Food & agriculture · c. 1840

Guano fertilizer

Seabird droppings dug from Peruvian islands became the world's most prized fertilizer.

From about 1840, ships hauled millions of tons of nitrogen- and phosphate-rich guano from Peru's Chincha Islands to Europe and the US. Its exhaustion by the 1870s, and then of Chilean saltpetre, pushed the search for synthetic nitrogen.

See it in the living treeWikipedia