I like worms in my no-till continually making new and fresh vermicast directly where they need to be - at the bases of my plants. Maybe the worms can help with your nitrate problems. They seem to make things very simple in my world.
This is what MM was saying about other life forms like protozoa and worms eating the azos and other bacteria, and then the worm shits and releases N, as well as becoming a N source when it dies... or at least that's what i understood.