Organic fertilizer

GUANO

This natural soil enhancer comes from seabird or bat droppings, often found in coastal caves or arid regions.

"Guano" is a natural fertilizer made from the droppings of seabirds, bats, or seals, often used in organic farming. The clue points directly to this term since it’s a well-known type of organic fertilizer with no wordplay involved. If you’ve heard of it in gardening or history (like the 19th-century "Guano Wars" over its value), that might have helped you connect the dots.