Farmers are continuing to battle with herbicide-resistant weeds impeding their ability to grow crops. While cover crops help curb weed growth, more tools are needed to support farmer success.  USDA’s Natural Resources Conservation Service (NRCS) Conservation Innovation Grant (CIG) partners, North Carolina State University (NCSU), Texas A&M University, and Iowa State University are developing technology to help. Using 3D computer imagery, they are mapping cover crops and weeds with precision, helping farmers make informed decisions on how to control the weeds on their operations. This technology can lead to improved herbicide resistance management, reduced herbicide use, better soil health, and improved water quality downstream.

The project began in early 2021 with the project’s principal investigator, Dr. Ramon Leon, William Neal Reynolds Distinguished Professor and University Faculty Scholar, and partners such as then NCSU graduate student Dr. April Dobbs, examining multiple fields growing cover crops in North Carolina, Iowa, and Texas. They used a hand-held GoPro camera, which takes aerial videos of the cover crops that are then analyzed using a technique called Structure-from-Motion that recreates the cover crop canopy in a 3D format. The use of 3D images provides a more realistic and accurate quantification of density, growth, and biomass of the cover crop than regular 2D images. This is particularly useful since cover crop growth can be patchy in fields, making biomass estimation difficult.

Once this 3D rendering has been generated, the image gives farmers a map showing cover-crop biomass throughout their fields. GoPro cameras are also used to generate a heat map of the field, showing areas of high and low cover crop biomass. Since cover crop production helps limit weed suppression, this method can help predict expected weed suppression levels in different areas of the field. Areas with the lowest biomass production may be most likely to have late season weed escapes.

This project focused on cereal rye, a cover crop widely used throughout the country due to its suitability in broad climates and its high biomass production potential. Also, cereal rye biomass reaches levels high enough to effectively suppress weed emergence and establishment. The next steps for the project are for current researchers, such as NCSU graduate student Avi Goldsmith, to test how accurately this method can predict late-season weed escapes in the field and optimize how 3D technology can be used to estimate biomass, including testing the method in mixtures of grasses and broadleaf species.

According to Dr. Leon, NRCS support has been key. He believes the vision and commitment of NRCS to incorporate modern technologies making it easier for farmers to adopt soil conservation practices will certainly pay off.

“The development of equipment and systems that farmers can use takes several years,” said Dr, Leon. “However, we must start somewhere, and as we make progress, we learn what needs to be improved. Having government agencies such as NRCS that invest in the future is what will help us to have more sustainable food production systems."