alt Hacker NewsRhizobacteria are not known to colonize the roots of cereal crops, typically only only legumes. You would think that scientists would spend more effort trying to create "super" rhizobacteria that can colonize even more aggressively and also fix many times more nitrogen than ordinary ones. I cannot say this one below has independent reviews by well published agroscientists, but it's a step in the right direction:
https://soilscapesolutions.com/products/RhizoGenesis-p668356...
Do a Google search: Methods for Breeding "Super Strains"
Chemical Mutagenesis: Scientists expose the rhizobacteria to alkylating agents like Ethyl methanesulfonate (EMS) to force point mutations.
Physical Radiation: Exposing bacterial cultures to UV light or gamma rays breaks DNA strands, inducing random repair variations.
Experimental Evolution: Google it.
> You would think that scientists would spend more effort trying to create "super" rhizobacteria that can colonize even more aggressively and also fix many times more nitrogen than ordinary ones
I think the problem with that idea is that the rhizobacteria needs energy to break the nitrogen tripple bond. A lot of energy. It gets that energy by getting carbohydrates from the host plant - which in turn are not available to the plant to grow.
I'm sure there's plants where not fertilizing with nitrogen at all would make the trade-off worth it, but the vast majority of our optimized crops can't spare double-digit percentage points of their total yield to feed bacteria. You're much better of just using natural gas (or green hydrogen) to fix the nitrogen.