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Rice
Canada and the US do not consume a lot of rice. Canada in 2007/08 consumed 10.5 kg per capita. Production varies a lot, average is 4 tonnes per hectare. So 315 m^2 for 12 crew. Rice grows 1 to 1.8 metres tall, and does not require flooding. Fields are flooded because it deters weeds and vermin, and other methods of irrigation require more effort. It may be easier to plant and harvest by draining the field, requiring a large tank to receive the water.
::Edit:: Adjusted, see below. 8 t/ha becomes 157.5 m^2
Last edited by RobertDyck (2014-01-02 11:16:22)
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Yield of potato in the west is about 40 tonnes/hectare, and intensive gardening can get 50 tonnes/hectare. It's one of the most efficient crops out there, in terms of calories per square meter. Corn is almost as efficient; wheat substantially less so. Cor growing is probably easier to automate though.
Use what is abundant and build to last
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Ok. If we use 40 tonnes/hectare then to produce 580.44 kg would require 145.11 m^2; round off to 145 m^2. Biosphere 2 found they didn't produce as much as they hoped, so shrinking greenhouse size too much could be dangerous. Besides, more potatoes are good!
Last edited by RobertDyck (2014-01-02 09:12:48)
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But you're basing your calculations on an American diet, right? Why not use more potato and less wheat, go more Irish? Potatoes have ~400kCal/kg, so you'd have to eat 2.5kg worth of potatoes each day in order to get 1000 calories (but potatoes and milk are a complete diet, if you fortify them with molybdenum). But that's potatoes as they come, so perhaps products using potato flour will be denser, once you've removed the water. Also, corn is a pretty good crop as well, at about 8 tonnes/hectare and 1600kCal/kg.
Also, since you're using a greenhouse, you're not limited to growing seasons. The lower sunlight isn't going to impact yields much; they're already oversaturated here with light.
Use what is abundant and build to last
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Corn
According to this USDA document (Table 04), yield for corn produced in the US is projected for 2013 as 10.07 metric tonnes per hectare. I found consumption figures for Iowa, but most is used for animal feed or pet food. What's human consumption? This document claims their source is USDA. For 1998, corn consumption per capita was 22.3 pounds. That excluded animal feed (fodder), pet food, ethanol production (fuel), caloric sweeteners (their term), and quantities used in alcoholic beverages. Consumption increased each year, I could project to today, but let's keep it simple and use the most recent data. Converting to kg and calculating for 12 crew: 121.38 kg. So that would require 120.5 m^2
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For wheat, I already included multiple crops per year. We could go Irish. I do like potatoes.
Rice yield is average, but this document claims in 2009-2013 Belgium produced 8.587 tonnes/hectare, The Bahamas 7.340, France 7.524, and Kuwait 8.804. Those are more industrial countries, so perhaps we should use 8 tonnes per hectare. Kuwait and The Bahamas are warm countries, so already include multiple crops per year. So doubling yield reduces greenhouse area in half.
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What about sweet potatoes? Gotta have sweet potato fries.
Use what is abundant and build to last
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Also, since you're using a greenhouse, you're not limited to growing seasons. The lower sunlight isn't going to impact yields much; they're already oversaturated here with light.
I posted about my greenhouse design before. My idea is a long narrow greenhouse, oriented perfectly east-west. Greenhouse width exactly twice it's height. And place flat mirrors beside the greenhouse, on both sides, oriented 45° so it reflects sunlight from directly overhead into the sides of the greenhouse. Top edge of the mirrors the same height above ground as the top of the greenhouse, so reflected light saturates the sides. This will exactly double the amount of light inside. Since Mars received 47% as much light as Earth, the result is close to the same. The reason for a long narrow greenhouse is to avoid tracking the Sun. At dawn light will reflect from the mirrors westward, shining into the greenhouse at a different spot. At dusk light will refect eastward. You will have to adjust mirror angle for latitude, and adjust a bit for change of seasons. It works out to 1° change of mirror angle every second week. That's so slight that you could do it by hand: a notched rod holding up the mirror, move to the next notch once every second week. Or automate with motors for a large farm.
Bottom line is as much light will shine through the sides as from the roof. As long as crops can utilize this light, total light will not be much different than Earth.
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Also, there's something that we haven't yet accounted for and that is our ability to completely eliminate pests, including both insects and microorganisms, from the food production process. This has to increase yield substantially. Having said that, we may want to have some bacteria around, or some way to prevent ourselves from falling victim to a Martian potato blight.
-Josh
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Also, there's something that we haven't yet accounted for and that is our ability to completely eliminate pests ... potato blight.
Bring clean seeds to Mars. The greenhouse will start with sterile soil, in fact we'll need a sample of soil with appropriate bacteria. That will stop most weeds and pests. But Biosphere 2 had a crop disease: their bean crop failed. No matter what they did, it kept coming back. One way agriculture on Earth deals with that is biodiversity. That means we'll have to bring more than one variety. If Irish potatoes fail, then plant red potatoes, or Russet, or Yukon gold, etc. And bring actual seeds, because they store longer. Potatoes are usually planted by cutting them, one eye per section. The eye grows into a root, becoming a new plant. But that's asexual reproduction, potatoes do have flowers and pollen like normal plants. If you let them grow fully, they will produce seeds. We would want to bring those to Mars. For long-term storage, and they're easier to transport through space.
What about sweet potatoes?
Gotta have sweet potato fries.
I see a corner of the potato greenhouse that hasn't been planted yet. Go for it.
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potatoes and milk are a complete diet, if you fortify them with molybdenum
That reminds me of colcannon. I heard about this on a TV show, so had to look it up. It's mashed potatoes with milk, butter, salt, pepper, chives, a bit of parsley... So far sounding like mashed potatoes with all the fixin's, isn't it? The thing that makes it colcannon is kale. I'm simplifying a bit, the exact recipe:
6 large Irish potatoes, peeled and boiled
6 spring onions, scallions or chives
.25 pint of milk or cream
salt and pepper to taste
8oz boiled green curley kale
2oz butter
1 tablespoon chopped parsley
Other websites say you can substitute kale with cabbage.
Green vegetables have magnesium and molybdenum. They also have silicon and strontium in a form the human body can metabolise; nutrients necessary for bones.
When I heard about this, I started making it myself. (Ok, part Irish. My great grandmother's maiden name was Strong.) I have a patch of chives growing in my garden. Nothing fresher than picking as you cook dinner. My microwave oven has a potato button: just scrub the dirt off, place in the microwave, and press the button once for each small/medium potato. In a few minutes, instant baked potato. I read many nutrients are in potato skin, and I'm lazy, so just leave the skin on. I use a steak knife to cut it into cubes, a potato masher doesn't break the skin. Then just mash with the same knife. I don't have butter or milk at home, so use soybean margarine and soy milk. It's the cheap stuff: powder without additives, just defatted soy flour. The powder will keep over a year, I find milk tends to spoil before I use it. But this powder costs 25¢/100g and 1/4 cup makes 1 cup of milk, while skim milk powder costs $1.25/100g and 1/3 cup makes 1 cup of milk. Ok, my cheap Scottish side is showing. But this means I'm actually using the stuff we'll use on Mars.
I also read that kale will lose much of its nutrients if you boil it. To retain nutrients, steam or microwave instead. Just chopping kale and putting a bowl in the microwave is a lot easier. I'm a bachelor, I like easy.
Do you want to add things like chives or kale to the garden?
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If we bring cubes of beef flavor and add the vegies such as potatoe, carrots, peas, green beens we have a soup or a stew depending on how thick it is made.
What I think we need is also a timing of grow of the items to make such a stew figured out so that we know what to grow in what length cycles as well as for how many plants that it will take for the foot print to grow it in.
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That's a lot more complicated. I'm not an agriculturalist; don't expect me to do all that. I can do a lot of technology things, but I'm not an aggie. Years ago I got a database from the USDA with nutrients in practically every food. Compare that to what humans need, you can design a diet. Dieticians do that, I found the task daunting. And most people don't want to be told what to eat. Besides, we crave foods with nutrients we need at the moment. If you can listen to what your body needs, instead of habit eating, then you will have the best diet possible. People who are now senior citizens point out when they were young and worked on a farm, they ate a lot, and their diet included foods extremely high in cholesterol. The reason is a lot of physical labour requires cholesterol. If you're sitting at a desk job, then you don't. My father described a traditional breakfast food his mother made, called cracklins. One restaurant in my city served that ethnic food, so I tried it one day. The first forkful was wonderful! The second not so much. There was a very small puddle of it on the corner of my plate, but I couldn't stomach a single bite more after just half of it. That's my body telling me enough. Cracklins are almost pure cholesterol. So don't get too fancy.
At the beginning of this discussion I talked about meat substitutes. I bought packages of Yves veggie products, and read the ingredient list. I don't know the steps or proportions, but ingredients are included in my list.
Facon: fake bacon. Made from firm tofu and soy sauce. Tofu is also made from soy.
Meatless Ground Round
Veggie Burger
Meatless Pepperoni pre-sliced for pizza
Yves has a lot of products. Check them out. Imagine making most if not all on Mars. What can you cook with all that?
The local chapter of the Mars Society hosted a convention hospitality suite at the local science fiction convention in 2008. One member made home made wine from a kit. I make home made wine from grapes in my back yard, but it wasn't ready that year, and I didn't want to diminish his effort. We came up with a recipe for chilli, a traditional convention food. As all chilli, it starts with kidney beans, but he added black beans and I added Yves meatless ground round. I could give you the whole recipe. I also tried to make oven baked potato chips from raw potatoes, but it was a lot of work to get just a single bowlful, and they didn't turn out well. If under cooked, they were rubbery. If cooked to be crisp, they were slightly burnt. But I also made my pea poi and gel candies. The gel candies were quite popular; they turned out very well.
To make chilli we would have to add kidney beans and chilli powder. That's made with cumin, paprika, oregano, garlic, and cayenne. To make gel candies we need to add strawberry, raspberry, blueberry. Should we add all that?
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I did not mean to put you on the spot for the growing time to meal planning but from a set of recipes one could figure out what to plan for a just in time meal from the garden. The chilli sounds good. I noticed that the Hawian base camp used canned spam in a number of dishes for meat.
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A herb garden is essential, especially if you're not going to have a particularly varied diet. So is a fruit garden. They shouldn't take up that much of the greenhouse I think.
Use what is abundant and build to last
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I've been working on a study of crops from a menu / nutrition point of view. It's very early stages at the moment, but I hope to be able to share it soon. Beyond taste and menu preference, there are certain foods we will need to bring to fill nutritional gaps in our diet. When we speak of fortifying foods, we need to bring the sources that we use to fortify them with.
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While I fully support the ideas pesented so far, there can also be this type of thing.
http://en.wikipedia.org/wiki/Inuit_diet
Inuit diet
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Inuit elders eating Maktaaq.Inuit consume a diet of foods that are fished, hunted, and gathered locally. This may include walrus, Ringed Seal, Bearded Seal, beluga whale, caribou, polar bear, muskoxen, birds (including their eggs) and fish. While it is not possible to cultivate native plants for food in the Arctic, the Inuit have traditionally gathered those that are naturally available. Grasses, tubers, roots, stems, berries, fireweed and seaweed (kuanniq or edible seaweed) were collected and preserved depending on the season and the location.[1][2][3][4][5][6][7]According to Edmund Searles in his article "Food and the Making of Modern Inuit Identities," they consume this type of diet because a mostly meat diet is "effective in keeping the body warm, making the body strong, keeping the body fit, and even making that body healthy".[6]
Of course the sea mamals are not an option, and the tundra plants are iffy, but the fish and seaweed might be possible.
Enclosures could be ice covered or made of manufactured materials, or both. In early days water would likely come from lower lattitude glaciers, but later when Mars is more developed, I see no reason not to liquify the polar caps into ice covered bodies of water, once the atmosphere becomes thick enough for stable ice, and then later after that there could be open water.
Energy for life could be though Ice or water (Depending on the thickness of the atmosphere), and also artificial lighting underwater, and also chemicals could be manufactured to drive living things like fish and shell fish ecologies. Such exist on Earth today.
I am starting to ask seriously "Why do I do this?"
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In the case of the polar ice caps, I am thinking of them as condensers for a solar concentrating power generating system, with a fluid such as Ammonia
or Ammonia/Water mix.
If the top of the ice layer is at some very cold temperature, just a guess, 100 degrees below (Pick your units), it is not likely to vaporize, but a layer of ice of sufficient thickness, transparent or translucent could insulate the ocean, holding in the heat. Even if the ice surface slowly vaporized, it has no where to go ultimately but back to the poles under the current tilt of the planet.
Ideally, I would prefer to just boil water, and quench it directly into ice water, but of course the sea water would be of poor quality for that, and the above surface piping would be subject to freezing during down time. However a massive seasonal energy source that also provides a biosphere in the current Martian or improved Martian conditions has to be of interest.
Further, just generating Oxygen and Methane and injecting them into the ocean should generate biological activity, and any Methane and Oxygen leaked to the atmosphere will simply make Mars more habitable. It stands to reason that if such a process were running leakage would occur.
It might be that Ammonia and Ammonia/Water would freeze, but perhaps there is another suitable fluid to drive the turbines.
I would also mention that I believe that Mars gets more solar energy at it's poles than the Earth, because of the tilt.
Last edited by Void (2014-01-08 11:35:21)
I am starting to ask seriously "Why do I do this?"
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Sweet Potatoes
I found an interesting website. This one gives nutritional information for vegetables. It says a 100 gram serving of potatoes (either white or red) contain 87 calories of food energy and 20 grams of carbohydrate, while each 56 gram serving of sweet potatoes contain 131 calories of food energy and 30.1 grams of carbohydrate. That means sweet potatoes have three times as many calories per unit mass of vegetable. That's surprising! It means sweet potatoes may be far more efficient per greenhouse area.
sweet potatoes: http://www.syscowinnipeg.ca/produce.cfm?id=4457
white potatoes: http://www.syscowinnipeg.ca/produce.cfm?id=3780
Last edited by RobertDyck (2014-01-16 03:59:40)
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Only if you can't grow 3 times as many potatoes... but I'm not sure we have the data on the efficiency of plants growing in an optimised environment.
Use what is abundant and build to last
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From Wikipedia
In 2010, the world average annual yield for sweet potato crop was 13.2 tonnes per hectare. The most productive farms of sweet potato breeds were in Senegal, where the nationwide average annual yield was 33.3 tonnes per hectare. Yields as high as 80 metric tonnes per hectare have been reported from farms of Israel.
The average world farm yield for potato was 17.4 tonnes per hectare, in 2010. Potato farms in the United States were the most productive in 2010, with a nationwide average of 44.3 tonnes per hectare. United Kingdom was a close second.
New Zealand farmers have demonstrated some of the best commercial yields in the world, ranging between 60 to 80 tonnes per hectare, some reporting yields of 88 tonnes potatoes per hectare.
That sounds like optimized growing conditions produce about the same mass of product per area.
Of course variation is so great that growing conditions become a major concern. How would these crops do in Mars soil? Remember my recommendation is soil in trays in a greenhouse. Hydroponics require extensive nutrient solutions, way to heavy to transport from Earth. And if Mars soil is the source of nutrients, then why not just let plants extract nutrients directly from soil? So the idea is to treat Mars soil with simple means, water, and plant seeds. The first treatment will be with carbonated water, made by applying Mars atmosphere under pressure to water. Carbonated water is carbonic acid, a mild acid. This would neutralize some of the soil alkali, and start the process of adding carbon. We would also add ammonium nitrate granules. Again, I could give you the step-by-step method to make that from nothing but air, water, and electricity, but since the Oklahoma bombing, publishing that on the internet is not a good idea. Potassium and phosphorus is simply a matter of selecting the right soil to start with.
Last edited by RobertDyck (2014-01-16 03:47:26)
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Ooh eck, so sweet potato has about 2300 calories per kilogram, and yields up to 80 tonnes per hectare have been reported...? That's 18.4 thousand calories per square meter. That means you could support an adult, calorie wise, on 40 square meters of land.
But I've heard yields for potatoes grown non-commercially of over 125kg/m^2, which is 87.5k calories/m^2. It only just reaches into the realm of possibility at that point. But perhaps we can get 50kg/m^2 (on Terra). If I had a garden, I'd experiment, to try and find out what the optimum conditions are and how to automate them.
Use what is abundant and build to last
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Sweet potatoes require 4 months of warm temperatures to develop full size tubers, they are surprising easy to grow.
Beauregard - Pale reddish skin with dark orange flesh. Popular commercial variety. (100 days)
Bush Porto Rico - Cooper skin with orange flesh. Compact vines with big yields. Good for smaller gardens, (110 days)
Centennial - Good disease resistance and relatively quick maturing. (90-100 days)
Georgia Jet - Reddish skin with orange flesh. Good choice for shorter season. (90 days)
Patriot - Copper skin/Orange Flesh. Great pest resistance. Good choice for organic gardens. (100 days)
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Small types of Radishes are ready to harvest in 3-4 weeks.
Most larger types take 8-10 weeks after planting.
Carrots are ready to harvest in about 90 days after planting.
Harvest Beets in 40-70 days or when they are 2"-3" for the best flavor.
Early Turnips will be ready for harvest in about 5 weeks.
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