Major source of methane (CH₄) emission in agriculture is:

Correct option is B

· Flooded rice → anaerobic conditions → methanogenesis → CH₄ release.
· Contributes ~48% of agri CH₄ emissions (IPCC).
· Key factors: waterlogging, organic matter, high temperature.
Why other options are wrong
· (a), (c) Aerobic soils → negligible CH₄.
· (d) Sugarcane emits some N₂O but low CH₄.