I've always heard that the two best fertilizers are worm castings and bat guano. I know worm castings are great from my experience with farming worms, but does anyone know anything about bat guano?
Robert - one of the permies was selling off Bat Guano along with other things last year, so they may be able to give you some insight into using it - I know it has been used for centuries as fertilizer and is considered one of the best, but I've never used and do not know what ratio would be recommended.
My sister discovered that if she added bat guano to her pineapple pots, the fruit matured at 8 inches rather than 3 inches.
bat guano is superior to worm castings. Worm casts are dependent on the substrate that the worms feed on. The plant material(intended as worm food) will decompose---with or without worms-- and the nutrients within are limited to what was originally in the plant material provided.
bat guano, on the other hand, is a mixture of digested and partly digested insects. Because animals, which of course include insects, generally have higher concentrations of protein(source of nitrogen), macro- and micro nutrients/trace elements than plant material, then the waste products of carnivores/omnivores should be richer in nutrients than the waste products of vegetarians. The only thing found less in animals are carbohydrates, but as we all know, carbs are generally not absorbed as such by plants. Both bats and insects are extremely mobile, so their sources of food come from much wider tracts of land. The wider your feeding range is, the better chances you have of getting all the micronutrients, because the fertility of the soil varies between geographic areas.
in analogy, a pasture-fed cow will be limited to the tract of land it feeds on, and will thus have excreta which approximate the fertility of the local soil. Bat droppings on the other hand, are a concentration of nutrients obtained from far and wide.
the only thing bad about guano is that it is so rich it could cause overdose. Nitrogen, primarily.