Department of Crop and Soil Sciences
Platform Director for Extension Outreach and Engagement
Assistant Professor and Soybean Extension Specialist
Plant Sciences Building
Cell – 919-616-6775
Dr. Rachel Vann provides leadership for the NC State Soybean Extension Program focused on providing soybean stakeholders across North Carolina with agronomic information that will aid in maximizing soybean yields.
Rachel directs her extension efforts towards general soybean agronomic management. The focus of her research program includes appropriate soybean maturity group selection, ideal planting windows, rotational effects on soybean production, maximizing cover crop benefits to increase soybean yields, product evaluation, and grain pea production. She teaches the agricultural institute and undergraduate course on soybean production in the spring.
Rachel grew up in Geneseo, Illinois and completed her Bachelor’s Degree at the University of Illinois Urbana-Champaign studying Natural Resources and Environmental Sciences with a minor in Crop and Soil Science (B.S. 2012). She completed her graduate degrees at NC State University. Her Master’s degree focused on cover crop management in organic corn production and organic canola production (M.S. 2015). Between her Master’s and Ph.D. she completed a U.S. Borlaug Fellowship in Costa Rica. Her Ph.D. focused on cover crop breeding and management and weed control in cotton (Ph.D. 2017). Prior to beginning her position at NC State as the Soybean Extension Specialist, Rachel was an Postdoc in the Organic Grains Program.
- Critical soil test values of phosphorus and potassium for soybean and corn in three long-term trials in North Carolina , SOIL SCIENCE SOCIETY OF AMERICA JOURNAL (2023)
- Soybean yield response to nitrogen and sulfur fertilization in the United States: contribution of soil N and N fixation processes , EUROPEAN JOURNAL OF AGRONOMY (2023)
- Effects of Nitrogen Source and Rate on Soybean Yield and Quality , COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS (2022)
- Helicoverpa zea (Lepidoptera: Noctuidae) Thresholds and Yield Compensation Between Soybeans with Determinate and Indeterminate Growth Habits , JOURNAL OF ECONOMIC ENTOMOLOGY (2022)
- Soybean yield response to sulfur and nitrogen additions across diverse US environments , AGRONOMY JOURNAL (2022)
- Winter crop effect on soybean production in the Southeast United States , AGRONOMY JOURNAL (2022)
- A survey of twin-row cropping systems in North Carolina , CROP FORAGE & TURFGRASS MANAGEMENT (2021)
- Agronomic management of early maturing soybeans in North Carolina , CROP FORAGE & TURFGRASS MANAGEMENT (2021)
- Differences among eighteen winter pea genotypes for forage and cover crop use in the southeastern United States , CROP SCIENCE (2021)
- Foliar fertilizers rarely increase yield in United States soybean , AGRONOMY JOURNAL (2021)
This project aims to begin addressing the North Carolina Soybean Producers Associationâ€™s priority to help growers evaluate AgTech on their operations by first incorporating unmanned aerial vehicles (UAVs) into the breeding program to estimate maturity. Not only will UAVs increase the speed and accuracy of data collection and accelerate variety release to meet the changing needs of growers, the best practices for UAV-based maturity estimates determined from this study can form the basis for growers looking to replace more traditional scouting on their operations for harvest aid (desiccant) application. Harvest aids are often used to remove any remaining green tissue to increase harvest efficiency and maintain seed quality. As the demand for early maturing varieties increases in North Carolina, one of the biggest challenges facing growers is timely harvest needed to prevent a decline in seed quality. However, application timing, based on maturity, is key to prevent crop damage and yield loss, and UAV-based maturity scouting could help address this issue. In this proposal we will determine if using a UAV can accurately estimate maturity by beginning on a research plot level to determine how well UAV-based maturity estimates compare to ground ratings. Furthermore, the most cost-effective camera and processing pipeline will be determined so that future grower equipment and software investment will be well-informed. Using the best practices developed, the project will scale to mid-sized research fields for additional evaluation and validation. The funding will be used to purchase UAV imagery processing software as well as to fund a graduate student that will lead the project. Overall, this research will determine whether UAVs can accurately estimate maturity and the best practices for doing so, both of which lay the groundwork for growers to use them on their own operations to assist in maturity scouting to aid their desiccant application decisions that protect seed quality and profits.
Potassium (K) is an essential macronutrient for plants, and its availability strongly affects biomass production, tolerance to stress, and yield. Since only a small fraction of the soil K content is plant available, plants must develop efficient strategies for its uptake from the soil. The most important strategy used by plants to acquire nutrients is the arbuscular mycorrhizal (AM) symbiosis, a mutualistic association between the majority of land plants and ubiquitous soil fungi. We have recently demonstrated that AM fungi can also have a positive impact on legume K nutrition, but the physiological and molecular mechanisms underpinning this symbiotic exchange are only poorly understood. A better understanding of the strategies used by legumes to acquire K will be crucial to improving future crop productivity and environmental sustainability of crop production. The increasing demand for food and the development of alternative strategies for enhancing crop yields while reducing the use of chemical fertilizers represents a critical research priority. The overall of this project is to (1) confirm that AM fungi can transport K from the soil to the host legumes Medicago truncatula and soybean (2) understand how environmental factors (especially water limitation), nutrient availability, and carbon transport from the host to the AM fungus affects the symbiotic transport of K, and (3) identify and characterize the molecular mechanisms used by non-mycorrhizal and mycorrhizal legume plants in response to K deficiency.
There is tremendous interest from growers and the agricultural industry on the soybean production issues that arise across the state annually. To date, this information has only been available through word-of-mouth, however having real-time access to this knowledge could be transformative in informing scouting and subsequent management decisions. This foundational project will support utilizing technology and strong relationships across the North Carolina soybean sector to develop a dynamic webpage that captures soybean production issues and summarizes them in a publicly available, visually appealing, and educational format for the benefit of the North Carolina soybean sector. A collaborative group of Extension Agents, Consultants, Private Industry, the NC State Plant Disease and Insect Clinic, and NC State Extension Specialists will collaboratively develop a public facing webpage (available through NC State and the NC Soybean Producers Association) that will house arising issues from the field and provide concise information about the issues, associated photos, and recommendations to resolve the issue when appropriate. The collaborating individuals will submit information associated with field problems using an app and the program manager will summarize this information and populate it into the public facing webpage. We envision 2023 as a beta-testing year and the webpage will be improved and expanded upon in subsequent years. We intend to invite broader collaborators to contribute to the webpage in subsequent years but will focus on a subgroup of collaborators during the beta-testing phase to ensure we can handle the initial process with excellence. The webpage developed through this project amplifies currently available soybean expertise across the state into educational benefit for the North Carolina soybean sector and beyond.
The NC State Soybean Extension program seeks to provide data-driven best management practice recommendations to soybean stakeholders in the state. To deliver these best management practices, a two-fold approach will be deployed that focuses on 1. collaborative research conducted across the United States; the backbone of the USB-supported Science for Success project and 2. North Carolina centric research that address high-priority areas identified in the NC Soybean Producers Association 2023 RFP. First, to collaboratively deliver soybean best management practices, the Science for Success team, comprised of University-based Soybean Extension Specialists across the US, will conduct common-themed research protocols to amplify our resources and deliver robust soybean best management recommendations to growers across the nation. The USB-supported outreach group leverages QSSB funding at the local level to generate best management practice recommendations of national relevance. This allows researchers to quickly capture a range of yield and environmental variability (ie 50 sites of data/year nationally verses 4 sites data/year locally) when determining production practice impact on soybean profitability. The continued success of the Science for Success project, led by NC State University, is contingent on the support of QSSB-funding for localized research efforts. This proposal seeks to request continued support from the NC Soybean Producers Association for collaborative research efforts with focuses for 2023 on biological seed treatments and harvest timing and desiccant interactions with yield, seed quality, seed composition, and profitability. These collaborative research trials will be deployed at 3-4 sites across North Carolina and 30-50 sites across the US annually. Second, the proposed research will investigate foliar products, including foliar fungicides, foliar fertilizers, and desiccants, that play a role in maximizing profit in North Carolina soybeans, particularly in high-yield situations where soybeans are planted before mid-May with a MGâ‰¤5 variety. These trials will be employed in 3-4 locations across North Carolina annually and production practices within each location will be determined using data generated by the NC State Soybean Extension program from 2019-2022 on optimal planting dates and maturity groups to maximize yield in North Carolina.
The cost of soybean production is increasing. Nutrient inputs are at historically high costs at a time where there is increased variability in growing season conditions. Crops can experience multiple kinds of stresses and better information is needed on strategies that allow the crop to perform as well as possible while using a minimum of inputs. In North Carolina three of the most substantial production costs are seed, nutrient inputs, and water management infrastructure. This project further develops relationships between water stresses and nutrient uptake so that the response to stress conditions will protect the varietyâ€™s yield potential, optimize nutrients, and suggest water management approaches â€“ addressing all the major cost centers. The larger outcome of this research and extension effort is in-season response to water challenges such that nutrient input may be reduced, applications timed to environmental stress and profitability improved. The ability to utilize UAV data to assess plant water and nutrient stress in-season as it occurs and ultimately use the data to prescribe an appropriate course of action is necessary to protect soybean crop profits. This process will provide a framework to quickly assess areas in the field and allow for corrective measures to protect the crop from climatic conditions that ultimately would cause severe yield reductions.