What would be rare about that, though? Even the usual corn we see on the regular can self-pollinate. It typically doesn't, accepting pollen from its neighbours instead, but it can. It is suggested that in a typical field of corn, ~3% of the plants will end up being self-pollinated.
True. As a corn grower, I assumed it meant nitrogen fixation on first read and didn't even consider your usage as fertilization, per your usage, isn't something we need to think about much in corn. Fertilize much more commonly refers to application of fertilizer in my world.
Context: Most plants pull nitrogen from the soil, and over time the soil becomes depleted and your crops grow more slowly. Bacteria in legumes convert atmospheric nitrogen to plant-usable forms, so historically you've needed to cycle nitrogen-"fixing" crops into your fields to 'restore' the nitrogen balance in the soil. Alternatively, you can use fertilizers, which supply N directly.
This is potentially interesting because the corn acts as its own fertilizer, fixing nitrogen from the atmosphere.
"Grown for centuries by indigenous farmers in rural Mexico, this incredibly rare corn can self-fertilise. In episode three of 'Planet Fix', we explore how this wonder crop could help tackle world hunger, and even end farming's toxic reliance on chemical fertilisers for good!"
In the video it said something about modulating the amount of nitrogen fixation based on the plant's needs. Could mean that it's able to scale it up if its needs are higher, but I imagine this is part of the breeding work they're doing.
Is that important? The corn (not to be confused with sweet corn) we grow now doesn't taste good, hence why we largely don't eat it directly, using animals or chemical processes to make it palatable.
Incredibly cool though.