Food

A mix of fresh raw vegetarian 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.

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	Weight of food (gram)	kiloCalorie/kg	calories per day
Fruit	500	500	250
Vegetables	750	300	225
Protein (meat and beans)	200	4000	800
Dairy	750	420	315
Grains	240	2100	504
Oils	40	5000	200
Total	2480	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 also known as biological reactors.
• 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 mostly 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

	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 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 and crop yields

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	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
Alfafla (luzerne)	Jordan	180	18	230	4140	Hydroponic : https://www.hindawi.com/journals/isrn/2012/924672/
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	5.9
		6	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	50	5
Bamboo		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).

Feed conversion ratios

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.

See also

• Food preservation