UPSC Prelims 2013 · Question 84 of 99

UPSC Prelims 2013 question on Soil Nitrogen Sources

Which of the following adds/add nitrogen to the soil?

1. Excretion of urea by animals
2. Burning of coal by man
3. Death of vegetation

Select the correct answer using the codes given below:

  1. 1 only
  2. 2 and 3 only
  3. 1 and 3 only
  4. 1, 2 and 3
Show answer

Answer: C. 1 and 3 only

Analysis

Animal excreta such as urea contribute nitrogen compounds to the soil through decomposition. Dead vegetation also decomposes and returns nitrogen and other nutrients back to the soil, helping maintain the nitrogen cycle. Burning of coal does not add usable nitrogen to the soil and instead mainly releases pollutants into the atmosphere. Therefore, statements 1 and 3 are correct.

Extra UPSC info

Nitrogen is an essential nutrient for plant growth and is continuously recycled through the nitrogen cycle.

More questions on Ecology and Ecosystem

All 30 questions on Ecology and Ecosystem →

← Full 2013 question paper · All Environment and Ecology questions