Corn

Great Smithsonian piece on our food supply, corn, and fertilizer:

For the great edifice of variety and choice that is an American supermarket rests on a remarkably narrow biological foundation: corn. It's not merely the feed that the steers and the chickens and the pigs and the turkeys ate; it's not just the source of the flour and the oil and the leavenings, the glycerides and coloring in the processed foods; it's not just sweetening the soft drinks or lending a shine to the magazine cover over by the checkout. The supermarket itself--the wallboard and joint compound, the linoleum and fiberglass and adhesives out of which the building itself has been built--is in no small measure a manifestation of corn.

There are some 45,000 items in the average American supermarket, and more than a quarter of them contain corn. At the same time, the food industry has done a good job of persuading us that the 45,000 different items or SKUs (stock keeping units) represent genuine variety rather than the clever rearrangements of molecules extracted from the same plant.

You just gotta click through to read the case for the Haber-Bosch process for fixing nitrogen being the most important invention of the 20th century.