UPSC Prelims 2016 GS Paper I · Q83 of 100 Economy medium

Which of the following is/are the advantage/advantages of practising drip irrigation? 1. Reduction in weed 2. Reduction in soil salinity 3. Reduction in soil erosion Select the correct answer using the code given below.

  1. (a) 1 and 2 only
  2. (b) 3 only
  3. (c) 1 and 3 only ✓ UPSC's answer
  4. (d) None of the above is an advantage of practising drip irrigation

Why the answer is (c)

• Drip irrigation delivers water slowly at the root zone of each plant.

• Because the inter-row soil stays dry, weed growth is reduced (1); because water is applied gently rather than flooded, soil erosion and run-off are reduced (3).

• Statement 2 is wrong: drip does not reduce salinity — salts can accumulate at the wetting front, though it avoids the waterlogging that flood irrigation causes.

• Drip also saves 30–50% water and raises yields; India subsidises it under PMKSY 'Per Drop More Crop'.

• Hence 1 and 3 only, option (c).

Why the other options are wrong

(a) 1 and 2 only
Statement 2 is wrong: drip does not reduce salinity.
(b) 3 only
Weed reduction is also an advantage.
(d) None of the above is an advantage of practising drip irrigation
Weed and erosion reduction are real advantages.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2016, held on 7 August 2016. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.

Reading the answer is not the same as getting it right under a clock. Practise this question with UPSC's negative marking, and anything you miss goes into an error notebook until you get it right twice.

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