There is one thing that distinguishes 60-year-old Vo Van Van’s rice fields from a mosaic of thousands of other emerald fields across Long An province in southern Vietnam’s Mekong Delta: It isn’t entirely flooded. That and the giant drone, its wingspan similar to that of an eagle, chuffing high above as it rains organic fertilizer onto the knee-high rice seedlings billowing below.
Rice must be grown separately from other crops and seedlings have to be individually planted in flooded fields; backbreaking, dirty work requiring a lot of labor and water that generates a lot of methane, a potent planet-warming gas that can trap more than 80-times more heat in the atmosphere in the short term than carbon dioxide. It's a problem unique to growing rice, as inundated fields stop oxygen from entering the soil, creating the conditions for methane-producing bacteria.
Van has been working with one of Vietnam’s largest rice exporters, the Loc Troi Group, for the past two years and is using a different method of irrigation known as alternate wetting and drying, or AWD. This requires less water than traditional farming since his paddy fields aren’t continuously submerged. They also produce less methane. Using the drone to fertilize the crops saves on labor costs.
The hope is that more countries will follow, though there is no 'one-size-fits-all,' said Lewis H. Ziska, a professor of environmental health sciences at Columbia University. 'The one commonality is that water is needed,' he said, adding that different methods of planting and irrigation can help manage water better.