Do rotting crops smell if they are not disposed of?

A pile of decomposing fruit can begin to ferment, to produce ethyl alcohol. This pile will have a strong odor of ethylene and attract both fruit flies and birds.

Rotting crops will smell if they go anaerobic. If you get a dense pile too wet it will begin to decompose anaerobically (bacteria that live in low oxygen) and these organisms produce hydrogen sulfide, the rotten egg smell. TO stop the smell just turn the pile so air gets in to restore aerobic bacteria and fungi decomposition. If the pile smells fresh, like turned soil, it is decomposing properly with sufficient oxygen to keep the anaerobic bacteria out..

If the pile has an ammonia odor, the crop has too much green nitrogen bearing material. Just add dry leaves, pine needles, straw, saw dust or shredded newsprint to add carbon and balance the decomposition. Or just add a few shovels of soil and turn the crop to reduce the smell.