Author Topic: Scaling Agriculture on Mars  (Read 237923 times)

Online Robotbeat

  • Senior Member
  • *****
  • Posts: 28698
  • Minnesota
  • Liked: 8771
  • Likes Given: 5698
Re: Scaling Agriculture on Mars
« Reply #540 on: 04/12/2016 01:59 am »
I agree it wouldn't be worth extracting (that's why the smiley). But my other statements stand. :) Propylene is slightly better, and often ethylene and propylene are co-produced from syngas (which is likely a far better way of producing plastics).
« Last Edit: 04/12/2016 02:00 am by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Hanelyp

  • Full Member
  • ***
  • Posts: 369
  • Liked: 65
  • Likes Given: 252
Re: Scaling Agriculture on Mars
« Reply #541 on: 04/12/2016 04:48 am »
Air filtration is a big, important issue to get right for Mars in general (aka, for people as well as plants).  Beyond outgassing and other contaminants.  The more we learn about Martian dust, the nastier of a substance it turns out to be and the lower our tolerance for even small amounts getting into the habitat.  You don't want to be breathing perchlorates, arsenic and hexavalent chromium mixed with silica grains ideally sized for silicosis.  You don't even want to touch the stuff; Martian dust is believed to be corrosive enough to organics that it would burn skin like handling lye.  Mars is a reducing environment, not an oxidizing one.  The surface chemistry is very different from Earth.
What happens to those nasties once you introduce a warm human friendly atmosphere with O2 and water?  A good dust cleaning system in airlocks still seems a good idea.

Offline Rei

  • Full Member
  • ****
  • Posts: 508
  • Iceland
  • Liked: 265
  • Likes Given: 103
Re: Scaling Agriculture on Mars
« Reply #542 on: 04/12/2016 11:38 am »
Quote
What happens to those nasties once you introduce a warm human friendly atmosphere with O2 and water?

If you're thinking that they disappear immediately, the answer is no.

Offline AegeanBlue

  • Full Member
  • ****
  • Posts: 535
  • Raleigh
  • Liked: 136
  • Likes Given: 41
Re: Scaling Agriculture on Mars
« Reply #543 on: 04/12/2016 05:37 pm »
In biology there is a definition of toxic, and ethylene in plants does not meet it: sure, it causes it's eventual death which is why fruit (that produces a lot of ethylene) is kept as separate from other biological materials (e.g. potato tubers) as possible. Fruit refrigerators require special fans that replace the air with new air instead of just keeping it and cooling. However ethylene is not considered toxic like say cyanide which gunks up the metabolic pathway, in both plants and animals. Indeed for plant ethylene we are talking about the ppm range, but the usual way we get rid of ethylene's effect is better aeration (basically, dilution). How would that would work on Mars, I have no idea, but ethylene is not a typical problem in greenhouses, no matter how closed they are. It is nothing compared to say moisture. Ethylene is a problem in refrigerators and other storage facilities.

My understanding is that Martian dust is in the PM2.5 and PM10 range. The usual solution on earth is to limit cars/industrial activities that produce these materials and to hope for rain to wash it off the air. No idea how to do it on Mars.

I agree that there is little to discuss anymore on the subject and it would be great to move to experiments. Alas I am not on a funding committee or anything. I will keep posting to this thread new new articles posted on the subject, unless we really want this thread to die

Offline Rei

  • Full Member
  • ****
  • Posts: 508
  • Iceland
  • Liked: 265
  • Likes Given: 103
Re: Scaling Agriculture on Mars
« Reply #544 on: 04/12/2016 08:01 pm »
Quote
In biology there is a definition of toxic, and ethylene in plants does not meet it: sure, it causes it's eventual death which is why fruit (that produces a lot of ethylene) is kept as separate from other biological materials (e.g. potato tubers) as possible. Fruit refrigerators require special fans that replace the air with new air instead of just keeping it and cooling. However ethylene is not considered toxic like say cyanide which gunks up the metabolic pathway, in both plants and animals. Indeed for plant ethylene we are talking about the ppm range, but the usual way we get rid of ethylene's effect is better aeration (basically, dilution).

:(  So many things wrong with this.

1. That's not what toxic means.

https://en.wikipedia.org/wiki/Toxicity
https://en.wikipedia.org/wiki/Toxin
http://www.atsdr.cdc.gov/
http://www.atsdr.cdc.gov/toxicsubstances.html
http://www.medicinenet.com/script/main/art.asp?articlekey=34093

Toxic means that it can harm life.  That's it.  It's not more specific than that.  It doesn't have to be deadly - although ethylene is.

2. Parts per billion, not parts per million.  Visible damage begins at as low as 10 parts per billion - that is  incredibly toxic.  For example, carbon monoxide toxicity begins at about 35 ppm (3500 times higher) for long-term exposure (OSHA allows up to 50ppm over an 8-hour work shift).  The OSHA PEL for hydrogen cyanide is 10ppm over an 8-hour work shift.  Yes, ethylene is three orders of magnitude more toxic to plants than hydrogen cyanide is to humans.

3. Ethylene doesn't just cause "eventual death" - ppb levels will only kill through accumulated long-term damage, but  but ppm levels kill them pretty quickly ("quick" from a botanical perspective... everything happens slowly with plants).  One technique to identify manufactured gas leaks is to look for dead plants:

http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=1460&Type=2

Under 24 hours causes severe epinasty in tomatoes - here's visual evidence after 24 hours treatment:

http://endowment.org/wp-content/uploads/2014/07/tomatoepinasty1.jpg

It can kill tomato plants within days if levels are high enough.

The reason ethylene causes ripening is because it causes cell death.  In most situations, it is the death hormone in plants - it triggers apoptosis:

http://link.springer.com/chapter/10.1007%2F978-94-011-4453-7_38#page-1

It's also the hormone that causes leaves to die and shed, causes flowers to fall off, causes stems to stop growing, etc.  It's the counter to auxin, the growth stimulation hormone.

(The exception is in the soil, where it things are reversed - it increases root formation, causes seed germination, etc)

Quote
How would that would work on Mars, I have no idea, but ethylene is not a typical problem in greenhouses, no matter how closed they are

You're arguing with someone who grows a veritable jungle of rare plants and has built greenhouses.  Yes, ethylene absolutely can and does cause problems in greenhouses on Earth when air circulation is closed off too tightly and/or artificial or dense natural sources are present.

Quote
It is nothing compared to say moisture

This has to be a joke.
« Last Edit: 04/12/2016 08:03 pm by Rei »

Offline AegeanBlue

  • Full Member
  • ****
  • Posts: 535
  • Raleigh
  • Liked: 136
  • Likes Given: 41
Re: Scaling Agriculture on Mars
« Reply #545 on: 04/13/2016 12:54 am »
I also have had greenhouse experience, growing tomatoes in Portugal and somehow ethylene in this context never came up, just as it never came up as a undergrad in the appropriate classes. So, I looked up Dr. Google; could it be that I have such a large lacuna in my education? No, not quite. The issue indeed exists, for cut flowers and potted plants:

http://www.hort.cornell.edu/mattson/leatherwood/
http://www.oardc.ohio-state.edu/joneslab/images/ethylene_extension.pdf

As you can see these are extension literature, "grey" but extremely important. The most complete list I found was in this one:

http://content.ces.ncsu.edu/ethylene-sources-symptoms-and-prevention-for-greenhouse-crops

It contains mostly ornamentals but also five horticultural plants (with reported concentration of some effect): cucumber (0.1 ppm), eggplant (0.8 ppm), lettuce (0.05 ppm), pepper (0.5 ppm), sweet pea (not reported) and tomato (0.05 ppm). On the other hand ornamentals were pages upon pages. What is consistent is that the comments are that damage is cause not by the innate production of the plant but rather from an external source at the greenhouse, such as cigarette smoke and badly working heater.

In the greenhouse I was working in Portugal there was no heater. In the Oeste region the temperature rarely drops below freezing. The problem was that with closed windows at night humidity was permanently high leading to one disease after another. It got so bad they ended their (experimental) runs at the end of June, instead of going all the way to fall and take advantage of higher producer prices. Ethylene was never an issue. Nor was it even brought up when I was an undergrad in Greece, ethylene was only discussed in terms of refrigerators.

You are working with tropical plant greenhouses, that was a hint to me: The tropics generally are hot and humid, unlike the hot and dry Mediterranean. Tropical plants are better adapted to high humidity, though my understanding is that they still suffer from fungi. Also I do not remember you mentioning any horticultural plants. Simply put there is not universal greenhouse experience, I remember reading how greenhouses in Martinique and tropical regions in general serve as umbrellas rather than blankets. Your experience with exotic plant greenhouses is not necessarily universal.

Offline Rei

  • Full Member
  • ****
  • Posts: 508
  • Iceland
  • Liked: 265
  • Likes Given: 103
Re: Scaling Agriculture on Mars
« Reply #546 on: 04/13/2016 03:02 am »
I also have had greenhouse experience, growing tomatoes in Portugal

Warm-weather greenhouses and cold-weather greenhouses are entirely different beasts.  Cold-weather greenhouses deal with sealing up as much of the greenhouse as possible, and also are more likely to be externally contaminated with ethylene (such as by a leak in a heater system).

Quote
The issue indeed exists, for cut flowers and potted plants:

Why are you acting as if I haven't already given references?

Quote
As you can see these are extension literature, "grey" but extremely important. The most complete list I found was in this one:

http://content.ces.ncsu.edu/ethylene-sources-symptoms-and-prevention-for-greenhouse-crops

It contains mostly ornamentals but also five horticultural plants (with reported concentration of some effect): cucumber (0.1 ppm), eggplant (0.8 ppm), lettuce (0.05 ppm), pepper (0.5 ppm), sweet pea (not reported) and tomato (0.05 ppm). On the other hand ornamentals were pages upon pages.

Cucumber, pepper, and tomato being some of the most important greenhouse crops grown on Earth.

The reason for the "pages upon pages" of ornamentals is twofold.

One, with ornamentals, appearance is everything.  With a food crop, if it takes on damage and reduced yield, it's a negative.  But with an ornamental, if it takes on damage, it's worthless.

Two is entirely unrelated to growing the crops - it's that ethylene causes flowers to age after being cut, so reducing ethylene damage is important in increasing their shelf life.

Quote
What is consistent is that the comments are that damage is cause not by the innate production of the plant but rather from an external source at the greenhouse, such as cigarette smoke and badly working heater.

The most common source of ethylene damage in greenhouses is defective heaters.  But it absolutely does happen in the absence of gas heaters when greenhouses are sealed too tightly, as plants themselves outgas ethylene.  Decaying plant matter is a particularly significant source.

Or, if you don't trust the experience of someone who has lost plants from ethylene buildup after an overly aggressive sealing effort:

http://ohiofloriculture.osu.edu/sites/ohioflori/files/d6/files/file/energy-conversion.pdf

Quote
An improperly functioning greenhouse
heating unit is the most common source of ethylene contamination.

Others sources of ethylene include:

Exhaust from combustion engines
Cigarette smoke
Leaky gas lines or contaminated fuel
Ripening fruits
Senescing flowers
Dying and decaying plant material
Wounded plant tissues

Note that all of the last four are plant sources.  In my case, I wasn't particularly diligent about hauling dead plant matter out to the compost heap.

It's simply a fact that plants outgas ethylene, and if there is little ventilation, it builds up to hazardous levels.  On Mars there is zero natural ventilation - only what you provide.

Quote
In the greenhouse I was working in Portugal there was no heater. In the Oeste region the temperature rarely drops below freezing.

Yes, and you're talking with someone who used to grow plants in Iowa and now grows in Reykjavνk.  You're used to warm weather, ample leakage growing. 

Quote
It got so bad they ended their (experimental) runs at the end of June

Funny that you couldn't manage to do what pretty much every other greenhouse grower on the planet manages.  Humidity is more often a benefit in the greenhouse environment, as it suppresses some pest populations like spider mites.  What diseases were you having problems with?

And really, your windows were closed at night in June?  Does it really get that cold at night in June in Portugal?

Quote
Nor was it even brought up when I was an undergrad in Greece, ethylene was only discussed in terms of refrigerators.

I'll refrain from commenting on the quality of your education there.  :ή

Quote
You are working with tropical plant greenhouses, that was a hint to me: The tropics generally are hot and humid, unlike the hot and dry Mediterranean. Tropical plants are better adapted to high humidity, though my understanding is that they still suffer from fungi.

The only fungal disease I've ever had problem with is rot in poorly situated bananas.  My biggest problem long term has always been spider mites - with periodic random problems in-between when I changed conditions (the aforementioned ethylene problem, excessive heat, excessive cold, phytotoxicity, etc... each one only bites you once, but it hurts when it does).  Some plants, I have to spray the leaves weekly or more if I don't wan't them mite infested (cocona, for example).  Whenever I get lazy, things are fine for several weeks, then all of the sudden I notice that the plants are dying and covered in webbing  :ή  I could get longer-term protection, but I don't want to use anything more toxic like organophosphates (I use neem + sucrashield).

Offline AegeanBlue

  • Full Member
  • ****
  • Posts: 535
  • Raleigh
  • Liked: 136
  • Likes Given: 41
Re: Scaling Agriculture on Mars
« Reply #547 on: 04/13/2016 04:22 am »
I've been looking my archives, and while I was not able to find a list of the diseases they had during that campaign, I did find a list of the substances used:

Table 48. Plant protection products used in the greenhouse

Product Active substance Containers Unit cost Total cost
Rufast Avance acrinatrina          1           11.44 € 11.44 €
Ortiva              azoxistrobina     1           47.98 € 47.98 €
Turex           Bacillus thurigensis 8            4.43 € 35.44 €
Ret-Bt          Bacillus thurigensis 2          17.45 € 34.90 €
Applaud       buprofezina            4            3.65 € 14.60 €
Thiovit          enxofre (wetable)  4            0.61 € 2.44 €
Aliete               fosetil-aluminum 1            6.91 € 6.91 €
Rovral              iprodiona            4            8.11 € 32.44 €
Plenum 25 WP pimetrozina        3            7.84 € 23.52 €
Scala                pirimetanil          1            8.94 € 8.94 €

The name of the active substance is in Portuguese. I was an Erasmus student and arrived on July 5th 2003. That year was exceptionally hot and dry, hence the multiple huge fires. However even in August, which was a record breaking August, I never felt the sort of heat I feel in Athens, it was rather comfortable and I was living at that point in Lisbon at Entrecampos, not in the countryside without the heat island effect. Even when the night temperature dropped at 20 C you still needed a jacket for the humidity which was bone chilling. In Lisbon there are entire neighborhood where they don't have central heating, even in brand new houses. I was not surprised that there was no heating in greenhouses, the surprising part was that we were talking about a high end hydroponic greenhouse. It was not however a commercial greenhouse, it was a demonstration greenhouse run by the local second level coop in cooperation with Instituto Superior d'Agronomia and with European funding. The idea was to see if the particular varieties grown could indeed grow under local conditions (think photoperiodism) and to demonstrate automations to farmers, including automated mechanized window opening and closing. Compared to the greenhouse we were taken at Ierapetra or Falassarna (both of these places are in Crete) and in Cyprus they were less advanced technologically. As Erasmus student I also took a few course at ISA and I was surprised that the agronomist degree was relatively easier and less intensive than in Greece. They only needed around 80-90 courses in 5 years to get their degree, as opposed to the 110 courses in 5 years that we needed at the Agricultural University of Athens

The humidity issue did come up not only in classes but also in discussions with farmers during field trips. It was an issue in the summer due to cooling panels, that wonderful invention that reduces noontime temperature from 40 C to 26 C by taking advantage that relative humidity is only 25%: you run water through a high porosity special material on one wall and pull air using fans you pull in outside air through that panel, leading to 26 C air at 100 % RH. No heat stroke for the plants but they get vulnerable to molds and rots. This is why you usually grow the plants in the off season on a Mediterranean greenhouse, when all you need is heating and no cooling and producer prices are higher.

We are indeed at the point where we need some sort of actual experiment if ethylene will be an issue on Mars. Let's not forget the first rule of plant protection: we intervene only if the intervention makes economic sense, if the income from production saved is more than the cost of the intervention. If we still get our tomatoes in the quantities we need but deformed, that is not an issue on Mars. We are looking for edible tomatoes, not good looking tomatoes. In any case greenhouses crops last most often 7-9 months in Greece. When the summer heat starts most farmers just cut off irrigation, harvest the last crop, cut off the plants and often solarize the ground and then move on to growing a far more lucrative crop: North European tourists.

Offline AegeanBlue

  • Full Member
  • ****
  • Posts: 535
  • Raleigh
  • Liked: 136
  • Likes Given: 41
Re: Scaling Agriculture on Mars
« Reply #548 on: 04/13/2016 12:54 pm »
Another new article about a CU student growing strawberries for Mars:

http://www.denverpost.com/business/ci_29756500/growing-strawberries-space-isnt-far-from-reality-says

From the article:
Quote
Plus, she added: "Turns out plants are really hard to grow. They don't just take care of themselves. A lot of people think you just add water and nutrients. If only it were that simple. Engineers are very good at killing plants."

Offline LMT

  • Lake Matthew Team
  • Full Member
  • ****
  • Posts: 707
    • Lake Matthew
  • Liked: 90
  • Likes Given: 0
Re: Scaling Agriculture on Mars
« Reply #549 on: 04/15/2016 02:18 pm »
Great thread.  Mind if I cross-thread a bit, to pull your thoughts over to our side?  We're looking at a specific challenge.

So, if you had:

- a Mars greenhouse structure, radiation-protected, admitting 60% incident light and having all required supplemental electric light, heat and water,

- enclosing 2,000,000 m3 of pressurized space, enabling

- 70 acres of growth

and you had:

- 20 years to prepare, so that cutting-edge tech could be plausibly perfected,

how might you load an MCT (i.e., 100 tons +/-) to stage the initial "biome"?



Goal: self-sufficiency for 350, any surplus being high-value bonus.



This "biome MCT" would be one of the eight MCTs required to complete the core colonial facilities proposed in our Lake Matthew scheme.  I'd be delighted if the clever contributors to this thread would take a shot or two at this aspect of the challenge.



Relevant posts:

Self-sufficiency and Local Provisioning

8 MCTs



Thanks.



Offline spacenut

  • Senior Member
  • *****
  • Posts: 2484
  • East Alabama
  • Liked: 433
  • Likes Given: 246
Re: Scaling Agriculture on Mars
« Reply #550 on: 04/15/2016 02:44 pm »
Ok, so we have to find a cold dry, maybe high altitude area to test a sealed greenhouse for Martian conditions.  North Chile desert maybe, at high altitude.  Thin air, little to no water, cold like Mars.  It must be done somewhere if we are going to colonize Mars. 

First, every eatable plant known should be grown to test everything and test productivity. 
Second, algae should be grown and processed into food pellets, and or grown with tilapia. 

Once plants are figured out, the introduce chickens, and maybe small animals.  They can eat parts of plants that humans do not eat, or waste from tilapia not reused in fertilizer could be processed to feed the chickens protein supplements as chickens can eat bugs, worms and such. 

Equipment for air circulation can have attachments to separate out gases, or other contaminents. 

Like I said, it must be done somewhere to simulate Martian conditions.  Artic areas might be another if a colony is built near a Martian glacier.  Anyone got any suggestions as to where this should be tried?

Offline Paul451

  • Full Member
  • ****
  • Posts: 1575
  • Australia
  • Liked: 797
  • Likes Given: 650
Re: Scaling Agriculture on Mars
« Reply #551 on: 04/15/2016 03:26 pm »
Ok, so we have to find a cold dry, maybe high altitude area to test a sealed greenhouse for Martian conditions.

There is nowhere on Earth that even crudely approximates Mars. Not even close. Not even "but it's good enough for a first run", nor "but it'll give us a basic idea". Nothing you learned from a greenhouse build on the Atacama plateau would tell you anything about building a greenhouse on Mars.

You are making the classic mistake that Mars is "like a cold, dry, high altitude desert, but a bit more".

Mars is a near vacuum. You cannot build a "greenhouse" on the ground because it cannot sustain the pressure (it will push up from the ground as soon as you pressurise it. You need ten tonnes of ballast for every square metre of surface area.) That means you're building an entirely enclosed pressure vessel, very heavy, no soil.

You cannot pressurise the external atmosphere without extreme equipment. Mars is a good quality vacuum, trying to concentrate the Martian atmosphere is the difference between pumping out a good vacuum, and pumping out an extremely hard vacuum. Your starting point with Mars is the point where most industrial processes stop trying, because the cost escalates quickly and you need specialist lab equipment that only works on a small scale.

The top of Mt Everest is an English summer garden by comparison.

It must be done somewhere if we are going to colonize Mars.

The only place to simulate a Martian "greenhouse" is in a completely artificial environment. And you can house that completely artificial environment anyway.

It'll be a hell of a project though. Good quality vacuum chamber, big enough to build a large structure inside, with enough distance between the test structure and the vacuum chamber walls to avoid complication from thermal radiation and circulation entrapment (of the remaining trace gas). Because you must cool the chamber continually to model the thermal conduction and radiation of the test structure and the convection of the trace gases.

And you have to do it safely enough that you aren't risking killing either your engineers or your test-crew.

(Thankfully, Mars is only a good vacuum. So the vacuum chamber itself only requires regular industrial vacuum systems. The thermal stuff will require customised systems though.)

Interestingly, it's vastly easier to test a deeply buried, artificially lit grow-room. You just need an airtight chamber and limited imports of resources; a limited power supply; and an outside wall temperature kept at the average annual temperature for the presumed site of a base on Mars. (At a certain depth, the ground temperature matches the average annual surface temperature above that spot. It's kind of neat.) Other than that, you can site it anywhere.

But if you a testing a "greenhouse" (something that uses natural light), you must test the thermal and near-vacuum effects. Otherwise, it's meaningless.

Offline AegeanBlue

  • Full Member
  • ****
  • Posts: 535
  • Raleigh
  • Liked: 136
  • Likes Given: 41
Re: Scaling Agriculture on Mars
« Reply #552 on: 04/15/2016 04:03 pm »
The most comprehensive current program to build a space colonization kit is ESA's MELiSSA. The MELiSSA project has gone as far as identifying 8 or so crops necessary to build a self sufficient and nutritionally balanced meal regiment. Now when MIT shot down the MarsOne concept they also used several other models of colony growth crop selections but MELiSSA has actually tried to use crops that can be grown as part of ECLSS.

350 people is a huge population. At this level the issue is not so much the short term technical matters of having functional food growth facilities. We are also taking about having large scale resource utilization and cycling. Rather than a greenhouse in Acatama or Antartica, try studying similar sized remote and not so communities: Where they get fertilizer, what high level inputs are necessary (e.g. pesticides), human resources etc. There is good reason why food is shipped to hostile and remote location like polar Canada and Antarctica instead of creating a system to grow locally. Studies ought to be in more temperate regions such as Europe

70 acres is a little over 28 hectares, which at 350 people means a little over 800 m2 per person. Hydroponics is able to grow sufficient food at this area per person. However when we are talking about a 350 person colony we would most likely also need a animal growth facility, which will process some of the byproducts of the plants. If we assume that at the peak of labor it will require 1 40/hr person per 500 m2, we will need during peak harvest 560 people! Of course, the 40 hr week is legal convention, but it is certain than during parts of the year we will require the entire colony harvesting. Hydroponics is high labor!

More ideas will follow later, but I found this interesting economic analysis from Texas A&M, which is where labor requirements were inspired

http://aggie-horticulture.tamu.edu/greenhouse/hydroponics/economics.html

Offline AegeanBlue

  • Full Member
  • ****
  • Posts: 535
  • Raleigh
  • Liked: 136
  • Likes Given: 41
Re: Scaling Agriculture on Mars
« Reply #553 on: 04/15/2016 07:32 pm »
The dirty secret about agriculture is that in reality it has never been self sustaining. Even in its more traditional form agriculture requires input, albeit from the environment rather than people. If we want a colony of 370 people, we need to find a location with the mineral resources required. CO2 comes from the atmosphere, H20 from the soil, we can created N fertilizer artificially from the atmosphere but P and K we need to find the proper rocks. 28 hectares is a gigantic area, we will need tons on P and K rocks, irrespective of the crop grown. According to Dr Google the largest greenhouse in the world is the Eden project in England, according to wikipedia the two biomes cover a bit over two hectares. 28 hectares is the area under cover you will find in entire counties, for example at Lassithi perfecture there were 843 ha of greenhouses in 1995/6. When we are talking about a facility that big this requires separate plant nurseries, seed production under protected conditions (from different diseases) and all sorts of infrastructure. This kind of area will also produce prodigious amounts of plant remains, it is better if we utilize them as feed. We will be producing a large quantity of compost anyway, so it is best if we differentiate and not have just hydroponics. There will be too much compost not to use as a soil amendment, plus we can better recycle the nutrients. Still we will need hydroponics for their intensity. It is very hard for me to calculate the labor demands, but it is certain that intensive horticulture is labor intensive.

If we go directly from nothing to growing that big an area under cover, you are courting disaster. As earlier discussion point out, the Icelandic greenhouse experience is quite different from the Mediterranean experience. We will need to get experience from 1,000 m2 greenhouses before we get to the 28 ha. We do not have experience with growing food for production purposes at an environment as closed as the one on Mars. Let's start small before we get big

Offline LMT

  • Lake Matthew Team
  • Full Member
  • ****
  • Posts: 707
    • Lake Matthew
  • Liked: 90
  • Likes Given: 0
Re: Scaling Agriculture on Mars
« Reply #554 on: 04/15/2016 09:35 pm »
Quote from: AegeanBlue
...P and K we need to find the proper rocks. 28 hectares is a gigantic area, we will need tons on P and K rocks

Thanks for this thought, and many thoughts.

In this scheme, energy production and storage are scaled to provide up to 10 MW, day or night, much of that power devoted to energy-intensive processing of regolith, brine and atmospheric gas, in early days.  ECLSS reprocessing of waste is also supported.  And so for simplicity, I'd like to assume that sufficient P, K, Fe, Mg, Ca and N are being extracted and cycled locally to enrich the 70 acres, if that's not too far-fetched for an exercise.

Quote from: AegeanBlue
We will need to get experience from 1,000 m2 greenhouses before we get to the 28 ha. We do not have experience with growing food for production purposes at an environment as closed as the one on Mars. Let's start small before we get big

Absolutely.  Every small-scale greenhouse experiment seems to turn up a new wrinkle in the lettuce leaf.  This "Biome MCT" challenge is intended only as a creative exercise, and best guess.  No warranty implied.
« Last Edit: 12/14/2016 07:13 pm by LMT »

Offline spacenut

  • Senior Member
  • *****
  • Posts: 2484
  • East Alabama
  • Liked: 433
  • Likes Given: 246
Re: Scaling Agriculture on Mars
« Reply #555 on: 04/15/2016 10:12 pm »
What about plant rotation.  You wouldn't harvest all at one time.  Plant a little each day, harvest a little each day, to spread out the work load over time.  You can do this in a controlled environment.  On earth we have seasons outside, but in a sealed greenhouse controlled environment, rotation is the only way, so it won't take 500 people to harvest for 350 people. 

I've told the story of a farm family who has a 1,000' greenhouse (about 300 meters).  The have pallets of plants on a giant slow moving conveyor belt.  They put on a pallet of planted seeds on one end each morning, and take off full grown vegetables at the other end.  The greenhouse has lighting for night growing.  This greenhouse and associated equipment take up about 10 acres.  They harvest the same amount of vegetables that the once did on about 240 acres once a year.  They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc. 

Offline LMT

  • Lake Matthew Team
  • Full Member
  • ****
  • Posts: 707
    • Lake Matthew
  • Liked: 90
  • Likes Given: 0
Re: Scaling Agriculture on Mars
« Reply #556 on: 04/16/2016 03:17 am »
What about plant rotation.  You wouldn't harvest all at one time.  Plant a little each day, harvest a little each day, to spread out the work load over time.  You can do this in a controlled environment.  On earth we have seasons outside, but in a sealed greenhouse controlled environment, rotation is the only way, so it won't take 500 people to harvest for 350 people. 

I've told the story of a farm family who has a 1,000' greenhouse (about 300 meters).  The have pallets of plants on a giant slow moving conveyor belt.  They put on a pallet of planted seeds on one end each morning, and take off full grown vegetables at the other end.  The greenhouse has lighting for night growing.  This greenhouse and associated equipment take up about 10 acres.  They harvest the same amount of vegetables that the once did on about 240 acres once a year.  They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc.

That's a tremendous efficiency, and the story seems quite relevant.  Thank you.  Is there a video or paper on the methods?

Btw, I posted a video of an experimental greenhouse in Japan, where "plant rotation" is really "plant rotation".  Post:  Self-Sufficiency and Local Provisioning.  Is there much similarity with your story, or do the methods seem very different?

Our proposed greenhouse would have the general form seen in this image of hab dome geometry.  It differs in that annular garden plots would be located on the terraced floor below, and "hanging garden" plots (perhaps rectilinear) would be added above.  It's not too hard to imagine spiral rotator automation on some annular plots, and linear conveyor automation on some rectilinear plots.  If necessary and feasible.



habitat rough geometry, as enabled by Lake Matthew micro-environment, 300m scale

« Last Edit: 12/14/2016 07:13 pm by LMT »

Offline Alf Fass

  • Full Member
  • ****
  • Posts: 452
  • The Abyss
  • Liked: 89
  • Likes Given: 83
Re: Scaling Agriculture on Mars
« Reply #557 on: 04/16/2016 08:16 am »
I wouldn't get too carried away mechanizing the plant beds, just more materials to take to Mars and more things to go wrong.

70 acres for 350 people is very generous, but perhaps you're working on less than optimal growing conditions, that is, it may be better to use larger areas rather than expect to easily have, for example, the perfect blend of nutrients. Where do you plan to get the nutrients from, not imported from Earth I assume? Certainly getting the N, P, K, S etc out of the Martian atmosphere and soil, with its toxic characteristic, wouldn't be easy.
When my information changes, I alter my conclusions. What do you do, sir?
John Maynard Keynes

Offline LMT

  • Lake Matthew Team
  • Full Member
  • ****
  • Posts: 707
    • Lake Matthew
  • Liked: 90
  • Likes Given: 0
Re: Scaling Agriculture on Mars
« Reply #558 on: 04/16/2016 06:01 pm »
Quote from: Alf Fass
Where do you plan to get the nutrients from, not imported from Earth I assume? Certainly getting the N, P, K, S etc out of the Martian atmosphere and soil, with its toxic characteristic, wouldn't be easy.

ECLSS recovery would supplement, but looking at the regolith: 

Regolith would be toxic to some extent, and when soaked it would make a potentially toxic brine.  The Water Treatment, Brine and Electrolysis MCT would need to recover fertilizing salts from the brine, which acts as the "waste stream" input for a "zero liquid discharge" (ZLD) system.  ZLD systems clean waste streams from oil fields, landfills, mines, etc., producing a series of fertilizing salts as output.  Regolith brine is unpleasant, but it would be just another waste stream for treatment, from the ZLD perspective. 



ZLD brochure





Quote from: Burke
We manufacture them, by the way.

« Last Edit: 12/14/2016 07:12 pm by LMT »

Offline LMT

  • Lake Matthew Team
  • Full Member
  • ****
  • Posts: 707
    • Lake Matthew
  • Liked: 90
  • Likes Given: 0
Re: Scaling Agriculture on Mars
« Reply #559 on: 04/17/2016 05:39 am »
They use box pallets with about 1' of topsoil.  They can grow small vegetables like carrots, cabbage, turnips, bush green beans, Swiss chard, etc.

Per previous posts, let's assume that both fertilizer and cleaned sand are provisioned locally, in adequate quantity.

Questions:

- What would you need to ship in the Biome MCT, to complete an optimal cubic foot of topsoil?  (.028 m3)

- And can you estimate the cargo mass required for that cubic foot?

- Stretch goal: Can you sketch a process to complete that cubic foot of topsoil in situ, using even less cargo mass?



« Last Edit: 12/14/2016 07:12 pm by LMT »

Tags: