RAS question
India's irrigation sources — the largest source is:
Correct answer: (A) Tube wells and borewells (about 46%).
Tube wells and borewells are India's largest irrigation source, accounting for about 46% of the net irrigated area.
Explanation
Tube wells and borewells are the largest irrigation source because they cover the biggest share of India's irrigated area. The official Agriculture Census table in Agricultural Statistics at a Glance 2020 lists tubewells at 29,165 thousand hectares out of a total 64,567 thousand hectares, which is roughly 45% and rounds to about 46%. Canals come next, followed by wells and tanks, so none of the surface-water options overtakes groundwater-based irrigation. This also explains why groundwater depletion matters for Indian geography: when the leading irrigation source is groundwater extraction, stress in regions such as Punjab, Haryana and western Uttar Pradesh becomes a core agrarian concern.
Why the other options are wrong
- (B) Tanks are a much smaller source, with the Agriculture Census table listing only 2,248 thousand hectares, or about 3% of India's net irrigated area.
- (C) Rivers directly are not the leading irrigation source; the large surface-water category in the irrigation data is canals, and it is still below tubewells.
- (D) Canals are important but not the largest source, since Agricultural Statistics at a Glance 2020 lists canals at 16,908 thousand hectares against 29,165 thousand hectares under tubewells.
Concept
This tests irrigation-source composition in Indian agriculture, especially the dominance of groundwater-based irrigation. It recurs in RAS because irrigation patterns connect physical geography with agriculture, regional development and groundwater stress.