Greening a concrete jungle

Greenhouses are supposed to be hotter than the ambient temperature because the glass or plastic traps heat inside so plants can grow in winter. But one greenhouse here on the southern fringes of Kathmandu is an exception: it is cooler than outside.

It feels like an enormous refrigerator, and there is no visible thermostat. The agro-tech company Muttho Nepal has deployed a combined concept of vertical layered farming and hydroponics, allowing for plants to grow in a relatively small space with nutrient-enriched water.

Muttha Agro is the brainchild of Kushal Gurung of Wind Power Nepal and Gandaki Urja, who has also been promoting alternative energy sources in Nepal with Nepal’s biggest industrial-scale biogas plant in Kaski and a series of wind farms.

“This is an alternative to traditional agriculture most suited to cities like Kathmandu with its limited land already crowded with concrete buildings and scarce water,” explains Gurung, showing visitors around his complex. “The once-fertile soil in Kathmandu is also becoming too acidic for crops because of the overuse of fertilisers and pesticides.

Muttha stepped into production in March 2023, and its applied demo system has also been installed in the International Centre for Integrated Mountain Development (ICIMOD)’s Living Mountain Lab in Godavari for other farmers to adapt to or learn from.

After rooftop farming and the Mikawaki method of forestation where diverse indigenous plants are densely planted in small city plots, hydroponics can maximise productivity in a limited area while saving water by circulating it again and again.

Muttha Nepal goes a step further by integrating the global practice with local knowledge, adds Gurung. “In Nepal, most hydroponics are investing millions and bringing experts from abroad to install their systems. But we installed the whole setup by ourselves, understanding our own needs,” he says.

Also unlike most hydroponics that have artificial heating or cooling, Muttha uses the natural temperature balance, bringing down energy cost and making the venture most cost-effective.

Read also: Back to the future of farming in Nepal

“Artificial temperature control is costly whereas sunlight is free," says Erik van Os, a Dutch expert with 40 years of experience in hydroponics.

Van Os is helping Muttha Nepal grow sustainably as part of Programma Uitzending Managers (PUM), which is committed to the sustainable development of small and medium-sized enterprises in developing countries and emerging markets.

In a natural temperature setup, the topmost layer gets most of the sunlight, which means plants that need more sun are placed above while others go in their shade.

Farming is seeing mechanical and technical advances globally, but Muttha is making the most of what it has with inputs from advisers. Gurung and the team do not consider the lack of high-tech appliances as setbacks.

Using a mid-tech greenhouse, surrounded by a white net, the vertical hydroponics structure provides enough space for ventilation. The net of the surrounding walls can be covered with plastic during heavy rainfall. The topmost layer below the plastic roof is a shade net that decreases the temperature by 2-3°C.

Read also: Hanging gardens of Kathmandu, Santa Gaha Magar

Inside the greenhouse, there are five perfectly aligned separate columns with four systems each of six levels of pipes, each having six pipes with 28,000 holes in which leafy greens are grown. Each row has a 500 l tank half-embedded below ground level.

The nutrient-filled water is circulated throughout the pipes through these tanks with the help of a water pump. The plants are high-value produce like lettuce, basil, kale, arugula and celery, and poke out of the vertically arranged holes in the pipes.

Read also: Waste to value with biogas in Nepal, Sushmita Dulal

“We have stuck with salads for two reasons. One, it has been the tested crop of hydroponics worldwide and is a sure success everywhere,” explains Gurung. “Second, it is a perishable high-value crop that cannot be imported.”

Muttha is also experimenting with growing strawberries, coriander, and tomatoes but salads are their priority. With an investment of Rs6 in each sapling, it can earn up to Rs30 when it grows.

Muttha also runs training workshops to share its knowledge to make farmers across Nepal climate-smart to keep up with rising temperature and droughts. Just this monsoon, parts of Nepal’s hills and much of Tarai were not able to plant paddy on time due to reduced rainfall. For now, deploying this combined alternative farming in urban centres is a start to greening concrete jungles, while increasing productivity of farms.

Von Os sums it up: “Integrating hydroponics is the way forward to intensify the produce in places like Kathmandu with limited space but high demand.”