Progress 09/01/24 to 08/31/25

Outputs
Target Audience:During this reporting period, our efforts reached multiple audiences relevant to organic grain production in the southeastern United States. The primary audience included organic grain farmers and conventional producers considering transition, with an emphasis on those interested in full-season soybean, wheat-soybean double crop, and forage-based systems. Agricultural professionals such as extension agents, crop consultants, and service providers were also targeted. We also directly engaged postdoctoral researchers, graduate students, and undergraduate students on project activities, building awareness and skills in organic grain systems. In addition to these groups, we also interacted with stakeholders who are specialized in fruit, livestock, and integrated organic farms about testing the potential of growing organic grains in their production systems. Seed suppliers and industry representatives were also reached through discussions on variety selection and market needs. In addition, faculty collaborators and members of the NC1178 multi-state project team were engaged through farm tours and knowledge exchange. Finally, stakeholders from local baking and brewing industries were identified as an important audience given their interest in sourcing grain from organic and transitional systems. Changes/Problems:The Decatur silt loam soils at the Tennessee site are highly prone to compaction, making the use of a roller crimper less effective for cover crop termination in the reduced till subplots. To address this, we replaced the roller crimper with a flail mower. This adjustment still provided comparable mulch cover in the reduced tillage subplots while minimizing soil compaction risk. At the Florida site, as described in other sections, we have experienced very high weed pressure that has prevented us from harvesting barley for forage or grain. All plots were terminated by disking, which had two major consequences: 1) we could not get realistic harvest data from the barley crops (i.e., we only got a manual harvest data, serving as a proxy for potential harvest at best) and 2) we could not separate the two subplots as originally intended for the soybean season (i.e., there was no residue retention in the soil health plots), leading to cultivation in the plots that were not supposed to be cultivated. Weed pressure was still high during the soybean season, but we hope that the delay between soybean harvest and cover crop planting will allow us to reduce weed pressure sufficiently to separate the two subplots for the corn season. The implementation of the reduced tillage subplot will continue to depend on weed pressure. Notably, these management adjustments will be carefully documented to ensure that results are interpreted in the proper context and to provide realistic recommendations for organic producers who encounter similar challenges in the southeastern region. What opportunities for training and professional development has the project provided?Lead PI Sindhu Jagadamma recruited a postdoctoral researcher to lead the agronomy and soil objectives at the Tennessee site. Although he worked on organic grain systems for his Ph.D. research, this project has been giving him more experience in managing organic grain-based field experiments and conducting advanced laboratory analyses. Beyond technical training, he has been gaining leadership and project management experience by working closely with the field staff at the research center to plan and execute important field operations such as tillage, planting, and harvesting. He has also had opportunities to engage with farmers and stakeholders during farm tours, which has enhanced his communication and extension skills. Collectively, these activities have been preparing him as a leader in organic and sustainable agriculture research and outreach areas. At the Florida site, one PhD student and one research technician are being trained in field activities/operations and management of transitioning systems in the challenging biophysical context of Florida (coarse-textured soils, subtropical climate). The PhD student is also trained in several crop and soil lab techniques, while also being trained by project PIs Gabriel Maltais-Landry and Zane Grabau to work with the PhD student for the soil lab techniques. During this reporting period, the project team has taken multiple steps to communicate activities and progress to a broad range of stakeholders. Specifically, the Tennessee project team have worked with Mr. Duane Gibson of Gibson Blueberry Farm and Mr. Asher Wrights of the Caney Fork Farms from the outset, providing input on seed selection, management practices, and organic herbicide use. Both farms are now coordinating with us to explore the feasibility of double-cropping in the region. Mr. Gibson visited the Tennessee field site twice and discussed the cover crop management and seed varieties. Engagement has also extended to broader research community. Jagadamma and Neelipally hosted a farm tour for members of the NC1178 multi-state project team, sharing early experiences and discussing both opportunities and challenges of organic double-cropping. Dr. Neelipally has further engaged with regional producers, including Bill Keener of Sequatchie Cove Farm, a 300-acre integrated organic operation. These discussions highlighted the potential role of organic grains as cattle feed and their growing demand in the baking industry. He also participated in the Southeast TN Young Farmers event at Sequatchie Cove Farm, where he exchanged insights on region-specific seed challenges with local producers and relayed these concerns to seed company representatives. Additional conversations with Chelsea Askew, a producer of heirloom corn and soybean seed varieties valued by local bakers, underscored the importance of regionally adapted seed choices for farmer adoption and market success. Beyond farmer and researcher engagement, the project has used social gatherings and social media platforms to share progress and visuals from the field, extending awareness to the broader public. The team is also preparing to host participants at the ETREC Field Day in September 2025, where on-site tours and consultations will further disseminate project activities. Looking ahead, once the first-year datasets are generated, multiple outreach events are planned to reach a wider spectrum of stakeholders. In addition, they will engage extension agents, crop consultants, students, seed suppliers, and end-users in the baking and brewing industries, thereby broadening the impact of the research across the southeastern region. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we will harvest soybeans across all systems, anticipated between late September and mid-October 2025, followed by the establishment of winter cover crops in late October before planting our second-year cash crop, that is corn. While subplot treatments are already established at the TN site, they will be fully implemented at the FL site once weed control is improved, allowing the intended contrasts between intensive and reduced-tillage management to be tested across both locations. Soil sampling will continue before each cropping phase and will include assessments of fertility, nutrient cycling, and soil health indicators. Plant samples will be collected at cover crop termination, during in-season growth, and at harvest, then dried, ground, and submitted for nutrient analysis. By August 2026, we anticipate completing analyses for all soil and plant samples collected to date, with the exception of samples taken at corn harvest later that year. Completion of soybean harvest and associated analyses will allow us to compare full-season and double-crop systems for yield, nutrient uptake, forage nutritive value, and weed pressure, while also assessing the effect of residue and weed management methods within each system. The ongoing soil sampling and laboratory analyses will contribute directly to quantifying the impacts of cropping systems and subplot management on soil fertility, nutrient cycling, soil organic carbon dynamics, enzyme activity, and nematode communities. With crop and soil data in place, we will also begin recording production costs, input costs, and yield outcomes to develop enterprise budgets for each system. These budgets will support cost-benefit analyses to compare profitability among full-season and double-crop systems, as well as between grain- and forage-based systems. Preliminary insights into marketing challenges will also be assessed. Finally, we will initiate extension and outreach activities based on the first year of results. Project findings will be shared at field days at both sites, producer meetings, and professional conferences. These activities will engage a broad set of stakeholders, including farmers, extension agents, consultants, students, seed suppliers, and end-users in the baking and brewing industries. We anticipate that the early results will generate strong producer interest, particularly regarding the success of double-crop soybean and the influence of management practices on soil health and nutrient availability in organic systems.

Impacts
What was accomplished under these goals? The project was initiated at two certified organic sites: the East Tennessee AgResearch and Education Center-Organic Grain Unit (ETREC-OCU) in Knoxville, TN, and the Plant Science Research and Education Unit in Citra, FL. At both locations, five organic rotation systems were established in fall 2024 with four replications, and each main plot was divided into two subplots with contrasting residue and tillage management, as described in the proposal. Subplot A represents intensive management with tillage and residue removal where applicable, while subplot B represents reduced tillage with surface residue retained as mulch. At the Tennessee site, after disking the plots and applying poultry manure (89 lb N ac-1 for wheat grain and 67 lb N ac-1 for barley grain), winter crops were planted on October 25, 2024, with rye cover, wheat cover, wheat grain, barley grain, and barley forage representing the five rotation treatments. Residue management rules followed system-specific objectives: in rye and wheat cover treatments residue was retained in both subplots but either incorporated by tillage (subplot A) or left on the surface (subplot B); in barley forage all aboveground biomass was harvested and removed from both subplots; in wheat and barley grain treatments, residue was removed from subplot A but retained in subplot B. Cover crops were terminated with a flail mower, while barley forage was harvested using a Carter harvester. Dry biomass of all winter crops was recorded. In early May 2025, wheat and barley were harvested for grain, and both biomass and grain yield were measured. Immediately after harvest, double-crop soybean was planted in grain plots, while full-season soybean had already been planted following cover crop termination. Weed management in subplot A relied on inter-row cultivation, while subplot B used OMRI-certified HOMEPLATE herbicide; all operations were performed manually given the small plot sizes. Biomass samples were analyzed for total carbon and nitrogen, with further nutrient analyses to follow. Baseline soil samples were collected in October 2024 to a depth of 60 cm (separated into 0-10, 10-30, and 30-60 cm increments), and all baseline analyses, except wet-aggregate stability, have been completed. Additional samples were collected after cover crop termination and after grain harvest in 2025 from 0-10 and 10-30 cm, and analyses of those samples are ongoing. Soybeans will be harvested at the R4-R6 growth stage, with annual soil sampling scheduled to continue at 0-10 and 10-30 cm to track system changes over time. At the Florida site, after repeated disking, barley and rye were planted on November 19, 2024, in a randomized block design with four barley-based systems and one rye system. Fertility management used OMRI-certified poultry manure with rates adjusted by system: 20 lb N ac-1 for cover crops, 80 lb N ac-1 for barley grain, and 100 lb N ac-1 for barley forage, with K inputs balanced using OMRI-certified K2SO4. Weed pressure during the winter was high, and barley and rye plots were terminated by disking to prevent contamination of harvested products and to reduce weed seedbank buildup. Biomass samples were collected prior to termination to quantify both crop and weed biomass. Following termination, a false seedbed technique was used to flush weeds, and soybean was planted. Four systems were planted on April 9, 2025, while the barley grain system was planted later, on April 30, following grain harvest. All soybean plots received 20 lb N ac-1 of poultry manure and K2SO4, with additional K sidedressed during the growing season. Weed management was carried out with sweep cultivations, and in subplot B reduced cultivations were supplemented with one OMRI-certified herbicide application. By the end of the reporting period, soybean plants had reached the R4-R6 growth stage. Plant growth and nutrient concentration were monitored during the season, and samples collected at key stages were dried and ground for nutrient analyses to be completed after soybean harvest. Soil samples were collected prior to winter crop planting and again before soybean establishment and are being analyzed for fertility, N cycling, nematode communities, and other soil health indicators. Nematode extractions have been completed, while analyses for other soil health parameters are ongoing. Despite challenges such as weed pressure in Florida, the project is on track. Agronomic and soil health objectives are being met, with data already collected on crop performance, residue management, soil fertility, carbon dynamics, and biological indicators. In line with the economic objective, we are currently recording all management operations, input costs, and yield outcomes. At the conclusion of the first year, these data will be compiled into enterprise budgets that will serve as the basis for a comparative economic analysis of full-season versus double-crop systems. Extension and education objectives are also underway: student training has been integrated into field and lab work, and plans are being made for outreach events once production and soil health trends become clearer. The foundation established in this first-year positions us to evaluate agronomic performance, soil health improvements, economic viability, and outreach impacts of organic double-cropping systems in the southeastern United States.

Publications