Drought has struck again in the African Sahel. Most of these people are nomadic herdsmen and there is no grass or forage left. War in Mali has sent millions of refugees pouring over the border into Niger, where conditions are no better.
They have, as far as I know, no aquaponics.
Aquaponics is an organic food factory that produces up to four times more food than conventional soil agriculture, using 90% less land and WATER than conventional agriculture in the process. This is revolutionary.
No expensive chemical fertilizers or pesticides are needed or can be used. Not only do you get vegetables and soft fruit such as melons out of an aquaponic system farm, but also tonnages of TILAPIA FISHto solve the famine problem. Using far less water than conventional farming.
So you can provide the refugees with food, stop the famine, and also, after a little basic on-site tilapia fish aquaculture and horticulture training, jobs and skills to take them further in life.
Famine, given this aquaponics technology, can be eradicated quite quickly. Green leafy vegetables such as lettuce and cabbage varieties come out of an aquaponics system as harvest only 8 weeks after switching it on, and continue to be harvested weekly thereafter, as long as the aquaponics system is correctly managed and maintained.
This is only intermediate technology and can be run of alternative energy systems such as concentrated solar power and anaerobic digesters.
The tilapia fish and vegetables all are in tanks, in a closed-circuit recirculating aquaculture system. This system can be built and set into motion within eight weeks of the equipment and stock ( tilapia fish fingerlings and seeds) arriving on site.
Only a half horsepower pump and two regenerating blowers (air pumps for water aeration) are needed to service 0.05 of a hectare of aquaponics system. This produces 5 metric tonnes of tilapia fish and weekly continous harvests of vegetables in quantity.
These units can be built using simple materials like concrete and plastic water piping.
Here at Aquaponics Global we are available as consultants on contract to mitigate famine and food security emergencies using aquaponics technology anywhere on the planet, for reasonable fees. We are all multilingual expatriates with years of experience of coping with unusual and stressful conditions and have the requisite qualifications and experience to be rapidly effective in problem-solving on the spot in our various disciplines of aquaponics, aquaculture, construction (architecture), and business administration.
If you are a logistics professional looking for rapid ways of slowing or halting famine situations in drought areas without needing vast inputs of fertilizer, water, and expensive genetically altered organisms, Aquaponics Global can help. Why not give us a call?
Hunger stalks the planet. There has just been massive crop failure in the grain and soy belts of North and South America, due to drought and the failure even of ‘drought resistant’ genetically modified crops. Climate change is seriously disturbing weather and rain patterns globally. With crop failures increasingly prevalent, hunger edges closer to us all.
Conventional agriculture, organic or GM, depends on rain and rapidly depleting underground water supplies. Fertilizer is essential and made from ever more expensive natural gas and oil feedstocks. These are also finite, will keep going up in price, and will eventually run out. The cost of all these chemicals is eventually passed on to the consumer.
In many parts of the world, this means that basic staple foods are out of reach of the incomes of many people already. Hunger has become a normal daily experience for many. Food grown conventionally is just becoming too expensive, and conventional agriculture is just too vulnerable to the crazy weather. Food insecurity and downright hunger are now stalking everyone.
How, then, are we going to eat? While debates rage and conventional agriculture goes on with business as usual, failing due to droughts, storms, and new crop-devastating diseases immune to modern controls, hunger is increasing its grip on human populations across the globe. Conventional agriculture is proving totally unsustainable, if not downright unworkable in current climate conditions. Hunger is even making its presence known among the urban poor of so-called rich Western countries. Food prices are rising at a steady 140% year on year globally. That includes the food prices in your local corner shop.
The answer has already been invented and is catching on. It is totally sustainable. It does not use soil, pesticides, herbicides, artificial fertilizers, genetically modified crops or fish, or antibiotics. It wastes 90% less water than conventional agriculture, whether organic or chemicated. It does not need expensive, risky genetically modified seeds, organisms, or plants. If more generally adopted by farmers worldwide, it promises to end food insecurity for millions of people.
It is a way to raise fish and vegetables intensively in the same recirculating water. It marries intensive fish farming and intensive hydroponics and by doing so, gets rid of the endemic problems of both technologies. The vegetables clean the water for the fish, so there are no uncontrolled effluent discharges to the environment. The fish fertilize the water for the vegetables, so no artificial fertilizers need be bought. Plants love this and grow up to twice as fast at up to half the spacing.
It’s part of the Blue Revolution of aquaculture-water farming-that is taking the world by storm. It’s called AQUAPONICS.
Aquaponics farms both the fish and the vegetables sustainably. Aquaponic systems growing fish and vegetables together can be certified organic. Everything grows in tanks in aquaponics, and water evaporation is stopped by shading the fish tanks and enclosing the water almost completely in the hydroponic raceways, so at least 90% less water wastage occurs than in conventional agriculture. Most water is constantly recycled between the fish and the vegetables. Only around 1.5% leaves the system every day as a consequence of fish solids flushing and cleaning, and this can be scavenged back by dewatering the solids, and reused for irrigating soil crops such as orchards.
Aquaponics is a proven technology that has been used commercially since the 1970s. It also uses around 17% of the energy used by conventional farming, since no trucks, tractors, and other machinery are necessary. As a modest user of energy, it is also very suitable to be operated using alternative energy sources such as wind power or solar panels. It’s all on the spot and harvesting is easy, especially with floating raft aquaponics systems, where the rafts are lifted onto trestles and harvested at waist height in a few minutes.
Aquaponics is a way to build efficient, highly productive, sustainable, largely organic food factories. It is industrial agriculture gone green. It’s renewable food. And it fits snugly into a climate controlled greenhouse, and reduces water use on the farm by at least 90%.
It’s taking off right across the United States and Australia. Properly designed and managed aquaponics can easily produce far more food, far faster, than any form of conventional agriculture using soil. Aquaponic farming is the farming method of the present now, not just the future.
You can use aquaponics to save water by up to 90% when growing food. In these times of global climate change and frequent drought, it is very important for farmers to save water!
First and foremost, food is grown in the hydroponics section of an aquaponics system. It usually consists of vegetables and soft fruit such as tomatoes, melons, squash and cucumbers. In the usual sort of farming, you irrigate them once and then throw away the water. In aquaponics, you save water because this water is sent for cleaning to the plants and re-used, for growing food.
Fish are intensively farmed in the fish rearing tanks of an aquaponics system. However, unlike usual fish farming, you save water because the water used by the fish is cleaned by the plants and re-used, since it is miracle gro for growing food, and is not thrown away.
The fish are the source of the nitrates for the plants, and the plants clean the nitrates out of the water, so it can be recirculated clean back to the fish. The water goes round and round like that. Growing food all the time at a tremendous rate!
The water is in tanks and hydroponic tanks made out of solid walls and lined with pond liner so they do not leak. You save water because the water you are using does not sink straight into the ground and flow away on the first use. It is used again and again for growing food.
None of the water in an aquaponics system soaks directly into the ground. It is kept and constantly re-used.
The water is also covered over and shaded by a shed over the fish tanks, and floating polystyrene rafts full of plants or at least two inches of growing medium such as expanded clay balls (hydroleca or hydroton brand clay rocks) which prevent the water surface heating up to evaporation temperatures.
Less than 10% of the water volume in the system is lost to the outside daily. Some, however, has to be used in a Deep Water system with floating rafts in it in order to flush out the fish poo from the filter into a settling pond for composting and subsequent dewatering.
Meanwhile, you can get five metric tons of basil and five metric tons of fish a year, just as an example yield (from the University of the Virgin Islands’s data on their commercial aquaponics system), off 0.05 of a hectare of growing space with aquaponics. By using aquaponics you save water, at 90% of the water you would otherwise had to have used to get the above results.
If you would like to download more articles from this site about aquaponics to read at your leisure, I have edited together the first six months’ worth of posts from this site into the ‘Aquaponics Global Anthology 1‘. It is immediately available for download and printing out here: [paiddownloads id=”1″]
Aquaponics differs in many ways from conventional agriculture and other kinds of factory farming.
I have made a chart of the differences between aquaponics and conventional agriculture:
Aquaponics is really green, and can be certified organic if the correct design and methods are used. It recycles at least 90% of the water used and uses far less space to grow far more food for far longer (all year, not just seasonally). Conventional agriculture with its use of artificial fertilizer and pesticide is not sustainable and is an envirommental disaster with long-term consequences which beggar description.
Even organic soil farming cannot compete in productivity with this marriage between intensive fish farming and ‘organic’ hydroponics. However, there are also a lot of differences between the kind of hydroponics practised in aquaponics and the usual methods and equipment used in conventional hydroponics. For instance, the piping is at least 3 inches in diameter in aquaponics to prevent clogging with fish mulm. Also, no liquid artificial fertilizer is used in aquaponics, while, just likewith conventional agriculture, hydroponics depends on liquid artificial fertilizer entirely.
Just like conventional agriculture, hydroponics eventually vents this artificial fertilizer sludge to the water table with toxic consequences.
No toxic artificial fertilizer residue or effluent is vented to the environment in aquaponics. The fish solids are composted into organic fish manure which can be used to fertilize field crops or sold on to gardeners. Aquaponic farming is factory farming of fish and vegetables that recycles nearly everything and processes its own waste properly. Fish manure is a very popular product!
Unlike other forms of factory farming, aquaponic farming does not produce any unmanageable sewage runoff. The fish solids can also be put into an anaerobic digester with the harvesting offcuts and composted to produce methane and compost. The methane can be used to fuel a steam boiler and turbine for homemade electricity to run the pumps and air blowers of the aquaponics system. Factory farming run off its own waste products!
No pesticides or herbicides need to be used, and energy use is minimal. Staffing ratios on an aquaponic system are very low except for harvesting which requires minim wage piece workers, just like conventional farming, but without the back breaking work of bending. Floating rafts can be harvested from special trestle tables at waist height! The conveyor belt planted with vegetables in your aquaponics factory farm has floating raft sections that can be lifted out of the water and placed for harvesting at an ergonomic height. Even the disabled can work on an aquaponic farm.
Lettuce seedlings in the UVI aquaponics floating raft system.
University of the Virgin Islands commercial tilapia aquaponics system
To any ambitious biology or business teacher, a small commercial aquaponic farm is a priceless gift. In any large flat roofed school building, you can have one on the roof and the students can run it as part of their classes, since it is automated largely. But keeping an eye on the aquaponic organic food factory on the roof will teach them more about real biology, farming and agribusiness than any number of textbooks.
It may also provide the school with a much needed source of income in these interesting times.
But what is aquaponics? Aquaponics is intensive fish farming in tanks married to intensive vegetable farming in tanks. So you should know all about fish and plant biology as it applied to intensive aquaculture and hydroponics. This gives your students first-hand experience of looking after a natural ecosystem in an artificial container. You also should know how to keep the water quality good enough to suit the plants and the fish. Chlorinated water cannot be used, since the disinfectant in the water kills the bacteria that make the fish waste into plant food, see the diagram below.
Aquaponics system biology flowchart
Fish excrete ammonia. Nitrifying bacteria in the filter part of the aquaponic system convert the ammonia to nitrates. The nitrates are absorbed by the plants, and the plants grow really fast. This makes the water clean. The water is pumped back to the fish to be used again.
In aquaponics, only 1.5% of the water is lost in a properly designed and run aquaponics system. So it is very good for saving water on the farm. In aquaponics, plants can grow up to twice as fast at half the usual spacing. So you get up to twice as many plants, twice as fast, compared to farming in soil. But this can only be done if you have the right aquaponics system and the right training. As with any business, proper management is very important.
You will also need to know how to run and clean water pumps, air blowers, and alternative energy sources such as wind and solar generators. You need a cheap source of electricity to run the machinery of your automated aquaponic food factory on the roof.
YOU DO NOT NEED SOIL IN AQUAPONICS. You only need water. And you do not waste any water.
Because you do not need soil, only tanks of water, you can do aquaponic farming anywhere, like on the school roof, as long as you have electricity and somewhere to put the tanks, the pumps, the air blowers, and the plumbing.
In the tropics, you do not need a permanent greenhouse, though in places like Hong Kong where the temperature goes down a lot in winter, you will need temporary plastic hoop houses to cover your aquaponic systems and also to protect them from typhoons. These have to be quite strong to keep the wind and rain off the system. For example, lettuces do not do well in temperatures below 10 degrees centigrade and above 20 degrees centigrade they start to die.
Pictured below is a gravity feed version of a small aquaponic system. You would need something larger than this to make the farm economically viable, but this give you a basic idea of what can be done with recycled materials and a tank or three.
Usually the first fish you use to make the fertilizer for your plants is the tilapia fish from the Nile originally. It is one of the most commonly farmed fish in the world. It is a tropical fish and does not stay alive in water below 19 degrees centigrade or above 30 degrees centigrade. You will need someone on your team who has kept tropical fish before and knows how to look after them! If you live in a cold climate you will need to have some equipment to heat the water to the proper temperature and keep it that way.
Gravity feed aquaponics system
No fertilizers or pesticides can be used in an aquaponics system. They kill the fish! Instead, the fish water contains the nutrients that the plants need, and the pests can be controlled using biological methods.
Biological pest control methods include using friendly insects such as lady bugs to eat up all your aphids, also called greenfly. There are also parasitic wasps and lacewings which also eat other pests as well. You can buy these online and they come in suspended animation in little blister packs. You spread them out with a camel hair paint brush so as not to damage them, and lift them onto the areas where the bad insects are eating your crops. That’s it!
Another way to get rid of pests such as caterpillars is to use a bacterium called bacillus thuringensis. This comes as a white powder which you spray on. It makes the caterpillars sick so they die, but is harmless to fish and people.
Here are some aphids and the ladybugs that like to eat them:
Aphids eating a plant
You can also use harmless fats and oils to drown the insects that are eating your plants. But no insecticides or pesticides. They really do kill the fish, even if they are labelled ‘organic’!! You can be sure that none of the children will get poisoned by aquaponics for schools.
There are no weeds in aquaponic farming systems, so you do not need to use herbicide. So aquaponics for schools is not a toxic or dangerous activity.
There is no digging in aquaponics, and you can put the grow beds and raceways for the floating rafts up on tables and stands, so even people with bad backs can and do farm with aquaponic systems.
You can do all the work you need to do, including regular testing of the water to make sure the pH and other factors are correct, in a few hours a day. Your aquaponic systems are low tech mechanical systems with fish and plants growing in them. You have to make sure the fish and the plants have the best growing conditions. This sometimes means adding garden lime or potash to the water in tiny measured quantities to make sure that the water stays at a pH of around 7.0, or neutral. This is something to do for your biochemistry classes. Looking at the kH and hardness of your water supply and other features of water quality analysis will give them lots of practical experience of how classroom work applies in the real commercial world of fish farming and modern recirculating aquaculture.
But before you go ahead and construct your own school aquaponics system, you need to look at all the business side of aquaponic farming in your area and do a business plan. If you cannot sell your fish and vegetables, you should not grow them! Aquaponic systems can produce up to four times as much food for the space used, compared to conventional soil farming. 1/16 of a hectare of rooftop space can produce around 5 metric tons of fish and up to double that of vegetable plants a year. That is a lot of food to not be able to sell locally! Schools that have their own aquaponic systems need to be sure that they are not going to have a lot of food that is simply rotting on the roof. This is also very intensive fish and vegetable farming.
Market research is the first thing you do when you want to start a business, and aquaponic farming is a business. Aquaponic systems are very efficient food factories if properly managed and operated. This is something really interesting to do for your business class as a project. From your market research in local shops, markets and restaurants you can work out how much food you need to grow to cover the expense of constructing and operating a commercial aquaponic farm on the roof of your school. So then you can work out if there is enough room on your school roof for a big enough farm to cover your costs and perhaps make a bit of a profit. Aquaponics for schools is not aquaponics for fools!
If you are considering this kind of small commercial aquaponic intensive fish and vegetable farm on your school roof, please get in touch with us here
» Get Skype, call free!
and we can help you set this up correctly over Skype for a reasonable fee. If your farm is very big, it might be worth your while for a consultant to come and oversee the installation of your farm and the first few months of the business. Aquaponics for schools can become aquaponics for whole communities. If you get the whole community involved in their intensive fish and vegetable farm on your school roof, the sky is the limit!
Aquaponics Global Anthology 1 is available for instant download and to print out here: [paiddownloads id=”1″]
Aquaponics, correctly constructed and managed, is an essential part of sustainable development. Aquaponics is intensive fish farming in tanks married to hydroponics in tanks. The reason that this has to be in tanks, not ponds, is that the tanks and associated plumbing and pumps allow much more intensive fish and plant production with close scientific water quality control. Also the water usage of an aquaponics system can be closely monitored and controlled to achieve water exchange rates of only 1.5%. The water exchange rate is the water that has to replaced in the system when it is filled and pumping. This compares favourably with water usage in conventional farming where the water exchange rate in an irrigated field is close to 100%.
Water loss is minimal in aquaponics, which is a recirculating aquaculture system for both fish AND commercial crops. Food yeilds per hectare can be up to four times that of conventional farming, using far less expensive inputs, with proper trained and experienced management. Little ecological footprint is involved and pollution is not generated, since all nitrates are removed by the plants in the rafts, and the water recirculated to the fish in a clean reusable condition.
As part of an arcology,aquaponics becomes a way of sustainably feeding thousands of people as a designed-in feature of the vertical self-sustaining city of the future. Water is lighter than wet soil, which means that the floating raft aquaponics system as pictured above is suitable for including in buildings without so many of the crushing weight load problems associated with raised bed soil gardens. These urban farms can also yield over a million pounds of food on 1.5 hectares, as with the documented Growing Power urban aquaponic and sustainable farm in the city of Milwaukee. A picture of the floating raft system at the University of the Virgin Islands commercial aquaponic farm is included below.
Lettuce crop in floating raft aquaponics system, UVI.
In the sustainable development of the city of the future, food security remains an urgent issue. Cities need to be unhooked from addicition to oil and gas, and the arcology requires no cars, as aquaponics requires no fertilizer or expensive pesticides and herbicides. The fish and pumps do most of the work! As a plumbing system that sustainably produces food, aquaponics can easily be included in the modern arcology. This makes the sustainable development of a city that produces its own food with few inputs from outside very easy.
The best-known proponent of arcology urban design is the designer of Arcosanti, an arcology being built in Arizona, by the famous architect, Paolo Soleri. He has developed and personally applied many of the design principles of the modern arcology. Another of his arcology designs is pictured below. There is easily space inside for a few large scale commercial aquaponics food factories and urban farms.
One of the arcologies designed by Paolo Soleri
Model of an arcology with built in farm on roof.
The tank systems for the hydroponics and the fish farm can be built in to the design for the water and waste management systems for the arcology. As part of the atria inside the city, they can also be modules in the ornamental indoor park area features, with all of the plants both ornamental and edible, as a pick as you go salad bar for the population, who also maintain the public aquaponic farms with their floating raft beds of vegetables and associated intensive fish rearing tanks, on the various levels of the building. Anaerobic digesters and wicking beds complete the picture, digesting organic waste and circulating the waste water from that as irrigation water for wicking beds that are used to grow root vegetables such as potatoes and carrots, that do not do well in floating raft systems.
A diagram of a wicking bed with its piping for the flowing waste water from the anaerobic digester is below. It uses waste water from the anaerobic digesters. It also uses digested solids that have been worm composted subsequently as the growing medium, thus returning organic waste at this last stage of processing to the state of edible food. These design principles all hinge on recycling everything in the city through long cycles that safely transform organic waste back into food, water, and usable fuel.
Wicking bed-irrigation from below
Anaerobic digester power plants are also a way of recycling water from waste management systems (such as sewage collection pipes). It is important to realize that all the organic waste, whether human or animal, fish or fowl, and all the vegetable and food waste, represent proper fuel for the anaerobic digester systems that produce methane gas that can be used to fuel boilers for hot water, heating, and steam generation for electricity producing turbines. This means that the aquaponic farm is a part of a sustainable development of a city which uses its own waste organic matter to generate both food and energy. Aquaponics is a very important technology in environmental engineering.
Waste solids from the anaerobic digester power plant are safe to use since they have been ‘cooked’ by the heat generated by the digestion process. These solids can be further digested by using the worm composting method in large compost bins, and then used as the growing medium in the wicking beds, see the diagram opposite. Many root vegetables, which have a high nitrate fertilizer requirement, simply thrive in worm compost of this high quality. No digging is required in wicking beds if the upper portions are made of easily removable narrow gauge galvanized chicken wire or similar tacked to supporting posts with removable ties.
All of these technologies can basically be put on castors with wheels, and used like furniture in ‘food factory chambers’ in an arcology. Alternatively, the tanks and beds can be plumbed into the design at the outset, with all the factors calculated so that they meet the nutritional needs of the tens of thousands of people. Urban aquaponic farms and aquaponic farm parks will be a normal part of the pedestrianized environments of the near future’s new arcology urban neighbourhoods. Environmental engineering is very important in arcology design.
In an arcology, everything you need is in your part of the urban vertical stack, only within 20 minutes’ walk of where you live. There is no urban sprawl, the city extends upwards, if you need to go up a level, you walk up stairs or take the lift. You do not need a car. The urban design has done away with the need for extensive road networks. Your neighbourhood is also your job, you participate in its maintenance and grow food with your community in your own area of the building, in a farm that is also a water pumping machine.
Light for the atria is brought into the building via lightwells with reflecting mirrors. Low-energy restricted wavelength grow lights can be used on crops to increase the day length and speed of growth, fuelled by electricity which is made from organic waste from the city, its farms and restaurants. Solar collectors and wind-powered generators on the outside of the building also contribute to meeting the energy needs of the city’s inhabitants. A city a thousand feet tall generates a lot of wind.
We at Aquaponics Global Ltd are available to assist in building the commercial aquaponic farm sections of any such civil engineering and architectural design and construction contracts.
Anaerobic digester methane tank, upper portion
Aquaponics Global Anthology 1 is available for instant download and to print out here: [paiddownloads id=”1″]
This week, the UK Environment Secretary, Caroline Spelman said genetically modified drought-resistant crops will be considered as a way of ensuring food security at the main conference of the country’s farmer’s union. Meanwhile, protests largely go unheard about the deadly toxicity of the methods used to grow such crops, including evidence from Purdue University’s plant pathology department in the US that the herbicide routinely used with such crops, glyphosate, commonly known as Roundup, is many times more toxic than DDT and causes premature ageing and infertility in cattle, sheep, pigs, and chickens fed on GM crops exposed to it.
However, there is another way to ensure food security in a drought. It is far more water efficient and safe than genetically modified food crops, and needs no GM seed or expensive chemical fertilizers or pesticides. It can grow up to 40% more food per acre/hectare than conventional agriculture using less than 10% of the water normally required by conventional agriculture. It is essentially drought resistant because of this water use efficiency which is built into the system from the start.
It is called aquaponics and it is a form of recirculating aquaculture (intensive fish rearing in recycled water) which uses plants grown in the same recirculating water to clean it of nitrates produced by the fish. In the process of filtering the water, the plants grow at up to twice the speed and up to half the normal spacing, outstripping even hydroponically grown produce, when grown in a mature aquaponic system. As well, but later in the day, you harvest generous amounts of edible sustainably grown fish such as tilapia or trout. All with no waste in water use.
No genetic modification, pesticides, herbicides, weeding, ploughing, irrigation, or artificial fertilizer are needed in this drought resistant agriculture method. Because the tanks in which it takes place are covered over with white-painted heat reflective polystyrene rafts, or else shaded in the case of the fish grow out tanks, evaporation of the water is kept to a minimum. At the University of the Virgin Islands, in the perennially drought-stricken Carribean, in Hawaii and high and low on the American continent, even in the icebound wintry streets of Milwaukee, you will find agriculture businesses using this technology to produce fish and vegetetables of many diverse kinds. It is becoming a useful weapon in their local food security arsenal. This is because it is a reliable form of drought resistant agriculture. It is also a good example of efficient water use. 90% or more of the water used for fish rearing and vegetable and fruit production is constantly recycled.
Although in the UK aquaponics is still largely seen as a new unproven experiment, in the United States this drought resistant technology is becoming very widely used, from small scale farmers’ markets to large scale commercial food production facilities, and has a 30 year old pedigree. Many university agriculture departments there are training people how to install and use this drought resistant agriculture method in one form or another. To see the extent to which it is being adopted as an agriculture method, just go to http://aquaponicscommunity.com and look up the Google map on that site, which charts the global spread of this drought resistant technology.
So in financially strapped Britain, why on earth are we not using this low-input, drought resistant agriculture more, instead of investing yet again in risky and demonstrably poisonous and ineffective genetically modified crops?
Links to the articles sourced from the scientific community about the virulent toxicity of genetically modified crops in the Links section of this website.
To download the transcript of an interview with Dr. Don Huber, plant pathologist, of Purdue University on the toxicity of glyphosate, click on the following: InterviewDrHuber-Part1.
If you have more questions about aquaponics, my old teacher at the University of the Virgin Islands Agricultural Experimental station, Dr James Rakocy, has brought out a standard FAQ answering book that is very helpful:
China is undergoing the worst water crisis in its history. In northern China, the fossil water supplies (ancient underground aquifers that cannot be resupplied by rainfall) are already mostly used up. However, the solutions being employed to date seem to be just a finger stuck in the dyke of this water crisis problem, given the magnitude of the shortfall and the rate of increase of demand for water in China. Food production and China’s industrial revolution are fuelling ever more extravagant water use. Here are some mind boggling China water crisis statistics from the experts:
‘China becomes drier each year—its freshwater reserves declined 13% between 2000 and 2009. Severe droughts occurred in 2000, 2007 and 2009. Normally the southern regions receive 80% of China’s rainfall and snowmelt, about 79 inches a year, while the north and west get 20%, 8 to 16 inches.
This winter, Beijing and the northern and eastern provinces had the worst drought in 60 years. It has left 2.57 million people and 2.79 million heads of livestock short of water, and affected 12.75 million acres of wheat fields, which sent global food prices soaring. South China experienced 50% less rainfall than normal, resulting in the drying up of rivers and reservoirs. While torrential rainfall fell on the south this week, northern regions are still suffering from drought.
China’s per capita availability of water is 1/3 the world’s average, and in the dry north where most of the grain and vegetables are grown, per capita availability is only 1/4 of that in the south. Over 300 million people in rural areas have no access to safe drinking water and 54% of China’s main rivers contain water unfit for human consumption.’ from ‘How China Is Dealing With Its Water Crisis’ by Renee Cho | – Blogs of the Earth Institute, Columbia University, 2011.
The wastage of water by conventional agriculture and industry in China does not only threaten China, but the world at large. What would happen if China, which has billions of inhabitants, should competely run out of water? Where would all these people go and how could this water supply shortfall be made up? How can China improve its water use efficiency?
The Chinese government is spending billions of yuan on ambitious schemes such as desalination plants to turn seawater into fresh water, and a huge canal project to take water from South China to North China to alleviate the drought there. However these projects do not really focus on water use efficiency. They are not designed to save water, only to provide more water from other areas which seem to have a more plentiful supply. The people of South China are already concerned that North China may soak up too much of their finite water supply via the new canal, and desalination projects have a problem: what do you do with the mountains of salt that result from boiling off all that H2O? China needs more water to ensure food production. Or does it?
Meanwhile water use in China is increasing exponentially as its booming economy ups the demand for water-intensive farmed products such as meat. Industry also uses and pollutes mind boggling quantitities of water every day.
Meanwhile, there is a solution to the extravagant water use in China’s agriculture. This water use efficiency solution is largely being ignored, despite the latest policy moves on the part of China’s central government to encourage new cutting-edge agriculture techniques and food production technologies . This proven water efficient and water saving agriculture technology has been in existence and proven to work in different climates and cultures at least since the 1970s, and it does not rely on expensive biotech, chemical fertilizers, or complicated widgets to work.
It is called modern, up to date water-saving water-efficient aquaponics and it is an upgrade on conventional aquaculture, which is already practiced all over China. It marries aquaculture to aquaponics and in so doing saves 90% or more of the water required to grow food:
‘The aquaculture industry largely has developed without regard to the increasing scarcity of water. Traditional intensive (high production per unit area) aquaculture systems require more water than less intensive
pond systems, being dependent on high volumes of fresh water flowing through fish-rearing tanks to supply dissolved oxygen and remove deleterious metabolites. Both= have very high water demand compared with other competing industries, arguing strongly for the integration of aquaculture with other industries or with agriculture (Phillips et al. 1991).
Integration of aquaculture with agriculture can reduce the water requirement for the production of quality protein and fresh vegetable products relative to both culture systems operated independently. Innovative fish/vegetable co-culture systems use the nutrient by-products of fish culture as direct inputs for vegetable production, constantly recycling the same water. While pond or cage aquaculture in arid environments is limited by the constraints of water supply and soil type, recirculating systems are unaffected
by soil type, use less than 1% of the water required by pond culture for the same yields and are efficient in terms of and utilization (Rakocy 1989) like the high-volume, flow-through systems….
The purpose of this work was to design and test a recirculating fish/vegetable coculture system with high efficiency of water use in production of quality food as well as high functional and technological simplicity.
The main features were a greatly increased hydroponic plant culture biofilter capacity relative to the fish rearing capacity compared with previous systems (Rakocy and Hargreaves 1993); also, the fish effluent, including solids, was pumped directly onto sand beds. The sand beds served as:
biofilters operating in the reciprocatingmode;
hydroponic plant growth substrate; and
the locus for oxidation of organic solids.
We have examined the water quality and general dynamics of the system as a function of the ratio of plant growth/ biofilter capacity to fish rearing capacity (McMurtry et al. 1997). In this paper we consider the effects of these four ratios of biofilter volume (BFV) to fish rearing tank volume (0.67/1, 1.00/1, 1.50/1 and 2.25/1) on the efficiency of water use in production of protein and food calories, and on the economic productivity of the system.
Abstract.-Fish and vegetable production were linked in a recirculating water system designed to achieve a high degree of efficiency of water use for
food production in addition to functional and technological simplicity. Hybrid tilapia Oreochromis mossambicus X O. niloticus L. were grown in tanks associated with biofilters (sand beds) in which tomatoes Lycopersicon esculentum were grown. The effect of four biofilter volume (BFV)/fish rearing tank volume ratios (0.67/1, 1.00/1, 1.50/1,2.25/1) on water use efficiency
was evaluated. ‘Laura’ (first experiment) or Kewalo’ tomatoes were grown 41m2 in biofilters of four different sizes and surface-irrigated 8 times daily with water from the associated fish tanks. Daily water consumption increased with BFV/tank ratios and with time. Fish production rates increased with biofilter volume in the first experiment, but were not significantly different in the second experiment. Total tomato fruit yield per plot increased from 13.7 to 31.7 kg (Experiment 1) and from 19.9 to 33.1 kg (Experiment 2) with increasing BFVItank ratio. For fish plus fruit, total energy production increased from 4,950 to 8,963 kcaU plot and from 4,804 to 7,424 kcallplot in Experiments 1 and 2, respectively, and protein production increased from 536 to 794 and from 352 to 483 g/plot in Experiments 1 and 2, respectively, with increasing BFVI tank ratio. Trends in water use efficiency for production of food energy (kcal/L) and of protein (g/L) in tomatoes and fish were complex. Water use efficiency for total energy production (fish plus fruit) did not significantly differ with biofilter volume. Economy of water use for total protein production (fish plus fruit) decreased significantly with increasing BFV/tank ratio. The component ratios of the system may be manipulated to favor fish or vegetable production according to local market trends or dietary needs, and thus may have economic potential in areas of limited water supply and high dand for quality food.’
From ‘Efficiency of Water Use of An Integrated Fish-Vegetable Co-Culture System,’ JOURNAL OF THE WORLD AQUACULTURE SOCIETY Vol. 28, NO.4, December, 1997
Since this was written many further advances have been made in making this technology, now called aquaponics, into a commercial and immensely water-efficient solution for areas with extreme and persistent water shortages. At the University of the Virgin Islands, where I was trained, their commercial aquaponic farm produces on average 5 metric tons of tilapia fish and at least that in vegetables (this varies depending on what is grown at the time). In a greenhouse, with vertical growing and the use of low energy grow lights, more biomass can be grown, but at the UVI, which is in the tropics, the system is outdoors.
The space taken up by the system covers only 1/8 of an acre (1/16 of a hectare).
This food is grown using 1.5% of the water normally required to produce that volume of food on that acreage. The UVI is in a Caribbean archipelago which is chronically short of water and arable land, so the whole system was developed to use MINIMAL QUANTITIES OF WATER.
It is a recirculating aquaculture and hydroponic system that recycles the water volume in which tilapia fish and plants live constantly throughout the system.
A clarifying unit removes the fish solids via a flushing procedure. This effluent is put into settlement ponds and dewatered, and the resulting fertile water and fish manure are used on field crops as irrigation water and organic fertilizer.
In the context of China’s water shortage, such units could be manufactured in bulk and rolled out to farmers all over the country with training in how to use them properly. This training is short, but very necessary since the techniques are not the same as conventional farming and require at least a high school level of scientific understanding to be effectively used. Otherwise systems will be deployed only to be abandoned as non-functional because their operatives do not understand how to use them in a water-efficient and food productive manner.
Aquaponics is a skill China desperately needs to save untold amounts of water and to ensure its future food supply. Its water use efficiency in fish rearing and vegetable farming make it a form of sustainable food production which is in sharp contrast to the methods currently used to feed most of China’s teeming billiions. Ironically, the aquaponic system as currently designed is actually just a techical upgrade on the traditional methods of fish rearing in rice paddies that were used in ancient China before the advent of artificial fertilizers and pesticides, which killed off this fish rearing practice since these artificial chemicals kill the fish. Artificial fertilizers are not necessary in an aquaponaic system, they kill the fish, and the fish waste is what feeds the plants in the hydroponic part of an aquaponic system. All chemical pesticides, even the ‘organic’ pyrethrin-based ones, kill the fish as well. You can only use modern organic biological pest control, such as friendly insects and bacteria, to control pests in aquaponics. However, this works very well and means that crops can be harvested soon after being treated for pests, unlike crops treated with toxic pesticides. This is sustainable food production with a very small environmental footprint, eminently suitable as a large part of the soution to China’s water crisis.
At Aquaponics Global, we can help with selection of appropriate systems and methodologies, and also with the design and implementation of fast-track training courses and with training trainers on water-efficient aquaponic systems once they are in place. There are also other greenhouse and recirculating aquaculture techniques such as biofloc tilapia aquaculture that also offer massive water savings in China’s water crisis at low cost and with fast roll-out times compared to more high-tech engineering water crisis solutions.
I also recommend the following books to anyone seriously considering setting up an aquaponic farm of any size:
Are you in greenhouse agriculture? Would you like to see the efficiency of your greenhouse be increased by hundreds of percent? By using aquaponics, among other organic growing methods, Will Allen of Growing Power in Milwaukee, in the United States, has grown a million pounds of food off three acres (1 ½ hectares) year on year. In the freezing cold. In the winter as well as in the summer.
Are you spending more and more money on artificial fertilizers and replacement composts to grow the same yields? Aquaponic farming needs no artificial fertilizers. The fish in the aquaculture part of the system produce the fertilizer for the crops with the help of a couple of different types of naturally occuring beneficial bacteria. These nitrifying bacteria come free.
Are your staffing and energy bills spiralling upwards? Aquaponics is largely automated agriculture. Staffing levels for a 1/8 of an acre system that produces 5 metric tons of tilapia a year and at least that in vegetable crops, are only 3 or 4 people for the technical management and a few extra casual staff weekly to help with harvesting.
What about the water bills? Aquaponics uses less than 10% of the water normally required by agriculture to produce much more food per acre/hectare than conventional agriculture.
Do you have enough water to really get the maximum production out of your crops or is your area (or country) getting increasingly arid? If you need to save water, aquaponics will help you do this and increase your yields at the same time. Aquaponic techniques make sure that most of the aquaponic system water stays shaded or covered to reduce evaporation of the water. Water in aquaponics is not used just once, but constantly recycled round the system.
Are you on the edge of a desert? Is soil salinification a problem? Irrigated soils gradually become loaded with salts from artificial fertilizer applications in arid climates. This makes the soil less and less fertile, and it needs more and more fertilizer to do the same job. What are you going to do when the soil eutrophicates (becomes too loaded with salts to work)? You will need to install a system that sits on the soil, but does not use it. Aquaponics does this, and does not waste water. Most of the water gets recycled round the tanks of the aquaponic system.
What are your heating bills for your greenhouses if you live in an area with a frigid winter? If you run an aquaponic system, you can use the offcuts and vegetable harvest waste to make compost. In a commercial sized system, considerable waste builds up, and as compost, it heats up. By piling compost heaps against the sides of your greenhouse to the required depth for the heaps to heat up (more than 1 meter x 1 meter) you can use the compost to reduce or eliminate your greenhouse heating bills.
What do you spend on pesticides? Because fish live in an aquaponic farming system, you cannot use ANY pesticides. Even ‘organic’ pesticides based on pyrethrum (a flower) kill the fish dead very rapidly. Without the fish, no fertile water for your plants can be made. You need to get hold of friendly insects such as lacewings and ladybirds, which feast on greenfly, whitefly, blackfly, and thrips. There is usually an insect predator bred commercially to get rid of most of your pests. However, bacteria such as bacillus thuringensis also are bred and sold to get rid of your caterpillars. You can use these kinds of pest control, some of which will continue to breed as long as there is a prey species to feed on and your greenhouse or outdoor tropical aquaponic system is at the right temperature. In this case, you are getting pest control for free…
Do you need another product just to break even? You do not only grow vegetables and soft fruit such as strawberries in an aquaponic system. You are also growing fish, if at a slower rate. If you take proper care of your fish, you will get a premium product which can be sold as sustainably produced antibiotics-free fish. You cannot use antibiotics on your fish since they will kill the nitrifying bacteria which convert the fish waste into plant fertilizer.
Do you need more space to get a profit? With aquaponics, you may not need more space. It reduces the space you need between plants by up to half the normal spacing. That means you can grow more plants in the space you have. Plants like lettuce also grow twice as fast in a floating raft aquaponic system since all stress is removed from their roots. They like to have their roots swimming in liquid fertilizer. And unlike hydroponic systems that run on chemical fertilizer, most aquaponic systems do not suffer from fungal infections and pythium outbreaks, so more of your crop will come in perfect and sell at a premium price.
What happens to your waste water? Do you have problems getting rid of fertilizer runoff? If you run an intensive fish farm, what are you doing about the gunge from the mechanical filters and the sewage from the fish? In aquaponics, you run it through a simple clarifier system and then out to the hydroponic element of the aquaponic system, where the plants use up the nitrates in the water. It goes back clean to the fish to be re-used and re-fertilized.
Does your back ache from bending over the crops all day? In commercial aquaponics, crops are growin in net pots in holes in floating polystyrene rafts. At harvest time, or when the plants need attention, you just lift out the floating raft in question and put it on a couple of trestle supports.
What do you use to control the weeds? There are no weeds in aquaponics. There is nowhere for them to grow.
How much time do you spend digging and tilling? There is no digging or tilling in aquaponics.
How many crops a year are you currently getting for all that work? You can get at least 12 crops of lettuce, for instance, a year out of an aquaponic system.
How reliable is your cropping schedule? An aquaponic growing trough full of floating polystyrene plants at various stages of development works just like a factory production line, with expert management, of course!
How often does the weather slow down or stop production? There are no droughts or floods in an aquaponic system. In a climate controlled greenhouse, you can increase yields even more, but in the tropics aquaponics works very well and reliably, all year, outside.
How easily can you change out crops if prices suddenly fail for what you are growing? In aquaponics, since your crops are on floating rafts, you can remove crops which are no longer economic and rapidly replace them with ones which are. Crops grow extremely fast in recirculated fish water.
How often do soil pests such as nematodes severely impact your crops? In aquaponics, the crops are growing in fish water, not soil. No soil, no soil pests.
Can you grow up to 40% more than other farmers without spending as much on inputs? In a well-run aquaponics system, you can.
Below is a very good little book by the leading expert on commercial aquaponics, Dr James Rakocy, who has put his over 30 years of experience of this technology into a clear Q & A problem solving format:
The problem with climates such as the Mediterranean or Saharan climate is severe limits on water supplies. Only so much food can be grown with very limited potable water, especially in summer, which is of course the height of the growing season, with the longest days being in summer and also unfortunately, highest temperatures.
Conventional irrigated crops use water only once. A lot of that water, even with the most sophisticated irrigation techniques, gets lost to evaporation. Bad irrigation management and bad water management generally also wastes massive amounts of water that could otherwise be used for agriculture.
The repeated application of doses of artificial fertilizers has a deteriorating effect on the soil. Fertilizer residues build up quite rapidly year on year in areas where rain is sparse or non-existent, so that salts change the soil PH and make it difficult for soil bacteria to do their job properly in breaking down nitrogenous matter and disposing of it safely. This makes it necessary to apply more and more artificial fertilizers to make up for the reduced soil bacteria activity, which reduces soil bacteria more, until eventually you are looking at a salt pan, not a soil any more.
Also, in hard water areas in the heat, irrigation lines scale up with lime-scale and have to be repeatedly checked and cleaned. This costs man hours and wages. A lot of Mediterranean areas are limestone areas with extremely hard water that does this lime-scale pipe blocking trick reliably and on time.
The cost of water in these areas goes up year on year, making farming at best a break-even activity except for landowners who can afford to put in hydroponic farms instead of the old fashioned kind.
However, hydroponic farms use artificial fertilizers too, and the problem with these, eco stories aside, is that the price of artificial fertilizers does not go down. It goes up and up. Add this to the price of water that you only use once, and soaring wage demands as the cost of living also rises, and you are on a hiding to nothing very fast indeed.
Importing food also gets very expensive to the consumer, again due to the rising price of fuel used to import the food. This fuel price gets passed on to the consumer as high staple food prices again.
Well, farm organically, locally, you say. This would be great, if you could guarantee the volume of food you need to survive as a family, a village, a town, a city, or a country. On all these scales, when you calculate the amount of food consumed plus the amount of food wasted, conventional organic soil agriculture no longer can produce the amounts needed to serve the present levels of food consumption and food waste in the Western world. Not without importing food from elsewhere as well. And using advanced food technologies that in many places are perceived as risky to health and the economy.
However, there is an advanced food production technology that produces up to 40% more food per hectare than soil agriculture. It uses less than 10% of the water normally required to grow crops conventionally, to do this. It doesn’t use genetically modified seeds or sophisticated agrichemicals. You don’t need expensive inputs like artificial fertilizer or pesticides. You can do this on any flat surface of adequate area with access to water and electricity. YOU DON’T EVEN NEED SOIL.
It’s called aquaponics. It is a form of recirculating aquaculture that grows fish and vegetables together in the same system of tanks, pumps and pipes. It’s a natural ecology living inside a food factory mechanism. If you use agrichemicals, you kill off all the crops and fish in an aquaponic system.
Crops like lettuce, properly managed, grow at up to twice the speed and half the spacing in this fish waste water fed hydroponic system. Fish water is the fertilizer, not expensive artificial nitrates. There are no toxic outfalls from the fish farm part of the system since the crops take up the waste products as food and send the water clean back to the fish to be re-used.
Most of the tank areas are shaded or covered in white-painted polystyrene rafts, that reflect back the heat onto the plants. This also means that water loss by evaporation is substantially reduced as the water is kept shaded. The main source of water loss is daily flushing out of fish solids to the fish manure making process. This lost water is fertile too. It can profitably be used on field crops. The fish manure, once dewatered, can also be used on field crops or sold on to farmers who don’t want to use artificial fertilizers.
There are other advantages to doing this, for instance, that the whole aquaponic system is mostly automated and requires no ploughing, digging, weeding, unblocking clogged irrigation lines, and so on.
But the continous harvesting procedure that you can initiate with this aquaponic form of agriculture produces premium produce at maximum speed,for less expensive inputs. THAT is what makes the money here, and THAT is what provides a solution to the above food price and food import conundrums.
What would happen if a lot more farmers adopted aquaponics as part of their growing strategy? Would it mean that we would not have to depend nearly so much on food imports and expensive chemicals for our food supply? Would it make the price of food stop increasing so rapidly?
There are of course other factors that can affect food prices, but the adoption of large-scale commercial aquaponic farming on a universal scale in countries like Spain and Morocco would certainly go a long way towards reducing food production costs over there as well. Because aquaponics uses so much less water, it would make sense for these regions to use it. The people there are also big fish eaters, which provides a ready market for the fish from the aquaponic systems when they reach marketable size. The Mediterranean sea is nearly fished out, and widespread use of fish farms to fertilize crops would take the strain off the sea and provide sustainably produced top quality fish from the land.
If clean, organic food were cheap enough to produce locally using aquaponics, in the Mediterranean and desert areas, would we do it and be able to sell it profitably, at a lower price than the chemical-soaked food we currently consume? I wonder.
For a more detailed look at how aquaponics works, and clear instruction on the practicalities of constructing and operating aquaponics systems, whether for pleasure or profit, please read the following very informative books:
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