[seiferteric]

In this case "self fertilization" refers to fixing nitrogen, not "fertilizing" in the sense of reproduction.

[seunosewa]

Knowing exactly how much nitrogen they can fix is important. It's unlikely to be enough to take care of the nitrogen requirements of high yield corn.

[darknoon]

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.