Food
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. Especially 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, the own food can be of higher quality and fresh, including a natural mix of vitamins and minerals.
Contents
Food requirements
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 | kC/kg | cal | ||
| Fruit | 500 | g | 500 | 250 |
| Vegetables | 750 | g | 300 | 225 |
| Protein (meat and beans) | 200 | g | 4000 | 800 |
| Dairy | 750 | g | 420 | 315 |
| Grains | 240 | g | 2100 | 504 |
| Oils | 40 | g | 5000 | 200 |
| Total | 2480 | g | 12320 | 2294 |
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 or on green walls in order to close the carbon cycle.
- Proteins, fat and carbohydrates can be produced by a biotechnological factory
- Animals, such as chicken or fish, may be raised in sections of greenhouses.
- It takes 2000 to 3000 litres of water to produce 1 kg of meat, it only takes 100 litres 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 just waste biomass. Pigs might be a more palatable alternative.
- Algae can produce large amount of food and oil. However, is is impossible to survive only on algae 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.
Nutrition and Energy Calculations
| Calorie calculation | ||||
| Human calorie intake | kilocalorie/day | 2300 | 2300000 | |
| days per year | 365 | 365 | ||
| energie 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 but remain bellow record yields and are usually for open field intensive agriculture unless otherwise noted.
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 probably be significantly higher.
| Food type | Tonnes
/ha |
kg
/m2 |
kilocalorie
/kg |
kilocalorie
/m2 |
Notes | |
| Apples, pears | Australia | 65 | 6.5 | 571 | 3714 | https://www.goodfruit.com/calculate-target-yield/ |
| Ontario | 25 | 2.5 | 580 | 1450 | ||
| Oranges, citrus | Florida | 130 | 13 | 470 | 6110 | https://www.hort.purdue.edu/newcrop/morton/orange.html#Yield |
| Israel | 50 | 5 | 470 | 2350 | https://www.haifa-group.com/citrus-tree-fertilizer/crop-guide-growing-citrus-trees | |
| Banana | Puerto Rico | 70 | 7 | 1000 | 7000 | https://www.hort.purdue.edu/newcrop/morton/banana.html#Yield |
| Strawberries | England | 30 | 3 | 330 | 990 | https://vegetablegrowersnews.com/article/tunnels-varieties-double-uk-berry-yields/ |
| California | 90 | 9.0 | 330 | 2970 | Hydroponic https://cals.arizona.edu/strawberry/Hydroponic_Strawberry_Information_Website/Costs.html | |
| Australia | 150 | 15.0 | 330 | 4950 | http://www.nuffieldinternational.org/rep_pdf/1450740021NickyMannFinalReport.pdf | |
| Dwarf fruit trees | California | 72 | 7.2 | |||
| Potato | UK | 50 | 5.0 | 850 | 4250 | https://potatoes.ahdb.org.uk/sites/default/files/GB%20Potatoes%202016-2017.pdf |
| Sweden | 26 [1] | 2.6 | ||||
| Sweet potato | california | 27 | 2.7 | 860 | 2346 | https://ucanr.edu/repository/fileaccess.cfm?article=54045&p=%20MKCWZJ |
| Tomatoes | 150 | 15.0 | 180 | 2700 | ||
| Water melon | 36 | 3.6 | 300 | 1071 | ||
| Cabbage | 90 | 9.0 | 250 | 2250 | https://www.kzndard.gov.za/images/Documents/Horticulture/Veg_prod/expected_yields.pdf | |
| Beans | 20 | 2.0 | 3470 | 6940 | Hydroponic https://uponics.com/hydroponics-yield/ | |
| watercress | 25 | 2.5 | 110 | 275 | https://ipmdata.ipmcenters.org/documents/cropprofiles/HIwatercress.pdf | |
| canola | 3 | 0.3 | 8840 | 2652 | ||
| Rice | China | 17 | 1.7 | 1300 | 2210 | http://www.xinhuanet.com//english/2017-10/16/c_136683786.htm |
| Wheat | 10 | 1.0 | 3400 | 3400 | ||
| Canada[2] | 5.9 | |||||
| 6[3] | 0.6 | |||||
| Oats | 4.3 | 0.4 | 3890 | 1673 | ||
| 3.2 | ||||||
| Barley | 7 | 0.7 | 3540 | 2478 | ||
| soya | 3 | 0.3 | 4460 | 1338 | ||
| Corn | 12 | 1.2 | 960 | 1152 | ||
| Fodder Corn | Canada[2] | 50 | 5 | |||
| Bamboo[4] | 4 | For wood type products |
Meat production
Energy in meat and meat products and dairy products.
| Food type | kg
/m2 |
kilocalorie
/kg |
kilocalorie
/m2 |
Notes | |
| Meat | 5000 | ||||
| fat | 9000 | ||||
| protein | 4000 | ||||
| Salmon | 2080 | ||||
| Tilapia | 1290 | ||||
| chicken | 2390 | ||||
| milk | 420 | ||||
| Eggs | 1550 |
Feed conversion ratio 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).
| Livestock | FCR | |
|---|---|---|
| Beef | 4.5–7.5 | calculated on live weight gain |
| Dairy | ||
| 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 |
| Poultry | 1.6-2 | A hen can lay up to 330 eggs per year. Maturation is about 40 days |
| Criquets | 0,9-1.0 | |
| Fish | 1-1.5 | Higher for fish to fish conversion |
| Rabbits | 2.5-3 |
Artificial food
- What is known about needed vitamins and minerals?
- Is it possible to make artificial food with an artificial mixture of vitamins and minerals, allowing humans to keep well and fit?
- Beyond meat, a vegetable meat substitute.
- In-vitro meat is possible, but requires large amounts of energy for its production. Modified vegetables might produce a better substitute.
