Topic 86: Soil Resources of Raj. – Types and

Study Material

Paper Paper II

Unit 3

1. Rajasthan has 7 principal soil types: desert/arid, alluvial, red, laterite, black (regur), brown/forest, and saline-alkaline soils.
2. Desert/Arid soils (aeolian) cover ~61% of Rajasthan's total area, concentrated in western districts from Bikaner and Jaisalmer to Barmer and Jodhpur.
3. Alluvial soils of eastern Rajasthan — along Chambal, Banas, Gambhir and Banganga rivers — support the state's most productive irrigated farming (wheat, mustard, soybean).
4. Red soils (ferruginous) occur in Dungarpur and Banswara districts of the south-eastern tribal belt, derived from Precambrian gneissic rocks.
5. Black soils (regur) — derived from Deccan basalt — are found in Kota, Bundi, Jhalawar, and Chittorgarh districts; they expand when wet and crack when dry.
6. Laterite soils are confined to the hilly regions of Udaipur, Sirohi, and Pratapgarh districts, formed under high rainfall leaching conditions.
7. Saline-alkaline soils (usar/banjar) fringe the inland drainage basins of Sambhar, Didwana, Degana, and the IGNP command area in northern Rajasthan.
8. The ICAR classification (Indian Council of Agricultural Research) categorises Rajasthan's soils into 8 orders: Aridisols, Entisols, Inceptisols, Alfisols, Vertisols, Mollisols, Oxisols, and Ultisols.
9. Major soil problems include wind erosion (Thar Desert — 59% of eroded land), waterlogging (1.54 lakh ha in IGNP command area), salinity/alkalinity, and micronutrient deficiency (zinc, boron, sulphur).
10. The Soil Health Card Scheme (मृदा स्वास्थ्य कार्ड योजना) was launched nationally in February 2015; Rajasthan issued 72.66 lakh soil health cards in the first two cycles (2015-17 and 2017-19).
11. Rajasthan has 27 soil testing laboratories (मृदा परीक्षण प्रयोगशालाएँ) under the Agriculture Department serving all 50 districts, with a combined annual testing capacity of over 4 lakh soil samples.
12. Wind erosion removes ~60–100 tonnes of topsoil per hectare per year in active Thar Desert zones; shelter belts (shelterbelt plantation) under CAZRI reduce soil loss by 40–60%.
13. Indira Gandhi Nahar Pariyojana (IGNP) command area irrigation has transformed ~7.9 lakh ha of desert in Bikaner, Jaisalmer, Ganganagar, and Hanumangarh — but secondary salinisation now affects ~1.54 lakh ha.
14. Contour bunding (समोच्च बंधन), terracing (सीढ़ीदार खेती), and check dams are the primary mechanical conservation measures in the Aravalli and Vindhyan hilly tracts of southeastern Rajasthan.
15. Under the National Mission for Sustainable Agriculture (NMSA), Rajasthan has implemented soil health management, on-farm water management, and rainfed area development across 18 arid and semi-arid districts. / NMSA के अंतर्गत राजस्थान के 18 शुष्क और अर्ध-शुष्क जिलों में मृदा स्वास्थ्य प्रबंधन लागू किया गया है। ---

Key facts

Rajasthan has 7 principal soil types: desert/arid, alluvial, red, laterite, black (regur), brown/forest, and saline-alkaline soils.
Desert/Arid soils (aeolian) cover ~61% of Rajasthan's total area, concentrated in western districts from Bikaner and Jaisalmer to Barmer and Jodhpur.
The ICAR classification (Indian Council of Agricultural Research) categorises Rajasthan's soils into 8 orders: Aridisols, Entisols, Inceptisols, Alfis…
Major soil problems include wind erosion (Thar Desert
The Soil Health Card Scheme (मृदा स्वास्थ्य कार्ड योजना) was launched nationally in February 2015;

Key Points at a Glance

1
Rajasthan has 7 principal soil types: desert/arid, alluvial, red, laterite, black (regur), brown/forest, and saline-alkaline soils.
2
Desert/Arid soils (aeolian) cover ~61% of Rajasthan's total area, concentrated in western districts from Bikaner and Jaisalmer to Barmer and Jodhpur.
3
Alluvial soils of eastern Rajasthan — along Chambal, Banas, Gambhir and Banganga rivers — support the state's most productive irrigated farming (wheat, mustard, soybean).
4
Red soils (ferruginous) occur in Dungarpur and Banswara districts of the south-eastern tribal belt, derived from Precambrian gneissic rocks.
5
Black soils (regur) — derived from Deccan basalt — are found in Kota, Bundi, Jhalawar, and Chittorgarh districts; they expand when wet and crack when dry.
6
Laterite soils are confined to the hilly regions of Udaipur, Sirohi, and Pratapgarh districts, formed under high rainfall leaching conditions.
7
Saline-alkaline soils (usar/banjar) fringe the inland drainage basins of Sambhar, Didwana, Degana, and the IGNP command area in northern Rajasthan.
8
The ICAR classification (Indian Council of Agricultural Research) categorises Rajasthan's soils into 8 orders: Aridisols, Entisols, Inceptisols, Alfisols, Vertisols, Mollisols, Oxisols, and Ultisols.
9
Major soil problems include wind erosion (Thar Desert — 59% of eroded land), waterlogging (1.54 lakh ha in IGNP command area), salinity/alkalinity, and micronutrient deficiency (zinc, boron, sulphur).
10
The Soil Health Card Scheme (मृदा स्वास्थ्य कार्ड योजना) was launched nationally in February 2015; Rajasthan issued 72.66 lakh soil health cards in the first two cycles (2015-17 and 2017-19).
11
Rajasthan has 27 soil testing laboratories (मृदा परीक्षण प्रयोगशालाएँ) under the Agriculture Department serving all 50 districts, with a combined annual testing capacity of over 4 lakh soil samples.
12
Wind erosion removes ~60–100 tonnes of topsoil per hectare per year in active Thar Desert zones; shelter belts (shelterbelt plantation) under CAZRI reduce soil loss by 40–60%.
13
Indira Gandhi Nahar Pariyojana (IGNP) command area irrigation has transformed ~7.9 lakh ha of desert in Bikaner, Jaisalmer, Ganganagar, and Hanumangarh — but secondary salinisation now affects ~1.54 lakh ha.
14
Contour bunding (समोच्च बंधन), terracing (सीढ़ीदार खेती), and check dams are the primary mechanical conservation measures in the Aravalli and Vindhyan hilly tracts of southeastern Rajasthan.
15
Under the National Mission for Sustainable Agriculture (NMSA), Rajasthan has implemented soil health management, on-farm water management, and rainfed area development across 18 arid and semi-arid districts. / NMSA के अंतर्गत राजस्थान के 18 शुष्क और अर्ध-शुष्क जिलों में मृदा स्वास्थ्य प्रबंधन लागू किया गया है।

Introduction and Syllabus Scope

Soil resources of Rajasthan should be studied as a Rajasthan-specific bridge between physical geography and agriculture, with emphasis on soil formation, district-wise distribution, degradation and conservation.

The RPSC syllabus places Soil under Unit III, Earth Science, in the Natural Resources portion, while the Rajasthan part of the same unit supplies the state frame through physiography, climate, vegetation, agriculture, minerals and population. The earlier draft treated soil as if it appeared only beside Rajasthan's mineral and water resources; the safer reading is that soil is explicitly named in the official syllabus and must be localised through Rajasthan examples. The official RPSC syllabus PDF for this examination runs to 3 pages, so a compact but exact mapping of topic, unit and sub-topic matters in revision.

This topic demands three levels of analysis: genetic classification (how each soil type formed through parent material, climate, vegetation, topography and time), geographic distribution (which districts and which physiographic zone), and management challenges (soil degradation, conservation and government policy). The examiner's focus is consistently Rajasthan-specific; generic pedology theory without Rajasthan districts, rivers, canal commands and conservation measures will not score well.

This is a PYQ Tier 5 (New/Gap) topic. It has not been directly tested in the recent RAS Mains papers used in this corpus: 2013, 2016, 2018, 2021, 2023 and 2024. Its presence in the revised 2026 syllabus alongside zero prior direct coverage makes it a credible surprise question target. When examiners introduce a revised syllabus, they often test precisely the topics that were absent before, especially when those topics connect two already familiar areas. Adjacent topics regularly tested include agriculture (Topic #87) and physiography (Topic #83); a soil question is the natural bridge between them.

Scope boundaries: This chapter covers soil types, distribution, problems and conservation. Irrigation infrastructure such as dams and canals, including IGNP, appears here only in the context of its soil impact, not in its engineering or administrative dimensions, which belong to Topic #91. Fertiliser policy and crop-soil matching belong primarily to Topic #87, though the soil-agriculture interface is referenced here. The geological parent material context links to Topic #83, especially Aravalli rocks, Banded Gneissic Complex rocks, Vindhyan rocks and Deccan Trap basalt in the south-east.

For answer writing, do not begin with a dictionary definition alone. Begin with Rajasthan's contrast: aeolian desert soils in the west, alluvial soils in the east, black soils in Hadoti, red and lateritic soils in the south and saline-alkaline soils in inland drainage or canal-command zones. That opening immediately signals that the answer is Rajasthan-aware rather than a recycled soil science note.

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PREDICTED Predicted RAS Questions

Based on PYQ trends and 2026 syllabus analysis

1 5M Name the major soil types of Rajasthan and their geographic distribution. 5 marks · 50 words

Model Answer

Rajasthan has five major soil types: (1) Desert/Sandy soils (Aridisols) — western Thar, Jaisalmer-Barmer; (2) Red-yellow soils — southeastern Udaipur, Dungarpur; (3) Black soils (Vertisols/Regur) — Hadoti region, Kota-Bundi-Baran-Jhalawar; (4) Alluvial soils — eastern plains along Chambal-Banas, Ganganagar; (5) Saline/Alkaline soils — Sambhar Lake basin and IGNP command area. Alluvial soils support the most intensive agriculture.

~50 words • 5 marks