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close this bookBio-Intensive Approach to Small-Scale Household Food Production (IIRR, 1993, 180 p.)
close this folderSoil management
View the documentKnow your soil
View the documentDiscovering your soil type firsthand
View the documentSoil modifiers
View the documentNutrient composition of various organic materials
View the documentComposting
Open this folder and view contentsComposting methods
View the documentLiquid fertilizer
View the documentFish emulsion as plant food for bio-intensive garden
Open this folder and view contentsGreen manuring
View the documentNutrient requirement of vegetables

Fish emulsion as plant food for bio-intensive garden

Made from a blend of saltwater fish wastes, fish emulsion is a thick, gooey concentrate with about five percent nitrogen and small but significant amounts of trace minerals. It also contains a lot of fish oil. Most of the nitrogen in fish emulsion is present as amino acids from the breakdown of protein or as ammonia and nitrate. These amino acids can easily be absorbed by the leaves or roots. Diluted in water, fish emulsion can be either sprayed on leaves or poured around the base of plants.

Significant Findings from Research

1. Fish emulsion applied once a week to greenhouse soil stimulated vegetative growth and delayed flowering and fruit ripening in tomatoes by over a week. (Virginia Polytechnic Institute of State University in Blacksburg, Virginia)

2. Fish emulsion fertilizer added to the soil reduced nematode population. (Biological Testing and Research Laboratory, California)


1. Put any kind of scrap fish or unused fish-parts in a glass jar or plastic container. Fill with water.

2. Cover the top with a cloth, securing firmly to keep out insects and animals.

3. Place the container in a storage bin and let it ferment for two to three months.

4. After this period, a layer of mineral-rich oil will float on top, water underneath and the bones and scales on the bottom. Skim off the oil and store in a container.

5. When ready to use, dilute one cup of oil with five gallons of water. The remaining sludge may be sun-dried and then mixed with the soil.