The amount of Food for human beings that can be brought from Earth to Mars is limited, and the logistics of a continued food transport for the long term is expensive. By definition, an autonomous colony needs it's own food production. Reasons for this are cost reduction and the achievement of independence from Earth. Last but not least, locally produced food can be of higher quality and fresh, including a natural mix of vitamins and minerals.
An average human requires about 2,7 kg of food per day, or 985 kg per year. A good target might be one tonne of food per year per colonist, to account for losses. Plants are composed of edible parts and non edible parts. The non edible portion is counted as biomass, and can be used for industrial production or recycled into the food production system. On average, of the solid parts of plants (not water) about 50% of a plant is edible and the rest is biomass. The following table presents a suggested diet based on the Canadian Food Guide.
|Food, canadian food guide||Weight of
|Protein (meat and beans)||200||4 000||800|
|Total||2 480||925||2 294|
Note: Calories as expressed in food guides and nutritional documents are actually kiloCalories. so the Calories of column 4 in this table are actually kiloCalories.
Food that can be brought from Earth
- Several varieties of dehydrated food.
- Food that contains large amounts of fat and carbohydrates, such as nuts and dried meats.
- Concentrated fruit juice.
- Lightweight, high energy foods with a long shelf-life.
Local Production Methods
- Vegetable can be grown in greenhouses, grow rooms or on green walls in order to close the carbon cycle.
- Proteins, fat and carbohydrates can be produced by a biotechnological factory also known as biological reactors.
- Animals, such as chicken or fish, may be raised in sections of greenhouses.
- It takes 2000 to 3000 liters of water to produce 1 kg of meat, it takes 100 liters of water to grow 1 kg of grain. Water will be a very valuable commodity on Mars, so the first generation of settlers may well be vegetarian by necessity. This may be mitigated by water recycling.
- Growing insects and their larvae (e.g. flour worms or fly maggots) can provide valuable proteins and might consume mostly waste biomass. Pigs might be a more palatable alternative, of fish.
- Algae can produce large amount of food and oil. However, is is impossible to survive only on algae alone in the long term(reference needed).
- Some food (possibly genetically modified) may be grown in the Martian atmosphere. Results from the Phoenix lander indicate that some vegetables may be grown in caves safe from radiation(ref needed).
Nutrition and Energy Calculations
|Unit||1 person||1000 persons|
|Human calorie intake||kilocalorie/day||2300||2300000|
|Days per year||365||365|
|Energy per year||kiloca||839500||839,500,000|
|Yearly energy production||kilocal/m2||4700||4700|
|Area to feed humans||m2||179||178,617|
Food and crop energy and yields
The following table has been compiled from various sources. The values are high but remain bellow record yields and are usually for open field intensive agriculture unless otherwise noted. Most of the energy in plants is stored in the form of carbohydrates, that store about 4000 kilo-calories per kg.
On Mars, these crops could be grown year round, with supplemental artificial lighting, no weather, extra CO2 concentration and optimum irrigation and fertilization. Some Yields might then be significantly higher.
|Dwarf fruit trees||California||72||7.2|
These are for 1 crop per year, 120 days per crop. So it might be possible to reach 200 tonnes/ha for 3 crops per year in intensive agriculture. So 17 000 kilocalories/m2.
|Beans||20||2.0||3470||6940||Hydroponic : https://uponics.com/hydroponics-yield/|
|US||40||4||150||600||Typical field grown|
|Hydroponic : https://www.hindawi.com/journals/isrn/2012/924672/|
|Wheat||US-Europe||10||1.0||3400||3400||Two crops per year, summer and winter. Often another crop (oats, maize, barley) and wheat|
|US||150||15||3400||50 000||Maximum theoretical, hydroponic in lab conditions, Bugbee_Monje_LimitsCropProductivity_BioScience_1992.pdf|
|US||80||8||3400||27 000||NASA This test cites the Bugbee study. Main difference is lower lighting levels. Doubling the lighting increases yields by about 80%.|
|Bamboo||4||For wood type products|
Many of the higher yield in this table are the result of multiple crops per year.
These a edible food crop yields. the actual biomass crop yields are about double these. Potatoes are about 80% edible yield while most plants are between 35% and 50%.
Meat production may someday be artificial, but may for some time come from animals. Vegetable alternatives exist for meat, and usually require less energy for their production. Therefore producing meat may be a question of demand and opportunity, rather than a question of need. Animals can produce meat from unused biomass, but the demand for other uses may be higher than the demand for meat production.
Feed conversion ratio (FCR) is a measure of efficiency. It is the ratio between the mass of feed and the mass of product output. For dairy cows, for example, the output is milk, whereas in animals raised for meat (such as beef cows, pigs, chickens, and fish) the output is the flesh, that is, the body mass gained by the animal, represented either in the final mass of the animal or the mass of the dressed output (from Wikipedia).
|Beef||4.5–7.5||calculated on live weight gain|
|Pigs||3.8-4.5||About 1 for piglets, grows higher and higher with time|
|Sheep||4-6, 40||4-6 on grain, 40 on straw. This is an example of the difference between the production from high value food and the production
from lower value biomass.
|Poultry||1.6-2||A hen can lay up to 330 eggs per year. Maturation is about 40 days.
Note than hens and many birds may require gravity for feeding/drinking, and transportation to Mars may be a problem.
|Criquets||0,9-1.0||Seems unlikely to be below 1....|
|Fish||1-1.5||Tilapia is 1. Salmon about 1,3. Higher for fish to fish conversion, almost 4 in many piscicultures.|
There is no existing complete food than might be considered artificial.
- See vitamins for the basic vitamin requirements that need to be obtained from food.
- Industrial proteins and carbohydrates are not produced directly from base chemicals but require biological reactors. There are a number of experiments being done to produce artificial food from the output of biological reactors, but these have not, to this time(2019), been proven to be more economical that naturally produced food.
- Beyond meat, a vegetable meat substitute, may be considered as artificial in some ways, but is more a modified food. Entirely vegetarian diets are possible.
- In-vitro meat is possible, but requires large amounts of energy for its production. Modified vegetables, such as Beyond Meat might produce a better substitute.
- Press release from Statistics Sweden and Swedish Board of Agriculture
- Comparison of Land, Water, and Energy Requirements of Lettuce Grown Using Hydroponic vs. Conventional Agricultural Methods Guilherme Lages Barbosa,1 Francisca Daiane Almeida Gadelha,1 Natalya Kublik,1 Alan Proctor,1 Lucas Reichelm,1 Emily Weissinger,1 Gregory M. Wohlleb,1 and Rolf U. Halden1,2,*
- Continuous Hydroponic Wheat Production Using A Recirculating System C. L. Mackowiak L. P. Owens C. R. Hinkle The Bionetics Corporation, Kennedy Space Center, Florida
- Report from State of Sweden
- Beef production feed rate https://web.archive.org/web/20190805235813/https://lib.dr.iastate.edu/cgi/viewcontent.cgi?referer=https://en.wikipedia.org/&httpsredir=1&article=1027&context=driftlessconference
- Pig FCRhttps://web.archive.org/web/20150917051750/http://www.pigprogress.net/Breeding/Sow-Feeding/2009/4/Taking-control-of-feed-conversion-ratio-PP005927W/
- Cronjé. P. B. and E. Weites. 1990. Live mass, carcass and wool growth responses to supplementation of a roughage diet with sources of protein and energy in South African Mutton Merino lambs. S. Afr. J. Anim. Sci. 20: 141-168