Plants in Mars

[Mr Rayon]

Is it possible to grow any plant in Mars?

[insane_alien]

not yet.

 

largely mars is too cold and dry (not to mention the really low pressure).

 

but if you set up a green house on mars it should be reasonable to expect something to grow.

[CaptainPanic]

The CO2 partial pressure on Mars is high enough for plants. There is about 600 Pa of CO2 partial pressure (or 6 mbar). We have about 40 Pa of CO2 partial pressure.

 

The use of greenhouses can raise the temperature (a bit), which may be enough for plants that are resistant to cold temperatures.

 

That leaves only the issue of water, and the possible need for N2 and O2 for plants. I believe that the nitrogen is not necessary? And can plants survive with much lower oxygen concentrations present?

[Blossom]

its possible to grow something if water, air and suitable temperature is provided to plants. but cannot say anything about the soil of mars...

[lemur]

The CO2 partial pressure on Mars is high enough for plants. There is about 600 Pa of CO2 partial pressure (or 6 mbar). We have about 40 Pa of CO2 partial pressure.

 

The use of greenhouses can raise the temperature (a bit), which may be enough for plants that are resistant to cold temperatures.

 

That leaves only the issue of water, and the possible need for N2 and O2 for plants. I believe that the nitrogen is not necessary? And can plants survive with much lower oxygen concentrations present?

Nice that you compared the CO2 pressures. I wonder how the amount of sunlight per unit ground area compares. I do think nitrogen is necessary. Whenever I try to grow plants without fertilizer they stay very small. Sorry that I don't have a more concrete biochemical explanation for this, but any farmer will tell you that soil needs available nitrogen for plants to thrive.

Edited February 25, 2011 by lemur

[CaptainPanic]

Nice that you compared the CO2 pressures. I wonder how the amount of sunlight per unit ground area compares.

Mars stands approximately 1.5 times further away from the sun than Earth. The intensity of the sun is therefore 1.5^2 = 2.25 times as weak. That's still more than adequate for plant growth though.

I do think nitrogen is necessary. Whenever I try to grow plants without fertilizer they stay very small. Sorry that I don't have a more concrete biochemical explanation for this, but any farmer will tell you that soil needs available nitrogen for plants to thrive.

Yeah, nitrogen is necessary, but I don't think it's necessary in the atmosphere. Nitrate in the soil is enough. Obviously, a lot of other elements are necessary too, sometimes in tiny concentrations.

 

I'd be surprised if a massive planet like Mars wouldn't be able to supply some greenhouses with all the necessary elements though. Since most of those do not enter a gasphase, and can be recycled from all the poo (manure/fertilizer), the problem will eventually be solved.

 

On Mars, any cycle of life that makes use of the gas phase (atmosphere) is the real challenge... which means that we just have to look at CO2, O2, and water.

[lemur]

Mars stands approximately 1.5 times further away from the sun than Earth. The intensity of the sun is therefore 1.5^2 = 2.25 times as weak. That's still more than adequate for plant growth though.

But is it enough to prevent overnight frost?

 

Yeah, nitrogen is necessary, but I don't think it's necessary in the atmosphere. Nitrate in the soil is enough. Obviously, a lot of other elements are necessary too, sometimes in tiny concentrations.

 

I'd be surprised if a massive planet like Mars wouldn't be able to supply some greenhouses with all the necessary elements though. Since most of those do not enter a gasphase, and can be recycled from all the poo (manure/fertilizer), the problem will eventually be solved.

 

On Mars, any cycle of life that makes use of the gas phase (atmosphere) is the real challenge... which means that we just have to look at CO2, O2, and water.

I would expect that before any kind of sustainable gardening is attempted on Mars, a system will have been developed and tested on Earth that is totally self-contained and filters sunlight to imitate the prospective Martian situation. I would also say that similar temperature patterns should be sought but I wonder whether the lower gravity and atmospheric pressure alter the effects of heat and light on plants.

 

 

[insane_alien]

But is it enough to prevent overnight frost?

 

no, but you'd be growing the plants in insulated environments anyway as the temperature is below freezing most places and times.

[CaptainPanic]

But is it enough to prevent overnight frost?

no, but you'd be growing the plants in insulated environments anyway as the temperature is below freezing most places and times.

Yup. On Mars we need greenhouses no matter what. They would have multiple purposes: to keep the heat in for the plants (we might need double glazing, lol), to keep the water in, to recover oxygen for the settlers.

I would expect that before any kind of sustainable gardening is attempted on Mars, a system will have been developed and tested on Earth that is totally self-contained and filters sunlight to imitate the prospective Martian situation. I would also say that similar temperature patterns should be sought but I wonder whether the lower gravity and atmospheric pressure alter the effects of heat and light on plants.

I agree that we should imitate Mars here on earth... but such a system doesn't have to be self-contained. I actually think it's ok to have some leaks to the outside atmosphere, both here in our test-labs and on Mars in the real thing... What's important is that you test the right things here. And later on Mars that you keep the moisture in the greenhouse.

 

The lower gravity and lower pressure (and therefore lower wind strength) will make for interesting plant shapes: very flimsy and tall.

[lemur]

Yup. On Mars we need greenhouses no matter what. They would have multiple purposes: to keep the heat in for the plants (we might need double glazing, lol), to keep the water in, to recover oxygen for the settlers.

Depending on the overnight temperature, you may even need to heat the greenhouses at night.

 

I agree that we should imitate Mars here on earth... but such a system doesn't have to be self-contained. I actually think it's ok to have some leaks to the outside atmosphere, both here in our test-labs and on Mars in the real thing... What's important is that you test the right things here. And later on Mars that you keep the moisture in the greenhouse.

If Martian atmosphere is completely dry, any mixing between outside air and greenhouse air will result in evaporation, no? Then how do you get more water to replace it? The soil is most iron oxide, I think, which could provide a ready source of oxygen, but is there any hydrogen available?

 

 

 

 

[CaptainPanic]

Depending on the overnight temperature, you may even need to heat the greenhouses at night.

If the design is crappy, then indeed, heating is needed. But there are designs already in existance which are capable of maintaining a relatively constant temperature. Think of some hot-water reservoirs that work on solar energy. They are able to supply hot water in the middle of the night too. So, they should be capable of maintaining mere room temperature in a greenhouse on Mars.

 

If Martian atmosphere is completely dry, any mixing between outside air and greenhouse air will result in evaporation, no? Then how do you get more water to replace it? The soil is most iron oxide, I think, which could provide a ready source of oxygen, but is there any hydrogen available?

As I said before, you must keep the water in.

And I think that we have to find actual water on Mars... making enough water is a bit of a nightmare.

[lemur]

If the design is crappy, then indeed, heating is needed. But there are designs already in existance which are capable of maintaining a relatively constant temperature. Think of some hot-water reservoirs that work on solar energy. They are able to supply hot water in the middle of the night too. So, they should be capable of maintaining mere room temperature in a greenhouse on Mars.

It all comes down to the R-value of the insulation and the outside temperature. Lower atmospheric density may help the situation, I think, since lower-density media seem to generally insulate better than high-density ones (vacuum being the best insulator, correct?)

[Moontanman]

I think genetic engineering holds more promise for growing plants on Mars than building greenhouses. I'm not completely sure but i think here are some lichens that could grow in some areas of Mars, the Martian rift valley is supposed to be deep enough for the air pressure to allow liquid water, lichens fix their own nitrogen and can live in areas of extreme cold and dryness. There are also colonies of cyanobacteria that live just under the surface of rocks on the Earth in extreme environments, lots of possibilities and of course there is always the possibility of native Martian life forms...

 

http://en.wikipedia.org/wiki/Atmosphere_of_Mars

 

The atmosphere on Mars consists of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and contains traces of oxygen, water, and methane,

[nilloc97]

Outside? no. However if you were to make an indoor environment like say a greenhouse you could create an indoor hydroponics system. This is assuming that the greenhouse itself doesn't get destroyed by solar winds.

 

Go to this link to see my science blog I'm starting it on the subject of Hydroponics. http://ecoscience11.blogspot.com/