>I am however utterly ignorant of the difficulty of doing this.
It is very difficult since the symbiotic relationship needed is difficult to recreate - it is not just a matter of introducing a few new genes.
Even doing this would not avoid the need for the Haber-Bosch process. The symbiotic bacteria just can’t produce the amount of organic nitrogen that we need to get into modern crops to have them produce at the level we need to feed everyone. Even crops like legumes which have the symbiotic bacteria are supplied with artificial nitrogen when grown under modern agricultural conditions.
It is very difficult since the symbiotic relationship needed is difficult to recreate - it is not just a matter of introducing a few new genes.
Even doing this would not avoid the need for the Haber-Bosch process. The symbiotic bacteria just can’t produce the amount of organic nitrogen that we need to get into modern crops to have them produce at the level we need to feed everyone. Even crops like legumes which have the symbiotic bacteria are supplied with artificial nitrogen when grown under modern agricultural conditions.