BharatNotes Built from the Soils chapter, whose figures come from the Government of Rajasthan's Economic Review 2025-26, two ICAR papers on the arid zone, and PIB's Soil Health Card document. The single largest trap in this topic is a scope error rather than a wrong number, and this page is built around it.
How to use this page
Every answer traces to the parent chapter, and no question invents a fact. The order-wise percentages are from a 1997 paper about the arid zone; the state's soil-card and gypsum figures are for 2025-26 up to December, which is nine months and not a year; the Soil Health Card design dates from 2015.
The distractors are the point. The commonest error in this topic is not a wrong figure but a right figure applied to the wrong area — 51.84 per cent is real, and it is not a share of Rajasthan. Every answer carries a "why not the others" line, because in a paper with negative marking the skill being tested is elimination.
Work in this order: Section A first, since the vocabulary decides whether you can read the options at all; then the scope questions in B, which is where the marks are lost; then the mechanism, the scheme and the problems.
Read the tag on each question
| Tag | What it tests | If you keep missing these |
|---|---|---|
| Type A · scope | A figure true of the arid zone applied to the state | Ask of every percentage: a share of what? |
| Type B · vocabulary | A descriptive soil name offered where a USDA order is wanted | Learn the order names; the exam stopped using colours |
| Type C · part-year figure | A nine-month position read as a full year | Anything marked "up to December" is not a year |
| Type D · target, not achievement | A planned number offered as a result | Ask: is this what was done, or what was intended? |
| Type E · remedy mismatch | The treatment for one soil problem offered for another | Saline and sodic are different problems with different cures |
| Recall / Concept | No trap — the fact, or the mechanism behind it | Ordinary revision |
Section A — The vocabulary RPSC now uses (Q1–8)
1. In RAS 2024 Prelims the commission asked which soil dominates Jaipur, Dausa and Alwar. Its key was — Recall
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(d) Alfisols — the moderately weathered, reasonably fertile soils of the eastern semi-arid uplands.
Why not the others: (a) Entisols are the horizonless soils of the dune country in the west; (c) Vertisols are the shrink-swell clays of the south-east; (b) Inceptisols are the young transitional soils. All four options are USDA orders, which is the point of the question — a candidate revising "red loam" cannot answer it at all.
2. An Entisol is defined by — Type B · vocabulary
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(c) the absence of developed horizons — soils too young, or too constantly disturbed, to have formed them. Sand dunes are the type case, which is why the order dominates the desert.
Why not the others: (a) defines Vertisols; (b) defines Aridisols; (d) defines Alfisols. The four definitions are the whole of section 2 of the chapter, and a question can be set on any of them.
3. Which order is characterised by an aridic moisture regime with carbonate or gypsum accumulation at depth? Type B · vocabulary
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(a) Aridisols — the soils of the stable desert plains, where the surface has stayed put long enough to build a horizon.
Why not the others: (b) Entisols are on the moving surfaces and have no horizon at all — that is the contrast between the two desert orders; (c) Alfisols need more weathering than an arid regime allows; (d) Mollisols are the dark, base-rich grassland soils and do not figure in Rajasthan's account.
4. Vertisols are distinguished by — Type B · vocabulary
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(d). They are the black cotton soils of the south-east, and the deep dry-season cracking is the diagnostic behaviour.
Why not the others: (c) describes Entisols of the dune country, the opposite texture; (a) and (b) describe features of orders that do not occur in Rajasthan's account.
5. The chapter warns that a candidate who knows "the eastern plains have red-to-yellow loamy soils" — Type B · vocabulary
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(b). The description is accurate; it is simply not in the taxonomy the commission set. The translation to hold is that the fertile eastern semi-arid uplands are Alfisols and the dune country is Entisols.
Why not the others: (a) is unfair to the candidate — the fact is right; (c) is irrelevant; (d) gives the wrong order for the eastern uplands.
6. The Economic Review defines Rajasthan's ten agro-climatic zones on which four criteria? Recall
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(b). Soil type is written into the definition of the zones, not added afterwards — which is why a question about zones and a question about soils can share an answer.
Why not the others: (d) drops two of the four criteria; (a) and (c) substitute criteria the Review does not name.
7. The total reporting area of Rajasthan, on the Economic Review's 2024-25 figure, is — Recall
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(c) 343.43 lakh hectares, of which 53.02 per cent is net sown area.
Why not the others: (a) 208.73 lakh hectares is the area under operational land holdings in the Agricultural Census 2015-16, a different and smaller quantity; (b) 20.8 million hectares is the hot arid zone; (d) is the state's long-period average rainfall in millimetres, not an area at all.
8. The Economic Review divides the state between a desert or semi-desert north-west and a fertile south-east in the proportion — Recall
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(d) 61 per cent north-west, 39 per cent south-east. Hold that 61, because it returns from a completely different source in the next section.
Why not the others: (c) inverts it; (a) and (b) are invented. Note the related but distinct 60:40 figure the Environment Department gives for the Aravalli's division of the state — a different measurement of a similar idea.
Section B — The scope trap (Q9–16)
9. The figures "Entisols 51.84 per cent and Aridisols 41.05 per cent" are shares of — Type A · scope
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(b) the arid zone of Rajasthan. The paper that produced them opens "A soil map of arid zone of Rajasthan is presented", and the percentages in its abstract are of that zone's area.
Why not the others: (a) is the error in almost every note in circulation — the numbers are real and the scope is wrong; (c) and (d) are not what any source measures. This is the single most valuable distinction in the chapter.
10. That arid zone covers how much area, and how many districts? Recall
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(c) 20.8 million hectares across twelve districts — Jaisalmer, Barmer, Bikaner, Jodhpur, Jalore, Pali, Nagaur, Jhunjhunu, Sikar, Churu, Hanumangarh and Sri Ganganagar, on the pre-2023 map.
Why not the others: (a) 34.2 million hectares is the whole state; (d) takes the right area with the wrong district count; (b) is invented.
11. Dividing the arid zone's area by the state's gives about 61 per cent. Why does the chapter make a point of that? Concept
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(d). The Economic Review says the desert and semi-desert north-west is 61 per cent of the State; the arid zone the ICAR papers map is 20.8 of 34.22 million hectares, about 60.8 per cent. Two documents, two methods, one answer — which is the strongest kind of corroboration available.
Why not the others: (a) inverts it, since the two agree; (b) dismisses a convergence that is the section's point; (c) is not claimed by any source here.
12. On the same 1997 mapping, the dominant suborder among the Entisols is — Recall
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(a) Torripsamments — the sandy soils of dune and hummocky plain.
Why not the others: (b), (c) and (d) are all Aridisol subgroups, not Entisol ones. The paper names Cambids and Calcids as the main Aridisol great groups, with Psammentic and Typic Haplocambids, Typic Haplocalcids and Typic Petrocalcids as extensive subgroups. The trap is that all four options are real names from the same abstract.
13. How many mapping units did that survey delineate? Recall
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(d) 30 units, in the paper's own words: "In all, 30 units have been mapped."
Why not the others: (a) 12 is the district count of the arid zone; (c) 41 is the state's districts; (b) 10 is the agro-climatic zones. Every distractor is a real number from a neighbouring fact, which is how a well-set question works.
14. Why does the chapter assert no state-wide order-wise percentage at all? Type A · scope
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(a). The eastern plains and the south-eastern plateau, where the Alfisols and Vertisols are, are not in that survey. A figure for the Alfisol or Vertisol share of Rajasthan would be the natural companion to the section and it is deliberately absent.
Why not the others: (b) is false — the taxonomy applies everywhere, and RPSC keyed Alfisols for eastern districts; (c) and (d) are inventions.
15. The 1997 paper is still the standard reference because — Concept
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(b). The 2021 CAZRI nutrient-mapping paper quotes the same two percentages and attributes them to Dhir et al. 1997 rather than superseding them — which is evidence that the field still treats it as current, and also the reason the chapter does not present it as a new measurement.
Why not the others: (a) overstates it; (c) and (d) describe procedures that do not exist.
16. Rajasthan's total geographical area, used as the denominator in the scope calculation, is about — Recall
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(c) about 34.2 million hectares, that is 3,42,239 square kilometres.
Why not the others: (a) is the arid zone, the numerator not the denominator; (b) and (d) are the right digits with the decimal in the wrong place, which is the commonest arithmetic slip on this conversion.
Section C — Why the desert soils are poor (Q17–23)
17. The 2021 CAZRI paper attributes weak weathering and pedogenesis in the arid soils to — Concept
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(a). The paper's own sentence is that "because of aridic moisture regime and hyperthermic temperature regimes weathering of minerals and pedogenesis are weak."
Why not the others: (d) inverts the finding, since these soils are low in organic carbon; (b) and (c) are human pressures that degrade soil but are not what the paper cites for weak pedogenesis.
18. The chain the chapter asks you to carry into an answer runs — Concept
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(b). No clay means no capacity to hold nutrients or water, which is why the order is Entisol — an order defined by the absence of horizons — and why fertiliser applied to a dune behaves differently from fertiliser applied in Kota.
Why not the others: each names a real process, but (a), (c) and (d) are degradation chains rather than the formation chain the question asks for.
19. The chapter draws a distinction between soils that are "young" and soils that are "exhausted". Rajasthan's desert soils are — Concept
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(c). A soil that has never developed a horizon is a different problem from a soil that has lost one, and the remedies differ: the first needs organic matter and moisture retention, the second needs the lost structure rebuilt.
Why not the others: (a) and (d) import an exhaustion narrative the evidence does not support; (b) contradicts the nutrient findings.
20. The landforms the 2021 paper lists as carrying these soils include all of the following EXCEPT — Recall
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(b) coastal mudflats — Rajasthan is landlocked, so no coastal landform appears.
Why not the others: the paper names sand dunes; hills and colluvial plains; alluvial plains; saline depressions; riverbed and water bodies. Three of the four options are on that list.
21. In the 2021 nutrient assessment, how many soil samples were analysed across the hot arid region? Recall
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(a) 5,655 samples.
Why not the others: (b) 4.79 lakh is the state's soil-sample collection under the Soil Health Card in 2025-26 up to December — a scheme figure, not a research one; (c) 1,92,000 is the Budget proposal for 2026-27; (d) 30 is the number of soil mapping units. Four real numbers, four different things.
22. DTPA-extractable iron in that study had a mean of 6.42 mg/kg, which the authors rate as — Recall
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(d) marginally adequate, on a range of 0.84 to 42.7 mg/kg.
Why not the others: (a) overstates the deficiency the authors report; (b) and (c) are contradicted by the paper. Note the width of the range — a mean of 6.42 across a spread of 0.84 to 42.7 conceals enormous local variation, which is the argument for testing soil field by field.
23. The soils of the arid region are described as low in all of the following EXCEPT — Recall
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(d) sand — the soils are described as predominantly sandy, so sand is the one constituent that is high.
Why not the others: clay, silt and organic carbon are all low, and the soils are poor in available nutrients. The question tests whether you read "predominantly sandy" as a presence rather than an absence.
Section D — The Soil Health Card (Q24–33)
24. The Soil Health Card scheme was launched on 19 February 2015 from — Recall
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(c) Suratgarh, in Sri Ganganagar district. It is the only part of a national scheme that is a Rajasthan fact, and a question pairing the scheme with a state will pair it with this one.
Why not the others: the remaining options are plausible Rajasthan towns and none is the launch site. Note the year too: 2015 was the International Year of Soils.
25. How many parameters does a Soil Health Card test? Recall
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(d) twelve — nitrogen, phosphorus, potassium and sulphur as macro-nutrients; zinc, iron, copper, manganese and boron as micro-nutrients; and pH, electrical conductivity and organic carbon.
Why not the others: (a) three is the NPK trio and the standard distractor; (b) and (c) are partial counts of the same list. The last three matter most for this state: EC measures salinity and pH measures sodicity.
26. A Soil Health Card is issued once every — Recall
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(d) three years, so that the next card in the following cycle captures the change in soil health over time.
Why not the others: the cycle is the design feature that makes the card a monitoring instrument rather than a one-off test, and the other intervals are invented.
27. The central government provides how much per sample under the scheme? Recall
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(a) ₹190 per sample, covering collection, testing, card generation and distribution.
Why not the others: (b) and (c) move the decimal; (d) contradicts the ₹1,706.18 crore released to states and UTs as of February 2025.
28. What share of samples is cross-checked in referral laboratories for quality assurance? Recall
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(c) 1 per cent.
Why not the others: (a) and (b) overstate it; (d) is contradicted by the scheme document. A one per cent referral check is the scheme's only stated quality control, which is worth noting when judging how far the resulting data can be pushed.
29. Since 2022-23 the scheme has run as a component of — Recall
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(b) RKVY, as the "Soil Health & Fertility" component.
Why not the others: all three are real schemes and none absorbed the Soil Health Card. Scheme-merger questions are common, and the year — 2022-23 — is as examinable as the destination.
30. In Rajasthan in 2025-26 up to December, soil health cards issued against the annual target stood at — Type C · part-year figure
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(d) 4,14,714 issued against a target of 4,05,000 — the target already exceeded in nine months.
Why not the others: (a) reverses target and achievement; (b) substitutes the sample count, which was 4.79 lakh, for the card count; (c) is the gypsum row, a different input entirely. All four numbers are real and on the same page of the Review.
31. Gypsum distribution in the same nine months reached — Type D · target, not achievement
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(a) 8,090 tonnes against a 30,000 tonne target — about 27 per cent delivered in nine months.
Why not the others: (b) reads a target as an achievement, which is the trap the tag names; (c) invents a target that would make the performance look like a success; (d) overstates the shortfall.
32. The chapter argues that the contrast between the card figure and the gypsum figure shows — Concept
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(b). A state that tests soil at better than its target and delivers the corrective at about a quarter of its target has an implementation gap, not an information gap — and that is the sharpest Mains point the chapter offers.
Why not the others: (a) inverts the finding, since testing exceeded target; (c) is false; (d) is contradicted by the two very different targets.
33. Nationally, how many soil testing laboratories had been set up as of February 2025? Recall
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(d) 8,272 in total.
Why not the others: each is a real component of that total — (a) 1,068 static labs, (c) 6,376 mini labs, (b) 665 village-level labs, plus 163 mobile labs. A question offering a component as the total is the standard form, and the components sum to the answer.
Section E — What goes wrong with these soils (Q34–41)
34. Splash and sheet erosion are caused by — Recall
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(a) rainwater — splash first, then sheet erosion, the loss of a thin layer across a whole surface.
Why not the others: (c) running water in channels gives rill and then gully erosion; (b) wind gives surface creep, saltation and suspension; (d) does not operate in Rajasthan.
35. Surface creep, saltation and suspension are the three forms of — Recall
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(d) wind erosion, in ascending order of particle fineness — creep along the surface, saltation bouncing, suspension carried in the air.
Why not the others: (a) covers splash, sheet, rill and gully; (b) and (c) are not erosion at all. Wind is the agent that distinguishes this state, which is what makes the trio worth learning.
36. Gully erosion in Rajasthan is most associated with — Concept
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(c) the Chambal ravines — the badland form that is the reason the Dang exists as an administrative category, with its own state development programme.
Why not the others: (a) is wind country, not gully country; (b) and (d) are not the ravine belt. The link between a landform and an administrative region is the examinable part.
37. A saline soil is best identified by — Type E · remedy mismatch
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(c) a white salt crust on the surface and high electrical conductivity.
Why not the others: (a) a pH above 8.5 identifies a sodic or alkaline soil, which is the confusion this whole section exists to prevent; (b) describes a Vertisol; (d) is not a diagnostic used here.
38. Gypsum is the remedy for — Type E · remedy mismatch
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(d) sodic or alkaline soils, where sodium has replaced other cations on the clay and destroyed the structure.
Why not the others: (a) saline soils are treated by leaching and drainage, not gypsum — applying the wrong remedy to the wrong problem is exactly the distinction a question is testing; (b) and (c) need physical rather than chemical intervention.
39. Which pair correctly matches problem to remedy? Type E · remedy mismatch
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(b). A saline soil has too much soluble salt and is washed out; a sodic soil has sodium on the clay and needs a calcium source to displace it — which is what gypsum supplies, alongside organic matter such as dhaincha and farmyard manure.
Why not the others: (a) swaps the two, which is the single commonest error; (c) and (d) collapse two distinct problems into one.
40. Which two Soil Health Card parameters measure the two problems in this section? Concept
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(c) electrical conductivity, which measures salinity, and pH, which measures alkalinity. That is why the card tests twelve parameters and not merely the three nutrients.
Why not the others: the remaining pairs are all real card parameters measuring fertility rather than these two structural problems.
41. Why does the chapter print no process-wise share of Rajasthan's soil degradation? Type A · scope
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(a). The erosion typology on the page is a classification, not a measurement.
Why not the others: (c) 62.06 per cent is the total area of Rajasthan under desertification and land degradation on the SAC/ISRO atlas, carried in the physiography chapter — a total, not a process split; (b) is false, since the atlas exists; (d) overstates a real dominance into a totality.
Section F — Assertion, reason and matching (Q42–45)
42. Assertion (A): Rajasthan's desert soils are classified as Entisols. Reason (R): An aridic moisture regime and hyperthermic temperatures leave weathering too weak to form horizons. Concept
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(a). An Entisol is defined by the absence of developed horizons, and weak weathering is precisely why they never form. The reason explains the classification directly.
Why not the others: (b) would require the two to be unconnected; (c) and (d) deny statements both papers support.
43. Assertion (A): Entisols cover 51.84 per cent of Rajasthan. Reason (R): Dhir et al. mapped the state's soils in 1997. Type A · scope
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(c) both are false, and each is false in an instructive way. A is false because 51.84 per cent is a share of the arid zone, not of the state. R is false because the 1997 paper mapped the arid zone, not the state — its own opening words are "A soil map of arid zone of Rajasthan is presented."
Why not the others: (a) accepts both errors; (b) and (d) each rescue one of them. This is the chapter's central correction put in assertion-reason form, and both halves fail on the same word: scope.
44. Match the order with its diagnostic feature.
(A) Entisols (B) Aridisols (C) Alfisols (D) Vertisols
(i) subsurface clay, high base saturation (ii) no developed horizons (iii) shrink-swell clay (iv) aridic regime with carbonate or gypsum at depth Type B · vocabulary
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(a) A-(ii), B-(iv), C-(i), D-(iii).
Why not the others: each remaining option misplaces at least one order. The pair to fix first is A and B, because both are desert orders and the difference between them — no horizon against an accumulated one — is what the whole western half of the state turns on.
45. Match the figure with what it counts.
(A) 20.8 million ha (B) 4.79 lakh (C) 8,090 (D) 1,92,000
(i) gypsum tonnes distributed, 2025-26 to December (ii) soil samples proposed for 2026-27 (iii) the hot arid zone (iv) soil samples collected, 2025-26 to December Recall
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(b) A-(iii), B-(iv), C-(i), D-(ii).
Why not the others: (a) swaps the two sample figures, which is the intended trap — 4.79 lakh were collected in nine months of 2025-26 and 1,92,000 are proposed for 2026-27, so the proposal is well below the recent rate and must not be read as a scaling-up. (c) and (d) cross the scheme figures with the area.
More in This Series
- Soils of Rajasthan: Classification, Distribution and Soil Health — the parent chapter
- Every RAS Prelims Geography question, 2013–2024 — the official soil question with RPSC's key
- Agriculture of Rajasthan
- Caution for Readers — the claims that are genuinely unsettled
