UPSC Prelims 2019 GS Paper I · Q41 of 100 Environment & Ecology medium

Consider the following statements : 1. Agricultural soils release nitrogen oxides into environment. 2. Cattle release ammonia into environment. 3. Poultry industry releases reactive nitrogen compounds into environment. Which of the statements given above is/are correct?

  1. (a) 1 and 3 only
  2. (b) 2 and 3 only
  3. (c) 2 only
  4. (d) 1, 2 and 3 ✓ UPSC's answer

Why the answer is (d)

• Reactive nitrogen escapes from agriculture in several forms.

• Fertilised soils release nitrous oxide and nitric oxide through microbial nitrification and denitrification (statement 1); N2O is a potent greenhouse gas.

• Cattle urine and dung release ammonia (statement 2), a major source of PM2.5 precursors and soil acidification.

• Poultry litter, rich in uric acid, gives off ammonia and other reactive nitrogen compounds (statement 3).

• The Indian Nitrogen Assessment (2017) found agriculture the largest source of reactive nitrogen in India.

• Hence 1, 2 and 3, option (d).

Why the other options are wrong

(a) 1 and 3 only
Cattle ammonia emissions are also real.
(b) 2 and 3 only
Soil nitrogen-oxide emissions are also real.
(c) 2 only
Soils and poultry also release reactive nitrogen.

Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2019, held on 2 June 2019. 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.

Practise this paper free