Lettuce, tomatoes, pak choi and potatoes: all can be cultivated on floating islands made of polystyrene. This was shown by a Wageningen Plant Research and Stichting Drijvende Eilanden experiment performed in Lelystad, where the first produced batch was recently harvested from the islands. Researcher Marcel Vijn expects there is still much to learn. ‘Part of our crops were eaten by waterfowl.’
© Sören Knittel
Cultivating vegetables on floating islands could be a solution for areas that are often flooded. Researcher Marcel Vijn of the Urban-Rural Relations group at WUR has been closely involved in the experiment with polystyrene islands. He is happy the project was successful. ‘We now have a proof of concept. With this first harvest, we have proven that agriculture is possible on water.’
The concept of floating islands is based on polystyrene blocks that are packed in plastic film. The blocks are then bound into rafts of two by three metres in size using nets. The vegetables are cultivated in cylindrical holes. This concept works, though they encountered an unexpected problem.
The researchers had not considered waterfowl, which consumed part of the harvest. Still, the damage was limited. Vijn: ‘They ate some pak choi and other vegetables. But they did not touch the lettuce, for example.’ The birds have proven that future projects will require protective measures, such as nets.
Vijn hopes that the floating islands experiment will get a follow-up, if only to think of a solution for areas that flood often, such as Bangladesh. ‘Or cities like Singapore, where the agricultural land is limited and the price of agricultural products is high.’