Micro Environment Subsistence System (M.E.S.S.)
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.
Hydroponics[]
In repeated texts hydroponics is reported to be cheaper and more efficient than soil gardening. It provides a means to provide optimum root conditions and avoid soil pathogens. Without root resources limits plants can grow to their optimum given heat, light, and CO2 limits. Hydroponics via aquaculture is the simplest to set up. The author has not done experiments in hydroponics to determine if it requires less or more water than a soil-based garden. In general there must be some means to support the roots. In general the solution must be pumped to/from the plants and the source of the nutrients, whether the fish tank, the black water tank, or ???? Typically there must be some medium for the roots to adhere to that holds enough moisture between nutrient floodings. Mediums that may work for you are gravel, smooth river rock, sand, marbles, etc., looking for something that holds moisture on its surface, while providing adequate air-space for the roots.
Check your library for books with further details on physical materials and layout.
As mentioned elsewhere regarding worm castings, to extract the nutrients from a compost for use in a nutrient solution think of a tea bag. Fill a sack with compost and put it in warm water for about a week, put your compost in a watertight can, etc. The nutrients seep out into the water. Filter (i.e. thru more soil, sand, etc.) to leave the solids behind for use elsewhere. NOTE: Many trace elements essential for plants may not dissolve in the water from natural sources. The needs to obtain and “insert” these elements in a more artificial “chelated” form is an inherent “problem” of hydroponics, vs soil where natural organisms handle all the balancing.
Construction[]
Think in terms of a "rooftop garden", which then of course can be located on virtually any surface exposed to sunlight. A lightweight, controlled environment where the growing conditions for plants are optimized.
For your growing area, envision you use planting beds 4' x 8', with 16” wide paths all around for ease of access. Using this method, for every 32 ft. sq. planted, your garden will cover about 5' x 10', therefore 1,000 ft. sq. of planting area would require nearly 1,600 ft. sq. of surface. Framing the area allows extra topsoil or compost to be added in to create a thicker growing area, raises the growing surface above night chilled air, and reduces the need to bend. Consider each 4' x 8' bed as a large self-watering planter.
Water-tight base membrane[]
Maintain some absolute minimum bottom moisture, avoiding enough to "drown" roots, with excess draining to storage / reprocessing. Maintain a reservoir by such method as you can to keep this bottom moisture in place. A small number of W/N roots can exist in the water, but depth should be no further than 15 cm due to the limited amount of dissolved oxygen. When the water level drops in a plants growing medium where roots are growing in the water, these water tolerant roots change into O roots, a process taking only 2-4 days. However, this is not reversible. If water returns to the original depth such that the changed roots are now flooded, the plants wilt within a few hours and do not recover. You need to create a medium with such large air spaces that no matter how much water is around, the roots will still find plenty of air, but dense enough that water can move up by capillary action and keep the medium moist.
Wick material[]
A durable, non-toxic, non-rotting material capable of wicking water up, 2" to 3" thick, which also serves as an air-gap.
Expanded volcanic rock, Perlite (Danger to worms), it's principal value is aeration, as it does not hold water & nutrients as well as vermiculite. It has a pH of 7.0 to 7.5. It can cause fluoride burn on the tips of some foliage plants.
Vermiculate is expanded mica. (Danger to worms) It will hold large quantities of air, water, and nutrients, with a pH of 6.5 to 7.2. It comes in four particle sizes, use larger sizes, at least 2 or 3. Fiberglass w/rock. (Danger to worms)
Filter screen / mat[]
For high-tech fiberglass screen or woven mat. Low tech sticks, twigs, stems (needs to be monitored/replaced). This holds growing medium above wick/air gap.
Enclosure[]
Whether vapor-tight canvas, adobe, stainless steel, or concrete, walls are necessary to exclude hungry critters, and avoid drying or damaging winds. A typical greenhouse has transparent walls to allow in more light. Is the engineering challenge and expense of walls of glass worth it, or even warranted? Consider you put into an otherwise open field your 1,000 sq. ft. garden. Your plants have access to all of the direct and indirect light from all angles that might fall on that 1,000 sq. ft.
Put an eight foot high solid opaque wall around your garden, and you plants are in shade at the bottom of a well. Line your wall though with highly reflective material and you plants are essentially back to receiving all of the light that would otherwise fall on their footprint. Place at the top of the structure a light selective surface (discussed earlier) and you could if desired have a virtually air-tight structure.
Typical soil[]
Soil is the loose mineral and organic material which provides nutrients, moisture, and anchorage for land plants. The mineral aspect starts as rock, which is physically broken in to smaller particles by mechanical weathering, wind, H2O, freeze/thaw, and life once it is established. Particles size ranges are:
Sand - 0.05 to 2.00 mm Silt - 0.002 to 0.05 mm Clay - < 0.002 mm
Cation exchange capacity[]
The smaller the particles, the greater the surface area for any given mass. Clay size particles have so much additional surface area that the permanent negative electrical charge of the surface electrons becomes a significant consideration, and they readily attach to molecules other than the parent rock. This electrical charge difference is referred to as the Cation Exchange Capacity (CAC). The higher the CAC, the more easily these particles make nutrients available to roots and soil life, including water. Zeolite means the stone that boils. I've read that a zeolite crystal the size of a pinhead, when devoid of water, will have an internal surface area equivalent to a bedspread. This porous structure provides significant cation exchange capacities when added to the growing medium.
CEC of Soil Textures, showing the relative amount of nutrients the soil can hold in a useful manner.
Sand 3 to 5 Sandy loam 10 to 20 Loam 15 to 20 Silt loam 15 to 25 Clay loam 20 to 50 Organic soil 50 to 100
Soil organic matter (90% carbohydrate), as it decomposes, makes the nutrients available to the crops. It increases water holding capacity, aeration, and buffers soil pH.
Soil PH[]
Soil pH is a chemical term "potential of Hydrogen" which is a measure of acidity (lower) or alkalinity (higher) of a solution or substance, numerically a reading of 7 is a neutral solution. As you move in either direction away from 7, the scale is logarithmic, that is a pH reading of 8.5 is ten times more alkaline than a reading of 7.5.
Any atom with a number of electrons that do not "match" the protons in the nucleus is an "ion". The "pH" of a solution is a count of the number of ions. In a glass of water there is generally one hydrogen ion in every 10 million water molecules. The pH of water is set at 7 (7 zeros in the count). Stomach acid has one hydrogen ion for every one hundred molecules, or a pH of about 2. (two zeros) The ions work to tear apart the molecules of food.
Soil pH depends of course on the elemental and molecular composition of the basic soil. Most of Arizona for example contains high amounts of the mineral calcium carbonate (free lime), which keeps the soil pH at around 7.5 to 8. Nearly all ofthe carclim carbonate would have to be neutralized with a strong acid to begin to drop the pH appreciably.
Remember, 98% of plant nutrition absorption is from minerals dissolved in soil water. The effect of soil pH varies with the mineral, presence of other minerals, and soil type.
In alkaline conditions micronutrients such as iron, zinc, copper and manganese become chemically bound and may precipitate out of solution. In acid conditions calcium, phosphorous and magnesium may become chemically bound and precipitate, while manganese and aluminum can dissolve to toxic levels.
Soil water retention[]
Of water applied to a soil of primarily one size of particles, the water held will generally be around: Fine sand - 2.0% Sandy loam - 8.5 % Silt loam - 10.9% Clay - 13.5% Soil physically typically consists of:
45% - Mineral material (sand, silt, clay) 1 - 5% - Organic matter (plant & animal remains) 2 - 3% - Micro-ogranisms 25% - Soil atmosphere 25% - Soil moisture
Water conservation[]
Exchange of water molecules into the air occurs only if there is a vapor pressure difference between the evaporating surface and the air, i.e. evaporation is nil when the relative humidity of the air is 100%. A change of state from liquid to vapor, and therefore necessitates a source of latent heat. To evaporate 1 gram of H2O requires 540 calorie of heat at 100 degree Celsius and 600 calorie at 0 degree Celsius.
Evaporation rate is affected by wind speed, 1 mm of the water surface the upward movement of vapor is by individual molecules -- "molecular diffusion", but above this surface boundary layer turbulent air motion -- "eddy diffusion" is responsible.
It is reported that even three or four stones around a tree in the desert make a difference between survival and non-survival. If you put a pile of stones in the desert, it is often moist below them.
Salinity depresses the evaporation rate. Sea water has 2-3% less evaporation rate than fresh water.
Evapotranspiration is a combination of evaporation from the free water surface such as oceans, lakes, rivers, streams, and ponds; and transpiration from plants, vegetation, soil and grounds.
Transpiration -- water loss from plants takes place when the vapor pressure in the air is less than that in the leaf cells. 95% of the daily water loss occurs during the daytime, water vapors transpired through small pores, or "stomato", in the leaves, which open in response to stimulation by light. The internal (stomatol) resistance of a single leaf to diffusion is an important control on transpiration, and it is dependant on the size and distribution of the stomato. External resistance of the air to molecular diffusion arises through frictional drag of air over the leaf (larger leaves have lower transpiration rates) and the interference between diffusing molecules of water vapor.
What factors control the net loss of water (or net evaporation) in the atmosphere:
Temperature: increase the temperature, increase the activity of water molecules and loss the water molecules, therefore, affect the net rate of evaporation. Temperature of the water, and the temperature of the evaporating surface. It takes great amount of input energy to change from liquid to gas. Temperature (evaporation) is a function of latitude, season, time of day, and cloudiness.
Relative humidity of the air: hot air can hold great deal more water vapor than cold air. Measure the water vapor content in the atmosphere expressed in percentage. What % of the water vapor has been saturated in the air. The higher the relative humidity, the slower the evaporation rate. Sometimes, this refers to the vapor pressure deficit - which is the difference in vapor pressure between the water surface and the atmosphere.
Wind velocity: The higher the wind velocity, the more the mix of the air, and the better the chance for evaporation rate. Stability of the air or the stillness of the air is also affect evaporation rate.
Above all, the temperature of surface is the most important factor affecting evaporation. The warm surface area gets largest evaporation. Arctic and Antarctic, or mid-latitude in the winter, evaporation gets very low. Sea has open water surface, tropical and subtropical areas, evaporation is high.
Availability of moisture: The moisture supply in the soil is limited, plants have difficulty in extracting water, and AE rate falls short of PE (Potential Evaporation) which is the moisture transfer from a vegetated surface is referred to as PE, and when the moisture supply in the soil is unlimited. The evaporation equivalent of the available net radiation.
To contemplate a perhaps complex approach to preserving your garden water, enclose the garden in essentially a water vapor tight structure. (For starters, think greenhouse.)
Although greenhouse glazing often gets credit-blame for interior heating by preventing radiation of the infrared from the heated greenhouse contents, tests show that even when the glazing is made of materials transparent to infrared, the greenhouse still warms. Even in greenhouses with infrared blocking glazing, night sky radiation still cools.
It appears that the glazing, whatever the material, provides a great deal more toward warming merely by preventing convection currents than does blocking ground level infrared radiation.
If the larger factor is convection currents and physical transfer of heat, then in areas such as the author's, where the purpose is avoiding water loss to open air flow, look to gmize entry of un-desired light frequency, and avoid within the greenouse dark colored heavy mass objects, that would create a miniature "heat island" within the greenhouse.
Use night-sky radiation to cool a thermal storage area, perhaps a large container of phase-change material. Use the atmospheric condensers discussed in the Appropriate Technology appendix to dry garden air, then re-heat it before exhausting it.
Optimized growing medium[]
A shallow bed of compost, worm castings, etc. 3" to 6". If you are taking a rooftop approach, weight can be critical. Weight estimates from ECHO for a 4' x 8' bed are:
DEPTH WEIGHT COMPOST WEIGHT SOIL 3" 598 lb. 947 lb. 8" 1,595 lb. 2,552 lb.
ECHO tells us a garden can be planted in fresh organic material if one does not have compost, grass clippings, food scraps, etc. as an example. Whenever possible, cover new such beds with an inch or more of compost before planting. So far compost appears to be the ideal medium. Transplanting holes may be filled with manure, and consider watering with manure tea. Transplanting from sprouting trays helps keep growing medium "in use".
Shallow rooftop type beds may require annual reworking, or after each crop, as the depth of the bed drops as the material turns to compost, but the trade-off is the quality of the medium, which is essentially pure compost, a near "ideal" medium. To rework the bed, temporarily remove the compost and put the new organic material in the empty bed, then put the compost remains back on top.
There is an element of artistry involved in creating a medium that hold sufficient air and water. In my containers I've been using a column of perile surrounded by the compost, with the perlite extending to the water mat, but the compost held away by rocks and a fiberglass mat. A key in all being at least 3 inches of soil above the water level.
Whether commercial mats of capillary material, fiberglass or other non-biological materials, or biodegradable items, the purpose is to provide a means of wicking water in a bed.
Compost tea, worm casting tea, even the runoff from water thru (first solar pasterurized) humanure can serve as an organic "hydroponic" solution. One approach involves is construction of a "wall" from cut and stacked tires, filled with inert material such as gravel. The professor's article is written around graywater, but I see no physical impediment to use of these other solutions.
In a "solid" growing medium, plant roots may only make contact with 1/10% to 3/10% of the particles in the soil. (Still, with our present open-loop system, how many crops does it take for most of the nutrients to be taken away?)
Rooting depth[]
Your particular crop selection obviously effects the details of your food production facility. In open field conditions, plant feeder root depths will typically be: Alfalfa 3 to 6 feet Beans 2 feet Beets 2 to 3 feet Berries (cane) 3 feet Cabbage 1-1/2 to 3 feet Carrots 1 1/2" to 2 feet Corn 2 1/2 feet Cotton 4 feet Cucumbers 1-1/2 feet Grain 2 to 2-1/2 feet Grain, SOrghum 2-1/2 feet Grapes 3 to 6 feet Lettuce 1 foot Melons 3-1/2 to 3 feet Nuts 3 to 6 feet Onions 1-1/2 feet Orchard 3 to 5 feet Pasture (Grass) 1-1/2 feet Pasture (w/clover) 2 feet Peanuts 2 feet Peas 2-1/2 feet Potatoes 2 feet Soybeans 2 feet Strawberries 1 to 1-1/2 feet Sweet Potatoes 3 feet Tobacco 2-1/2 feet Tomatoes 3 to 4 feet