Mars has some atmospheric pressure, so pressure for plants might not be a problem. The equator on Mars is about 32 degrees F, so cold tolerant plants could grow at the equator like in the tundra areas of earth. Reindeer eat this stuff, and it could be harvested mechanically and fed to Reindeer for meat. They might could even grow cold tollerent wheat or corn genetically developed. All this could grow outside greenhouses as long as water was available. Plants could be harvested by pressurized electric tractors. I also know of a company locally that has 20 acres under greenhouses. They grow starter veggatable plants, and flowers for sale at places like Lowe's and Home Depot. It is not impossible to build whole cities under greenhouses connected by covered trailways for carts to move on. Using iron, aluminum, or other resources found on Mars, structures could be built for colonists on a continuous basis. Farming expanded, resource exploration, structure manufacturing could all keep colonists busy for years. Once something is found or could be made in the lower gravity of Mars that could be traded with Earth, then they could eventually become self sufficient. Mars could become the launching point for further exporation in the asteroid belt, Ceres, or the moons of Jupiter and Saturn. It took almost 200 years for America to grow to the point of getting independence. It may take the same for Mars. Continuous colonization, building, expanding to become self sufficient, then launching further outward exploration.
I am alergic to soy and cow's milk, so I have to use almond milk. I know soy has a lot of protein, but maybe other sources of protein can be made. Like I said nitrogen is going to be the problem with Martian plant growth. So some small animals or fish will be needed to provide a source of nitrogen for plants to grow as well as human waste.
Quote from: spacenut on 12/29/2014 05:11 pmI am alergic to soy and cow's milk, so I have to use almond milk. I know soy has a lot of protein, but maybe other sources of protein can be made. Like I said nitrogen is going to be the problem with Martian plant growth. So some small animals or fish will be needed to provide a source of nitrogen for plants to grow as well as human waste. To grow fish you need protein food first, that gives them the nitrogen. Fortunately the martian atmosphere contains a lot of nitrogen. The gas will be a byproduct of fuel ISRU. Nitrates can be produced unsing the Haber Bosch synthesis.Just yesterday I have seen a report on local TV about an new company that grows both fish and use the nutrient rich water from the fish to grow a large variety of vegetables, keeping the water in a closed circuit between fish tanks and plant greenhouse. A method that would be very suitable for a closed circuit ecology on Mars.Proteins for feeding the fish could be produced with bacteria that feed on methane with added nitrates and trace elements. A method that is already approved for producing animal feed in the EU.
@AegeanBlueIt is not that hard to keep the greenhouses warm. The martian atmosphere is near vacuum and will not transport heat the way the earth atmosphere does. As it is a greenhouse that takes sunlight in and stops infrared from escaping it may be necessary to implement methods to dispose of excess heat.
The effect of radiation is often overestimated because there is so much talk about it. While higher than recommended exposure for humans it is actually very low. Nutrients are not at risk.
A question on lighting. Is light used in greenhouses to increase yield or is it mainly to extend daylight hours to get plants into growth phase early, when the day is still short? On Mars early settlements would be near the equator, where days are quite near to 12 hours day, 12 hours night. That should be enough for the needs of plants. Maybe reflective mirror sheets can augment light level if required.
Both. Dreary northern Europe does not have sufficient lighting in the winter for the subtropical vegetables grown in the greenhouses, so they have lights. It is only though in northern Europe (perhaps Canada?) that artificial lighting is used to increase photosynthetic activity. Lighting and shading is used all over the world to grow off season crops that require specific day and night length to change phenological stage. If you have chrysanthemum in the winter, no matter what temperature you keep the greenhouse on it will not flower, it requires long days to flower. Seed companies have been creating day-length neutral varieties of major, but it is definitely better to design the greenhouse with artificial lighting anyway. Do we really want production to stop because a planet wide dust storm comes along and drops incoming radiation to pathetic levels, below what the plant needs to keep growing?While some effects on the seeds can be overcome through vernalization, plants need their proper GDDs and day lengths to go through an entire cycle. It is best to select species for food productivity even if it means artificial lighting and day length control than to select for day length and low radiation, let's not forget what colonists can't grow locally they need to import from Earth.If the first Mars trip is to stay there for a year rather than 30 days they need to grow their food rather than carry all of it which also means though that landing site must also be selected based on P and K rock richness, so as to provide local fertilizer. My thinking is that just considering how had it is to set up a farm without a biosphere, the first Expedition should be a 30 day type excursion with food for all 30 days but still have someone dedicated to setting up a farm and do grow something fast and edible these 30 days. By setting up a farm I mean setting up fertilizer production facilities, habitats, air pumps etc. When the second expedition lands they should start using the facility set up during mission 1 and plant a crop on day two to provide food, but still bring enough food for their entire duration. It would be after expedition 2 proves Mars farmable that they should forgo bringing all the food necessary. I am ambivalent if expedition 2 should be a 30 day or one year mission, but expedition one should definitely be a 30 day missionBTW I am familiar with PLANTS, I used it for my dissertation
BTW fPAR (fraction of photosynthetically active radiation) is one of the products that MODIS produces, --which you can download from NASA LP DAAC.I believe in colonization of Mars but I do not believe in Terraforming for philosophical reasons: The methane results coming out of Curiosity and Mars Express can be read as strong indications that there is life on Mars. I prefer that we do not extinguish it by transplanting the whole Earth ecosystem and overwriting the Martian ecosystem, we do not have that right.