This will be a really hard relationship to properly measure because the answer is both to varying degrees - depending on the species. Plants absorb tons of nutr

This will be a really hard relationship to properly measure because the answer is both to varying degrees - depending on the species. Plants absorb tons of nutrients from symbiotic colonies but they also regulate how much and how fast they absorb those nutrients using a variety of chemical and physical means. Figuring out those relationships is an intractable problem with current technology (which isn't even capable of isolating or identifying most bacteria) This is really easy to demonstrate on the plant side with cannabis: start out with some clones in your choice of grow medium and grow them until you can seal a nonpermeable material over the top of the plant (around the stem but above the medium so that the flowers/lighting is separated from it). Then, control the CO2 in the cavity so that the leaves and most of the stem is in high-CO2 conditions and the medium in atmo. Compared with plants that grew entirely in high CO2 and entirely in regular conditions using the same lighting/nutrition/medium. Once you've got a large enough sample size to weed out the noise, the effects are rather pronounced: high CO2 significantly increases the size of the buds, which increases the absolute amount of THC in the plant relative to its root network size, apparently depriving several other metabolic pathways of nutrients. The concentration of terpenes and other cannabinoids will be significantly lower in the high CO2 plants regardless of whether only the flowers were in high CO2 or everything was (at least, that was the result with a common Sour Diesel strain on a 200 plant sample size). That's a lot of factors to control for but there is a lot of underground research into this very topic because the quality of cannabis can vary dramatically based on small changes in growing conditions. Figuring out the various relationships between timing/CO2/temperature/lighting/nutrients and the active ingredients in the final product is worth a ton of money so I'm hoping that industry will make some headway into this research field.