Algae from urine to grow tomatoes in space

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Tomatoes grown on algae have more flavor than conventionally grown tomatoes. Ghent University developed this as a new way to recycle fertilizers, an international first.

As much as 86 percent of the applied fertilizers is lost during crop cultivation and production of animal products. Only 14 percent of the manure effectively reaches the consumer in the form of food. The rest of the fertilizer ends up in waste streams or enters into the water or the atmosphere, creating environmental problems.

Algae from urine

To counteract this loss of fertilizers and reduce the environmental impact of food production, researchers at Ghent University studied how fertilizers can be recovered from waste streams.
Researcher Yuri Coppens says: “Urine contains the majority of the nitrogen and phosphorus that is present in domestic waste water and supplies those substances in concentrated form. Via a biological stabilization process, we succeeded to transform the human urine into a stable and safe nutrient solution. This solution was found to be extremely suitable for the cultivation of microalgae. These microscopic algae, also known as Spirulina, are rich in valuable proteins. “

More tasty tomatoes

The microalgae were used as organic fertilizer in tomato cultivation. The impact was remarkable. “The greenhouse test showed that the algae tomatoes contained as much as 30% more sugars and 70% more natural color pigments over standard tomatoes,” says Coppens. “Algae tomatoes are more red and more sweet than conventionally grown tomatoes.”

Also in space

The results are not only relevant on earth; they grasped the interest of the European Space Agency (ESA). “This way of recycling fertilizers offers prospects for growing food on the moon, or a manned mission to Mars,” says Yuri Coppens.
The production of algae from urine to use them later as fertilizer for crop production is a unique combination of cleantech and greenhouse cultivation. The researchers are currently working on the further development of the project together with a number of industrial partners.