Building foundations for perennial grain agriculture in the Southeast

Commodities

Practices

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.

1. IWG breeding for adaptation to the Southeast
   1. Phenotypic analysis of IWG breeding lines, on station & with farmers
   2. Genomic analyses of IWG breeding lines
   3. 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.

2. On farm and research station assessment of IWG performance
   1. Farmer field trials of IWG
   2. 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.

3. 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.

4. Build local IWG value chains for multiple end-uses
   1. Baking protocol development
   2. Testing IWG terroir from different sites in baked products
   3. 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).