fertilis

Fertilizer comes from the verb fertilize, from Latin fertilis (fruitful, productive), from ferre (to bear, to carry). The word entered English in the seventeenth century for any substance that makes soil more productive — manure, bone meal, guano, ash. The concept was ancient. The word was new. For most of human history, farmers knew that adding certain materials to soil improved crop yields, but they did not have a single word for the category.

Guano — seabird excrement — was the first fertilizer traded as a global commodity. In the 1840s and 1850s, Peru exported millions of tons of guano from the Chincha Islands. The United States passed the Guano Islands Act of 1856, authorizing American citizens to claim any uninhabited island with guano deposits. Wars were fought over bird droppings. The word fertilizer, in this era, mostly meant guano.

Fritz Haber and Carl Bosch changed everything. In 1909, Haber developed a process to fix atmospheric nitrogen into ammonia. By 1913, Bosch had industrialized it. Synthetic nitrogen fertilizer could now be produced in unlimited quantities. The Haber-Bosch process is estimated to support the food production that feeds approximately half the world's current population. Without it, roughly 4 billion people could not eat.

The word fertilizer now names one of the most consequential and destructive products in human civilization simultaneously. Nitrogen fertilizer feeds billions. It also causes algal blooms, dead zones in oceans, nitrous oxide emissions, and groundwater contamination. The Gulf of Mexico dead zone — an area the size of New Jersey where nothing can live — is caused primarily by fertilizer runoff from Midwest farms. The word for making things fruitful also names one of the largest sources of environmental damage on earth.