Dbrins, bone meal is used sometimes by organic growers. I have been growing citrus 30 years, and have never ever seen bone meal as the source of "P" in a commercial fertilizer. Field test have shown over and over again that a yearly loss of the main elements per hectar, in a mature commercial orchard producing 30 tons of fruit, is as follows: N180 -220; P2O5 30 -40 kg; K2O; 90 -120 kg. This is a 5-1-3 ratio. Which is the ration that a citrus tree absorbs nutrients. There are many commercial fertilizers. They must be chosen according to the replacing minerals and their ratio. 5 parts N, 1 part P and 3 parts K. Obviously, in cases of over dosage or deficiency of one or more elements this ratio must be changed to a more appropate one.