Blood Meal

Blood meal is a dry, inert powder made from blood used as a high-nitrogen fertilizer and a high protein animal feed. N = 13.25%, P = 1.0%, K = 0.6%. It is one of the highest non-synthetic sources of nitrogen. It usually comes from cattle as a slaughterhouse by-product. It can be spread on gardens to deter animals such as rabbits, or as a composting activator. It may also be used as an animal food supplement for cattle, fish and poultry and is in fact widely used due to the high lysine content. In some countries, it is mixed with molasses before use as animal feed. At least one major marketer is offering blood meal derived from hogs, as an alternative to bovine-derived product.

Blood meal, bone meal, and other animal by-products are permitted in certified organic production as soil amendments, though they cannot be fed to organic livestock. Blood meal is different from bone meal in that blood meal contains a much higher amount of nitrogen, while bone meal contains phosphorus. Alternatives to Blood Meal include feather meal and alfalfa meal.

Nitrogen is more typically missing from soils than the other elements provided by most fertilizers (phosphorus and potassium). Plants grown in soil lacking proper amounts of nitrogen will yellow from the leaves down due to nitrogen deficiency. Applying blood meal will help plants become green again.