Bone Meal vs Blood Meal
Q: What is the difference in bone and blood meal? How are they used and where do they come from?
A: Blood meal is made by flash-drying blood that is collected at a slaughterhouse. It is high in nitrogen, with few other nutrients. A typical analysis is 12-0-0. Organic gardeners use it instead of synthetic nitrogen (34-0-0).
Bone meal is made from slaughterhouse bones which have been cooked and ground into a powder. It is high in phosphorus but contains little else. A typical analysis is 1-11-0.
Both are used by folks who want organic sources of plant food. Since no potassium is contained by these two products, a gardener could use cow manure (1-1-1) or greensand (0-0-6) to supply that nutrient.
MORE INFORMATION
Converting a synthetic fertilizer recommendation to its organic equivalent