Q1. Which of the following is the most dominant factor influencing the formation of soils in the western region of Rajasthan?
Soils of Rajasthan: RAS Prelims MCQs
37 RAS Prelims MCQs on the soils of Rajasthan cover the soil types, their districts and properties. Desert sandy soils, alluvial soils of the eastern plains, black soils of Kota and Bundi, the Bhangar and Khadar deposits, the Entisols of USDA taxonomy and the problem of salinity are asked as facts and causes.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 1–10 of 37 questions
Q2. Consider the following statements regarding soil formation in Rajasthan:
Statement I: The parent rock in the Hadoti plateau region is primarily basaltic.
Statement II: The weathering of this basaltic rock has led to the formation of widespread sandy desert soils.
Which of the following statement(s) is/are correct?
Statement I: The parent rock in the Hadoti plateau region is primarily basaltic.
Statement II: The weathering of this basaltic rock has led to the formation of widespread sandy desert soils.
Which of the following statement(s) is/are correct?
Explanation
The Hadoti plateau region is geologically defined by basaltic parent rock originating from ancient volcanic activity. While the weathering of this basalt creates deep, fertile black soils known for their clayey texture, it does not produce sandy desert soils. Sandy soils are instead characteristic of the western arid regions where aeolian processes and different parent materials dominate the landscape.
Q3. Consider the following factors of soil formation:
I. Climate
II. Topography
III. Time
Which combination of the above represents the passive factors of soil formation in Rajasthan?
I. Climate
II. Topography
III. Time
Which combination of the above represents the passive factors of soil formation in Rajasthan?
Explanation
Soil formation involves both active and passive factors. In the context of Rajasthan, topography and time are considered passive factors because they provide the physical framework and duration for pedogenesis without providing energy. In contrast, climate and biological organisms are active factors. Topography influences water runoff and erosion, while time determines the overall maturity and development of soil horizons.
Q4. Given below are two statements, one labelled as
Assertion (A) and the other labelled as Reason (R):
Assertion (A): The soils found on the slopes of the Aravalli ranges are generally shallow and stony.
Reason (R): The high slope gradient accelerates the removal of weathered rock materials through water erosion. In the context of the above statements, which one of the following is correct?
Assertion (A) and the other labelled as Reason (R):
Assertion (A): The soils found on the slopes of the Aravalli ranges are generally shallow and stony.
Reason (R): The high slope gradient accelerates the removal of weathered rock materials through water erosion. In the context of the above statements, which one of the following is correct?
Explanation
The Aravalli ranges feature steep gradients that significantly influence soil characteristics. High slopes accelerate the velocity of surface runoff during rains, leading to the rapid removal of weathered materials. This continuous water erosion prevents the accumulation of deep soil layers, resulting in the presence of shallow, stony, and skeletal soils that are typically found throughout these prominent hilly terrains.
Q5. Match the comprehensive soil orders of the USDA classification (List I) with their predominantly associated regions in Rajasthan (List II):
| Soil Orders | Associated Regions |
|---|---|
| A. Aridisols | i. Hadoti Plateau |
| B. Alfisols | ii. Eastern Plains |
| C. Vertisols | iii. Western Desert |
| D. Inceptisols | iv. Flanks of the Aravallis |
Explanation
The USDA soil taxonomy classifies Rajasthan’s diverse pedological landscape into specific orders. Aridisols are characteristic of the western desert’s dry climate, while Alfisols dominate the mature eastern plains. Vertisols, known for high clay content, are found in the south-eastern Hadoti plateau. Inceptisols, representing soils with minimal development, are frequently observed along the flanks and slopes of the Aravalli range.
Q6. Consider the following statements regarding Aridisols in Rajasthan:
I. They possess very low organic matter content.
II. They are primarily found in the districts of Kota and Bundi.
III. They frequently feature a calcic horizon at some depth.
IV. They are characterized by a coarse texture and high permeability.
Which combination of the above statements is correct?
I. They possess very low organic matter content.
II. They are primarily found in the districts of Kota and Bundi.
III. They frequently feature a calcic horizon at some depth.
IV. They are characterized by a coarse texture and high permeability.
Which combination of the above statements is correct?
Explanation
Aridisols are the dominant soil order in the arid regions of Rajasthan, characterized by a lack of moisture and very low organic matter. They often feature a calcic horizon at varying depths due to the accumulation of carbonates. These soils typically have a coarse, sandy texture and high permeability, allowing water to drain quickly without developing deep or mature profiles.
Q7. According to the comprehensive USDA soil taxonomy, which soil order occupies the largest geographical area in Rajasthan?
Explanation
In the comprehensive USDA soil taxonomy applied to Rajasthan, Entisols occupy the largest geographical area across the state. These are youthful soils with little to no evidence of horizon development. They are predominantly found in the vast western sandy plains where active wind deposition and shifting sand dunes prevent the formation of mature, well-defined soil layers within the profile.
Q8. Which of the following pairs of soil type and its prominent occurrence district is correctly matched?
Explanation
Deep black soil is found in Jhalawar in the south-east. The other pairs are wrong: desert sandy soil is found in Jaisalmer and Barmer, not Banswara.
Q9. Desert sandy soils in western Rajasthan are pedologically characterized primarily by which of the following properties?
Explanation
The desert sandy soils covering western Rajasthan are characterized by sandy to loamy sand textures. These soils exhibit very weak profile development due to the arid environment and constant wind action. They possess a single-grained structure, low water-holding capacity, and minimal organic matter, reflecting their youth and the dominance of physical weathering over chemical or biological pedogenic processes.
Q10. Match the sub-classifications of sandy soils (List I) with their prominent characteristics or locations in Rajasthan (List II):
| Sub-classification | Characteristics/Locations |
|---|---|
| A. Sandy Dune Soil | i. Sub-surface hardpan of calcium carbonate |
| B. Calcic Brown Sandy Soil | ii. Found in depressions of Luni basin and Ghaggar bed |
| C. Gypsiferous Sandy Soil | iii. Mobile and devoid of distinct soil horizons |
| D. Saline Sandy Soil | iv. Presence of subsurface calcium sulphate layer |
Explanation
The desert landscape features specialized sandy soil variations. Sandy dune soils are mobile and lack distinct horizons, while calcic brown sandy soils contain a subsurface hardpan of calcium carbonate. Gypsiferous sandy soils are identified by a calcium sulphate layer, and saline sandy soils are typically found in low-lying depressions such as the Luni basin and the ancient Ghaggar bed.Answer key for these questions
| Q | Correct answer |
|---|---|
| 1 | (b) Prevailing extreme climatic conditions |
| 2 | (c) Statement I is correct but Statement II is incorrect |
| 3 | (b) II and III only |
| 4 | (a) Both A and R are true and R is the correct explanation of A. |
| 5 | (a) A-iii, B-ii, C-i, D-iv |
| 6 | (b) I, III, and IV |
| 7 | (a) Entisols |
| 8 | (c) Deep Black Soil - Jhalawar |
| 9 | (a) Sandy and loamy sand textures with weak profile development |
| 10 | (a) A-iii, B-i, C-iv, D-ii |
Key facts from Soils of Rajasthan
- In the arid west, extreme climate is the dominant factor in soil formation.
- Alluvial soils are most extensive in Bharatpur, Dholpur and Tonk; older alluvium is called Bhangar.
- Desert sandy soils have sandy and loamy sand textures with weak profile development.
- Black soils of Kota and Bundi shrink and swell because of the mineral montmorillonite; deep black soil is found in Jhalawar.
- Entisols occupy the largest area under the USDA soil taxonomy.
- Salts rise to the surface by capillary action and cause salinity.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Soils of Rajasthan?
This page has 37 practice MCQs on Soils of Rajasthan (Rajasthan Geography). Each has the correct answer, and most have an explanation.
Which soil occupies the largest area in Rajasthan?
The Entisols, according to the USDA soil taxonomy. They are young soils with little profile development, typical of sandy desert areas, and they cover the arid west of the State from Jaisalmer and Barmer to Bikaner.
Why do black soils crack and swell?
Because they contain the clay mineral montmorillonite, which expands when wet and shrinks when dry. This gives the black soils of Kota and Bundi their deep cracks in summer.
What is Bhangar?
The older alluvial deposits of the eastern plains, found on higher terraces above the flood level. The newer flood-plain deposits are called Khadar, and the two are used to describe the alluvial plains of north India.