The pellets were tested over the summer in small-scale trials in a climate laboratory and large-scale field trials at Bioforsk Nord and in the field at the property of one of Ottar's members.
Releases late
"Previous trials have shown that shrimp shell is suitable as fertiliser," says Tor Johansen at Bioforsk Nord at Holt.
"The pellets were developed to make the fertiliser more user-friendly. This year's trial confirms that, but we still have some challenges to solve."
The main challenge is to release the nutrients at the correct time.
"The nutrients become available a bit late, but this is not necessarily a disadvantage," says Johansen. "We are now going to study this further. We need to carry out a lot of analyses and we have really only just begun."
The conclusions from this year's trials are unclear, but no one doubts the potential of shrimp shell as a fertiliser.
High demands
"From shrimp shell to organic fertiliser in North Norwegian crop production" is a collaboration project between potato producers' organisation Ottar, peeled shrimp producer Stella Polaris AS, Bioforsk and Nofima Ingredients.
The project, which is owned by Ottar, wants to verify whether it is possible to use shrimp shell as fertiliser for organic cropping. Ottar wants fertiliser with a one-year shelf life that is as practical and easy to use as today's fertilisers.
"In order to satisfy these demands, we need to dry and grind the shrimp shell then transform it into pellets of the desired form and quality," says Tor Andreas Samuelsen at Nofima Ingredients.
Need alternatives
Alternatives to animal fertiliser are needed in order to fulfil the government's target of 15 percent organic agriculture by 2015.
Fish waste has long traditions as fertiliser. Shrimp shells contain nutrients in high concentrations. The substance chitin, which has a documented effect on plant health, is also found in shrimp shells. The substance can hamper fungus growth and activate natural defence mechanisms in plants.