Mess 2

Micro Environment Subsistence System (M.E.S.S.)

Photosynthesis efficiency
Plants use light to rearrange molecules to store solar energy as chemical energy in the form of starch and glucose (sugar). The present globally photosynthetic atmospheric processing limit appears to be 2 x 1017 grams of carbon (200 billion tons) per year, which is about 10% of the atmospheric content. This carbon is being used by organisms and returned by respiration. We humans with our increasing numbers, burning ancient stored carbon, and depletion of plant mass are raising carbon levels. In plant cells water and carbon dioxide enter the cells, and impacted by the right frequency and intensity of light, sugar and oxygen leave the leaf. The chemical equation for this process is:

6CO2 + 12H2O + 48 photons light → C6H12O6 + 6O2 + 6H2O

6 molecules of carbon dioxide (6CO2) and 12 molecules of water (12H2O) are consumed in the process, while glucose (C6H12O6), six molecules of oxygen (6O2), and six molecules of water (6H2O) are produced.

Plants have limits on their rate of converting light to stored energy. Remember that plant biological processes continue at night, and that this uses up some of the energy accumulated in the presence of light. I've read that the overall theoretical efficiency of photosynthesis may be 4.5%. At 6 hour exposure, and if you could eat the entire plant, this would be an area 9 feet on a side. I've no idea what the crop would be, but you would probably be able to watch it grow…

If this "perfect" rate were potatoes, production would be (86 mt dry or 346 mt fresh) / ha). The real-world yield is (12 mt dry or 29 mt fresh) /ha, less then 1/10 of theoretical.

In various sources I find that overall photosynthesis efficiency in open nature and for typical food crops (corn,wheat,rice) is .1% to .2%. For 1/10% efficiency, each of us requires 21,600 sq. ft. /hours per day. With an average of 6 hours solar exposure per day this requires a fully productive food crop area of 3,600 sq. ft., 1,800 for 2/10%  This is an area much less than the 1/4 acre per person typically available for manual farming (see information on farming in Cuba post-USSR), yet higher than the 1,000 sq. ft. information from Ecology Action. More (concentrated) sun is not the answer. C3 crops (wheat, barley rice, sugar beet, potatoes) all have FALLING conversion efficiency rates as light intensity goes above 20% of full sunlight.

Potato efficiency goes up to .4%, so with 6 hours exposure you need a minimum of 900 sq. ft. In various places, I've read the most "efficient" crop is claimed to be spirulina, with production of between 5 and 15 gram per sq. yd. per day. If each gram is around 5 calories, we get somewhere between 243 ft. sq. to 720 ft. sq. per person. At the upper level of production, is we're still assuming an average of 6 hours good sun exposure, we're looking at just under 2% efficiency on converting sunlight to food energy.

While I do not really expect to find a more efficient crop than algae, perhaps hydroponic or aeroponic methods can bring up the efficiency of more traditional foods. For those with a sweet tooth, Sugar cane (a C4 crop) comes in at a yearly average of 1%, requiring 360 sq. ft. with 6 hours sunlight, and with crops such as corn and sorghum can utilize higher sun intensity.

Reduced Light
Studies in Israel show increased growth of young citrus trees under reduced mid day light in a semi-arid climate, using up to 60% shade cloth. With too much light, some plants shut down photosynthesis, and physically "wilt" their leaves to minimize light exposure. Shade particularly benefits plants grown for their leaves.

The photosynthesis rate increase tracks increased intensity of direct light only from 0 to 50 watt per meter sq., then increased production tapers slightly up to 100 watt, and for many plants goes almost flat at 200 watt per meter sq.

I also read of plants benefiting from flickering light, vs constant. Perhaps a means to disperse sunlight as momentary sparkles would allow a greater growing area than the available solar window (welcome back the disco ball?).

Consider methods that rather than block a portion of the light, rather split the light into 2 or more separate beams. Route each beam via mirrors, lenses, fiber optic, etc, to separate, perhaps stacked growing areas, then diffuse each beam so that it illuminates an area of plants equal in area to the original light collection area. Do we accomplish the reduced sun that many plants need, while doubling or more the growing area?

At a minimum, line the growing area with reflective material, and perhaps you can "recycle" some of the light that otherwise would escape back to the sky, or just go to heat the surrounding area. A reflective northern wall may add as much as 12.5% "extra" light.

Lighting periods
Plants that genetically need specific lighting periods and be "tricked" in to acting as though there is a longer or shorter photo tropical period. Shorter is easy, you just need an opaque cover. The "trick" is making their genes think that daylight is longer. At the mid-darkness period, provide artificial light of 10 to 30 foot candle for times such as 3 minutes in every 30 minutes, 6 seconds in every minute.

A 40 watt florescent tube power is:

Inch Distance       Ft. Candle

1                              1000 2                                950 3                                750 4                                650 5                                560 6                                400 7                                430 8                                370 9                                360 10                               350

Estimated Light Requirements Per Square Foot Plant	Watt/Ft.Sq. Tomato 	8.3 Eggplant 	2.32 Peppers 	2.32 Soybeans 	2.32 Green Peas 	2.32 Spinach 	2.32 Carrots 	2.32 Cucumbers 	15.77 Wheat 	2.32 Lettuce 	2.5 Strawberries 	7.06

Temperature control
Earth berming or burying a contained growing area would minimize the effect of external temperature variations, and provide greater pest protection. Earth sheltering combined with insulation  should, if the intrusion of heat is avoided, provide for appropriate year round temperatures. Unless intended / used as human shelter for a CBR threat, the structure does not need to be airtight or constantly overpressured. Root temperature in general should not exceed 82 degrees F, above which growth processes drop off, with 68 to 77 preferred. A root zone temperature of 105 degrees F is probably fatal to most plants. Leaves usually prefer 61 to 68 F.

Growing area
Readily available information suggests that 1,000 sq. ft. minimum of growing area is needed per person. With a typical modern diet, the upper fertilizing limit for humanure looks to be around 1600 ft. sq., with the limiting nutrient being potassium,  and a potential "minimum" area of 600 ft. sq. based on a nitrogen concentration limit. In the interest of pest control, I would not suggest a single large facility for a family. Instead, a number of separate units would permit growing a wider variety of plants, in differing conditions, concentrated with other plants needing similar conditions. It may also be simpler and cheaper to make a series of smaller units even per person, rather than a single 600 to 1,600 sq. ft. "greenhouse" for each person. The commercially available concept and products that blend well with the MESS concept are those intended for "roof gardens", and their design factors. A bottom water proof membrane and roof penetration protection, a layer of drainage and aeration, a means to prevent soil penetrating the drainage, and compost above. Protect the top of the soil with another aeration barrier, then wind barrier above, which has penetrations for plantings. Weight is a major consideration in a roof garden or say gardening in containers on raised benches. If your gardening media is enclosed and suspended above ground, then consider if you can walk under the garden. How far can you lean and reach if you are tending the garden? If you can walk under, and come up thru san a square 2’ on a side to tend by leaning, then you eliminate a lot of waster path space. If you can reach 3 foot (or a hair more) then think in terms of each 8’ x 8’ growing area having a 2’ x 2’ hole in the middle. Each 64 sq.ft. of surface area has 60 sq.ft. of growing space. If you “fudge” the math a bit (remember, the growing area can be from 1,000 to 1,600 sq. ft), you could have these units in a grid either 4 or 5 on a side. This is a A square with sides between 32’ and 40’. (Is there a commercially available bubble 8’ x 8’?)  If a single  test facility for your area is to have just plants on benches without walk-under capability, the above therefore would put a single test unit at around 8’ x 12”.

The bulk of my container tinkering was in "Wal-Mart" plastic tubs setting on cheap steel shelves. (Which of course rusted-out in a few short years.) "Rubbermaid" heavy duty shelving costs more, but in the 4th year of outdoor use shows no signs of decay.

The growing level. A mix of composted biomass and inert water holding substances. The depth will vary depending on the crop. The medium must hold surface tension water, yet drain well and allow air into the "pores" between particles.

Next down is a drain / filter level, I use fiberglass garden cloth, some of which has been in use for 5+ years (2007). Under this is 1 to 3 inches of "volcanic" rock, light but it holds the filter above the water and provides air space.

Under the rock I've been having success with another layer of fiberglass cloth as a wick, and keeping an upside down bottle, down thru a sleeve to keep the wick wet. The greater the control & isolation from external influences, the better. But, your facility can be anything from a hedge rimmed garden to a miniature version of the Biosphere II facility, or the NASA CELESS. It's up to you and your resources. If you want to exclude excess heat (my situation most of the year) the only light to reach the garden should be that intensity and frequency needed by the plant, all else is waste heat. Insulate and protect the growing medium from light and moving air.

Humidity recovery
At the moment, short of a sealed greenhouse and running mechanical HVAC, I'm unclear on a method. (See Appropriate Technology - Dew Collection) I've read of fans blowing air from above the plants thru buried porous pipes, with the lower ground temperature leading to condensation, then the water draining from the pipes.

If the greenhouse IS sealed, then the largest challenge is getting heat OUT of the plant growing structure. Consider a bottle top up filled with water inside the greenhouse, another empty one outside top down, and the mouths of the bottles connected by hose. If the bottles and hose are solid enough, the temperature of evaporation can be “set” by controlled imposition of a vacuum on the unit. When the temperature of the inside bottle is greater than that of the outside bottle, water will evaporate, the vapor flow then condense, and the liquid water run back.

WATSON WICK WARNING CHECK WITH YOUR LOCAL HEALTH OFFICIALS A method of recycling human effluent rather directly to the growing medium is the Aerobic Pumice Wick presented by TOM WATSON. Black water drains thru a filter tank to hold solids for aerobic composting, allowing the liquid to drain to a bed/tank. In this container you want a lot of wicking material, with a lot of air. Mr. Watson suggests an 18" bed of pumice in a waterproof base, with a cover of around 6" of soil. The bottom 1/2" to 1" needs to be water-tight. Absent pumice, consider coarse sand. Without a watertight membrane, use the old approach of a layer of straw and manure to help anaerobic bacteria create a water impermeable "clogging" layer. The intent is to create an area to convert the smelly end product of human digestion, which scientifically can be seen as 0.16 g/l dissolved solids, 0.23 g/l suspended solids, 0.007 g/l phosphate, and 0.51 g/l nitrogen, into a nutrient righ garden bed. Plant roots access the bed use the nutrients and transpire the water. In the case of too much liquid, the wick acts as a filter and filtered water drains out of the exit pipe. Please ensure liquid does not rise to the compost level.

Perennial plants are best used because of their permanent roots. Lawns, shade trees, fruit trees, berries, grape arbors etc. are all suitable as there are no disease vectors transmitted via the roots. WARNING CHECK WITH YOUR LOCAL HEALTH OFFICIALS AIR STORAGE

If used as a CBR shelter, air storage is needed to avoid drastic swings in air composition. Consider the earth, with plant and animal activity taking place on the surface or in the first 100 feet or so, yet with miles of effective storage overhead. A potential methods to combine the garden with a large sealed volume of air is a rooftop garden over your sealed home.

Planting planning
Companion planting. Some plants grow better together, or immediately following each other, while some plants cannot tolerate each other or growing in a medium just after other particular plants. Nitrogen Replenishment. Nitrogen fixation may be accomplished by symbiotic organisms of legumes, or other plants which harbor the correct microbial population. Plants can not fix nitrogen gas but legumes have evolved a symbiotic relationship with the bacteria of the genus Rhizobium, which grow in special nodules in those plants. The plant provides the bacteria with the nutrients they need for growth and in return obtain nitrogen which the bacteria convert from N2 into NH4+. These nitrogen fixing crops should preceed heaving nitrogen feeding crops. Nutrient Concentrations. The life cycle of plants, animal intervention, earthworm or microbe systems may cause temporary concentrations (therefore also temporary areas of shortages). Overages or shortages can be tested in a non-technology manner by selected plantings and ovservation of the plant reactions. Crop cycling. In addition to companion planting, keeping a growing range from seed to mature plants, based on the needs of he plants and your consumption rate. For example, if you use a head of lettuce every week, you need to plant lettuce weekly. For every plant completely harvested you should have it's replacement already growing and ready to set out. Cycle planting also includes considering that there are plants which cannot tolerate being in the growing medium immediately after certain other plants. Seed Crops. You'll want to keep seeds of the "best" plants for your next generation. Cloning. Many plants can be cloned from cuttings, or with the right technology from far smaller portions than would happen in nature. A large enough genetic base, in the form of stored seeds, needs to be maintained to prevent deleterious mutations being concentrated due to inbreeding or cloning of the "defective" plant.

A "Grocery Store" recipe for cloning "difficult" plants is 1/8 cup sugar, 1 cup water (or coconut milk), 1/2 cup pre-mixed water and fertilizer, 1/2 inositol (125mg) vitamin tablet, 1/4 vitamin tablet with thiamin, 2 tablespoon agar flakes (or corn starch, jello, etc.)

The growth promoting substance in plant shoot tips will, if the tips are crushed, diffuse into surrounding substances, and therefore be collectable in substances, such as galatin.

Plants being rooted may not be able to manufacture their own "food. They may be helped along by sugar water, coconut milk, fruit juices, etc.

Algae cultures
Algae grows quite well naturally in most ponds and ditches, taking its carbon dioxide from the water plus utilizing what minerals are in the water. Logically if you harvested a portion each day and minerals were added, the crop would be much larger than it is naturally. Potentially three foot wide, 20 feet long, one foot deep plastic-lined troughs filled with the water could supply all the algae wanted.

For animal feed, the harvested algae could be mixed with the dead flies, dried and pelletized or broken up. As chicken feed it would supply all the protiens, vitamins and minerals required, even by chicks. For human consumption, Spirulina is sold as a health food. While I'm not enthused by the taste, I had Spirulina growing for several years from a starting of commercially available supply. As part of it's nutrient source, I pour water thru local sand, and potting soil.

Spirulina, a one-celled form of algae, perhaps a "link" between plants and animals, thrives in slightly saline "fresh" water, 8 to 11 pH, of 85 to 112 degrees F, up to 140 degrees F. The conditions are such that most other microorganisms cannot survive. It is perhaps the most "efficient" means to grow a nutritious food, which is over 65% complete protein, that is all essential amino acids in balance. It is 8 to 10 percent efficient in use of light, and is one of the few plant sources of vitamin B12, usually found only in animal tissues. A teaspoon of Spirulina supplies 250% of the Recommended Daily Allowance of vitamin B12 and contains over twice the amount of this vitamin found in an equivalent serving of liver. It also provides high concentrations of many other nutrients - amino acids, chelated minerals, pigmentations, rhamnose sugars (complex natural plant sugars), trace elements, enzymes - that are in an easily assimilable form.

Certain desert-adapted species will survive when their pond habitats evaporate in the intense sun, drying to a dormant state on rocks as hot as 70 degrees Centigrade (160 degrees F). In this dormant condition, the naturally blue-green algae turns a frosted white and develops a sweet flavor as its 71 percent protein structure is transformed into polysaccharide sugars by the heat.

The blue-green algae, and Spirulina in particular, have a primitive structure with few starch storage cells and cell membrane proliferation, but rich amounts of ribosomes, the cellular bodies that manufacture protein. This particular arrangement of cellular components allows for rapid photosynthesis and formation of proteins. The lack of hard cellular walls assures that Spirulina protein is rapidly and easily assimilated by consuming organisms.

Any water-tight, open container can be used to grow spirulina, provided it will resist corrosion. Its depth is usually 16 inches (twice the depth of the culture itself). Temperature is the most important climatic factor influencing the rate of growth of spirulina. Below 68°F growth is practically nil. The optimum temperature is 99°F, but above 108°F it is in danger. Growth takes place in light (photosynthesis), but illumination 24 hours a day is not recommended. It cannot stand a strong light when below 68°F. It preferes 1/3 of full sun, with cells destroyed by prolonged strong light.

The water used should be clean or filtered, but consider it's natural conditions.

When in good condition harvesting is an easy operation, but when it gets "sticky" harvesting may become a mess. Harvesting in early morning for the cool temperature, more sunshine hours to dry the product, and the % proteins in the spirulina is highest in the morning. Harvest by a filter of a fine weave cloth.

The nutrients extracted from the culture medium by the harvested biomass must be replaced. The major nutrients can be supplied in various ways, preferrably in a soluble form, but even insoluble materials will slowly be disolved as the corresponding ions are consumed by the spirulina in the medium. Urea is an excellent nutrient for spirulina but its concentration in the medium must be kept low (below about 100 mg/liter). If sugar or other easily oxidizable organic materials are used as a source of carbon, nitrates cannot be fed in large concentration either, as they may be reduced to ammonia that is toxic above 150 mg/liter. Excess urea can be converted either to nitrates or to ammonia in the medium. A faint smell of ammonia is a sign that there is an excess of nitrogen, not necessarily harmful ; a strong odour however indicates an overdose. Balance salinity at 15 grams per liter and alkalinity at 0.1 N

Per liter based on chemicals: NaHCO		-	8 gram (sodium bircarbonate) Sea Salt		-	5.0 NaNO3 or KNO3	2.0 or Urea		-	0.07 NH4H3PO4 	-	0.1 K2SO4		-	0.1 MgSO4*7H2)	-	0.1 FeSO4		-	0.001

Natural approach: Use ashes from wood fires rich in potassium, sea salt, urine, and iron such as from old nails with vinegar and lemon juice. Blood also is a good source of iron. In case of necessity ("survival" type situations), all major nutrients and micronutrients except iron can be supplied by urine (from persons or animals in good health, not consuming drugs) at a dose of about 15 to 20 liters/ kg spirulina. Iron can be supplied by a saturated solution of iron in vinegar (use about 100 ml/kg).

Freshly harvested and eaten is best, it will not keep more than a few days in the refrigerator, and no more than a few hours at room temperature. Adding 10 % salt is a good way to extend these keeping times up to several months, but the appearance and taste of the product change : the blue pigment (phycocyanin) is liberated, the product becomes fluid and the taste is somewhat like anchovy's paste. Freezing is a very convenient way to keep fresh spirulina for a long time. It also liberates the blue pigment, but it does not alter the taste. Drying is the only commercial way to keep spirulina. If suitably packaged and stored, dry spirulina is considered good for consumption up to five years. But drying is an expensive process and it very generally gives the product a different and possibly unpleasant taste and odour. Dried spirulina is also not so easy to use.

Direct sun drying must be very quick, otherwise the chlorophyll will be destroyed and the dry product will appear blueish. Whatever the source of heat, the biomass to be dried must be thin enough to dry before it starts fermenting. Drying temperature should be limited to 158°F, and drying time to 5 hours.

Aquaculture

Fish present a means to "process" bugs, worms, etc. into a pleasing protein source. Tilapia do well in small captive tanks, and in fact may breed too well, with an exploding population of a LOT of small fish with few bigger (and more eatable) fish. Think of them as producing liquid fertilizer.

Tilapia have been successfully grown in a 725 gallon tank, catfish in 55 gallon drums. In such crowded conditions, 10% or more by volume must be siphoned out monthly from the bottom sludge. Tilapia is a hearty freshwater fish native to the Middle East and Africa which grows rapidly within a range of environments, with a high tolerance for bad conditions including relatively low oxygen and high silt, with a diet that can include algae, agricultural "waste", or bugs (see notes elsewhere on fly-farming). The growing fish must be fed roughly one and one-half times their average daily body weight throughout the course of their lives. They have 19.7 g protein and 2 g fat per 3.5 oz (100 g) serving. Tilapia need warm-water from 82° to 86°F. They need minimum dissolved oxygen level of 3 parts per million, requiring some pumping system in a crowded tank. Tilapia grow best in water with a pH of 7; as nitrogenous wastes (urea, uric acids) build up and make the water acidic, neutral pH is maintained by added buffers such as KOH or (Ca(OH)2), added daily or every other day. Iron is supplied through the addition of an iron chelate once every three weeks and the recommended amount is 2ppm.

Each individual fish (harvested at .45 kg or 450 grams), would consume 2.5 times that amount, or 1,125g, of which 40% becomes increased body mass, 20-30% is used for energy and maintaining body functions, and 30-40% is waste. Our 10 person homestead tank would require fish feed of 1,125 kg, in order to reach the target weight.

Fish waste products of urea and solid excrement accumulate in the tanks, which must be removed and recycled to the growing plant crops, including algae as fish food.

The Columbia study shows one tank 8’ in diameter by 4’ deep (1,250 gallons) can be stocked with 800 30g male tilapia fingerlings grown for 6 months before harvest, even with a high mortality of 25%, fish harvested at 450 grams, edible filets of 40% of live weight. With 600 surviving fish at 450 g per fish, one tank harvest should provide .45kg x 600 = 2700kgs x .40 = 108 kg edible fish. This is an average of around 600 gram of fish flesh per day. (To feed six people) Our target per family size is 10 people, so we need a tank that is 160% larger in volume, and twice again the area to provide for a full year. Their example tank is around 200 cubic feet. Each homestead needs about 640 cubic feet (4166 gallon), which weighs around 33.332 pounds (don't put it on the roof with a LOT of reinforcement). If we keep the same depth as the Columbia example, then the diameter must increase to around 10 feet. The size of each of the two tanks is still not much more than an above ground kid pool.