Fish emulsion is a type of organic liquid fertilizer made from fish waste. While fish emulsion can be produced from many different types of fish (including wild caught salmon), a small fish called Menhaden is the most common source of this liquid fertilizer. An oily, bony fish with little edible meat, Menhaden comes from the Atlantic Ocean and Caribbean Sea.
How are liquid organic fertilizers made? The fish is steam-heated and then transferred to a large pressing equipment where the liquids and precious fish oil is rendered. All the solid substances are made into animal feed, while the oil is further refined into fish oil. As for the remaining liquids, it is simmered until it is transformed into a thickened fish emulsion.
A small amount of phosphoric acid is added to the fish emulsion to lower the pH. Lowering the pH makes the liquid fertilizer more acidic, which prevents it from decaying and fermenting into gas. Before phosphoric acid was added in the manufacturing process, containers of fish emulsion were known to burst from fermentation. Because the amount of added phosphoric acid is so small (less than one percent by weight), the product is still considered organic.
Standard composition of organic fish emulsion fertilizers is about 5% Nitrogen, 2% Phosphorous, and 2% Potassium. It also contains micronutrients that are vital for promoting plant growth.
Adventurous gardeners make their own liquid fertilizer from fish. It’s a smelly, messy process, but it could be economical for gardeners with a ready supply of fish waste.
Liquid organic fish emulsions are an exception to other organic fertilizers because they release nutrients to the plant immediately. Hence, liquid fish emulsions are used for transplanting seedlings because it makes them more viable. To use as fertilizer, the liquid fish emulsion is diluted in water and sprayed on plants or used to water the soil.
Fish emulsion is a fairly mild liquid fertilizer, but it can burn if applied too strong, so it’s important to follow mixing directions. It has a definite fishy odor, but the odor goes away in a day or two after application. Some manufacturers add a deodorizer to their products. Fish emulsion must be used when it’s mixed; it can’t be stored after it is diluted. By the way, the undiluted liquid must be stored at room temperature because it degrades if it gets too hot.
Production of liquid fish emulsions fertilizers is environmentally sound from start to finish. Only fish parts that are unused or are considered as waste by fish and feed processing companies are used. Thus, the use of fish emulsions organic fertilizers thus decrease toxins in our food and helps make zero waste possible.
