Do earthworms need a complete diet, or can they survive (and be productive) on a single unbalanced source of food, very high in N, P, or K?
I think that composting earthworms can survive on a single food source, BUT that food source must contain at least minute amounts of the minerals they need. For example, only paper or only cardboard would support a worm population very well. But they do need a bunch of minerals just as we do to survive. I’m guessing nitrogen, calcium, phosphorus and magnesium would be the most important ones just as they are for us. Earthworms do not actually eat the food materials themselves, but the BACTERIA that are feeding on the materials. These bacteria do the work of extracting the minerals and making more complex organic compunds for the wormies, like amino acids and vitamines and what not.
