By Abby Massey
Weeds are the bane of any farmer’s existence, stealing nutrients, sunlight, and water that should be readily available to crops. According to Land Care of New Zealand, weeds are responsible for $95 billion a year globally in lost food production. To fight weeds, many farmers use herbicides that are not environmentally sustainable, contaminating streams and rivers and harming nearby ecosystems.
Farmers looking for alternatives to herbicides can use "steam" weed control alongside other weed control methods like mulching, crop rotation, and hand removal. (Photo credit: Bernard Pollack)
To combat weeds without herbicides, the Australian company Weedtechnics produces equipment for “steam” weed control. Using technology that heats water over 100 degrees Celsius, direct steam is applied to sprouted weeds, causing the cell structure to collapse so that the plants wilt and brown or die within two days. The weeds are left on the ground and eventually their nutrients are recycled back into the soil.
Weedtechnics offers different units for use in urban, horticultural, and farm settings. A “Versitec” steam wand can be used as an alternative to hand weeding. And instead of distributing herbicides widely on a field of crops, farmers can use the “Rowtech” dome head for vineyards and orchards, or the “Agritech” head for row crops. The two heads are attached to a vehicle and designed so that they fit around rows of plants, targeting weeds. The company claims that steam technology can be used in any weather, whereas herbicide application is affected by rain and wind.
The system runs on gas and on biodiesel fuel. Although the start-up cost is higher than for herbicides, in the long run, having to refill the system only with water and fuel energy keeps costs low.
Thermal weed control is still uncommon, but groups like Weedtechnics and U.S.-based Sunburst are ushering in a new phase in weed control technology. Commercialization of steam weed control offers yet another step toward sustainable farming. Farmers looking for alternatives to herbicides can use this alongside other weed control methods like mulching, crop rotation, and hand removal.
Abby Massey is a research intern with the Nourishing the Planet project.