Nitrogen fertiliser! That is a great choice, the ability to feed millions and to increase the productivity of land! The Haber process has been one of the great discoveries of the modern age, without which, we would have a different population dynamic! On the other hand, it has come with some costs...

I'm pretty curious about the possibility of fixing nitrogen directly from the air! Sounds intriguing and much more of an elegant solution... how far is the research down this track?