Kudzu, red clover, pigs, blood red shrimp and water hyacinth are examples of some over 6500 "invasive species" that have taken up residence in the US.
There are many many known benefits these plants and fish have brought with them. Kudzu for soil erosion is also a great nutrient consolidator, same goes for clover, pigs have become about as American as apple pie (for better or for worse), the blood red shrimp is a delicious freshwater fish that could help with marine fish shortages and the future of inland aquaculture. Water hyacinthg is a waste water treatment plant, like duckweed and also holds promise as a biofuel.
This article from National Center for Public Policy Research gives a good summary of the issues:
"The zebra mussel, for example, is one of the most feared "invasives," referenced in almost any article on exotic species and the purported raison d'etre for numerous bills pending in the U.S. Congress and state legislatures. The tiny mollusk inhabits fresh water lakes and rivers and is infamous for clogging industrial plant water pipes, particularly in the Great Lakes and Mississippi Basin, where they have exploded on the scene. Believed by scientists to have been brought over from Europe in ships' ballast waters, some observers claim these hardy, prolific shell-fish could wipe out native aquatic life, though there is no conclusive evidence to support this theory.
Rarely reported is the zebra mussel's positive effect on water quality. These "filter feeders" eat algae and fertilizer runoff from lakes and, as a result, waters they populate are frequently clear and free of pollution. As reported by the U.S. Geological Survey:
"...there has been a striking difference in water clarity improving dramatically in Lake Erie, sometimes four to six times what it was before the arrival of zebra mussels. With this increase in water clarity, more light is able to penetrate deeper allowing for an increase in aquatic plants. Some of these macrophyte beds have not been seen for many decades due to changing conditions of the lake mostly due to pollution. The macrophyte beds that have returned are providing cover and acting as nurseries for some species of fish."18
The plant purple loosestrife, maligned for crowding out natural wetlands vegetation and wildlife, has been called everything from "the poster child" for invasive species19 to the "purple plague."20 Yet there is no scientific evidence that the plant causes actual displacement in the life cycle of native flora or fauna.21 Moreover, some biologists acknowledge actual benefits, including the plant's ability to absorb nitrogen and phosphorus from the water better than even cattails and to help prevent soil erosion.22
Similarly, the South American water hyacinth blankets lakes and ponds in tropical climates, halting boat activity and, some claim, depleting aquatic life by blocking sunlight and crowding out native plant life. But the plant also has a newly discovered talent - it eats raw sewage. The alien species is used by a growing number of sewage treatment plants around the country23 to help purify water and performs the job at a fraction of the cost of conventional methods. NASA, which is researching the new-found technology, planted water hyacinth over 40 acres of sewage lagoons and reports: "The plants flourished on the sewage and the once-noxious test area became a clean aquatic flower garden." They are also being researched for fertilizer, animal feed and biofuel."
It's great to see movement in this area as this is the key to Bioponica's core mission of closed loop farming sustainability.
Bioponica's method extracts all the phosphorus we need from food waste other green biomas (waste) and or simply human urine. It works because it relies on the natural and subtle energies of life and its ecosystems to fertilize the farm.
1. Phosphorus exists freely, abundantly and in excess everywhere there is life and
2. Plants are the great collectors of inorganic phosphorus. When we collect plants that have already mined the mineral from the soil we have organic phosphorus.
3. We also have inorganic phosphorus in our urine in sufficient quantities to supply the key fertilizer element to grow an amount of plants equivalent to that what was consumed. It is supplied to us as plant derived proteins in the form of vegetables, fruits and seeds. And there are loads of it in the animal protein we eat, along with sufficient nitrogen and minerals.
So it may be said, that this challenge need look no further. Simply be prepared to change the entire worlds paradigm of thinking when it comes to waste, biomass and urine as it related to agriculture and plant fertility.
The below italicized is a commentary on an important study pertaining to urine as a tomato plant fertilizer.
I take issue however with the quoted comment by 'eco-agriculture expert' Hakan Johsson in Sweden.
What an individual consumes, an individual urinates. When we change our paradigm of thinking we'll get out of the box that constrains on to believe we need centralized industrial models to grow our food.
If instead growers can supply their own urine to grow their own family garden plot of edible produce, they will have greater food security. There is no reason to create a centrallized urine infrastructure when, now, greater access is afforded to the home gardener. It can be done cost free, with much less labor than composting organically and as a 100% dependable source of plant ready fertilizer.
We use a lot of urine in our bioponic systems. It is ideal for tomatoes because of abundant nitrogen, phosphorus, potassium and sodium. Urine considerably reduces the total amount of biomass required to fertilizer all plants when taking a Bioponica approach. Yet, a balance has to be struck with sodium, nitrogen and chloride as they can be in excess from urine-only systems. There also need to be additional trace elements supplied from biomass as it is less available in urine. That's probably because humans aren't getting enough trace mins in their own diet, due to top soil erosion and depletion in world food sources.
A tomato plant grown with sufficient levels of sodium has a flavor that's not to be found from one without.
"Using human urine as a fertilizer produces bumper crops of tomatoes that are safe to eat, scientists have found.
Surendra Pradhan, an environmental biology researcher at the University of Kuopio, Finland, and colleagues gave potted tomato plants one of three treatments: mineral fertiliser, urine and wood ash, urine only, and no fertiliser. Urine is rich in nitrogen, phosphorus and potassium.
Yields for plants fertilized with urine quadrupled and matched those of mineral-fertilized plants. The urine-fertilized tomatoes also contained more protein and were safe for human consumption.
"This is a very simple technology. Urine can be collected in a urine-diverting toilet or it can be collected in a separate jerry can from an ordinary, pre-existing toilet. If wood ash is available, this can be use as a supplement of phosphorus, potassium and other nutrients," Pradhan told SciDev.Net.
He says that the method is a free alternative to expensive mineral fertilizer, which is also not easily available in remote or hilly areas. Pradhan also believes that the idea could improve sanitation by incentivising toilet-building.
A pilot programme based on the research will be launched in Nepal in November, says Pradhan.
But Håkan Jönsson, eco-agriculture and sanitation system technology expert at the Stockholm Environment Institute in Sweden, told SciDev.Net: "The amount of urine that can be collected from a person or a family is fairly small (equivalent to about two bags of fertilizer per year for a west African family). The technique is of great value to a subsistence farmer but does not suffice for even a medium-scale cash-crop farm."
Where to get duckweeds?
Duckweeds are available from many sources.
How to handle duckweeds?
Duckweed plants are delicate and easily damaged by fingers, forceps and other instruments. Individual plants and small colonies may be picked up and moved without damage using a bacteriological loop. Just place the loop in the medium beneath the plant and lift up. To collect larger quantities of plants, use lightweight screening material to net the plants from below. Fiberglass screen material is available in hardware stores. Alternatively, fabric stores sell strong, light-weight netting used for making veils. Duckweed roots are sticky and will adhere to screens and nets, so it may be necessary to gently scrape the plants off the net with a knife or a thin spatula.
How to grow duckweeds?
Growing duckweeds is like growing any other plant. Moderate conditions of temperature and light and a liquid medium with the necessary nutrients are essential for good growth. Fortunately, duckweeds adapt well to a wide range of conditions and are easy to grow.
Duckweeds can be grown in the pond water from which they were collected in open containers. It is important to replace the water frequently, since evaporation will result in concentration of salts. Using open containers prevents overheating if you place the containers outside or in a sunny window. See below for more about lighting duckweeds for the best growth.
In nature duckweeds grow in water from many sources and compositions. They can be grown in artificial pond water or in diluted aquaculture media, such as Hoagland's solution. It is important to provide a source of chelated iron and to adjust the pH to the optimal range.
It is important to keep your duckweed cultures clean. If you collect fresh duckweed specimens from nature, the water will contain a variety of other organisms. These will include bacteria, fungi, algae, protozoa, and even small multicellular animals and insect larvae. You can clean up your duckweed cultures by transferring the plants individually to clean fresh water. Remove damaged and aged (yellow or white) fronds from your cultures as they appear.
Native populations of duckweeds may be mixtures with varying genetic compositions. For serious work it is advisable to start cultures from a single clone. This will help increase uniformity for experimental work. It is easy to clone duckweeds.
Lighting duckweeds for the best growth.
Direct sunlight is a natural condition for duckweeds. Duckweeds commonly grow in open ponds or shallow wetlands with little or no shade. However, direct sunlight can be a problem if you grow duckweeds in small containers. Sunlight will warm the water and cause evaporation. Replacing the lost water frequently (not just topping off the lost volume) is important. Otherwise, you will gradually concentrate the salts in the growth medium. Duckweeds are freshwater plants (glycophytes) that do not tolerate high salt conditions. Plants grown in covered containers may not lose water from evaporation, but under direct sun the interior will overheat, bleaching and killing the plants.
Indirect sunlight, from a north window or skylight may be an acceptable light source, but growth may be slow, particularly if the days are short and there is much cloud cover. If you use indirect sunlight, remember that radiation cooling can be a problem at night during the colder months. Radiation cooling results from the difference in temperature between the plant (room temperature) and the night sky (very cold). Radiation cooling will slow duckweed growth, although most duckweed species are not damaged by cool temperatures. It may be necessary to cover the window at night to prevent excessive cooling. [ Read how greenhouses work. ]
Incandescent light bulbs are a poor choice. A major fraction of the light that they emit is in the form of infrared radiation that will directly overheat your plants. It is hard to obtain sufficient light from incandescent lamps for good photosynthesis without overheating, so they are not recommended.
Fluorescent lights are recommended if closed culture vessels are used, or if a sunny window is unavailable. Unlike incandescent bulbs, fluorescent tubes produce much less infrared energy. Most labs use two to four F40cw tubes in simple fixtures (often sold as shop lights) hung roughly 30 to 50 cm above the cultures. These conditions will supply sufficient light for photosynthesis and plant growth without overheating the plants.
Newer compact fluorescent fixtures that combine a twisted fluorescent tube with an electronic power supply in a screw-in base are especially convenient for building small duckweed growth areas. These fluorescent fixtures are also available in reflector mounts like floodlights. Plans for building an inexpensive portable plant growth stand are available.
Different duckweed species grow from the Arctic and Antarctic Circles to the Equator and from sea level to the high mountains. However, different species are better adapted to various temperature conditions. If you are going to experiment with duckweeds outdoors, you may be more successful with a locally gathered species than with a culture from a stock center.
Duckweeds can tolerate hot midday air temperatures if the water on which they rest warms more slowly than the air. Thus, a deep container (like a bucket) will be necessary if you want to grow duckweeds outdoors in hot weather.
Under cool cool conditions, duckweeds may form dormant buds, called turions. Duckweeds can overwinter in frozen ponds as turions or seeds. Freezing vegetative fronds will cause frost damage, as in other plants.
Studying the effects of stresses, like high or low temperatures, is an excellent subject for research.
Landolt, E. and Kandeler, R. (1987) The family of Lemnaceae - a monographic study. Vol. 2, Phytochemistry, physiology, application, bibliography. Veroff. Geobot. Inst. ETH, Zurich, 638 pp.
Here is a simple project for raising algae that is practical, as a tabletop exercise, for high school education labs.
Growing in this fashion is similar to the process of high tech bioreactors and various tube systems commonly used in the biotech industry. Researchers feed algae with CO2 from combusted exhaust emissions, a method which holds great promise for sequestering CO2 and reducing greenhouse gasses. Additional nitrogen, phosphorus, bicarbonate, trace minerals and salts must also be added also. In the algal biotech industry, as with this experiment, a sterile environment is generally engineered to optimize growth of an algal monoculture. A closed system such as this does not risk contamination with algal spores indigenous to the region. Most often raised are specific algal varieties that are high in fat content. This is necessary to profitably yield biofuel. The science and technology of growing algae is being heavily researched and invested in and so there will be a lot of jobs coming out of this industry in the years ahead. However, many believe that the industry’s movement towards genetically produced algae with high fat content is a mistake. If this was unleashed into the atmosphere, and it most certainly would be, the GMO algae could overwhelm naturally occurring algae. As described in this NY Times article, the threat of genetically modified algae may be detrimental to ecosystems worldwide. Algae is the most important element in the food chain, and it can be produced in open ponds by simply adding nutrient rich waste and sunlight. In ones back yard algae can be raised at near zero cost, from worm teas, submerged decomposing organic matter, grass clippings, kudzu, grasses, clover and other high nitrogen sources such as urine and chicken manure. From algae we get zooplankton made up of various larva, aquatic insects and animals including aquatic fleas and worms. The zooplankton follows plankton, floating together and feeding off the living and dead biomass, as do tilapia, bass, sturgeon, grass carp and even whales in the ocean. Fish fry and fingerlings live primarily off of plankton and zooplankton. Algosolar offers education on raising these plants and animals in open ponds and in its aquaponic troughs. We will soon provide tables for calculating quantities of site derived ingredients to match your plant and fish growth needs.