Marine-derived fertilisers: significant possibilities, and some challenges to solve.

Summary

Significant volumes of organic material from captured fish and seaweed (brown macroalgae) are available and poorly utilised in Norway. A combination of fishbone residues, rich in N, P and Ca, and seaweed residues, rich in K, Mg and S, may constitute a complete fertiliser to be applied in organic growing. Field and pot experiments at NORSØK, Tingvoll, NoRway have demonstrated rapid growth effects of fish bones, and high and long-term beneficial effects of seaweed residues. Potentially toxic elements such as arsenic and cadmium pose a challenge with marine-derived materials, which calls for further studies.