Residues from aquaculture and marine harvesting may be used for fertilisation purpose, to close current nutrient gaps from land to sea, and for a better utilisation of valuable resources of nutrients and organic matter. However, some challenges need a further study. One is arsenic (As), which accumulates in marine organisms. How will As, e.g. in seaweeds used for fertilisation, affect the content of As in soil and plants? Another is related to technology: Fishbone silage (from hydrolysis of fish residues) contains large proportions of N and P and may be a very valuable fertiliser. However, the addition of acids for preservation complicates a further utilisation as fertiliser. Could other technologies replace the preservation with acid which is until now mandatory for food safety regulations? One option could be drying at hot temperatures, which may convert fish bone particles to a powder, which would be beneficial for production of fertiliser granules. NORSØK works with these issues(and more), to explore marine raw materials applied for fertilisation purpose. The overall aim is to phase out the current use of conventional dried poultry manure form organic farming.
NORSØK (www.norsok.no ) is a national centre of competence aimed at conducting research required to develop more and better organic agriculture in Norway and elsewhere. Due to our location near to the North Atlantic sea, in a region with a lot of blue industry, we have participated in several bioeconomy projects, including transdisciplinary blue and green-projects, where our role has often been to assess residual organic materials as feed and/or fertilisers. NORSØK staff counts about 25 People, mostly scientists, and we are engqaged in national and international projects in this field.