UPSC
2022

Question:

Among the following crops, which one is the most important anthropogenic source of both methane and nitrous oxide?

A

Cotton

B

Rice

C

Sugarcane

D

Wheat

Correct Answer

(b) Rice

Solution:

  • Methane and nitrous oxide are important greenhouse gases. They contribute to global warming. To a large extent, emissions of methane and nitrous oxide are connected with the intensification of food production.
  • Important anthropogenic sources of biogenic methane are wet rice fields, cattle, animal waste, landfills and biomass burning.
  • Important anthropogenic sources of biogenic nitrous oxide are land-use change, fertilizer production and use and manure application.
  • Flooded rice cultivation has been identified as one of the leading global agricultural sources of anthropogenic methane (CH4) emissions. Furthermore, it has been estimated that global rice production is responsible for 11% of total anthropogenic CH4 emissions.
  • Paddies are a potential source of anthropogenic nitrous oxide (N2O) emission as well. In paddies, both the soil and the rice plants emit N2into the atmosphere. The rice plant in the paddy is considered to act as a channel between the soil and the atmosphere for N2O emission.