As a commercial producer of organic worm castings I have used 50% castings as well as just worm tea for food. The use of just worm tea worked fine but I didn't quite get the yields as compared to using organic nutes, guano, kelp etc. Worm tea is not so much about nutrients as it is about innoculents, microbes, soil conditioning, and just about evrything a soil needs to remain healthy. Worm tea will make your soil and plants very healthy, allowing them to use the different nutes and other things more efficiently. I believe one of the most important benefits is the symbiotic relationship between the plant and the microbes in the root zone. Plants feed the microbes and the microbes produce or make available all of the food and medicine the plant needs to thrive, in other words it allows the roots to more easily absorb, and process materials more efficiently. I find it more useful as a foliar spray, plants will produce more foliage and larger stems. This is a good treatment for plants that are stressed or lacking enough sun. I could go on forever about the positive effects it has but for high yields of good bud use nutes as well.
