Touted as the future of agriculture to mitigate the effects of climate change on food production, the aquaponics method of integrating fish and plant cultivation is gaining ground in Kerala. Writes K. Rajendran for India Climate Dialogue.
P.T. Antony, a farmer in Ashtamichira village of Thrissur District in Kerala, couldn’t believe his luck. He harvested as much as 1,180 kg of Tilapia, also known as gift fish, and 200 kg of leafy vegetables within six months when he experimented with aquaponics in his 250 square feet farm.
Not only did Anthony earn INR 300,000 from his tiny field but also won a provincial award for being an innovative farmer who could tackle climate change effects on yields by adopting an alternative method of agriculture.
Aquaponics has triggered new hope at a time fishermen and farmers have been bearing the brunt of climate change. Unseasonal rainfall and unexpected droughts have affected farmers in the southern state of Kerala. Last year, 105 farmers committed suicide in those regions of the state where cash crops are cultivated, according to data available with the National Crime Records Bureau.
The impact of climate change is more severe in the fisheries sector as the Arabian Sea has been witnessing the depletion of many fish varieties, especially sardine, known as the poor man’s fish.
Both fishery and farming experts say climate change is one of the main reasons for the drop in yields. Many experts, at levels from global to local, are trying to find ways to make food production more resilient to climate change.
Way to Anthony’s farm
The modest home of Anthony now sees a steady stream of people intrigued by his success in aquaponics. “Don’t be hesitant,” he tells visiting farmers. “Aquaponics will give you both organic vegetables and freshwater fishes irrespective of the ups and downs of heat and rains.”
Aquaponics is a careful blending of fish and vegetable cultivation. It essentially consists of a flood tank, grow bed and a fish tank. The three compartments are interlinked by pipes and a pump is required to keep a continuous flow of water between them.
The flood tank is usually situated on the top of the aquaponics system. It consists of water from the fish tank. Here the water containing ammonia is converted to nitrates by sponges on the tank bed. At the second stage, nitrate-rich water created by the bacterial process from the flood tank flows to the grow bed made of gravel. The high concentration of nitrates enables plants to grow. Fresh water after the refining process in the grow bed goes into the fish tank positioned at the end of the system. Fishes grow in the tank without being affected by the usual reversals at sea.
Gift Tilapia, a cultured variety of the popular fish, is preferred as it has a high growth rate. Leafy vegetables such as coriander, mint, spinach and lettuce are usually planted in the grow bed.
Merits and demerits
Aquaponics farming has several advantages. Neither drought nor torrential rains impact an aquaponics farm. It also requires a third of the space that traditional farming needs. Water requirement also reduces drastically since most of it is recycled.
Another advantage of aquaponics is that the produce is organic. The fish catch off the coast of Kerala is often contaminated with compounds of mercury due to heavy pollution. Also, fish and plants grown in the conventional methods often suffer from soil-borne diseases. In an aquaponics farm, fishes and plants are protected from the attacks of pathogens by around 240 types of microorganisms living within the system.
Despite the advantages of aquaponics, it is neither a panacea nor risk-free. For most farmers, the initial investment is often too high. Antony spent INR 500,000 (USD 7,459) to set up his aquaponics system although his investment was recovered after only a year.
“How can I change to aquaponics with such a huge investment?” asks K. Raveendran, a neighbouring farmer who is interested but still reluctant to take the plunge.
The Kerala Fisheries Department is now carrying out a study to build a model aquaponics farm in Thiruvalla, which will be both affordable and durable.
“Nowadays we are facing huge demands of subsidies and incentives for aquaponics. We can proceed only after getting a green signal from the feasibility study,” S. Ajayan, Joint Director of the state fisheries department, told indiaclimatedialogue.net.
Another cost is the electricity bill, though Antony has got a subsidy. “I had to pay only INR 700 as monthly electricity charges. In the Kerala context, it is quite affordable,” he said. Considering the importance of Antony’s venture, the Kerala Fisheries Department has provided a 75% power subsidy to him.
A potentially bigger problem is the need for uninterrupted supply of electricity to run the pumps. Although power cuts are rare in Kerala, they do happen. Some farmers are solving the problem by using solar energy. “My aquaponics farm will be operated by the solar panel fixed on the roof of my home,” Joseph Mathew told indiaclimatedialogue.net. An engineer turned agriculturalist, Mathew has been inspired by solar-powered aquaponics systems propagated at Aquaponics Ideas Online.
Farmers in south China, Thailand and Indonesia who farmed rice in one field and cultivated fish in the adjacent pond are inventors of aquaponics. Although the method shows promise, in the Indian context, most farmers are asking for subsidies and loans with lower interest before taking the plunge.
It is easy for big corporations to get cheap loans but farmers willing to innovate are passed by, says K. Mohanan, a farmer from Palakkad who is striving to get a cheap loan to get into aquaponics. “Why does the system neglect us?” he asks.