Which of the following are the sources of Nitrogen in an ecosystem?

1. Agricultural land

2. Fossil fuel

3. Livestock

4. Urban waste

Select the correct answer using the code given below.

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

Answer (Detailed Solution Below)

Option 4 : 1, 2, 3 and 4
Free
UPSC Civil Services Prelims General Studies Free Full Test 1
21.6 K Users
100 Questions 200 Marks 120 Mins

Detailed Solution

Download Solution PDF

The correct answer is 1, 2, 3, and 4.

Key Points

  • Burning fossil fuels, application of nitrogen-based fertilizers, and other activities can dramatically increase the amount of biologically available nitrogen in an ecosystem.
  • The main sources of nitrogen in the atmosphere therefore include:
    • Atmospheric precipitation,
    • Geological sources,
    • Agricultural land,
    • Livestock (ruminants like cows, sheep, goats etc) and poultry operations and
    • Urban waste,
    • Fossil fuels
  • Hence, Option 4 is the correct answer.

Additional Information

  • Fossil fuels
    • It is buried flammable geologic deposits of organic substances such as dead plants and animals that got deposited under several thousand feet of silt.
    • These deposits decayed with the passage of time and got converted to natural gas, coal and petroleum due to the extreme heat and pressure inside the earth’s crust.
    • They are also known as non-renewable sources of energy as it takes a very long time for them to replenish.
    • Fossil fuels are of the following types:
      • Coal
      • Petroleum
      • Natural gas
Latest UPSC Civil Services Updates

Last updated on Jul 6, 2025

-> UPSC Mains 2025 Exam Date is approaching! The Mains Exam will be conducted from 22 August, 2025 onwards over 05 days!

-> Check the Daily Headlines for 4th July UPSC Current Affairs.

-> UPSC Launched PRATIBHA Setu Portal to connect aspirants who did not make it to the final merit list of various UPSC Exams, with top-tier employers.

-> The UPSC CSE Prelims and IFS Prelims result has been released @upsc.gov.in on 11 June, 2025. Check UPSC Prelims Result 2025 and UPSC IFS Result 2025.

-> UPSC Launches New Online Portal upsconline.nic.in. Check OTR Registration Process.

-> Check UPSC Prelims 2025 Exam Analysis and UPSC Prelims 2025 Question Paper for GS Paper 1 & CSAT.

-> UPSC Exam Calendar 2026. UPSC CSE 2026 Notification will be released on 14 January, 2026. 

-> Calculate your Prelims score using the UPSC Marks Calculator.

-> Go through the UPSC Previous Year Papers and UPSC Civil Services Test Series to enhance your preparation

-> The NTA has released UGC NET Answer Key 2025 June on is official website.

Get Free Access Now
Hot Links: teen patti gold downloadable content teen patti apk download all teen patti teen patti sequence