From time immemorial, cultivators have been growing a variety of flora in water for its vast resource of minerals which are conducive for the growth of aquatic plants. The process has acquired a new meaning with the advent of commercial ‘aquaponics’, which uses the goodness of water used by fish to grow crops, primarily green leafy vegetables. Aquaponics refers to any system that combines conventional aquaculture, that is, raising aquatic animals such as snails, fish, crayfish, or prawns in tanks, with hydroponics (cultivating plants in water) in a symbiotic environment. In an aquaponics system, water from an aquaculture system is fed to a hydroponic system where the by-products are broken down by nitrifying bacteria initially into nitrites and subsequently into nitrates, which are utilised by the plants as nutrients, and the water is then recirculated back to the aquaculture system.
After the initial set-up costs, the recurring cost is low in aquaponics and there are two sources of revenue: fish and vegetables. an aquaponics system requires very little in terms of financial input. So, growers can reap huge rewards.
Aquaponics is an ecologically sustainable model and should not be confused with hydroponics; rather it combines hydroponics with aquaculture. Hydroponics is the soil-less growing of plants, where soil is replaced with water, like growing money plant in a discarded booze bottle, whereas aquaculture is the raising of fish. In aquaponics, both fish and plants are grown in one integrated ecosystem.
This model of farming is best suited for dry and arid regions of the world where water conservation is high priority, but its growth and spread in India will take time unless the concept becomes commercially viable.
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aquaponics combines aquaculture, cultivating fish and other aquatic animals in tanks with hydroponics, where plants are cultivated in water. Both hydroponics and aquaponics are soil-less cultivation processes. But while hydroponics yields inorganic produce, the produce from aquaponics is organic and natural.
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The Workings aquaponics consists of two main parts: the aquaculture part for raising aquatic animals and the hydroponics part for growing plants. The method in aquaponics involves pumping water from the fish tank onto the beds where plants grow. While the fish excretions provide nutrients for the plants, the clean water is recirculated back to the fish tank. So, a large tank is filled with water. In this, fish are bred in adequate numbers. The water, which becomes rich in ammonia and other minerals over time from the waste discharged by fish, is then used to grow plants without any interference with soil in a controlled environment. So, fish naturally produce the nutrients that plants need to thrive. In an aquaponics system, fish are kept in tanks and their waste is collected at the bottom. This waste is then pumped through a filter to make it into ready food for plants. The microbes or nitrifying bacteria eventually convert the ammonia from the fish waste into nitrates which plants need to grow. The plants are set up in ‘grow beds’, which allow the roots of the plants to dangle in water absorbing nitrates from the fish waste, while the leafy heads absorb the goodness from sunlight above. After the nutrients are absorbed by the plants, the water is ploughed back into the fish tank. This is a continuous process that goes on uninterrupted.
The fish, harvested after every six to nine months, make for an interesting by-product of this process, which also has a ready market and adds to revenue. More than 95 per cent of the water is recycled through this process, while the earning comes from selling both, the fish as well as the vegetables grown purely in water.
Components of Aquaponics The components of the aquaponics system are: (1) Biofilter: a place where the nitrification bacteria can grow and convert ammonia into nitrates, which are usable by the plants; (2) Hydroponics subsystem: the portion of the system where plants are grown by absorbing excess nutrients from the water; (3) Settling basin: a unit for catching uneaten food and detached biofilms, and for settling out fine particulates; (4) Sump: the lowest point in the system where the water flows to and from which it is pumped back to the rearing tanks; and (5) Rearing tank: the tanks for raising and feeding the fish.
The Need Given the ever-growing global population, it has become clear to many people that the very nature of farming needs to change, as its current output is not sufficient. By 2050, the earth will hold 2 billion more people, bringing the Earth’s total to 9 billion. We currently do not feed all the mouths on this planet, so this leap is alarming. The world needs something that produces more food, at a faster rate. Many attempts at sustainable farming have been made, with various levels of success. But, undoubtedly, the hope now rests in aquaponics. Aquaponics has already made waves in USA as well as other parts of the developed world. It is an incredibly simple, effective, and reliable way to grow large quantities of organic fruit and vegetables, and all without needing acres of land. This amazing technique is set to revolutionise food production. Not so long ago, the farming sector looked for organic farming. Non-GM, chemical free, and naturally grown food was all the rage for its health benefits. However, more recently, the organic trend has moved aside to make way for ‘sustainable’ farming. There is an increasing demand for organic and good quality produce not only from general consumers but also from restaurants and hotels that often require unusual, out-of-season, and non-native ingredients. These can all be grown in an aquaponics system, which is now being seen as a possible solution to address the problems of growing scarcity of food and hunger.
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Benefits and Weaknesses
The most important facet of aquaponics is that it is nature-friendly, eco-supportive, energy-saving, and leaves a minimal carbon footprint on the planet, thereby making a world of difference when compared to any other form of cultivation.
Aquaponics gardening eliminates weeds. It reuses resources currently considered ‘waste’. In aquaponics, there is no more toxic run-off from either hydroponics or aquaculture. It uses only 1/10th of the water of soil-based gardening, and even less water than hydroponics or recirculating aquaculture. In terms of taste, quality, and appearance, aquaponically grown produce relies solely on naturally produced fertilisers. This ensures plants get macro and micronutrients, making the produce nutrient-dense and improving sensory credentials. The Food and Agriculture Organisation (FAO) of the United Nations put out a technical paper in 2014, detailing the positives and negatives of the practice.
The specific benefits from aquaponics are as follows:
* Higher yields (20 to 25 per cent more) and qualitative production
* Grow up to 5 times the plants in half the time
* Use only 10 per cent of the water used in traditional farming
* Can be used on non-arable land such as deserts, degraded soil or salty, sandy islands
* Can be done in a fraction of the space used in traditional farming
* Creates little waste
* Daily tasks, harvesting and planting are labour-saving and, therefore, can include all ages of the population in cultivation
* Both fish and plants can be used for consumption and income generation
* Grow fruits, vegetables, and herbs that are completely organic
* Have multiple revenue stream in the form of fruits, vegetables, and fishes
* Grow foods that are non-native or usually out of season all year around
The failings of the method are as follows:
* Expensive initial start-up costs compared with soil production or hydroponics
* Knowledge of fish, bacteria, and plant production is necessary
* Optimal temperature ranges needed are 17° C to 34° C
* Mistakes or accidents can cause a catastrophic collapse of system
* Daily management is mandatory
* Requires reliable access to electricity, fish seed, and plant seeds
* Alone, aquaponics will not provide a complete diet.
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The Indian Experience The two largest commercial aquaponics farms in India are Red Otter Farms and Madhavi Farms. Red Otter Farms, in Kotabagh, a tiny hamlet near Corbett Park, Nainital, Uttarakhand is one of India’s earliest and fastest-growing aquaponic farms. It is a 10,000 sq ft aquaponics farm that produces about 150 kg of plants, especially green leafy vegetables (lettuce, swiss chard, kale). It is delivering fresh chemical-free greens to resorts and even at the doorsteps of customers in South Delhi and Gurugram. Now it plans to start recipes and cooking ideas. Bengaluru-based Madhavi Farms has long been associated with the growing of plants and herbs for the medical and perfume industries. In 2017, it began its aquaponic operations. In collaboration with Waterfarmers, a Canadian company that has set up projects in Hong Kong, China, Oman, and Australia, Madhavi Farms’ homegrown brand Satvik Sabji has been delivering salad greens, herbs, and veggies like tomatoes and cauliflowers locally.
In 2016, Sushant Madaan started Urban Kheti, north India’s first aquaponics farm near Sohna in Gurugram. The farms produce soft herbs like mint, basil, and coriander as well as everyday veggies like tomato and lady’s finger.
In the National Capital Region, the Dharampal Satyapal Group (DS Group) popularly known for the Rajnigandha pan masala, has been cultivating roses and jasmine in hydroponics farming since 2015, to cater to its captive need of essential oil.
Last month, it formally launched the Nature’s Miracle brand of vegetables which are being cultivated 30 km from Delhi by using hydroponics.
Ayurvet Ltd, a company manufacturing hydroponic machines, is helping dairy farmers, educational institutes, corporate houses, and even gaushalas to set up hydroponics system for producing green feed for the livestock. Its most prominent client is Naveen Jindal’s stud farm in Noida.
It is also working with the National Bank for Agriculture and Rural Development (Nabard) for hydroponics projects to set up paddy nurseries, where the seedlings can be grown in 10 days, compared with 30–40 days in conventional methods.
South India has led the way with aquaponics. Cheri, a coastal village near Kochi, has over 200 projects. In 2016, spurred by low crop yield due to over farming of soil, the Pallipuram Service Co-operative Bank launched an aquaponics project. Recipes made of aquaponics vegetables are in high demand in the star hotels of India and the chefs’ favourite. For instance, at the new ITC Royal Bengal in Kolkata, a plant-forward shiitake and aquaponic red spinach burger is a hit. Other aquaponic stars include morning glory, cress, pok choi, as well as a variety of greens and leaves that are integrated into stir fries, stews, and casseroles. Chefs play a key role in creating awareness, influencing and inspiring their diners to reconsider their sourcing approach.
Though, aquaponic produce in India is not labelled as ‘organic’, these produces are not only organic but also pesticide-free.
Cost, Consumer, and the Market While the technology has several advantages and could be a boon for an increasingly water-starved country like India, widespread commercialisation of aquaponics is constrained by its high cost. Normally, an average investment of at least ` 2.5 to ` 3 crore per acre is required for setting up a proper commercial aquaponics farm. The cost might go down by 30 to 35 per cent if power supply is guaranteed 24×7, rendering investment in solar power redundant. A one-acre aquaponics unit needs about 600 units of power a day to run all the systems. Unless there is a regular and consistent market for products grown through aquaponics and there is demand from customers, such a large-scale investment is unviable. Aquaponics has to find a place in metros, where awareness and affluence supports organic product consumption. Commercial aquaponics is not for small and marginal farmers, as the investment is big. Also, one cannot use this technology to grow crops that cannot be harvested daily and need to be stored. Green kale from aquapoincs farming fetches ` 200 to ` 300 and spinach, ` 70 in the market, currently.
The organic market in India at present is estimated to be worth 1.3 billion dollar, and is expected to double by 2021. The market for organic fresh products in Delhi-NCR requires 5 tonnes of produce daily. The market for the aquaponics and hydroponics segment is expected to grow at an even faster rate than the organic market in India, as the demand for chemical-free food increases with rising awareness among consumers.
It seems that aquaponics has a great potential in India. Since it is not dependent on land, it can be moved to inhospitable terrains and even urban locations; it is resource-smart, saves vast quantities of water, and is chemical-free. Yields are 10–12 times greater and the quality is far better. So, aquaponics is a responsible and sustainable farming system.
Internationally, aquaponics has attained some maturity as a farming alternative, especially in the US and in Australia. Many out-of-the-box solutions are now available and it is comparatively simpler to set up a farm. In India, aquaponics is in a nascent stage as yet. The supply side is very slow in the uptake and most set-up projects require that equipment is custom created. This is a challenge for high-speed scale-ups for aquaponics as is the initial capital required for a set-up.
With increasing demands to reduce pressures on land-based farming, aquaponics may become popular. It is expected that the ancillary and inputs will improve and become cost-effective sooner rather than later. If these challenges are addressed, then the potential to market the products and the services can thrive. The focus thereafter will shift back to the processes of production. Then, aquaponics can be considered a viable alternative to traditional farming systems.
Aquaponics has the potential to drastically change our production patterns and indeed make us competitive internationally in yields per hectares. With higher productivity, the enhancement of food security would improve across India while reducing the burden on land and limiting the resource wastage prevalent currently. With the ability to grow nearly all crops in aquaponics, it could be the leverage the agriculture sector requires in future.