Growing intermediate wheatgrass as a perennial grain crop in the United States: exploring the multifunctionality of agriculture within socio-technical constraints

Renewable Agriculture and Food Systems · 2026-01-01

Abstract Over the past decade, interest, stakeholder engagement, and investment in the cultivation of intermediate wheatgrass (IWG) as a perennial grain crop have increased across the Upper Midwest, USA. IWG has been promoted as a multipurpose crop that provides both agricultural products and ecosystem services. Our objective in this study was to describe the current IWG landscape in the Midwest from the perspective of farmers growing the crop, including their objectives, management practices, and the challenges they face. We also examined the concept of multifunctionality within the context of integrating a minor crop into existing farming systems. Semi-structured interviews were conducted with IWG growers in the Upper Midwest. Results show that, beyond direct agronomic benefits, these growers were motivated by a broader vision of agriculture. Due to its distinctive traits, IWG served as a tool to accomplish various non-commercial dimensions of farming such as environmental conservation, education, and community building, and for fulfilling farmers’ roles as producers, environmental stewards, and citizens. At the same time, the regional socio-technical context imposed strong constraints on IWG production, particularly in terms of profitability and processing. Cropping practices reflected both the influence of uniform technical recommendations and the need for adaptation to individual farm systems and farmer expertise. Overall, this study provides insight into farmers’ perspectives, motivations, and concerns regarding IWG cultivation in the United States.

Biotechnical, economic, and environmental assessment of dairy systems in the Peruvian Amazon utilizing the CLEANED tool

Agroforestry Systems · 2025-01-22 · 3 citations

Performance, feed-sorting behavior, methane and carbon dioxide emissions, nitrogen balance, and nutrient digestibility of dairy heifers fed Kernza intermediate wheatgrass straw

Journal of Dairy Science · 2025-11-21

Kernza straw (KS) is a high-fiber, low-energy byproduct of intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D.R. Dewey) that may serve as an alternative forage to increase dietary fill and reduce the risk of over-conditioning in late-pregnant heifers. We hypothesized that inclusion of KS in the diet of late-pregnant heifers would reduce feed intake and BW gain, nutrient digestibility, and urinary N excretion, but increase enteric methane production depending on the level of inclusion. Thus, a complete randomized design study lasting 12 wk was conducted with 24 heifers (507 ± 2.87 kg BW) fed a TMR that included either 0% (0KS), 20% (20KS), or 40% (40KS) KS, with a 40:60 mixture of corn silage and alfalfa haylage (DM basis), and urea to equalize dietary CP. Heifers were evaluated for DMI, ADG, BCS, stature-related body measurements, feed-sorting behavior, nutrient digestibility, methane and carbon dioxide emissions, and N balance. In this study, KS averaged 71.1% NDF, 4.8% CP, and 50.6% TDN (DM basis), TMR NDF was 41.0%, 47.1%, and 53.3%, and TMR CP was 13.3%, 12.8%, and 12.2% for the 0KS, 20KS, and 40KS diets, respectively. The DMI was 12.7 ± 0.13 kg/d for the 0KS diet but decreased to 11.7 ± 0.10 and 11.7 ± 0.14 kg/d when heifers were fed the 20KS and 40KS diets, respectively. In contrast, NDF intake was 5.0 ± 0.05 kg/d for the 0KS diet but increased to 5.4 ± 0.05 and 6.2 ± 0.08 kg/d when heifers were fed the 20KS and 40KS diets, respectively. The ADG was 1.35 ± 0.05 kg/d for the 0KS diet but decreased to 1.10 ± 0.05 and 0.86 ± 0.06 kg/d when heifers were fed the 20KS and 40KS diets, respectively. Change in BCS was lower when heifers were fed the 40KS diet compared with the other 2 diets, but dietary treatments did not alter stature-related body measurements. Heifers fed the KS diets sorted consistently against long particles but increasingly in favor of fine particles over time. Methane production and yield averaged 270 ± 5.70 g/d and 23.6 ± 0.50 g/kg DMI, but methane intensity increased when heifers were fed the 40KS diet compared with the 0KS diet (165 ± 7.89 vs. 207 ± 15.9 g/kg ADG.) The NDF digestibility declined when heifers were fed the 40KS compared with the 0KS diet (65.8% ± 0.36% vs. 61.8% ± 0.32%). Nitrogen intake was 356 ± 9.34 g/d for the 0KS diet but decreased to 312 ± 7.25 and 301 ± 11.1 g/d when heifers were fed 20KS and 40KS diets, respectively. Fecal N excretion was reduced when heifers were fed the 20KS compared with the 0KS diet (104 ± 4.86 vs. 79.7 ± 2.98 g/d), but urinary N excretion was reduced when heifers were fed the 40KS compared with the 0KS diet (212 ± 10.5 vs. 182 ± 6.71 g/d). This study demonstrated that KS can be used as a feed ingredient to modulate performance (DMI, ADG, BCS) and manure N excretion of dairy heifers.

Managing nitrogen fertility and stand density for sustaining Kernza intermediate wheatgrass yields

Crop Science · 2025-09-01

Abstract Kernza intermediate wheatgrass (IWG) [ Thinopyrum intermedium (Host) Barkworth & D.R. Dewey] is a promising perennial grain and forage crop, but experiences grain yield decline, potentially due to limited nitrogen (N) and stand overcrowding. We evaluated the effects of N fertilization and stand thinning on grain and forage yield, weed biomass, thousand‐kernel weight (TKW), and harvest index (HI). We used a full factorial design with N rates of 0, 75, and 150 kg N ha −1 and thinning intensities of 0%, 25%, 38%, or 50% stand density reduction via banded herbicide at two locations in Wisconsin over 2 years. Fertilization and thinning did not interact. Grain yields increased with N fertilization except at Madison in Year 2. At Lancaster, grain yield increased from 293 with no N to 497 and 701 kg ha −1 with 75 and 150 kg N ha −1 , respectively, across years. At Madison, grain yield increased only in Year 1. Forage mass also increased with N at both sites except Madison in Year 2. At Lancaster, forage mass ranged from 4016 to 6500 kg ha −1 across years and N rates. TKW and HI increased with N at both sites, except at Madison in Year 2. Weed biomass was unaffected by treatments. Thinning had no effect on grain yield at Lancaster in Year 1, but in Year 2, grain yield increased from 368 to 505 kg ha −1 with 50% thinning. These results suggest that applying 75 kg N ha −1 is important for maintaining IWG productivity and that thinning can help sustain grain yield in older stands.

Productivity of intermediate wheatgrass responds more to local soil and climate factors than fertility treatments in the first establishment year

Frontiers in Agronomy · 2025-06-27 · 4 citations

The intensive cultivation practices of annual cereal crops have been causing unprecedented degradation of natural resources. Perennial crops such as intermediate wheatgrass (IWG) could provide numerous benefits to address these issues, but there is still little comprehensive information about the establishment, fertilization needs, or range of IWG productivity on a regional basis in the first production year, which can be the highest over the lifespan of IWG’s grain production. The objective of this study was to evaluate how IWG establishment and first-year grain and forage yields varied across soil types, climate conditions, and in response ten fertilization treatments at six locations in the Midwestern USA. The 10 treatments included N fertilizer application at 5 rates; N application with or without P or K; varied timing of N application, and varied N fertilizer source. We found that fertilization influenced summer and fall forage yields but not grain yields. We also found that grain and forage yields varied greatly between locations, ranging from 556–1343 kg ha -1 for grain yields, 3732–8930 kg ha -1 for summer forage, and 927–3561 kg ha -1 for fall forage yields. Using a multiple linear regression approach, we found that a combination of local edaphic soil and climate factors explained 74%, 92%, and 69% of variance in grain, summer forage, and fall forage yields, respectively. Anomalies in expected and actual yields across locations led us to identify potential critical periods for IWG grain and forage production. We found accumulated precipitation in the 60 days before anthesis explained the most variance in grain and summer forage yields while the accumulated precipitation from May through October explained the most variance in fall forage yields. These findings are a first step toward identifying the regional expectations for IWG yields and could inform grower management and decisions regarding grain and forage harvest.

Short communication: performance of beef cows fed Kernza intermediate wheatgrass straw mixed with alfalfa haylage

Translational Animal Science · 2025-11-29 · 1 citations

Abstract Kernza intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D.R. Dewey) is a novel dual-use perennial grain and forage crop with environmental and economic benefits for farmers. Perennial crop byproducts, such as Kernza straw, have been suggested as an alternative forage source in livestock systems. However, there is limited information on cattle performance offered Kernza straw. Therefore, our study assessed the performance of mature beef cows fed Kernza straw mixed with a haylage composed of alfalfa (Medicago sativa L.) and cool-season grasses. Grasses included orchardgrass (Dactylis glomerata L.), meadow fescue (Festuca pratensis L.) and Kentucky bluegrass (Poa pratensis L.). Two feeding trials conducted in two different years were performed with 36 pregnant Angus cows (Bos taurus) in six pens of six animals each in a completely randomized design with three replications. Dietary treatments included: (i) a 100% grass-alfalfa haylage (control), and (ii) a 50% Kernza straw − 50% grass-alfalfa haylage. Average daily gain was lower in the Kernza straw cows than in the control group (0.41 vs 0.92 kg day−1) in Trial 1 (P = 0.02) with no differences in Trial 2 (P = 0.13). Daily dry matter intake did not change in Trial 1 (P = 0.08), while for the cows offered Kernza straw it was reduced from 12.9 to 11.3 kg cow−1 day−1 in Trial 2 (P < 0.01). There were no changes in body condition among cows fed different diets in both trials (P > 0.05). Therefore, 50% Kernza straw can be successfully used in beef cow diets at least for 60 days without negative impacts on animal performance and potential economic and environmental benefits.

Network of networks: Time series clustering of AmeriFlux sites

Agricultural and Forest Meteorology · 2025-06-24 · 2 citations

• Air temperature and net radiation followed a latitude gradient in clustering. • Clustering of fluxes was related to mean annual temperature and precipitation. • Site uniqueness was quantified, and proximal sites pairs were more similar. • Unique sites were in urban, open water, mountains, Hawaii, and Latin America. Environmental observation networks, such as AmeriFlux, are foundational for monitoring ecosystem response to climate change, management practices, and natural disturbances; however, their effectiveness depends on their representativeness for the regions or continents. We proposed an empirical, time series approach to quantify the similarity of ecosystem fluxes across AmeriFlux sites. We extracted the diel and seasonal characteristics (i.e., amplitudes, phases) from carbon dioxide, water vapor, energy, and momentum fluxes, which reflect the effects of climate, plant phenology, and ecophysiology on the observations, and explored the potential aggregations of AmeriFlux sites through hierarchical clustering. While net radiation and temperature showed latitudinal clustering as expected, flux variables revealed a more uneven clustering with many small (number of sites < 5), unique groups and a few large (> 100) to intermediate (15–70) groups, highlighting the significant ecological regulations of ecosystem fluxes. Many identified unique groups were from under-sampled ecoregions and biome types of the International Geosphere-Biosphere Programme (IGBP), with distinct flux dynamics compared to the rest of the network. At the finer spatial scale, local topography, disturbance, management, edaphic, and hydrological regimes further enlarge the difference in flux dynamics within the groups. Nonetheless, our clustering approach is a data-driven method to interpret the AmeriFlux network, informing future cross-site syntheses, upscaling, and model-data benchmarking research. Finally, we highlighted the unique and underrepresented sites in the AmeriFlux network, which were found mainly in Hawaii and Latin America, mountains, and at under-sampled IGBP types (e.g., urban, open water), motivating the incorporation of new/unregistered sites from these groups.

Knowledge graph applications for identifying resilient forage systems

Agricultural & Environmental Letters · 2025-06-01

Abstract Knowledge Graphs organize and connect disparate data for integrating information in a user‐friendly interface for recommendations and applications. This analytical tool for supporting data interrogation has not been widely applied in agronomy. This article focuses on Knowledge Graph applicability and specifically the utility of the recently released Esri ArcGIS Knowledge platform for identifying system resilience using a community‐driven database ( Forage Data Hub ; 52,997 entries from 108 unique locations over 51 years) comprising legacy datasets encompassing multiple temporal and spatial scales. Overall, perennial systems had greater drought risk resilience estimates (DRRE) than annuals, with alfalfa ( Medicago sativa ) having a “very high” DRRE across ecoregions. Knowledge Graphs provided information on how geography and agronomic systems interact to impact resilience. Results can be used to design agricultural systems within specific geographic locations with greater resilience and stability in the face of a changing climate per geographic region.

Reproductive and Vegetative Yield Component Trade-Offs in Selection of Thinopyrum Intermedium

Agronomy · 2025-12-16

Integrating perennial grain crops into agricultural systems can become a key milestone for increasing the provision of ecosystem services of food production systems. Intermediate wheatgrass is a novel perennial grain and forage crop that is undergoing domestication. Potential trade-offs between resource allocation and reproductive and vegetative plant structures can challenge the response to selection for both grain and forage production under dual-purpose use. Our goal was to understand the genetic relationship between grain and forage yield components, quantify potential trade-offs between vegetative and reproductive allocation, and optimize the response to selection under dual-purpose management. Phenological, grain, and forage traits were evaluated in 30 half-sib families across two field experiments conducted over three years. No trade-offs were detected between grain and forage yield traits, indicating that the simultaneous improvement of both traits is feasible. Grain yield per spike and spikes per plant are promising secondary traits for indirect selection, given their moderate-to-high heritability (h2 = 0.58 and 0.41) and strong Pearson correlation coefficients with grain yield per plant (0.68 and 0.82). These traits could be assessed in the first year, increasing genetic gain per unit time. Intermediate wheatgrass germplasm could therefore be efficiently developed by shortening the time to first evaluation, using secondary traits, and performing selection under dual-purpose management.

Genetic variation and heritability of agronomic traits in a native perennial forage species from drylands: breeding potential of Festuca pallescens

Scientific Reports · 2025-02-26 · 1 citations

Festuca pallescens is a native forage grass species of Patagonia, playing a crucial role in supporting sheep production in arid and semi-arid ecosystems. This study assessed genetic differentiation among populations and estimated the heritability of traits linked to biomass production and phenological development as part of its domestication effort. A common garden trial was established with ten half-sib families from four preselected populations, and phenological and morphological traits were measured over three seasons. Trait correlations were analyzed, and a mixed model approach was employed to estimate Wright’s QST and narrow-sense heritability. QST estimates ranged from 0.18 to 0.47 for phenological traits and from 0.086 to 0.093 for morphological traits; heritability values ranged from 0.33 to 0.78 for phenological traits and from 0.27 to 0.50 for morphological traits. Results indicate strong genetic structure for most phenological traits, suggesting diversifying selection. A population effect and within-population variability were also observed for most traits, highlighting potential for genetic improvement. We propose selection strategies to establish a breeding program for this species, aiming to develop adapted synthetic varieties with greater fitness. These new varieties could enhance forage productivity and potentially be applied in regions with similar climatic and environmental conditions.