Doing more with less is the motto farmers this day in age seem to abide by as they aim to maximize production while also reducing input costs. One way to do this is by using precision spraying technology, which can include weed mapping using drones. In an Iowa State Integrated Crop Management blog, extension specialist Doug Houser explained the benefits of using this precision spraying technology.

Traditional spraying methods include broadcast applications of herbicide for both pre- and postemergence. As chemical costs continue to climb, farmers are looking for alternative, cheaper routes to help the farm’s bottom line. Using drone mapping techniques, researchers at Iowa State University were able to map fields for weeds prior to application to identify problem areas. From this, they were able to spray certain areas of the fields that needed spraying the most, reducing the amount of chemical used compared to traditional spraying methods. “Leveraging precision spray technology can provide chemical savings for both postemergence applications where the reduction in cost and chemical usage will depend on the initial weed pressure, but it is not uncommon to see reductions of 50% or higher,” Houser said.

Ground and aerial application options are available in the precision spraying space, most of which use multistep approaches to achieve results. Spray drones perform zone spraying and spray a minimum zone size of 0.1 acre, generally in conservation areas, while ground sprayers can spray much smaller areas, reducing the minimum spray area. “Some offerings use low-resolution drone or satellite imagery to generate weed pressure maps based on large weeds, which can be used to identify major issues, direct scouting, or hand-draw zones for late season rescue application of weed escape patches,” the extension specialist noted. Some technologies generate grids, allowing the user to mark cells that contain weeds and export a grid prescription.

If choosing to incorporate precision spraying practices on your farm, it is important to understand your weed prevention needs to identify which spraying route to take. By using precision spraying, operators can optimize tank mixes and identify the correct volume for the specific weed pressure the farmer may be experiencing. One can expect greater cost savings with lower weed pressure, and smaller savings with higher weed pressure, Houser said.