RAS question
Consider the following pairs of Rajasthan districts and their dominant soil orders: 1. Ganganagar - Aridisols (arid zone sandy soil) 2. Jhalawar - Vertisols (black cotton soil) 3. Udaipur - Alfisols (red and lateritic soil) 4. Bharatpur - Inceptisols (young alluvial soil) How many pairs are CORRECTLY matched?
Correct answer: (C) All 4.
All four listed Rajasthan district-soil order pairs are correctly matched: Ganganagar-Aridisols, Jhalawar-Vertisols, Udaipur-Alfisols and Bharatpur-Inceptisols.
Explanation
The match works because each district is being read through broad soil taxonomy, not just surface appearance. Rajasthan's soils are grouped under five orders: Aridisols, Alfisols, Entisols, Inceptisols and Vertisols. Ganganagar belongs to the arid north-western setting, where Aridisols have calcic or gypsic horizons. Jhalawar lies in Hadaoti, where Vertisols are deep black cracking clay, the black cotton soil type. Udaipur fits Alfisols, associated here with argillic B-horizon soils and red-lateritic conditions in southern Rajasthan. Bharatpur is matched with Inceptisols because the relevant alluvial soils are young and show limited horizon development.
Why the other options are wrong
- (A) Only 2 undercounts the matches because Ganganagar-Aridisols, Jhalawar-Vertisols, Udaipur-Alfisols and Bharatpur-Inceptisols are all treated as correct in the soil-order mapping.
- (B) Only 3 leaves out one valid pair, even though Ganganagar's base arid-zone soil is Aridisols along with the other three matches.
- (D) Only 1 is far too low because all four district-soil order pairs are correctly matched.
Concept
This tests Rajasthan soil taxonomy at the order level and its district-wise distribution. It recurs in RAS because soil regions connect physical geography with agriculture, irrigation and regional planning.