earthworms dont compete with the plants for nutrients come on now worms have been is soil longer than humans have been in existance, they do eat up organic materail thas is usually unavailable to the plant and process it into castings which the plants can feed on, thas why when u raise worms u feed them things like table scraps, cannalope rinds, coffee grinds, those things would take alot longer to break down in a natural enivroment if worms wernt in our soil to eat them up, the trick is to not kill those worms in ur soil, alota liquid nutrients will have a bad effect on worms even if they are organic liquid nurtients, and if u have a bunch of dead worms in ur soil the ph of ur soil is gona swing like a mafucka trust me ive learned this from expirence, if ur plannin on keepin the worms in ur soil go with a more natural approach to feeding, use organic material like bone meal and kelp meal instead of liquid nutrients, keep those worms alive and they will work to help ur plant