Progress 09/01/23 to 08/31/24

Outputs
Target Audience:In 2024, our project continued to target the following primary audiences: 1) farmers in the southeastern U.S. managing Fescue-dominated pastures during the summer; 2) conventional forage farmers interested in transitioning to organic farming practices; 3) students and agricultural professionals focused on organic farming techniques; and 4) consumers and the general public who support organic meat and dairy products. This year, we expanded our outreach by conducting workshops, conference presentations, and field days tailored for farmers, students, extension agents, and agricultural professionals. These events provided practical demonstrations and discussions on establishing organic native warm-season grasses (NWSG). The students recruited for this project gained valuable hands-on experience in field experiment setup and maintenance, data collection, soil sampling, lab analysis of soil and plant samples, and preliminary data processing. Notably, the Ph.D. student supervised by lead PI Jagadamma at the University of Tennessee-Knoxville (UTK) presented posters on the short-term soil health impacts of various organic NWSG establishment methods at the Soil and Water Conservation Society (SWCS) annual conference and the University of Tennessee-Knoxville (UTK) Beef and Forage annual meeting. Additionally, the M.S. student, supervised by Co-PIs Philipp and Nieman at the University of Arkansas (UARK), presented an overview of our project at the Organics in the Ozarks Field Day held at the University of Missouri Southwest Research and Extension location in Mt. Vernon, MO, on April 12, 2024. This event attracted around 100 participants from Missouri and northern Arkansas interested in learning about organic crop and livestock production. Co-PI Cui also organized the Digital Agriculture Summer Camp and Digital Agriculture Academy events in the summer of 2024, introducing 28 high school students and 20 non-formal educators from the Middle Tennessee area to scientific experimentation concepts and the benefits of organic NWSG production. Through these efforts, we successfully reached and engaged a diverse audience interested in sustainable agriculture and organic farming practices. Changes/Problems: We encountered an armyworm outbreak at both the UARK and MTSU sites, which we managed to control effectively through pest scouting and application of Entrust insecticide (OMRI approved). Middle Tennessee experienced its most severe flooding event in the past 50 years, which inundated our research plots at the MTSU site. Fortunately, despite this setback, our seeds could still germinate successfully following the event. What opportunities for training and professional development has the project provided?PI Jagadamma is mentoring a Ph.D. student responsible for tasks under Objective 2. For research activities related to Objective 1, an M.S. student is co-advised by Co-PIs Philipp and Nieman at UARK, and a research associate has been recruited by Co-PI Cui at MTSU. Additionally, a part-time postdoctoral researcher under Co-PI Keyser will be undertaking tasks related to Objective 1 at UTK. Three undergraduate students are actively participating in lab and field work at the UTK site. All students and early-career professionals involved in the project are gaining critical knowledge on organic forage production as well as soil and plant sampling and analysis. These individuals will continue to have access to valuable networking opportunities and other professional development resources throughout the project's duration. How have the results been disseminated to communities of interest?This year, we were able to present our research to farmers, agricultural professionals and students at different conferences. We were also able to introduce this project and the status of our research to the attendees of the field day event at the Organics in the Ozarks at the University of Missouri Southwest Research and Extension location in Mt. Vernon, MO. What do you plan to do during the next reporting period to accomplish the goals?Our primary focus for Year 3 will be to closely monitor NWSG growth across all four establishment strategies. We will continue collecting and analyzing soil and plant samples from the NWSG plots. Additionally, we plan to initiate the economic analysis by the end of Year 3. Team members will also carry out outreach demonstrations throughout the next reporting period.

Impacts
What was accomplished under these goals? 1.Assess the forage yield, nutritive value, and weed suppression capacity of three NWSG species treatments relative to a common non-native warm-season perennial grass under four establishment methods Field experiments are ongoing on certified organic land at three locations: the University of Tennessee-Knoxville (UTK), Middle Tennessee State University (MTSU), and the University of Arkansas (UARK). At the Knoxville site, we were able to accomplish all activities expected this season. After the harvest of the first smother crop, pearl millet, we planted our second smother crop, cereal rye, in October 2023. NWSGs were planted on time; March 21 for dormancy planting (TRT 3), April 30 for smother crop harvesting treatment (TRT 1), May 24 for smother crop rolling-crimping treatment (TRT 2) and June 15 for till treatment (TRT 4). All tillage passes were done for the tillage treatment. Treatments 1 to 3 were clipped on June 28 and August 15 to control weed growth. The second clipping in August was done because continuous rain after the first clipping led to more weed proliferation. At the MTSU site, the second smother crop was planted in September 2023. NWSGs were planted as per schedule: March 18 for dormancy planting (TRT 3), May 1 for the smother crop harvest treatment (TRT 1), May 3 for the smother crop rolling-crimping treatment (TRT 2), and May 16 for the tillage treatment (TRT 4). All tillage activities were conducted as outlined in the experimental plan. Clipping of Treatments 1 through 3 was done on June 28 and August 8 to control weed growth and reduce competition. Similarly, at UARK, the second smother crop, cereal rye, was also planted in September 2023. NWSGs were subsequently planted as follows: March 5 for dormancy planting (TRT 3), April 24 for the smother crop harvest treatment (TRT 1), May 21 for the smother crop rolling-crimping treatment (TRT 2), and June 20 for the tillage treatment (TRT 4). Clipping for Treatments 1 through 3 occurred on June 25 and August 14. Cereal rye that was planted 2023 Fall was harvested in Spring 2024. We recorded cereal rye plant and tiller counts and weed rating data (mid to late April 2024) at all three sites. Before harvesting rye, we also took plant samples using three 0.25 m2quadrats per plot to assess the yield and forage value of cereal rye as a potential forage while allowing NWSGs to establish. Samples were clipped at 7.5 cm stubble heights, the samples were separated, weighed and dried at 55 ºC for 72 hours, weighed again to determine dry matter content. Six samples were selected at each site randomly, including three samples that are only for cereal rye and three samples that are mixed with dominant weeds in each plot, to be used for NIRS analysis. At the same time, we visually recorded data on weed pressure per plot. Native warm-season seedlings were counted at 42 days after planting in Knoxville because rain made it difficult to do that activity at 35 days after planting. Treatments 1 and 3 (Smother crop harvesting and Dormant season planting, respectively) were counted at the same time while treatments 2 and 4 were counted at the same time. Data analysis is currently ongoing. Weed growth in the Smother Crop Rolling-Crimping treatment was lower compared to the other treatments due to the residue layer on the soil surface. The Tillage-only treatment received occasional tillage passes as needed, with all tillage passes documented at each site. 2.Assess the effects of different establishment methods and forage systems on soil health Baseline samples were collected from 0-60 cm in each plot and divided into three depth increments (0-10 cm, 10-30 cm, and 30-60 cm). These samples were analyzed for bulk density, inorganic nitrogen, microbial biomass carbon, extracellular enzymes, pH, permanganate-oxidizable carbon, Mehlich I-extractable nutrients, soil texture, soil organic carbon, and total nitrogen. The Ph.D. student supervised by the lead PI, along with part-time undergraduate assistants, completed the laboratory analysis of baseline soil samples collected from three experimental sites. The Ph.D. student also performed statistical analyses on each soil health metric. Since the baseline soils have not yet undergone treatment, differences among parameters were only assessed by soil depth. At the Knoxville site, bulk density ranged from 0.96 to 1.76 Mg m?³. Inorganic nitrogen was highest in the top 0-10 cm layer (40.06 mg kg?¹), followed by 10-30 cm (20.69 mg kg?¹) and 30-60 cm (19.74 mg kg?¹). All soil health parameters followed a similar trend, with values generally higher at the surface (0-10 cm > 10-30 cm > 30-60 cm). Microbial biomass carbon content ranged from 82 to 359 mg kg?¹, and soil organic carbon stock varied from 12 Mg C ha?¹ at lower depths to 23 Mg C ha?¹ in the topsoil. Average pH was 6.33, with a clay loam texture. Enzymatic activities (alpha-glucosidase, beta-glucosidase, cellobiohydrolase, N-acetyl glucosaminidase, and leucine aminopeptidase) were highest in the 0-10 cm depth and lowest in the 30-60 cm depth, a trend also observed in Mehlich I-extractable nutrients, total nitrogen, and permanganate-oxidizable carbon. At MTSU site,bulk density values ranged from 0.93 to 1.73 Mg m?³. Inorganic nitrogen levels varied between 4.27 and 24.03 mg kg?¹. Microbial biomass carbon ranged from 63 to 427 mg kg?¹, and soil organic carbon stock ranged from 22 Mg C ha?¹ at greater depths to 25 Mg C ha?¹ in the topsoil. Average soil pH was 6.49, with a silty clay loam texture. Enzyme activities were highest in the 0-10 cm depth and lowest at 30-60 cm. Mehlich I-extractable nutrients, total N, and permanganate-oxidizable carbon levels followed the same depth-dependent trend. At the UARK site, bulk density ranged from 0.96 to 1.76 Mg m?³, increasing from topsoil to subsoil. Inorganic nitrogen levels peaked in the 0-10 cm layer (5.7 mg kg?¹) and decreased with depth to 2.56 mg kg?¹ at 30-60 cm. Microbial biomass carbon ranged from 114 to 509 mg kg?¹, and soil organic carbon stock varied from 28 Mg C ha?¹ in surface soils to 24 Mg C ha?¹ at deeper levels. The soil's average pH was 5.74, with a silt loam texture. Enzyme activities, Mehlich I-extractable nutrients, total nitrogen, and permanganate-oxidizable carbon showed a depth-dependent decline, with the highest activity in the 0-10 cm layer and the lowest at 30-60 cm. Soil samples at the end of Year 1 were collected from all three sites, from the 0-30 cm depth, divided into two increments (0-10 cm and 10-30 cm) to assess how NWSG establishment methods influenced soil health and nutrient status. The Ph.D. student is currently analyzing these samples in the lead PI's lab at UTK. 3.Conduct a comparative economic analysis for different establishment methods and forage systems to identify the most profitable approach for organic production systems The Ph.D. student has been systematically recording farm management activities at the UTK field site to support the economic analysis led by Co-PI Griffith. In addition, this student is documenting similar data from other project sites to ensure a comprehensive dataset. The economic analysis is set to begin in Year 3 of the project. 4. Integrate the knowledge generated into Extension and education programs that aim to improve producers' awarenessof organic forage production At MTSU, Co-PI Cui included a module where he used task-based learning (TBL) and project-based learning (PBL) approaches to teach the organic establishment of NWSGs in two courses he is offering: PLSO 3330 "Field Crop Production" and PLSO 4310 "Forage Crops". While teaching both courses, Cui talked about challenges associated with organic NWSG production, cropping system concepts and regulation issues. He also introduced the benefits of NWSG production to high school students and educators during their summer camp events.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Kallingal, B., and Jagadamma, S. 2024. Soil health impact of different methods of establishment of organic native warm season grasses. 79th Soil and Water Conservation Society International Annual Conference, July 21-24, Myrtle Beach, NC (Poster)
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Kallingal, B., Keyser, P., and Jagadamma, S. 2024. Sustainable forage solutions: organic native warm season grass establishment methods and soil health in the Southeast U.S. 2024 University of Tennessee Beef and Forage Center Annual Research Meeting, October 8, Knoxville, TN (Poster)
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Kallingal, B., Keyser, P., and Jagadamma, S. 2024. Organic native warm season grasses: soil health impacts of conventional and sustainable land preparation methods. 2024 ASA, SSSA, and CSSA Annual International Meeting, November 10-13, San Antonio, TX (Poster)

Progress 09/01/22 to 08/31/23

Outputs
Target Audience:The primary target audiences for this study are 1) farmers in the southeastern U.S. who manage Fescue-dominated pasture in the summer, 2) farmers following conventional forage systems who would like to transition to organic farming, 3) students and agricultural experts who are interested in organic farming techniques, and 4) consumers and the general public who prefer organic meat and dairy products. During the first year of this project, we focused mainly on student training. We recruited a part-time postdoctoral scientist, one MS student, one Ph.D. student, one research associate, and three undergraduate students. These students are gaining experience in field experiment establishment and maintenance, field data collection, soil sampling, laboratory analysis of soil and plant samples, and preliminary laboratory data processing/analysis. Changes/Problems: Organic pearl millet seeds were not available to purchase. Hence, we used untreated non-GMO seeds of pearl millet in all three locations after receiving approval from organic certifiers at all three locations. Due to the limitation of available certified area at the MTSU field experiment location, the plot size was reduced to accommodate all treatments and replications. What opportunities for training and professional development has the project provided?PI Jagadamma recruited a Ph.D. student, who conducts the tasks outlined in Objective 2. For undertaking research proposed under Objective 1, an MS. student is recruited by Co-PI Philipp at UARK and a research associate is recruited by Co-PI Cui at MTSU. A part-time postdoc under Co-PI Keyser will be undertaking the tasks under Objective 1 at UTK. Three undergraduate students have been participating in lab and field work at the UTK location. All these students and early career professionals have been receiving critical knowledge about the production of organic forages as well as soil and plant sampling and analysis. These individuals will also receive many opportunities for networking and other professional development opportunities in the coming years of the project. How have the results been disseminated to communities of interest?This year, our focus was to recruit the students and other personnel and establish the field experiment. Once we collect data, we will begin the outreach activities as described in the proposal. We received one opportunity to introduce this project to the attendees of the field day event at the UARK field experiment location. What do you plan to do during the next reporting period to accomplish the goals?Our main focus in Year 2 will be to complete implementing the weed control strategies (by growing cereal rye as a smother crop and completing the tillage activities in the tillage-only treatment) and plant native warm season grasses in all treatments. We will continue collecting soil samples as well as plant samples (from cereal rye smother crop and native warm season grasses) and analyze them. The team members will start conducting outreach demonstrations towards the end of the next reporting year.

Impacts
What was accomplished under these goals? 1. Assess the forage yield, nutritive value, and weed suppression capacity of three NWSG species treatments relative to a common non-native warm-season perennial grass under four establishment method The field experiments were started in the certified organic land at three locations: University of Tennessee-Knoxville (UTK), Middle Tennessee State University (MTSU), and University of Arkansas (UARK). The fields were tilled in March 2023 and planted with pearl millet as smother crop in three out of four treatments. The fourth treatment is a tillage-only treatment to represent the conventional seedbed and weed control technique, where we performed three rounds of tillage. In the pearl millet plots, we recorded pearl millet tiller count and weed rating data in July 2023 to characterize the pearl millet stand. Before harvesting pearl millet, we collected plant samples using a quadrat to assess the yield and forage value. The pearl millet was harvested from all three sites by August 2023. Overall, we noticed that the weed growth in smother crop-planted plots was less compared to the tillage-only treatment. After the smother crop harvest, all plots received tillage to further reduce the weed seed bank. The second smother crop, i.e., cereal rye, is scheduled to be planted in September 2023. The tillage-only treatment has been receiving occasional tillage passes as and when needed (the number and type of tillage passes have been documented in all sites). 2. Assess the effects of different establishment methods and forage systems on soil health To assess the baseline soil health and nutrient status, we took soil samples from 0 to 60 cm depth from all plots and divided them into three depth increments (0-10 cm, 10-30 cm, and 30-60 cm). Samples from all three sites were sent to the lead PI's lab in UTK , where the Ph.D. student has been analyzing the samples for a suite of soil health parameters. Upon arrival, core sections were weighed and sub-samples (~10 g) were oven-dried at 105ºC to determine the gravimetric soil moisture content. Using the wet weight and gravimetric moisture contents, bulk density was determined. The rest of the samples were portioned into two. One part (~150 g) was stored under 4ºC for inorganic N, microbial biomass C, and extracellular enzymes measurements, and the rest was air-dried, sieved through a 2-mm sieve, and retained for the analysis of a suite of soil physical and chemical properties. All the time-sensitive analyses such as gravimetric moisture content, microbial biomass, inorganic N, and extracellular enzymes have been completed. The Ph.D. with the support of two part-time undergraduate students is currently working on measuring other properties using the air-dry soils. 3. Conduct a comparative economic analysis for different establishment methods and forage systems to identify the most profitable approach for organic production systems The Ph.D. student has been recording the farm management activities at the UTK field site to enable economic analysis by Co-PI Griffith. This student is also documenting similar information received from other sites. The economic analysis will start in Year 3 of the project. 4. Integrate the knowledge generated into Extension and education programs that aim to improve producers' awareness of organic forage production Outreach activities are proposed to start from Year 2 only. However, the project PIs have been taking advantage of any opportunities to make producers and other stakeholders aware of the initiation of this project. Co-PI Keyser received a Partnership for Climate-Smart Commodities grant to work on the production and marketing challenges faced by livestock producers in the Fescue Belt region. The producer and other stakeholder meetings as part of this large project will also be a platform to discuss the outcomes of our project. The PIs have also been providing one-on-one educational training to the participating postdoc and students, and staff at the research centers where field experiment is being implemented. At MTSU, Co-PI Cui included a module on the organic establishment of native warm season grasses in two courses he is offering: ABAS 3330 "Field Crop Production" and ABAS 4310 "Forage Crop Production".

Publications