Fish emulsion fertilizer is derived from the guts of waste fish that are ground up and processed as plant food. A naturally derived fertilizer, fish emulsion is considered suitable for organic gardening and organic crop cultivation. This fertilizer has high percentages of readily available nitrogen that promotes plant growth.
Fish emulsion fertilizer is made from emulsified fish parts that are then dried. The fish parts must be partly decomposed in order for the nutrients to break down and be usable for the plants. The drying process is used to kill microorganisms present in the product.
Organic gardeners and crop cultivators are limited in the types of fertilizer they can use. As chemical fertilizers are not allowed, organically derived materials, such as fish parts, make good organic fertilizers. The plants get the nutrients they need and no chemicals are used.
Using fish for fertilizer is only sustainable if the fish used are a waste product that would otherwise be thrown away. Most fish emulsion fertilizers are made from the small fish that do not make the grade and from by-catch from fisheries.
Fish emulsion fertilizer usually has a nitrogen-phosphorus-potassium (NPK) ratio of 5-1-1 or 5-2-2. A fertilizer that has an NPK ratio of 5-2-2 is then 5 percent nitrogen, 1 percent phosphorous, and 1 percent potassium. This fertilizer is particularly noted for its high percentages of nitrogen that the plants can access quickly.
Not just for organic gardens, fish emulsion fertilizer is good for sensitive plants, too. Many plants are sensitive to the salts in chemical fertilizers that burn the foliage and can damage the roots. For salt-sensitive plants, using a fish-based fertilizer can help solve the problem. Fish-based emulsion fertilizers provide the plants with nitrogen without adding salts to the soil around the plants.
There are two drawbacks to consider when using fish emulsion fertilizer in the garden. One is the smell. The dead and decaying fish smell is unmistakable, but in order to work as a fertilizer, the fish must be partially decomposed. Once diluted and applied to the soil, the smell lessens and goes away in a few days.
A second drawback is the necessity of frequent applications. Fish emulsion fertilizer is a natural fertilizer. It is a good source of nitrogen, but it is not as strong or as long lasting as some chemical fertilizers. When using these fertilizers in the garden, more applications are required, and it may not be enough for heavy feeding crops such as bananas.