40% of corn grown goes to produce ethanol. [1] The silage by product is then sent to feed cattle.

[1] https://civileats.com/2022/02/14/how-corn-ethanol-for-biofue...

One way of looking at the fodder for cattle is that the human palatable parts of it are reserves. We can "downshift," downsize our herds and redirect that without redisman's "send you a bag of corn every month" (plus calcium hydroxide for nixtamalization) extreme which more belongs to something like a post-nuclear war scenario.

The big problem is going to be the places that don't have reserves of most anything including money, like the parts of the Middle East and thereabouts that normally get their wheat from Russia and the Ukraine, the latter long called "the breadbasket of the world."

Sure but thinking that the American people don’t implode if the stores are empty and you’re sent a bag of corn every month for your calories is also not realistic.

You can grow other calories on the land you're growing corn for ethenol and livestock feed.

With the massive efficiency of corn its actually kinda hard to do that to the level you expect. Corn is very effective at turning space into starch.

What massive efficiency? You're feeding it to animals. 80% of the calories are immediately pooped out.

Which is why you could just feed it to people instead - or grow something else.

Solar panels destroy corn in terms of converting solar power to energy. Ethanol is geopolitical and special interests, definitely not efficient.