Arid and desert soils constitute one of the eight major soil groups recognised in Indian soil classification by the Indian Council of Agricultural Research (ICAR) and the National Bureau of Soil Survey and Land Use Planning (NBSS&LUP, Nagpur). Designated Aridisols under the United States Department of Agriculture (USDA) Soil Taxonomy adopted by NBSS&LUP, they develop in regions receiving under 250–300 mm of annual rainfall where evaporation exceeds precipitation. In India they occupy roughly 4.4 per cent of the geographical area, concentrated in western Rajasthan (the Thar/Marusthali), and extending into the Rann of Kutch in Gujarat, southern Punjab, Haryana, and parts of the Saurashtra coast. Their parent material is largely wind-deposited (aeolian) sand transported from the Indus basin, mixed with weathered material from the Aravalli flanks.
Texturally these soils are sandy to sandy-loam, friable, and structureless, with low water-retention capacity and high permeability that causes rapid percolation and moisture loss. Because there is little leaching, soluble salts accumulate in the upper horizons, producing high salinity and alkalinity, while sub-surface layers often develop a hard kankar (calcium carbonate) pan that obstructs water infiltration and root penetration. They are deficient in nitrogen and organic matter owing to scant vegetation, but the phosphate content is normally adequate and the lower horizons may hold appreciable lime. A defining feature is high soluble-salt content and, in saline patches, salt-encrusted surfaces. Soil colour ranges from red to brown, and dune-forming sands shift readily under wind action, accelerating desertification.
These soils are inherently low in fertility but become productive where irrigation is supplied and salinity controlled. The Indira Gandhi Canal (formerly Rajasthan Canal), drawing Sutlej–Beas waters, has transformed parts of western Rajasthan—Ganganagar, Hanumangarh, Bikaner—into wheat, cotton, mustard and gram tracts, though over-irrigation has triggered waterlogging and secondary salinisation in stretches. Drought-resistant crops such as bajra (pearl millet), jowar, pulses and guar are traditionally grown on residual moisture. Management measures include gypsum application to reclaim alkaline soils, shelterbelts and afforestation under the Desert Development Programme, and drip irrigation to economise water. As of 2026, controlling desertification under India's commitments to the UN Convention to Combat Desertification (UNCCD), of which India hosted COP14 in 2019, remains a live policy concern, with ISRO's Space Applications Centre mapping land degradation.
For the UPSC examination, arid and desert soils are tested in Geography (Indian physical geography) within both Prelims and GS Paper I (Mains), and intersect with environment and agriculture topics. Candidates should be able to map their distribution, distinguish them from neighbouring red and black soils, and link their properties to crop suitability and irrigation challenges. Typical question angles ask why desert soils are saline and nitrogen-deficient, how the Indira Gandhi Canal altered land use, and the relationship between soil type and desertification under the UNCCD framework. A precise grasp of the ICAR classification and the Aridisol order strengthens both factual recall and analytical answers.
Example
The Indira Gandhi Canal, fully extended by 1987, converted arid sandy soils of Ganganagar and Bikaner districts in western Rajasthan into irrigated wheat and cotton farmland, though waterlogging later emerged.
Frequently asked questions
Sparse vegetation and low organic matter limit nitrogen and humus accumulation. Because rainfall is too low to leach minerals, soluble salts are drawn upward by intense evaporation and accumulate in the upper horizons, raising salinity and alkalinity.