining feature of Indian agricultural geography.
Q140. Which soil retains moisture particularly well and is commonly linked with cotton cultivation?
[RRB NTPC UG CBT-I (7 May 2026, Shift 2)]
- (A) Black soil
- (B) Laterite soil
- (C) Sandy soil
- (D) Red soil
Answer: (A) Black soil
Explanation: Regur or black soil swells on wetting and shrinks into wide cracks on drying. Its fine clay particles retain water, helping crops withstand intermittent dry spells. The soil is widespread on basalt-derived landscapes of the Deccan Plateau.
Q139. The mixed red-and-black soil belt of Rajasthan chiefly includes which districts?
[Rajasthan Police SI, GK & GS Paper II (6 April 2026)]
- (A) Bhilwara and Chittorgarh
- (B) Barmer and Balotra
- (C) Ajmer and Tonk
- (D) Nagaur and Jhunjhunu
Answer: (A) Bhilwara and Chittorgarh
Explanation: Mixed red and black soils occur in parts of southern and south-eastern Rajasthan where terrain and parent materials vary. Bhilwara and Chittorgarh represent this transitional zone, contrasting with the sandier, arid soils dominant across much of western Rajasthan.
Q138. Under USDA soil taxonomy, which soil order occupies the largest area in India?
[Rajasthan Police SI, GK & GS Paper II (5 April 2026)]
- (A) Entisols
- (B) Inceptisols
- (C) Alfisols
- (D) Vertisols
Answer: (B) Inceptisols
Explanation: Inceptisols display relatively weak or beginning soil-horizon development. They are extensively distributed over Indian landscapes, including river basins and hill slopes. The USDA classification differs from familiar geographical groups such as alluvial, black, red and laterite soils.
Q137. Which description correctly identifies the Great Indian Desert?
[DSSSB PRT (31 March 2026, Shift 1)]
- (A) Humid northeast with alluvial soil
- (B) East of Aravallis with dense wet forests
- (C) Northwestern arid zone with sandy soils
- (D) Southern volcanic region with black soil
Answer: (C) Northwestern arid zone with sandy soils
Explanation: The Thar Desert lies mainly in northwestern India, especially Rajasthan. Scarce rainfall, substantial evaporation and wind action favor sandy or arid soils. These conditions contrast with the river-deposited alluvium of northern plains and basalt-derived soils of the Deccan.
Q136. Which activity upsets the natural balance between the formation and loss of soil?
[SSC MTS 2025 Paper (9 February 2026, Shift 1)]
- (A) Deforestation
- (B) Afforestation
- (C) Organic farming
- (D) Intercropping
Answer: (A) Deforestation
Explanation: Trees and ground vegetation intercept rainfall and their roots stabilize the topsoil. Removing them exposes the surface to rain splash, runoff and wind, often making erosion faster than soil formation. Afforestation, conversely, is a major protective measure.
Q135. The entire Northern Plains of India are chiefly composed of which soil?
[SSC MTS 2025 Paper (5 February 2026, Shift 2)]
- (A) Black
- (B) Laterite
- (C) Yellow
- (D) Alluvial
Answer: (D) Alluvial
Explanation: The Northern Plains consist of thick river-borne deposits carried by the Indus, Ganga, Brahmaputra and their tributaries. This alluvium contains varying proportions of sand, silt and clay. Its fertility helps sustain intensive cereal cultivation and large rural settlements.
Q134. Which apex body oversees the Indian Institute of Soil Science, Bhopal?
[RRB Group D (3 February 2026, Shift 2)]
- (A) Indian Council of Agricultural Research
- (B) Central Soil Salinity Research Institute
- (C) Council of Scientific and Industrial Research
- (D) National Horticulture Board
Answer: (A) Indian Council of Agricultural Research
Explanation: The Indian Institute of Soil Science in Bhopal functions under the Indian Council of Agricultural Research. Its research supports soil fertility, nutrient management and sustainable agricultural practices. The institute is distinct from the Central Soil Salinity Research Institute at Karnal.
Q133. Black soil in India is concentrated mainly in which geographical region?
[MP Police SI (19 January 2026, Shift 1)]
- (A) Deccan Trap
- (B) Gangetic Plains
- (C) Thar Desert
- (D) Himalayas
Answer: (A) Deccan Trap
Explanation: Basaltic rocks of the Deccan Trap weather into dark, clayey soil with high moisture-holding ability. It is common in Maharashtra and adjoining plateau states. River alluvium, not volcanic regur, dominates the extensive plains of the Ganga.
Q132. Laterite soils are ordinarily deficient in which of the following?
[MP Police SI (18 January 2026, Shift 2)]
- (A) Salt
- (B) Water
- (C) Sand particles
- (D) Plant nutrients
Answer: (D) Plant nutrients
Explanation: High rainfall and temperature cause intense leaching of soluble substances in laterite soils. Although iron and aluminium oxides remain concentrated, essential plant nutrients and humus are often scarce. Fertilizer and organic inputs are needed for productive plantation agriculture.
Q131. Which soil dominates the Northern Plains of India?
[Delhi Police Constable (6 January 2026, Shift 1)]
- (A) Alluvial soil
- (B) Black soil
- (C) Red soil
- (D) Laterite soil
Answer: (A) Alluvial soil
Explanation: The Northern Plains are built of sediments deposited by Himalayan-fed rivers over long geological periods. Alluvial soil is therefore widespread there. The fresh floodplain portion is known as khadar, while older alluvium on higher ground is called bhangar.