Fish products are excellent sources of N-P-K and trace minerals for a farmer or gardener, but how do you know which one to choose? Fish products come in the form of meals and emulsions.
Fish Meal Fertilizer: a ground, dried fish waste with the oil removed, generally dried at high heat and is used in soil applications. It has a high nitrogen & phosphorus analysis and is a slow to medium releasing source of nitrogen.
Liquid Fish Emulsion or Enzymatically Digested Hydrolyzed Fish: a fast-acting, water soluble fish fertilizer. Enzymatically digested hydrolyzed fish retains more of the proteins, vitamins and micronutrients than emulsions, which can be processed with high heat and acids. Heat tends to denature amino acids in proteins, making them unavailable to the plants. Enzymatic digestion of fish allows the minerals and amino acids to become readily available to plants and makes those nutrients water soluble, so you can use them in foliar spraying or through drip and other irrigation systems (fertigation).