The first beans were recently harvested after being grown in soil from Mars and the moon, fertilised with human urine.
Since November, 2019, Wageningen University & Research in the Netherlands has been experimenting with cultivation of string beans on artificial Martian and lunar soil.
Part of the crop is treated with struvite (a fertiliser produced from urine).
The experiment is designed to research the possibilities of feeding future inhabitants of the moon or Mars with locally grown crops.
Scientist Wieger Wamelink said: “After a few experiments, we now know how to do this. But simply getting plants to grow is not enough. We need to use urine and faeces produced by astronauts to fertilise the plants.”
The experiment compared crops from artificial lunar and Martian soil, and from normal earth, and also looked at treatment with struvite obtained from wastewater purification.
Beans planted in normal soil, or in lunar soil with struvite, grew best.
Martian plants with struvite started promisingly but slowed. Their growing season in Martian soil took one week longer.