Difference between revisions of "Food"
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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 [[Financial effort estimation|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 and trace elements in food|minerals]]. | 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 [[Financial effort estimation|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 and trace elements in food|minerals]]. | ||
| − | == Food requirements == | + | ==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, about 50% of a plant is edible and the rest is biomass. | 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, about 50% of a plant is edible and the rest is biomass. | ||
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*[[:category:plants|Vegetable]] can be grown in [[greenhouse]]s or on [[green wall|green walls]] in order to close the [[carbon cycle]]. | *[[:category:plants|Vegetable]] can be grown in [[greenhouse]]s or on [[green wall|green walls]] in order to close the [[carbon cycle]]. | ||
*Proteins, fat and carbohydrates can be produced by a [[biotechnology|biotechnological factory]] | *Proteins, fat and carbohydrates can be produced by a [[biotechnology|biotechnological factory]] | ||
| − | *[[In-vitro meat]] | + | *[[In-vitro meat]] is possible, but requires large amounts of energy for its production. Modified vegetables might produce a better substitute. |
*[[:category:animals|Animals]], such as chicken or [[fish]], may be raised in sections of greenhouses. | *[[:category:animals|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 [[flies|fly maggots]]) can provide valuable proteins and might consume just [[waste biomass recycling|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). | |
| − | |||
| − | *Growing [[insects]] and their | ||
| − | *[[Algae]] | ||
*Some food (possibly [[Genetic engineering|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. | *Some food (possibly [[Genetic engineering|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. | ||
Revision as of 08:51, 17 May 2019
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, about 50% of a plant is edible and the rest is biomass.
Food that can be brought from Earth
- Several varieties of dehydrated food.
- Food that contains large amounts of fat and carbohydrates, such as nuts.
- Concentrated fruit juice.
- Light weight, 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
- In-vitro meat is possible, but requires large amounts of energy for its production. Modified vegetables might produce a better substitute.
- 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
Assuming we have no genetically modified plants for the Martian colony we can only try to provide optimized conditions in the greenhouse for maximization of harvest. The following calculation is, therefore, based upon terrestrial agricultural figures.
Potatoes
Under best conditions on Earth it is possible to grow 3 kg potatoes per m2 per year. 3 kg potatoes contain 8820 kJ energy, which roughly serves the energy requirements for one person for one day. So, a person needs about 365 m2 cropland at a minimum to survive.
Wheat
The average harvest of wheat is 0.28 kg per m2 per year. Under best conditions it is possible to grow 0.7 kg per m2 per year. 0.7 kg wheat contain 9198 kJ energy, which roughly serves the energy requirements for one person for one day. So, a person needs about 365 m2 cropland at a minimum to survive.
Facts and figures
- Sweden: 26 tonnes of potatoes per hectare [1]
- Sweden: about 6 tonnes of wheat per hectare [2]
- "Plain boiled potatoes are naturally low in fat and provide 72 kcal/100g (306 KJ/100g)" [3]
- "Wheat flour provides 310 - 340 kcal/100g (1320 - 1450 KJ/100g)"[4]
- Bamboo can yield 4 tonnes per hectare[5]
Crop yields[6]
| Crops | Yield (tonnes per hectare) |
|---|---|
| Winter Wheat | 5.9 |
| Spring Wheat | 3.1 |
| Fall Rye | 2.6 |
| Oats | 3.2 |
| Barley | 3.3 |
| Mixed Grain | 2.8 |
| Grain Corn | 10.5 |
| Canola | 2.6 |
| Soybeans | 3.1 |
| Dry White Beans | 2.3 |
| Coloured Beans | 2.3 |
| Fodder Corn | 50.2 |
| Hay | 6.3 |
On Mars, these crops might be grown year round, with supplemental artificial lighting, no weather, extra CO2 concentration and optimum irrigation and fertilization. Yields would then probably be significantly higher.
Meat production
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 |
Open issues
- What sorts of food are required to keep the settlers healthy? We need a nutrition plan on a scientific base.
- What esculent animal/insect/worm etc. needs the smallest amount of vegetable? The best mass ratio is sought-after. A list would be highly welcome.
- 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?
See also
References
- ↑ Press release from Statistics Sweden and Swedish Board of Agriculture
- ↑ Report from State of Sweden
- ↑ British Nutrition Foundation - Potatoes
- ↑ British Nutrition Foundation - Flour
- ↑ http://afribam.com/index.php?option=com_content&view=article&id=49:bamboo-for-plantations&catid=22&Itemid=116
- ↑ https://ourworldindata.org/yields-and-land-use-in-agriculture
