Astronaut pee could keep plants alive in space for decades

Astronauts on a mission to Mars or beyond may be able to survive on plants watered with their own urine. Our liquid waste is 95 per cent water. The other five per cent is composed of nutrients, such as nitrogen, potassium, and phosphorous, which may pose harm to humans over the long term — but not to plants.

Using computer-generated test crops of dwarf wheat and soybeans, a team led by Federico Maggi at the University of Sydney in Australia simulated how these plants take up nutrients from human urine. They simulated…