Ok, read this whole study when it was first posted, and again today. It is some pretty intense reading but this was what I gleaned from it and the questions that came to mind:
"A core community of microbes was present in all samples regardless or soil properties and strain." Samples were not pre-inoculated, so these microbes are apparently present in most (maybe all?) soils, and the observed variations occurred on their own. I think that this would mean in theory you could isolate these core microbes and have a base inoculation pack of sorts, kind of like Cap's Bennies, for indoor growers. This also got me thinking that if this core community occurred naturally and spontaneously, that if one is growing outdoors or in a greenhouse, inoculation is not needed - you simply need to crate a favorable environment and the microbes will colonize the soil all on their own. It would be very interesting to see if these same core microbes are present in other parts of the country and other parts of the world.
"Soil properties determine microbial community composition, but abundance was determined by cultivar". Certain strains favor certain microbes but ultimately the soil has the largest impact. This was no surprise to me - my theory with growing has been that it is 'all about the soil'. Other than genetics, in my experience the soil has the largest impact on yield, plant health, quality, disease and pest resistance, etc. Now if you have grown much outdoors you have probably noticed that even the same clone will grow differently depending on it's environment. Weather, location, soil, and other environmental factors can produce a fairly broad range of expression even within the same phenotype. It would seem that the soil microbes are yet another factor in this variation. I though it was very interesting that different strains seem to select for specific amount of the different microbes - which makes me wonder why certain strains select for these particular microbes at specific levels, and why it is not the same for all strains.
"Higher THC composition and concentration was found plants from one of the soil types". This to me was one of the most interesting lines of the whole study. I have usually regarded methods of increasing THC to be largely be a bunch of BS (specially the THC booster products sold in hydro stores). However you do see potency variation even with the same clone - usually as a result of environment. Better environment makes for a healthier plant, a healthier plant can reach it's pull potential, hence slightly higher potency. Other than UV radiation, there have been few proven ways to boost potency. However, it appears that a properly structured microbial community and a specific soil type did result in higher potency. So what I want to know - which I did not see in the study - is what type of soil resulted higher potency? That would be pretty amazing if something as simple altering your soil properties could actually boost potency. Again I find this intuitive - soil properties determine so many other factors, why not THC composition and concentration as well?
However, the "association between microbiota and THC was very hard to disassociate from soil physicochemical variables". Ultimately this means it might be the soil itself, not so much the microbes that resulted in increased potency. Sounds like further study is needed on this one.
"Nitrogen had the strongest effect in structuring the [microbial] communities, followed by carbon and water." No surprise with that one - nitrogen and the nitrogen cycle plays a HUGE part in how cannabis grows. Cannabis is a nutrient hog, especially when it comes to nitrogen, and consumes more nitrogen than any other plant (at least that I am aware of). So it would seem that nitrogen has a big impact not just not on the plant itself, but the microbes in the soil as well. I think with more study one could really fine tune their nitrogen inputs to maximize the soil microbes, which would in turn maximize the performance of the plant itself.
Finally, "Cellvibrio was an indication of root decay." This could be very, very useful if there was an easy way to test the level of Cellvibrio in the soil. It could act as an early warning system of sorts before root decay took hold. Unfortunately if you do have root decay/stem rot by the time physical symptoms appear it is usually too late to save the plant. Knowing ahead of time that you have a potential problem would be a massive advantage.
Anyway, some pretty interesting info to mull over. I'd be curious what a real scientists take would be on this. Regardless it is further evidence to how important soil microbes are, and how little we really understand about them at this point.
