Corn or Potato? The Crops That Could Feed Humanity's Last Days

If civilization collapsed and humanity could keep only one crop alive, which would it be? A Chinese grain researcher argues the answer most likely comes down to a two-way fight between corn and potatoes — and the choice says a lot about how we feed eight billion people today.

Cui Kai, author of the book The Story of Grains and an academic adviser to the documentary series Once Upon a Bite: Grain Planet, laid out the question in an essay published for World Food Day on October 16. He framed it as a thought experiment familiar from science fiction: in The Martian, an astronaut stranded on Mars survives by growing potatoes, while Interstellar imagines a blight that destroys the world’s crops one species at a time.

Both crops belong to the broad category of staple foods, the energy-dense plants that supply most of humanity’s calories. Corn wins on raw productivity. It converts sunlight into starch with an efficiency few crops can match, and centuries of breeding have pushed yields higher and higher. It also stores and ships well as dry grain, which is why it anchors industrial food systems, animal feed and even fuel production.

Potatoes take a different route. They pack more edible calories per hectare than most cereals and grow in a startling range of climates, from sea level to high mountain valleys. They need less processing to become food — you can boil one and eat it. That combination of yield and resilience is why the potato helped feed Europe’s population boom after it arrived from the Andes, and why it remains a staple across China’s cooler northern and western regions.

The trade-offs matter. Corn is vulnerable to drought and depends on fertile land and inputs to hit peak yields. Potatoes are heavy and perishable, spoil faster, and are more easily wiped out by disease — the Irish potato famine of the 1840s is the classic warning about betting everything on a single variety. Cui’s point is not that one crop wins outright but that diversity is itself the real insurance policy.

That lesson is urgent now. The global food system relies on a small number of crops, and climate change, water shortages and disease all threaten them at once. Researchers in China and elsewhere are breeding varieties that tolerate heat, salt and drought, and gene banks hold thousands of corn and potato landraces as backup. Crop diversity, in other words, is not nostalgia — it is infrastructure.

There is also a cultural dimension. Corn and potatoes both traveled the world from the Americas, reshaping diets in Asia and Europe within a few centuries. Today they appear in everything from street snacks to industrial starch, quietly underwriting the meals of a planet with eight billion mouths.

So who wins the doomsday showdown? Cui suggests the smarter answer is not to crown a champion but to keep both — and hundreds of others — alive. Survival, in agriculture as in anything else, is rarely about the single strongest player. It is about having options when the rules change.