The most accurate comparison of the gases commonly released by fertilizers and landfills is:
Chemicals from fertilizers can release nitrous oxide, while landfills release methane.
Fertilizers, particularly nitrogen-based ones, can lead to the production of nitrous oxide (N₂O), a potent greenhouse gas. Landfills, on the other hand, are significant sources of methane (CH₄), which is generated during the anaerobic decomposition of organic materials.