The rooftop of agriculturist Ibad Ali's house is like an agricultural research lab. There he has developed "root technology", which is changing ideas about rooftop gardening. The method grows many crops in little space with little soil, and after four years of research he says it can produce ten times as many vegetables as an ordinary rooftop garden using the same amount of soil.

He says the method could also produce large amounts of vegetables in the waterlogged Bhabadah area. Md. Mosharraf Hossain, deputy director of the Department of Agricultural Extension (DAE) in Jashore, said spreading the technology could transform rooftop farming.

Ibad Ali, of Hamidpur village in Jashore Sadar upazila, holds bachelor's and master's degrees in food engineering from Bangladesh Agricultural University. Although he works in the Local Government Division, agriculture, innovation and research are his passion. His two-storey house lies a few hundred yards off the Jashore–Narail highway; there is a children's school on the ground floor and the family lives on the first floor. In 2022 he began cultivating with root technology on the roof and now grows 22 kinds of vegetables and fruit, including bottle gourd, pumpkin, cabbage, yardlong beans, onion, garlic, amra, beans, lemon, dragon fruit and green chilli, meeting family needs and selling the surplus.

He defines it as using soil, water, air, light and fertiliser correctly according to the structure and layout of plant roots. Plants take food from shallow soil through root hairs, and yield rises with the number of root hairs, which increases when there is more space around the plant and measured food and water.

• Vegetables are sown or planted in beds, and fruit trees in a channel system, not in drums or tubs.
• Soil depth is 4 inches for vegetables (a 6 ft by 3 ft bed) and 10 inches for fruit; fruit containers must be at least 3 ft across.
• All nutrients are mixed into the soil according to a formula, and measured irrigation is given regularly.
• Each plant gets exactly as much soil as its roots need, no more and no less.

The method uses 12 kg of soil per square foot; an 18 sq ft bed needs 3.5 sacks, or 154 kg, the same as one ordinary drum, yet the same soil can grow ten times more crops. Beds leave plenty of walking space and make the roof look attractive, while drums and tubs cost more and yield less; planting fruit or vegetables with root technology doubles yields, he says.

"Conventional rooftop farming has low profit and high cost," Ibad Ali said. "My root technology produces more in less space at low cost, and commercial rooftop farming is possible. Floating beds in the waterlogged Bhabadah area could also produce large amounts of vegetables. With government and private support I want to spread this technology."

DAE's Mosharraf Hossain said Ibad Ali has written a book on root technology that will help anyone wanting to use it; rooftop gardens using his method would keep homes cooler and supply safe, nutritious vegetables, and the department will also take steps to extend the technology.

Source: Jagonews24. First published in Bengali on The Agro News.