Astronauts urine as manure for vegetable growth on Mars
Did you ever think of your urine as manure? We do! We are going to use urine as manure to grow crops on Mars soil simulant. It is the ‘only logical’ next step in our Food For Mars & Moon (FFMM) project to feed humans on Mars. Support our research and donate, There will always be a reward for you whether you donate 10 or 10.000 euros or dollars.
'To boldly grow where no plant has grown before'
(after Start Trek, The Next Generation)
As a science fiction enthusiast (yes I did watch ‘The Martian’ several times) I can not imagine a more thrilling adventure than a trip to Mars or the Moon to establish a human settlement over there. Science fiction? No, by conducting the research now we facilitate this epic journey! And as an ecologist who as a child wanted to be an astronomer am now am able to combine these two passions in this research.
Why your pee?
A settlement on Mars or the Moon can not allow anything to go lost. Losses have to be compensated by import from Earth or excavation from Mars or the Moon. Both options are time consuming and costly. This also applies to manure used to grow crops on. Without manure no plant growth. This implies that not only dead plant parts that are not eaten have to be returned to the soil, but also the faeces of the astronauts. And do not forget to bring the poo and pee from your travel to Mars or the Moon. Upon arrival on Mars or the Moon the faeces can then immediately be used to fertilize the soil. The moment that the first human will set foot on Mars is closing in. Therefore, now is the moment to investigate if we can grow crops on these solar bodies by applying pee.
Up till now we have never used human faeces in our experiments to grow crops on Mars and Moon soil simulants. To create a closed sustainable agricultural ecosystem for Mars the faeces have to be returned to the soil. We start with the urine. Water treatment facilities can purify this into struvite, a very good fertilizer that is guaranteed free from diseases. This experiment is the next step in our effort to feed future colonists on Mars and the moon. We also will learn more how to turn infertile soil (again) in to productive soil, which may have applications on Earth as well, e.g. in desserts.
‘Our research will be one of the most important steps towards a self-sustainable settlement of humans on Mars, recycling of urine. Without this a Mars settlement will not be possible.’
(Wieger Wamelink, principal researcher Food For Mars & Moon, Wageningen UR).
The donations will be used to buy materials. Renting the greenhouse and the hire of greenhouse personnel assisting the research. For the first time we will use an automated water supplying system based on sensor readings in the Mars soil simulant. And of course we have to purchase Mars soil simulant and seeds. A special acquisition will be a pro camera so everybody can follow the experiment via life stream.
However all this is not possible without your support, so help us out and donate!
Follow the progress of our experiments on
Do your own experiment: https://www.wur.nl/en/Education-Programmes/Case-Food-for-Mars-and-Moon-in-development.htm
selection of pictures: https://www.wur.nl/en/Library/Imagecollections/Collections/Food-for-Mars-and-Moon.htm
Q&A with Wieger Wamelink – Mars and moon soil researcher
Researcher Wieger Wamelink gets many questions about his research on growing vegetables on Mars and moon soil. Here are the answers.
- Where does the urine (struvite) originate from?
The struvite is delivered by the Amsterdam sewage plant. The urine of the male festival visitors in Amsterdam is collected separately and then purified and transformed into struvite. Thus the male festival visitors in Amsterdam contribute to our experiment.
- Why do you want to grow plants on Mars?
When people travel to Mars in future they will have to live there for longer periods of time. They could of course bring along all the food they need, but it would be much tastier and more convenient to be able to grow your own food there. And if the food tastes good the astronauts will eat more of it, which is good for their health.
- Where does the Mars and moon soil in your research come from?
The moon and Mars soil don’t really come from the moon or from Mars. Moon soil is hard to come by and no Mars soil has yet been brought back to Earth. That’s why NASA looked for soil that closely resembles Mars and moon soil. The Mars soil we use in our experiments comes from a volcano on Hawaii and the moon soil from a desert near Flagstaff in Arizona. They cleaned it and used a big roller to roll over the moon soil to make it extra dusty, as it is on the moon.
- Is it safe to eat food that was grown on Mars and moon soil?
This is an important question because we know that there are heavy metals in the Mars and moon soil simulants we use, just as there are heavy metals in real Mars and moon soil. We tested this in two ways. First we checked whether heavy metals such as lead, mercury and cadmium from the soil ended up in the water we give the plants. This was not the case: we didn’t find any metals, except a little bit of aluminium in the water of the moon soil. We also tested whether there were any heavy metals in our harvest: the tomatoes, peas, radishes, and rye. They turned out to be safe to eat. We did have to carefully wash anything that grows underground, such as radishes, but also carrots and potatoes, because they were covered in soil. And eating too much soil could make you ill in the long run.
- What are the biggest challenges of growing plants on these soils?
Apart from the heavy metals, one of the problems is that these soils contain very little of a specific fertiliser: nitrogen in a form that plants can absorb (nitrate). However there is a special group of plants, known as legumes, which include clovers, but also lupins and peas, that work together with bacteria to absorb nitrogen from the air. By growing these plants and digging in the non-edible parts (stems and leaves) we can fertilise the soil.
- Isn’t it very cold on Mars and does the planet lack air? How can people live there at all?
There is almost no air on Mars, and the temperature varies from -60 to -100 degrees Celsius, sometimes it is above zero. This is why people would always have to wear a space suit when going out. But you could of course live indoors. In fact you would have to, because Mars has hardly an atmosphere and no electromagnetic field to protect people from cosmic radiation. To protect themselves from this radiation, people might have to live under one metre of Mars sand. And this applies not only to people, but also to plants; plants cannot live without air, or in such low temperatures. Plants are less sensitive to radiation than people, but they can still suffer from it. This is why vegetables would also have to be grown indoors, under LED lamps.
- Do Mars vegetables taste different?
Opinions differ on whether Mars and moon vegetables taste different than their equivalents from Earth. We had lots of people taste the tomatoes, beans and rocket, and most people did experience a difference in taste. Some people found the Mars vegetables tastier, while others preferred the Earth vegetables. We still have to find out whether there is a real difference, for instance by checking how many sugars there are in the various vegetables.
- Can you cook on Mars? Or do you have to eat all the vegetables raw?
You can cook on Mars, but only indoors. Because that’s where the air and air pressure are the same as on Earth. Outside the water would immediately evaporate and partially freeze. The vegetables would freeze as well, but you could still eat them in principle, since this is a bit similar to molecular cuisine.
- Can you also keep animals on Mars? Chickens, cows, pigs? As food or to make manure for the plants?
You could keep animals on Mars, but that would require a tremendous amount of food and space. Animals are very inefficient in processing what they eat into meat and other products. The manure would be welcome for fertilising the soil. But for now, there are no plans to bring animals to Mars. We might make an exception for chickens. A chicken will eat any vegetable and produces manure that is easy to use. And a chicken is relatively efficient in processing what it eats into meat and eggs. In addition, a chicken could be kept as a pet, to offer comfort in difficult times.
- What is the next step in your research?
One of the things we would like to investigate is whether worms can live in Mars soil. Worms eat plant residues and partially secrete them back. In this way they spread plant residues throughout the soil. This is better for the soil because it helps it retain water better. Worms also aerate the soil so that it’s easier for oxygen to reach the roots, which need it to grow. We would also like to find out whether bacteria can live in this soil, because bacteria can transform dead plant residue into food for plants, and they help convert nitrogen from the air into fertiliser.
- When do you think people will be able to travel to Mars?
There are plans to send people to Mars within ten years, but I think that’s a bit too optimistic. I expect that people will first set foot on Mars only after 2030.
No, I think it’s much too far away; you have to travel for at least six months to get there. I would like to go to the moon, though, that’s only a two-day trip. And anyway, by the time people will really be able to fly to Mars it will probably be 2030 and I will be too old to join one of the early missions.
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Thank you for your donation, you are helping us with the purchase of the seeds. As a reward we will send you a sticker with the logo of the project.5 donors
our logo for on a shirt
With your donation it will be possible to buy 1 kg of Mars or moon soil simulant. As a thank you you will recieve two logo's which can be steamed on a shirt (shirt not provided)4 donors
Thank you for your donation. With your contribution we can rent the greenhouse for half a week and water the plants. You will recieve a poster as a reward. There will be a choice out of three different posters.3 donors
€ 100 Recommended
For 100 euro we can do an analyses on the harvested crop for heacy metal content and investigate if the crop is save to eat. As a reward you will recieve a T-shirt from the project. There are several sizes and seperate T-shirts for women and man available
Your donation is good for 4kg of moon soil simulant. As a reward you will recieve our specially designed apron
For 250 euro we can buy 10 kg moon soil simulant. As a reward you get a Food For Mars and Moon linnen bag with a small amount of Mars soil simulant, a sticker, a card, a button and a poster of the project.
For 500 euro we can water the plants for a month. As a thank you, you can have a skype with Wieger Wamelink, principal investigator, and ask all kinds of questions about the experiment. A goody bag will be sent as well. This reward is especially interesting for school classes wanting to do their own Mars experiment.10 available
This donation makes it possible to rent the greenhouse for two months and conduct the first fase in our faeces experiment. As a reward ypu will receve a book with photos of our second experiment and either a T-shirt or the projects apron
Your donation finances a major part of the research. As a true friend of the project you will receive a T-shirt and an apron. As a special gift you will receive a sample of all soils used in the experiment.
I want to choose my own amount