Yea so azos don't just fix N they synthesize what turn out to be PGRs (plant growth regulators-aka plant hormones) and may actually secrete them in proximity to root growths which are exchanging nutrients with them. Or at least thats how my pitiful understanding of the rhizosphere paints it---the same interaction, wherein the plant literally secretes glucose from the roots and fungal mycelia exchange trace micro/macronutrients for the glucose is known to exist between plants and fungi, why not bacteria? But like I was getting at earlier, there should be cultivar/azos strain selectivity at work too, a study with like 10 strawberry cultivars and 6 azos strains found that only 3 of the cultivars were able to be colonized by 2 of the azos strains. This means that there is a chance azos are applied with reduced benefit---I'm suggesting that they probably still synthesize the PGRs regardless of colonization if they have glucose, and thus you are probably getting the extra minute PGR dose, but if you luck out and get colonization of the root mass, you should really have a noticeable boost in the success rate of that cultivar---biomass, yield, canopy thickness, leaf size, I mean it should really stand out, and you could test for the azos as the effector by running side by side inoc'd vs not to show that the inoc'd ones outpace the not once you've confirmed the azos strain/cultivar combination etc. It just seemed from the research with strawberries that it is really likely that you won't get a match, so that much more important to know for sure if you come across it....Kind of like phenoing out all of your females(and even males too if you are serious about your gene pool) even if you don't like the structure---just to see what effect/flavor ends up manifesting. The benefits seen in the strawberries if memory serves were like 10-25% increases in biomass/fruit yield---obviously only for the cultivars where colonization was successful.
Side note, there are plenty of sources for PGRs in the veganic/organic/natural amendment realm. I use coconut, corn, and willow, in different forms and applications but my goal is to have the plants benefit from the PGRs present. Happy to expound on this another time, tired and fading fast now tho, peace.
MPP
edit:
was just looking at the wiki page for indole butryic acid (clonex active PGR), same PGR in the corn/willow sources so go figure, relevance abound