Consider posting that question to the Megacrop thread. Greenleaf Nutrients MEGA CROP Q&A/Support/Pictures/Feedback/Anything thread
But quickly, a large proportion of the Megacrop ingredients are in the soluble ionic nutrient form. Which means, plants are able to directly uptake the nutrients. Although, microcrobes in the soil can also certainly utilize the nutrients and could potentially produce other chemistry including ammoniums, plant hormones, amino acids, etc depending.