Progress report for LS25-401
Project Information
Perennial grains contribute to sustainable agriculture through soil quality improvement, carbon sequestration, and as a unique food and forage product. An example of a successful perennial grain is intermediate wheatgrass (IWG; Thinopyrum intermedium), which has been bred by The Land Institute and marketed as Kernza®. While IWG popularity and acreage has grown in the Great Plains and upper Midwest, IWG remains largely untested in the Southeast, and thus requires agronomic research, plant breeding for adaptation, assessment of soil health changes, and investment in regional value chains. The value of IWG research for the Southeast is particularly notable in Kentucky and Tennessee: these states have highly erodible farmlands that may benefit from novel perennial crops, and local grain organizations that can promote this new crop in the region.
In this proposal, we ask: How well does IWG grow in our region, and what practices can we use to improve IWG performance? Can we use plant breeding to develop new varieties that are adapted to our soils, climate, and end-uses? And, what is needed to cultivate sustainable regional value chains for IWG? To address these questions, our project brings together new collaborators in plant breeding and soil science, as well as farmers and end-users in Kentucky and Tennessee. With a systems approach towards developing regional perennial grain agriculture, we will work to build infrastructure for IWG (e.g., breeding, agronomic recommendations, education), and incentives for growers and end-users to adopt IWG (e.g., end-use testing, soil health metrics, networks).
The proposed research includes multi-location trialing of IWG on-farm, under different production environments (e.g., animal agriculture), as well as intensive trials on research farms in Kentucky and Tennessee. This set of trials will provide quantitative and qualitative measures of IWG performance, and will help us identify which locations or management practices (such as grain versus dual purpose management, or agronomic practices) contribute to more successful IWG cultivation. This multi-location data will inform plant breeding for IWG regional adaptation by defining key variety needs for successful production in our region (e.g., appropriate maturity date, pest resistance, etc.). In collaboration with farmers, we will begin plant breeding to develop locally-adapted IWG populations. In addition, trial data will indicate opportunities by which IWG adoption may be incentivized for improvement of soil health or other sustainable farm metrics, and/or as a unique, high-quality grain. On research farms, we will conduct intensive soil health measures and we will assess baking quality in connection with locally-grown wheat. Importantly, these trials will test the degree to which these measures and end-use quality vary across locations in our region. The results will be shared through education materials, field days, and a value-chain gathering. Overall, perennial grains have potential for improving cropping systems sustainability in Kentucky and Tennessee, and we propose a collaborative systems approach to integrating IWG into local grain value chains.
- IWG breeding for adaptation to the Southeast
- Phenotypic analysis of IWG breeding lines, on station & with farmers
- Genomic analyses of IWG breeding lines
- Cross-pollination of breeding lines to develop new Southeast-adapted IWG populations
The primary goal of this objective is to breed IWG adapted to the Southeast. We will evaluate yield, maturity, resilience and quality traits and establish the foundation for breeding new regionally-adapted varieties. First, we will evaluate spaced plants for three years in multiple locations covering different agroclimatic zones in Kentucky for agronomic performance and grain traits (Obj 1a). We will then use that data along with genotyping data provided by TLI to assess genetic and genotype-by-environment variation for key traits, and conduct genome-wide association studies and genomic prediction (Obj 1b). Finally, the field and genomic evaluations will allow us to begin development of new Southeast-adapted IWG breeding populations (Obj 1c). Using both the quantitative data generated on research farms and input from Kentucky farmer collaborators (Chadwell, Skees) who will visit early-generation plots to provide valuable feedback to establish regional breeding targets, we will cross pollinate IWG to create multiple breeding populations for different needs (e.g., facultative flowering, high grain yield, or farmer-specific). While beyond the timeframe of this grant, these populations will become the basis of new IWG varieties for Kentucky and Tennessee.
- On farm and research station assessment of IWG performance
- Farmer field trials of IWG
- Research station replicated IWG trials
We will assess IWG regional performance across agroclimatic zones and production systems in Kentucky and Tennessee. Specifically, we will measure IWG yield and quality while testing different production methods using on-farm (Obj 2a) and university research plots (Obj 2b). In Obj 2a, Farmers will host IWG field trials that span different end uses (forage, grain, soil health; Figure 5). The research team will meet with farmers on their farms in Spring 2025, and seed will be distributed to farmers in Summer 2025 for planting along with written management protocols to test one treatment of interest, like seeding rate or nitrogen rate. We will work with each farmer to adapt the protocols to their operation to ensure feasibility. On-farm measures will quantitatively and qualitatively assess suitability of production, overall performance, and key challenges for their farms, including quality of forage harvest (Skees), potential as a locally-produced high-value grain (Chadwell), and soil health benefits (Vaught). In Obj 2b, replicated plots on University of Kentucky (UKY) and Middle Tennessee State University (MTSU) research farms will intensively quantify yield, biomass, maturity, and quality measures. Together, on-farm and research IWG plots will provide critical information for regional production.
- Quantify soil health and soil carbon metrics associated with IWG production
We will quantify soil carbon and other soil health metrics in the IWG plots compared to plots in a conventional double crop winter wheat rotation (see Previous Submission section). We hypothesize that the perennial IWG plots will lead to greater soil carbon, and that the degree to which it exceeds a conventional rotation will vary across locations and with management practices. Because of the labor necessary to achieve different replicated management conditions within the same field, this will primarily be conducted on UKY (led by co-PI Poffenbarger) and MTSU (led by co-PI Haruna) research farms in three locations. In addition, an on-farm trial (on farmer collaborator, Vaught’s farm) will be established in Tennessee to 1) assess the ease of incorporation into current cropping systems, and 2) increase likelihood of adoption of IWG by local producers through peer education and outreach. Because of his influence with the Tennessee Farm Bureau and various soil conservation districts, Mr. Vaught will be helpful in achieving this objective and critical in farmer-peer education and outreach.
- Build local IWG value chains for multiple end-uses
- Baking protocol development
- Testing IWG terroir from different sites in baked products
- Host value-chain focused field day
We will evaluate IWG for the regionally-specific application of baking with locally grown soft red winter wheat flour. After quality assessment and protocol development (Obj 4a), we will test genetic and site variation in flavors from IWG grown in multiple locations (Obj 4b). In Obj 4a, PI-Brzozowski and co-PI Van Sanford will conduct IWG baking trials with Kentucky-grown soft red winter wheat. To date, most IWG baking tests have been conducted with hard red winter wheat (Marti et al., 2015, 2016; Rahardjo et al., 2018; Paravisini et al., 2019; Cetiner et al., 2023), which is rarely grown in the Southeast. Hard red winter wheat is used for breadmaking, while soft red winter wheat is used for baked goods, such as scones and cookies. As such, we will develop testing protocols IWG baking with local wheat, and then we will then bake with the grain from farm and research station plots to test site variation, or terroir, in quality and flavors (Obj 4b). While it is established that the aroma of IWG baked goods differs from that of wheat baked goods (Paravisini et al., 2019), site variation of IWG products has not yet been tested. The end-use products will be used by researchers with the help of collaborating farmers in Outreach to local farmers, end-users and the general public grow value chain connections, including at a value chain focused field day in Year 3 (Obj 4c).
Cooperators
- - Producer
- - Producer
- - Producer
Research
Objective 1. IWG breeding for adaptation to the Southeast
Intermediate wheatgrass has been bred by The Land Institute (TLI), and additional plant breeding is necessary to adapt IWG to the Southeast. TLI provided PD-Brzozowski with >2000 IWG genets from The Land Institute C13 breeding cycle (from Dr. DeHaan) in 2023 to use in breeding. As an outcrosser, IWG is advanced by populations. The population has improved grain yield, but individual plants are unique, untested genotypes. The genets represented 80 half-sib families (HSF; half-sib families share a seed parent, but have different pollen parents) from an improved population. The genets were individually planted at 42” spacing (Figure 2) at farms in areas with different agroclimatic zones and agricultural intensity (Figure 5). HSF were replicated across and within locations (Table 2). The plants are managed with the same agronomic practices detailed in Obj 2. In this objective, we do not evaluate forage quality, because it is established that forage yield of spaced plants is not correlated with plot biomass (Mortenson et al., 2019); forage yield and quality is assessed at a plot basis in Obj 2.
Obj 1a. Phenotypic analysis of IWG breeding lines, on station & with farmers
IWG will be evaluated for yield and adaptation for three grain producing seasons in all locations. Spike emergence and anthesis will be recorded when 50% of the spikes have emerged from the boot, and 50% of plants are at anthesis, respectively. As spike emergence and anthesis vary within IWG populations (Altendorf et al., 2021a; b), all plants are scored on an ordinal scale once in the season. Yield component traits will also be measured, rather than yield itself, as total plant yield in spaced plants is not predictive of row crop yield. We will record the number of reproductive tillers, spike weight, spikelets per spike and thousand grain weight, as these traits correlate with yield and established protocols exist (DeHaan et al., 2018; Bajgain et al., 2019a; Altendorf et al., 2021a). In addition, winter survival, and incidence or severity of pests will be noted. Traits will be measured on an individual plant basis, and statistics will be conducted at the level of HSF, where each individual plant is a replicate within a HSF. These measurements will be used in Obj 1b.
IWG is expected to produce grain in three summer seasons following winter vernalization. The space plants were established in April 2023, and so that grain data will be collected from 2024-2026. Data was successfully collected in 2024 (Figure 3), and this proposal would fund field data collection and sample processing for 2025-2026 (Years 2-3 of production). Travel to the sites is feasible (two sites within <30 min of UKY campus; other sites are 1.5 and 3 hrs away) and included in proposed budget. Scoring spike emergence and flowering data for all locations is made feasible by recording it on a single day per site, as demonstrated in 2024. Harvest and yield data will be processed throughout the year.
In addition to quantitative measurements taken by researchers, Kentucky farmer collaborators (Chadwell and Skees) will be invited to visit research sites to share their perspective on characteristics of breeding lines each summer. During these visits, they will learn about the plant breeding process. Their input will be used as an important criterion for selection (Obj 1c).
Obj 1b. Genomic analyses of IWG breeding lines
We will first assess the genetic and environmental bases of trait variation. TLI genotyped the IWG with 28,701 genotyping-by-sequencing (GBS) markers, and provided those data to the PD. Using all markers and all phenotyped plants, we will be able partition to what degree traits are influenced by genetic differences, differences between locations (environments), or the interactions thereof (Hudson et al., 2022). This analysis is informative for plant breeding for two reasons. First, it provides estimates of trait heritability, which is a measure of how reliably the phenotype we measure reflects genetic value. Second, by providing insight into the extent to which genotypes respond to different environments, and coupled with weather station data from research farms, it informs whether different IWG varieties need to be developed for different locations within our region.
We then will conduct genome-wide association studies (GWAS) to assess the genetic architecture of yield component and disease resistance traits. GWAS provides insight into whether traits are controlled by a single gene or many genes. We will conduct single trait GWAS using a robust Q+K model accounting for population structure and kinship, respectively, and will be implemented with established methods in the R statistical computing software. This approach has been used successfully by other IWG researchers (Bajgain et al., 2019a; b, 2022; Altendorf et al., 2021a; b), but will yield different results in Kentucky, where the plants experience different conditions and stresses.
We will also conduct genomic prediction. Genomic prediction leverages genotypic and phenotypic data to make more accurate decisions in developing new, regionally-adapted populations (Heslot et al., 2015; Mohammadi et al., 2015; Crossa et al., 2017). This technique has been applied successfully in IWG (Zhang et al., 2016; Bajgain et al., 2020a; Crain et al., 2021b; a) and the PD has expertise in these analyses. We will conduct genomic prediction using genomic BLUP and Bayesian models and will report accuracy as the correlation between predicted and observed values using cross validation, as well as correlations within families. Data from the 2024-2026 field seasons will be used. This work will allow us to create populations for genomics-enabled plant breeding.
Obj 1c. Cross-pollinations to develop new Southeast-adapted IWG populations
Seed will be selected from the best plants in Fall 2025 and will be sown in UKY research greenhouses for pollinations. We will follow established TLI greenhouse pollination protocols using 60 plants per pollination (DeHaan et al., 2018; Bajgain et al., 2023). Seed from the pollinations will then be sown in the field in 2026 in HSF plots and evaluated in Summer 2027 as in Obj 1a. Variety development would continue after this grant with at least two additional recurrent selection cycles and evaluation.
Objective 2. On-farm and research station assessment of IWG performance
There will be on-farm and research station assessment of IWG. These trials will share some basic agronomic practices. First, the plots will be established in fall of 2025, and evaluated for two seasons (summer 2026 and 2027). While we have successfully established plots (Figure 1; Table 1), we would replant in the following year if there was not successful establishment. We will sow a commercial IWG seed variety (MN-Clearwater) between late September and early October (Peters, 2021; Olugbenle et al., 2021), with a seeding rate of 10 lbs/acre at a depth of 0.25-0.5 inches on 6” rows (The Land Institute and Forever Green Initiative, 2021). A commercial variety is used in these trials for uniformity across sites as well as seed availability. Except where noted, soil fertility will be managed with nitrogen application of 45 kg/ha in fall and spring, as shown to be the most effective in our preliminary trial (Table 1). We do not plan for disease/insect management so that we can observe potential production challenges; however, if Fusarium head blight, a common fungal pathogen in other local grains, is found to be a significant problem in Year 1, we will use standard IPM practices for management in Year 2. Weed management is a significant challenge in IWG production, and will be specific to sub-objectives, and can include herbicide application in spring (Fernandez et al., 2020; Kernza® Multi-State Agronomy Technical Assistance Team, 2022), mowing, intercropping, or increasing the seeding rate (Table 1).
IWG grain will be harvested once 70% of the spikes have mature seeds (Peters, 2021), which was mid- to late-August in Kentucky in 2024. For plots only intended for forage harvest (some in Obj 2a), forage will be harvested when plants reach maximum biomass in late summer (Pugliese et al., 2019; Mortenson et al., 2019). Forage will be cut in the dual-use plots (Obj 2b) after the summer grain harvest, and in late Fall to maximize grain yields (Culman et al., 2023). No forage cuttings will be taken in Fall 2025 to allow stands to establish.
2a. Farmer IWG trials
Growers will plant between 1000 ft2 and 1 acre of IWG. The rationale for this size is that the plot will be large enough to effectively observe IWG, is workable with their equipment, but manageable to maintain for three years. While not possible on every farm, this site ideally has a low weed seed bank and will be planted with a legume to precede the IWG. Seeds will be sown between late September and early October 2025 with the farmers’ own, or rented, equipment. The PD will supply and operate a push seeder, if necessary.
On-farm trials will test one agronomic practice relevant to the farmer, including fertilizer type or rate or seeding rate, in a split-plot or randomized complete block design. Yield or biomass samples for IWG and weeds will be separately collected by the research team from three 1m x 1m samples, and analyzed as described in Obj 2b, and total yield or biomass will be estimated by farmers. The plots will be harvested with available farm equipment, with support from the research team. If needed for small on-farm plots, grains can be hand harvested with rice knives. Forage can be used on farm, and the grain will be used by the research team in baked products for Outreach.
Plans have been discussed with farmers, and the research team has visited and identified sites for the IWG plots at the farms. All farmers reside within two hours of the research team, making it feasible to visit regularly. Travel and material costs are included in the proposed budget. On-farm trials will further contribute to farmer peer education and IWG adoption.
In addition to conversations throughout the collaboration, we will interview farmers in 2026 and 2027 about their experience. We will ask about overall performance of IWG and suitability for their farming system. We would also inquire about challenges and opportunities related to their specific end-uses. This information will be shared in Outreach efforts.
2b. Research station replicated IWG trials
In addition to on-farm trials, UKY (PI-Brzozowski, co-PI Poffenbarger) and MTSU (co-PI Haruna) research farms will host replicated IWG plots for quantitative agronomic and quality measures. These trials will occur at UKY North Farm (Lexington, KY) and UKY C. Oran Little Research Station (Versailles, KY) and MTSU Experimental Farm (Lascassas, TN), where space has been allocated for the research team and appropriate equipment is available. In each of the three locations, there will be a replicated no-till trial with a IWG grain (only) treatment, and a dual-use IWG grain-forage treatment. Alongside these plots will be two winter wheat double crop ‘treatments’ that are offset such that each cycle of the rotation is represented each year (e.g., every year there is a separate corn and soy plot; winter wheat is grown every year). This allows us to provide practical information regarding yield potential in grain versus dual-use management, and the winter wheat rotations are an important comparison to the perennial plots for soil carbon analysis (Obj 3).
The plots will be 20 ft wide by 30-40 ft long to accommodate equipment size, and will be replicated four times within each treatment (grain, dual-use) and location. The fields used will have been previously managed as row crops (not pasture) and IWG planting in Fall 2025 will follow terminated soybeans (Summer 2025). Planting protocols are described above. Briefly, the MN-Clearwater seed plots will be drill seeded, 45 kg/ha N applied in fall and spring, and weed management by annual herbicide in spring, as necessary.
We will record plant emergence, survival, pest damage and severity, spike emergence and anthesis for all plots (see Obj 1a). The plots will be harvested annually using a small grain header on a combine, and total yield, thousand grain weight, threshability and seed size will be measured. Grain quality and end use potential will be assessed in Obj 4. For dual-use plots, forage biomass will be cut following summer grain harvest annually, and in late Fall in the second year using a Wintersteiger forage harvester. Total forage weight and percent dry matter will be evaluated for each plot, and forage quality will be assessed at the UK Research and Extension Center (UKREC). Finally, winter wheat yields from double crop plots will be recorded. Findings from these studies will be compiled into an extension report and local grower guide.
Objective 3. Soil health, soil carbon.
We will quantify soil health in grain and dual-use IWG plots compared to a no-till conventional double crop rotation in three locations. Because of the labor necessary to achieve different replicated management conditions within the same field, this will primarily be conducted on UKY (co-PI Poffenbarger) and MTSU (co-PI Haruna) research farms, where the co-PIs have experience conducting experiments of similar scale. In addition, co-PI Haruna will establish an on-farm field site with collaborating farmer Vaught. Overall, in each location, there will be 16 plots from which soil health metrics will be assessed (four planting rotations: IWG-grain, IWG-dual, double crop 1, and double crop 2; four replications; described in Obj 2b).
Soil sampling will be conducted prior to tillage in the first year (2025), and then annually in fall of the subsequent years (2026, 2027). We will collect cores from the plots using either a drop hammer or ATV-mounted soil probe with the same diameter (5 cm). Soil samples will be collected at 0-10, 10-20, and 20-40 cm depths. Using these samples, we will determine bulk density from two intact cores at the three depths per plot and bulk soil organic C concentration from one composite sample per plot. This will allow us to calculate carbon stocks in each plot. We will also assess the mass and C concentrations of particulate and mineral-associated organic matter, which represent more decomposable and more stable forms of organic matter, respectively. This will be complemented with above- and belowground biomass sampling to determine net primary productivity, harvest index, and residue inputs to the soil from each crop of each system. Specifically, we will sample the annual crops at maturity and partition the aboveground biomass into grain and aboveground residue. For the IWG plots, we will sample and partition aboveground biomass into harvested and unharvested components when the grain is mature, as well as at the end of the season to capture fall regrowth. Belowground biomass will be sampled using cores collected at the grain harvest of each crop. For the second-year IWG plots, early spring above- and belowground biomass samples will be collected to account for biomass maintained from the previous year and winterkill losses. We will assume that all unharvested residue from the annual crops is contributed to the soil in the year they are grown, while for IWG unharvested straw and winter-killed regrowth is added to soil the year of production, while roots are deposited at the time the IWG is discontinued.
Additionally, root morphology, topology, and architecture of IWG will be analyzed and compared with their annual winter wheat using a WinRhizo® analyzer (led by co-PI Haruna). This will provide information on IWG adaptation to local soil conditions. Finally, soil water infiltration capacity and soil microbial biomass (by phospholipid fatty acid analysis, PLFA) will be measured at the Tennessee sites by co-PI Haruna. A potential challenge in this objective is that the soil properties may not change substantially within the time frame of the experiment. Based on previous experience, we anticipate minimal changes in year 1, but for some changes to be evident in the second year.
co-PI Haruna will work with Mr. Vaught (collaborating farmer) on sample collection, in situ measurements, and analysis. Due to his interest in soil health, Mr. Vaught will benefit from this objective by being involved in the evaluation of soil health parameters. This will further aid with farmer-peer education and outreach.
Objective 4. Value chains, outreach.
Obj 4a. Baking protocol development
Beginning in 2024, we will purchase commercial IWG flour and Kentucky grown soft red winter wheat for initial recipe testing. Perennial grain enthusiasts have found that dough with soft white winter wheat including up to 75% IWG flour held the shape of scones (Kaplan, 2021). We will then test recipes for IWG biscuits and scones using a range of 10-75% IWG flour blended with Kentucky soft red winter wheat, with the initial recipes based information found on perennial grain baking blogs (Kaplan, 2021). Recipes will be evaluated for consistency and flavor, and we will choose the recipe to use in terroir evaluation (Obj 4b). By developing protocols for a standard recipe, we will be able to quickly test for site variation in IWG terroir once grain is available from our trials.
Obj 4b. Testing IWG terroir from different sites in baked products
We will first assess grain quality and composition by near infrared (NIR) spectroscopy (Perten DA 7250 NIR Analyzer; available at UKY) of all grain samples collected from on-farm and research station plots (Obj 2). Then, using the protocols developed in Obj 4a, we will make two to three replicates of products from each Obj 2 site (up to six sites, 18 products) per end use. A volunteer tasting panel and farmers will evaluate baked good quality (Outreach), as per co-PI Van Sanford’s established protocols for testing wheat flavor and quality.
As there are many trial sites, we anticipate having sufficient grain, even if a harvest fails at one site. If multiple harvests were to fail, we will either compare the local IWG available to commercial purchased IWG. If no local IWG flour is available, which we do not anticipate based on previous successful grain production, the tasting panel will instead assess the percent blended products developed in Obj 4a.
Obj 4c. Hosting a value chain-focused field day.
We will host a value chain focused event in August 2027 (Year 3), as detailed in Outreach.
Educational & Outreach Activities
Participation summary:
The target audience participating in the project are three farmer collaborators who are interested in growing IWG, as well as MTSU and UKY undergraduate students and UKY graduate students. The farmer collaborators in the project are evaluating IWG on their own farm (Obj 2a), and are collaborating with PI-Brzozowski on IWG selection (Obj 1a) and co-PI Haruna on soil health (Obj 3a). The farmer collaborators will also attend some local conferences (detailed below) that will further connect them to all parts of the project and to other interested farmers; conference expenses for farmers are included in the budget. Students in agricultural research fields at both UKY and MTSU will also engage in multiple project objectives. At UKY, A PhD student under the supervision of PI-Brzozowski will conduct their dissertation research on IWG genetics and end-uses (Obj. 1, 2, 4), and a MS student will work under the supervision of co-PI Poffenbarger to conduct their thesis research on soil health (Obj 2, 3). UKY Undergraduate students would be supervised by both PI-Brzozowski and co-PI Poffenbarger and will learn relevant research skills towards careers in sustainable agriculture. Both PI-Brzozowski and co-PI Poffenbarger have a strong record of recruiting motivated students to conduct research in their project. Co-PI-Haruna will recruit undergraduate students from some of his experiential classes and the honors’ college to participate in the research. Co-PI Haruna has a record of including undergraduate students in his research projects and some of these projects have led to several completed honors theses.
The target audience for information, education and outreach are grain and forage farmers in Kentucky and Tennessee, extension agents, consumers and other participants in local grain value chains, as well as other agricultural researchers, and students. We will present results from our research at annual field days on UKY and MTSU research farms. The University of Kentucky hosts field days on research stations in Princeton, KY (The UK Winter Wheat Field Day) in May and the Robinson Center (Quicksand, KY) will host field days in the Fall. These field days draw farmers, extension agents, and other agricultural workers and researchers. PI-Brzozowski and graduate students will present at these events in 2026 and 2027. In Tennessee, co-PI Haruna will host a virtual seminar for all participants and a farmer field day (along with collaborating farmer, Mr. Mike Vaught) during the fall of 2026 and 2027, respectively. These efforts will be designed to demonstrate the adaptability of IWG and any management challenges associated with IWG in the Southeast region. Based on such previous efforts, a total of 85 producers are expected to be impacted during both years. Education and outreach activities are also held at MTSU Farms periodically for local high-schools, producers, and students. While IWG breeding and end uses are key parts of our research (Obj 1, 4), our results presented at field days will focus on the most relevant results for farmers: on-farm and research station agronomic trials (Obj 2) and implications for soil health (Obj 3). The field day presentations will include the basic information about IWG, IWG planting and management strategies, as well as expectations for yield in Kentucky and Tennessee. We will provide handouts at field days that will contribute to a white paper or extension publication. We will leverage these project activities towards producing a grower guide. Current guides for IWG production are available as web pages or white papers (e.g., kernza.org), and we will model our content on this successful strategy. We plan for these results to be available to growers through UKY extension, and also linked on the central kernza.org website as a Kentucky-Tennessee IWG Grower Guide. Because The Land Institute has invested in commercialization of IWG from grower guides to markets (Cureton et al., 2023), our work will complement and build upon the resources they have already developed to provide regionally-relevant information, including information about no-till planting and comparisons to locally-relevant crop rotations. Efficacy of outreach will be assessed by number of attendees at field day talks, and website clicks or downloads.
In addition to farmer outreach, a specific goal of our education and outreach efforts are to connect farmers to other actors in the value chain. As shown in a recent survey of IWG growers, many farmers are drawn to growing IWG for the environmental sustainability benefits, but connecting to buyers who are willing to pay a premium for the grain is likewise critical (Lanker et al., 2020). Our research team has a strong record of fostering local grain value chains. Co-PI Van Sanford spearheaded the SSARE-funded 2019 Southeast Grain Gathering, which brought together farmers, researchers and end-users, and has grown to become the new organization, The Ohio Valley Grain Exchange (OVGE; https://www.ohiovalleygrainexchange.org). OVGE has since hosted multiple events, including another Grain Gathering in 2024 with over 150 attendees, and PI-Brzozowski and co-PI Poffenbarger contributed to the event. Likewise, co-PI Van Sanford and PI-Brzozowski are actively involved in the ‘Bringing Back Rye to Kentucky Initiative’, which connects all pieces of the value chain for sustainable local rye production. In this proposed project, we will be able to draw upon our collective experiences and networks to lay a foundation for IWG value chains in the region. Specifically, we will host an event specifically focused on IWG production and value chains in Kentucky and Tennessee called “Perennial Grain Value Chains”. It will be hosted at the University of Kentucky research farm in August 2027 (Year 3). We choose to host the Perennial Grain Value Chains event in August as the IWG will be reaching maturity then, and so participants can see the mature grain, as well as harvesting methods. The Perennial Grain Value Chains event will be hosted at the research farm and will include field tours, research presentations, sampling IWG products, and networking. Funds are requested so that there will be no cost for farmers or for other participants requesting a fee waiver (up to 50 participants). Industry and research professionals will be asked to pay a $40 registration fee. This event will be promoted by the OVGE and Rye Initiative networks to connect farmers to buyers and end-users of IWG.
Part of this value-chain focused outreach will also include presentations at local food and grower gatherings. At these events, we will present a shortened summary of the information given to growers (described above) at these conferences, but will spend more on end-use quality as to bring people in different parts of the local grain value chain together. Importantly, we will bring samples of IWG or Kentucky soft red winter wheat biscuits or scones (Obj 4a) to promote and increase awareness of IWG products. We have identified four events that are well suited to this outreach: the Tennessee Local Food Summit (Lebanon, TN), the Organic Association of Kentucky Conference (Frankfort, KY), the University of Kentucky Local Food Systems Summit (Lexington, KY), and the Ohio Valley Grain Exchange Grain Gathering (Lexington, KY; https://www.ohiovalleygrainexchange.org/segg). Locations for the previous cycle are given, but can change year to year. PI-Brzozowski, co-PI Poffenbarger and/or co-PI Van Sanford or their students have presented about local grain value chains at all of the above conferences in 2023-2024, and would submit conference proposals for perennial grain sessions at these events. Funding is requested for the graduate students on this project to attend these conferences (as described above, funding is also requested for farmer participants to attend these conferences). Efficacy of outreach at these local events will be measured through post-conference surveys, with questions including change in interest for growing, using or buying IWG.
In addition to connecting with regional stakeholders through local conferences, our research team will publish and present material nationally. We anticipate that this work will result in at least four scientific publications, which we will publish open access so that the research is available without paywalls. In this proposal, we have budgeted for one open-access publication, and have funds from other sources to cover additional publications. In addition, the research team regularly attends national conferences, including the Crop Science Society of America, Agronomy Society of America and Soil Science Society of America conferences, and will present this work. Funding is available through other sources at UKY for the graduate student and faculty to attend this conference.
Finally, as university educators, the research team will also integrate results from this work into lectures and hands-on learning opportunities with students. PI-Brzozowski teaches an undergraduate genetics class (ABT 360), and will integrate examples of the IWG genomics research into the “Genomics” lecture. She also works directly with undergraduate and graduate students to teach them skills and techniques in this area. Co-PI Poffenbarger teaches Soil Nutrient Management (PLS 470) and will integrate findings on carbon inputs and soil health changes from this study into her section on soil organic matter. Co-PI Van Sanford teaches “Climate Change in Agriculture” (PLS 302) and co-teaches PLS 386 “Plant Production Systems”, another course in which IWG production is discussed. In addition, both PI-Brzozowski & Co-PI Poffenbarger contribute guest lectures to courses at University of Kentucky such as “Climate Change in Agriculture” (PLS 302), where they have the opportunity to highlight perennial agriculture systems. Additionally, Co-PI Haruna at MTSU teaches Soil Fertility and Fertilizers (PLSO 3350) and Soil and Water Conservation (PLSO 4370). Farm visits by his classes will provide a visual and hands-on demonstration of the benefits of IWG on soil health, nutrient availability, and environmental sustainability. Together, these opportunities will expose undergraduates to new ideas about sustainable agriculture in the context of their course material.
Learning Outcomes
Project Outcomes
None
Progress has been made in all objectives to develop a sustainable perennial grain system in the Southeast. Progress towards each objective is described below:
- IWG breeding for adaptation to the Southeast
- Phenotypic analysis of IWG breeding lines, on station & with farmers
- Genomic analyses of IWG breeding lines
- Cross-pollination of breeding lines to develop new Southeast-adapted IWG populations
A population of intermediate wheatgrass (IWG) consisting of eighty half-sib families (HSF) was obtained from The Land Institute (TLI). It was established across four experimental locations in Kentucky: Lexington (LEX), Princeton (PRN), Quicksand (QKS), and Woodford (WDF). Phenotypic data collection began in 2023 and will be collected through 2026. Several agronomic and reproductive traits were evaluated across sites, including plant diameter (cm), spike length (cm), anthesis and spike count. Plant diameters were measured at the widest point of the plant canopy. Spike length was measured when spikes were 50% emerged from the boot. It was measured from the tip of the apical spikelet to the base of the flag leaf sheath. Anthesis were recorded using a standardized ordinal scale categorized by Altendorf et al., 2021. The codes for anthesis included: (1) boot stage where no spike is visible, (2) heads emerging or < 25%, (3) heading 25%, (4) heading 50%, (5) heading 75%, (6) heading complete but no anthers visible, (7) beginning flowering, where yellow anthers are beginning to emerge at the center of the spike, (8) flowering 50%, where anthers are visible through the center and top of spike, (9) flowering 100% where anthers (possibly white or dehiscing) were visible throughout the spike. Spike counts were performed for each genet after harvesting and drying of spike. In total, 1,840 genets were planted, of which 1,516 plants successfully established and 1,498 had phenotypic measurements from all years (Table 1.1). Summary statistics were performed which indicated phenotypic variation across environments (Table 1.2). Spike count varied from an average of 30.7 spikes per plant at QKS to 85.1 spikes at WDF. Mean spike length also differed widely among environments and years, ranging from 14.82 cm at QKS (2024) to 47.13 cm at PRN (2024). Anthesis scores varied across locations, with mean values ranging from 3.94 at PRN (2025) to 7.50 at QKS (2025) on the 1-9 flowering scale. The patterns suggests increased tillering capacity in later years, as plants in early years tend to prioritize vegetative growth before allocating resources to reproductive structures. In contrast, anthesis timing showed relatively little variation across locations in both years, suggesting stable flowering despite environmental variation. Following this, trait correlations were analyzed across locations and years (Figure 1.1). Correlation values were consistently positive, although their strength varied by trait, location and year. Plant diameter showed moderate positive correlations with both spike count and spike length in 2024 and 2025. This indicates that larger plants tend to support greater reproductive development. Spike length exhibited the most consistent correlations across years, with high associations between years across all locations (0.63-0.92). Anthesis was also strongly correlated between years (0.59-0.71), suggesting consistent flowering patterns across environments. In contrast, spike count showed weaker and more variable correlations between years, indicating a stronger influence of environmental conditions. Overall, these positive but varied correlations highlight the influence of genotype × environment (G × E) interactions on phenotypic traits in IWG.
To assess G × E interaction, phenotypic data were analyzed using a mixed linear model to partition genetic and environmental sources of variation among HSF. In this model, family, location and their interaction were treated as fixed effects, while block nested within location was treated as a random effect. Analysis of variance (ANOVA) revealed that both location and family significantly influenced most traits, indicating strong environmental effects across sites as well as genetic variation among the evaluated HSF (Table 1.3). The G×E interaction was generally limited, with significant interaction detected only for plant diameter in 2023 and 2025. This suggests that most traits exhibited relatively stable genetic performance across environments. Broad-sense heritability was estimated using variance components derived from mixed models with location as fixed affect and family and block treated as random effects. Heritability estimates varied among traits and environments (Table 1.4). Spike length exhibited consistently high heritability (0.81 at QKS), indicating strong genetic control. Anthesis showed moderate to high heritability across locations (0.38-0.68), suggesting flowering as a relatively stable trait for selection. In contrast, plant diameter and spike count displayed more variables and generally lower heritability (plant diameter: 0.06-0.60; spike count: 0.03-0.51). This suggests stronger environmental influence on these traits. Together, these results indicate that reproductive traits such as spike length and anthesis possess sufficient genetic variation to support effective selection within the HSF population.
Phenotypic data collection will continue in 2026 to further characterize the agronomic performance of the evaluated IWG genets across environments. This addition will allow improved estimation of genotype performance, stability across environments and G × E interaction analyses, and will be used in genomic analyses for objective 1.2.
In addition to evaluation of breeding lines, we have planting crossing blocks to develop two new Kentucky adapted IWG populations - one that prioritizes selection for high yielding, early varieties, and one that prioritizes minimal vernalization requirement (facultative). We split individuals from the breeding populations and planted them in isolation on Spindletop farm in Lexington in February 2026. Seed will be harvested from these populations in August 2026 and planted in family rows in September 2026.
- On farm and research station assessment of IWG performance
- Farmer field trials of IWG
- Research station replicated IWG trials
Three on-farm trials were established. In Kentucky, we worked with Brian Chadwell and Jerry Skees to establish each 1 acre of intermediate wheatgrass in September 2025. In Tennessee, we worked with Mr. Mike Vaught (collaborating farmer) to convert a 1-acre plot to IWG. The seeds were planted in November of 2025.
In addition to on farm trials, research station trials have been established in Kentucky and Tennessee. In Kentucky, the cropping system study includes four treatments at three locations. The first two treatments are intermediate wheatgrass planted for grain harvest only and planted for dual-purpose grain and forage harvest. The second two treatments are conventional double crop rotations of corn, wheat, and soybean, with alternate phases of the rotation. At the Spindletop and Woodford research sites, prior to initiating the study, soybeans were planted as a cover crop in all plots in early June 2025 and terminated in late July. Intermediate wheatgrass was planted in the grain-only and dual-purpose treatment plots in mid-September. Wheat was planted in the double crop year 1 treatment plots in early November. The remaining plots, the double crop year 2 treatment, are currently fallow and will be planted with corn in May of 2026. In Tennessee, research plots were established at Middle Tennessee State University (MTSU) farm laboratories during 2025. Using a randomized complete block design, 16 plots (each measuring 20 ft 40 ft) were delineated. Soybean were first planted in all plots during June of 2025 and terminated during August. Subsequently, soil samples were collected (at 0-10, 10-20, and 20-40 cm soil depths) during September 2025 for analysis of inherent soil properties prior to planting IWG. The IWG were planted using a seeding rate of 10 lbs/ac at 0.25 inch depth in about half of the plots, with annual wheat planted in the other half. All plots were managed with no-tillage and are rainfed. These sites will be used for systems research in Y2.
- Quantify soil health and soil carbon metrics associated with IWG production
Soil sampling at all research sites took place throughout August of 2025 prior to planting the intermediate wheatgrass. Sampling included taking composite cores with hand probes, taking larger cores for bulk density using a tractor-mounted Giddings probe, and using a shovel to sample for wet aggregate stability. The composite cores are used to assess pH, cation exchange capacity, Mehlich-3 nutrients, particulate organic matter (POM) and mineral-associated organic matter (MAOM) fractions, and soil organic carbon (SOC). The baseline soil characteristics and wet aggregate stability have been evaluated, and the fractionation process is still ongoing. The table reports mean pH and bulk density for each depth, 0-10cm, 10-20cm, and 20-40cm, at each site across all plots (Table 3.1). It also reports the average mean weight diameter for the soil in the top 10cm at each site across all plots, as a measurement of wet aggregate stability (Table 3.1).
- Build local IWG value chains for multiple end-uses
- Baking protocol development
- Testing IWG terroir from different sites in baked products
- Host value-chain focused field day
A sensory evaluation study was conducted to compare commercially available Kernza®-based products with wheat control. We prepared flatbreads and biscuits using commercially available Kernza flour and Kentucky field-grown red winter wheat flour as the control. A standardized recipe and formulation were used for all products to ensure consistency across samples. Flatbreads were prepared using a simple formulation consisting of flour, water, and salt whereas biscuits were prepared using flour, water, salt, baking powder and butter. Products were prepared with different levels of Kernza incorporation (10%, 20%, 30%, 50%, and 75%) relative to control (0%) to evaluate how increasing Kernza content influences sensory traits. For both products, we used a panel of same twelve panelists. A triangle test was used to determine whether panelists could detect Kernza products relative to control. Panelists identified the odd sample among three. The probability of correct identification was evaluated using a binomial model assuming a 1/3 probability of correct response by chance. For this, we hypothesize that consumers will be able to detect product at 30% Kernza incorporation. Following this, panelists completed a detailed semi-structured questionnaire using a hedonic scale (1-5) to evaluate attributes such as different flavor and overall liking. Questionnaire also included open-ended questions where participants could express their response about product. Results from triangle test showed that detection ability increased as the proportion of Kernza flour increased in both flatbreads and biscuits (Figure 4.1). At lower incorporation levels (10%), panelists were able to detect differences only for flatbread. However, at higher incorporation levels (50% and 75%), detection rates increased and were statistically significant (p < 0.05). This indicates that sensory differences between Kernza and wheat products become more distinct as Kernza content increases. Although our hypothesis, consumers would detect Kernza-based products at 30% incorporation level was rejected, the results indicate that higher incorporation levels (50% and 75%) statistically improve the ability to detect differences.
Estimated marginal means (Emmeans) were used to compare responses for nine sensory traits (aroma intensity, sweet flavor, sour flavor, wheat flavor, nutty flavor, bitter flavor, overall flavor, flavor liking and texture liking) across different Kernza® incorporation levels relative to control (Figure 4.2). In flatbread, 75% Kernza incorporation led to higher aroma intensity and bitter flavor compared to control. Overall flavor showed an increase at 30% incorporation, a significant positive difference from the control. Texture liking also improved at higher Kernza levels of 50%. This suggests that moderate incorporation may enhance textural perception in flatbread. In contrast, traits such as nutty flavor and flavor liking showed slightly negative differences relative to the control, indicating that increased Kernza levels did not enhance this characteristic. For biscuits, most traits showed even smaller differences from the control compared to flatbread, indicating a weaker sensory response to Kernza incorporation (Figure 4.2). Aroma intensity and bitter flavor fluctuated across treatments without a consistent pattern. Texture liking in biscuits increased at higher incorporation levels (50-75%), indicating improved texture with greater Kernza inclusion. Overall, these results suggest that Kernza incorporation has a noticeable impact on sensory traits in flatbread and biscuits, with moderate to high inclusion levels affecting aroma, bitterness, overall flavor, liking and texture. Principal component analysis (PCA) was then performed to visualize patterns among sensory traits and Kernza incorporation levels (Figure 4.3). The PCA biplots showed clear separation of treatments along with the principal components. The x-axis represents PC1 and the y-axis represents PC2. In both products, PC1 explained most of the variation in the data (~89% in flatbreads and ~91% in biscuits), while PC2 explained a smaller proportion of variation (~6-8%). PC1 captured differences associated with flavor-related traits and Kernza incorporation levels. The biplots showed that wheat control samples clustered closely with low substitution levels (10-20% Kernza), while higher incorporation levels (50-75%) were associated with stronger flavor and texture. Overall, the PCA indicates that increasing Kernza incorporation shifts the sensory profile of the products toward stronger flavor and texture. Following this, we performed pairwise correlations to determine associations among sensory attributes (Figure 4.4). The correlation analysis revealed that most sensory attributes exhibited significant positive relationships. Flavor liking showed strong positive correlations with both texture liking and overall flavor perception in both flatbread and biscuit. Bitter flavor in flatbread and sour flavor in biscuits, in contrast, showed weak negative correlations with flavor liking. This suggests that increased perception of these attributes may affect consumer preference. This suggests that consumer acceptance is influenced by a combination of flavor and texture attributes.
This work thus completes the first objective of a value chain study. The second objective of this project will be continued following grain harvest in summer 2026, and a value chain field day will be hosted in summer 2027.
A new research partnership has developed between three farmers and researchers involved in this project to grow intermediate wheatgrass in Kentucky and Tennessee. Outreach in Y2 is expected to further develop new partnerships, market opportunities and research.