Camelina (Camelina sativa L. Crantz) can produce substantial oil yield with limited N fertilization, providing a low-environmental-footprint feedstock for renewable fuel production. This study aimed to: (i) analyze and summarize existing literature on camelina N fertilization, (ii) identify optimal N rates, sowing dates, and tillage practices for camelina production in northern Italy, (iii) evaluate greenhouse gas (GHG) emissions from the agricultural phase of camelina production, (iv) and for the first time compile these three aspects of camelina production in a single manuscript. A three-year field study (2020–2023) conducted in northern Italy, using camelina cultivar ‘Alba’, evaluated two tillage practices (minimum tillage and no tillage), two sowing dates (early October and early November), and three top-dressed N rates (0, 60, and 120 kg N ha−1). Sowing date significantly affected plant height, plant density, seed yield, and oil yield. Tillage practice significantly affected plant density, seed oil content, and straw, seed, and oil yields. Nitrogen rate significantly affected thousand seed weight (TSW) and straw, seed, and oil yields. Highest seed and oil yields resulted from later sowing, minimum tillage, and ≥ 60 kg N ha−1. Nonetheless, the lowest carbon intensity (CI) was achieved without N fertilization, under both minimum and no-tillage, a scenario compliant with current European Union (EU) regulatory criteria for GHG emissions from the agricultural phase of biofuel production. Although less productive, this approach minimized GHG emissions, as N2O emissions from fertilizer and crop residues have the highest impact on overall CI. Further research, including breeding for improved N-use efficiency, will support scale-up of camelina as a sustainable biofuel feedstock.

Camelina [Camelina sativa (L.) Crantz] is an oilseed of interest as a feedstock for sustainable aviation fuels due to its low carbon intensity. Camelina is reported to have salinity tolerance and able to establish in marginal lands but there is no knowledge on how spring and winter biotypes tolerate exposure to different salts and salt concentrations. The objective of this study was to determine seed germination and vigor of spring camelina (C046) and winter camelina (Joelle) under salinity and sodicity. A set of 50 seeds and a subset of 15 seeds were germinated in Petri dishes saturated with of NaCl, CaCl2, and Na2SO4 solutions at concentrations of 0, 40, 80, 120, and 160 mM L-1, in an incubator set to a constant temperature of 20 degrees C. The experimental design was a randomized complete block with three replicates. Germinated seeds were counted daily for 7 days. With the exception of seedling dry weight and hypocotyl length, the winter biotype of camelina produced significantly lower values for measured parameters than the spring biotype. Averaged across varieties and salt concentrations, Na2SO4 reduced germination, vigor, and seedling dry weight more than NaCl and CaCl2. In addition, Na2SO4 almost completely inhibited radicle and hypocotyl growth at concentrations > 80 mM L-1. This is of significance, because Na2SO4 is commonly present in sodic soils in the northern Great Plains and sodium is known to disrupt soil structure and reduce water infiltration, which can inhibit root growth. Results from future studies using an advanced and genotyped recombinant inbred line (RIL) population from a cross between Joelle and C046 will help to identify loci and candidate genes associated with salinity tolerance, and provide breeders and genetic engineers knowledge for improving salinity tolerance in camelina.

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.

Aims: Persistent land use change throughout the North American Great Plains increases the need to maintain and improve ecosystem service delivery from remaining rangelands to meet production and conservation goals. Vegetation structure is an ecosystem property influenced by management that has site selection and use implications for wildlife and livestock. In this study, we investigated the efficacy of patch-burn grazing to increase structural heterogeneity on semi-arid post-Conservation Reserve Program (CRP) grasslands in southwestern North Dakota. Location: Hettinger Research Extension Center in Hettinger, North Dakota. Methods: We surveyed plant community composition and structural characteristics in patch-burn grazing pastures during the 2017-2020 summer grazing seasons. Three pastures were stocked with cow-calf pairs and three were stocked with sheep. We also surveyed structural characteristics on units with conventional management (hay or idle) for active and post-CRP enrolled grasslands during the summers of 2018-2020. We tested for vegetative and structural differences between patches with varying time since fire and between grazer types on patch-burn pastures using mixed-effect models and ordination. We used variance partitioning to determine if structural contrast on patch-burn pastures increased over the study period and if structural contrast was higher on patch-burn grazing pastures relative to conventional management. Results: Time since fire was significant for all structural characteristics, with recently burned patches being different from other patches. There were no structural differences between cattle and sheep pastures, but forb and legume cover were lower in sheep pastures. Structural contrast on patch-burn pastures increased over the study and was greater than conventional management. Conclusions: Increased structural heterogeneity is important for supporting a broad suite of rangeland wildlife and can stabilize forage production. This study supports the expectation that patch-burn grazing with moderate stocking rates will increase structural contrast regardless of grazer type, but practitioners should consider which suites of species that management may benefit.

Fall-seeded cover crops (CCs) enhance soil health and sustainability providing soil coverage, reducing soil erosion and NO3-N leaching. The objective was to evaluate the yield and composition of sugarbeet (Beta vulgaris L.) planted after cover crop treatments. The experiment was a randomized complete block design, with a split-plot arrangement, at two locations; Prosper and Hickson, ND. Forage radish (Raphanus sativus L.), winter camelina (Camelina sativa (L.) Crantz), winter wheat (Triticum aestivum L.), oat (Avena sativa L.), and winter rye (Secale cereale L.) were planted into spring wheat stubble in August 2017 and 2018. A control treatment without the cover crop was included. In late fall, soil NO3-N (0–15 cm) was significantly lower in all cover crop treatments (36

Camelina [Camelina sativa (L.) Crantz] has been selected as a low-carbon-intensity (CI) feedstock for sustainable aviation fuels (SAF). The objective of this research was to determine how seed yield and CI of spring and winter camelina are affected by nitrogen rates and seed yield (0, 20, 40, 60, and 80 kg ha-1). Three experiments were conducted in Glyndon, MN and Fargo and Prosper, ND in 2023-2024. Carbon intensity was estimated using a life cycle assessment (LCA) methodology. Spring and winter camelina maximum seed yield was 1521 kg ha-1 and 1410 kg ha-1, at 80 kg N ha-1 and 55 kg N ha-1, respectively. The minimum CI for spring camelina and winter camelina was 33.6 and 21.5 g CO2 equivalent (CO2e) MJ-1, at N rates of 34 and 32 kg N ha-1, respectively. Plotted data from all seed yield and CI data obtained from this study highlighted the immense impact that seed yield has on CI. The regression model indicated the minimum CI (22.1 g CO2e MJ-1) was obtained with a seed yield of 1561 kg ha-1. In the rainfed areas in the northern Great Plains, camelina can easily produce seed yields of 1100 kg ha-1, which would have a CI of 30.1 g CO2e MJ-1. Overall, this study suggest that various nitrogen rates can increase camelina seed yield, which can offset the resulting increase in CI due to N fertilizer and N2O emissions. Based on this study, N application rates should be less than 40 kg N ha-1 to minimize CI. These results confirm that camelina is not always a low CI feedstock. One single, default CI value for camelina oil-based jet fuel should not be used for estimations of greenhouse gases emissions reduction. The final CI of camelina-based jet fuel depends largely on seed yield and N2O field emissions.

Understanding how management influences forage nutritive value and grazer selection within grazing seasons is an ongoing effort for researchers and land managers globally. We used six, 65 ha pastures managed with patchburn grazing and stocked with either cow-calf pairs (0.45-0.5 ha center dot AUM-1) or gestating ewes (0.4-0.48 ha center dot AUM-1) to explore how patterns in rangeland forage drive grazer selection in semi-arid rangeland over four summer grazing seasons at monthly intervals. We used near-infrared spectroscopy to determine nutritive value parameters from monthly forage clippings. We evaluated livestock performance as the average daily weight gains of each animal. We used mixed-effect models and ordination to compare patch and grazer types across the timesince-fire gradient and found that time-since-fire was significant for all measured variables. Cattle and sheep consistently preferred recently burned patches throughout grazing seasons. These recently burned patches typically contained available forage with higher crude protein and moisture content, lower biomass, and lower acid detergent fiber, acid detergent lignin, and neutral detergent fiber compared to intermediate time since fire patches and patches burned three years ago. Differences between patch-burn grazing with cattle and sheep were observed as additional patch contrasts for available biomass and crude protein, but grazer type and ecological site were not statistically significant factors for the nutritive value ordination. Our study indicates that patchburn grazing is capable of imposing and maintaining heterogeneous, grazer selection, forage biomass, and nutritive value patterns desirable for heterogeneity focused land management, regardless of grazer type. These findings are especially relevant to the northern Great Plains where introduced grasses are homogenizing the structural environment of remaining rangelands. With prescribed fire currently an uncommon practice throughout the region, these findings provide a baseline of expectations for practitioners and land managers implementing patch-burn grazing and illustrate how grazing livestock can benefit from the patch contrast in forage nutritive value and biomass.

There is an intense argument about the environmental impact of annual vs. perennial forage production systems. In this study, a systematic review was employed to obtain 47 empirical studies from 13 published papers between the years 2017–2023 to help clarify the issue. The objective of this study was to determine how perennial and annual forage (business-as-usual, BAU) production systems affect dry matter yield (DM) and energy of production including specific environmental impact variables. Impact variables were classified into three main groups: human health, ecosystem quality, and resource consumption. Net energy of lactation (NEL) was considered as a functional unit. Overall, perennial forage production systems varied less in DM yield and energy production than annual monocrop systems, indicating stability in perennial production. There was no statistically significant difference in human health and resource consumption variables between perennial and annual forage production systems, except for ozone layer depletion potential. However, perennial forage systems significantly lowered variables within the ecosystem quality category. Ecotoxicity potential decreased by two and 18 times compared with BAU—control (only annual monoculture forages), and BAU—improved (any annual cropping system other than BAU—control), respectively. Perennial forage systems showed a significant effect size of −8.16, which was slightly less than the effect size of the BAU—improved system but two times less than BAU—control in terms of terrestrial acidification potential. While BAU—control showed an insignificant effect size in relation to eutrophication potential (EUP), perennial forage systems reduced EUP by approximately five and two times compared with BAU—control and BAU—improved, respectively. Therefore, this study highlights the importance of promoting perennial forage production system to foster resilience and stability in DM yield and energy production, with improvements in environmental human health (ozone layer depletion potential) and ecosystem quality variables.

Rangeland ecosystems can meet both livestock production and conservation objectives, but managers often prioritize one over the other. While the conservation benefits of patch-burn grazing are established, it remains understudied from a livestock production standpoint, with most work restricted to crude protein content from limited timeframes and few direct comparisons to alternative grazing practices. We conducted a controlled, ranch-scale experiment to compare forage nutritive value and livestock performance on patch-burned pastures to rotational and continuous grazing. From permanently-established sample points, we clipped available forage and counted fecal pats at monthly intervals during four grazing seasons in pastures with identical stocking but assigned to either patch-burn, rotational, or continuous management (N = 4 each). We used Near-Infrared Spectroscopy to determine multiple components of forage nutritive value, which we reduced via ordination into a single Forage Composition Index. We also weighed cows before and after the grazing season to assess livestock performance for each grazing practice. Fire increased crude protein, neutral detergent fiber digestibility, and energy, and decreased acid detergent fiber, neutral detergent fiber, and lignin components of forage nutritive value relative to unburned patches and grazing systems without fire. While many components followed seasonal trends, recently-burned patches had the best forage nutritive value throughout the grazing season. Cows spent more time in recently-burned patches compared with other patches in pastures managed with patch-burning. Patch-burning created heterogeneity in forage nutritive value and grazer selection throughout the duration of the study. Recently-burned patches had the highest proportion of points that met grazing animal requirements throughout the grazing season. As such, cows from patch-burned pastures performed better over the course of the grazing season. Patch-burning can benefit livestock production and performance while creating heterogeneity necessary to achieve rangeland conservation goals. Patch-burning best met the nutritional requirements of grazing cattle, which resulted in better weight gains on patch-burning pastures.

Winter oilseed cash cover crops are gaining popularity in integrated weed management programs for suppressing weeds. A study was conducted at two field sites (Fargo, North Dakota, and Morris, Minnesota) to determine the freezing tolerance and weed-suppressing traits of winter canola/rapeseed (Brassica napus L.) and winter camelina [Camelina sativa (L.) Crantz] in the Upper Midwestern USA. The top 10 freezing tolerant accessions from a phenotyped population of winter canola/rapeseed were bulked and planted at both locations along with winter camelina (cv. Joelle) as a check. To phenotype our entire winter B. napus population (621 accessions) for freezing tolerance, seeds were also bulked and planted at both locations. All B. napus and camelina were no-till seeded at Fargo and Morris at two planting dates, late August (PD1) and mid-September (PD2) 2019. Data for winter survival of oilseed crops (plants m−2) and their corresponding weed suppression (plants m−2 and dry matter m−2) were collected on two sampling dates (SD) in May and June 2020. Crop and SD were significant (p < 0.05) for crop plant density at both locations, and PD in Fargo and crop x PD interaction in Morris were significant for weed dry matter. At Morris and Fargo, PD1 produced greater winter B. napus survival (28% and 5%, respectively) and PD2 produced higher camelina survival (79% and 72%, respectively). Based on coefficient of determination (r2), ~50% of weed density was explained by camelina density, whereas ≤20% was explained by B. napus density at both locations. Camelina from PD2 suppressed weed dry matter by >90% of fallow at both locations, whereas weed dry matter in B. napus was not significantly different from fallow at either PD. Genotyping of overwintering canola/rapeseed under field conditions identified nine accessions that survived at both locations, which also had excellent freezing tolerance under controlled conditions. These accessions are good candidates for improving freezing tolerance in commercial canola cultivars.

Data repositories using legacy data are needed to minimize research redundancy, enable knowledge synthesis, and optimize productivity and resiliency of agricultural systems. However, a framework is needed to develop an online searchable database to identify optimum systems for sustainable agricultural intensification and diversification, particularly for forages. Therefore, this paper outlines the development of a community-driven forage database (Forage Data Hub) using legacy datasets encompassing multiple temporal and spatial scales and species to analyze system functionality and resiliency. Specific steps outlined included (1) developing minimum and preferred data requirements; (2) data standardization, structuring, and compilation; (3) creating a data thesaurus, data shapes, and data model; and (4) creating a web-based system interface to facilitate database access. We demonstrate utility of curating these diverse datasets by quantifying forage system resiliency during extreme weather occurrences (relationship between standardized yields and yields during years receiving 25th percentile of the 30-year normal precipitation) for three systems (monocrop annual, monocrop perennial, and mixed perennial) spanning 52,997 data entries (108 unique locations and 51 years). Overall, during low-precipitation years, monocrop annual systems achieved 67% of their expected yield, while monocrop perennial systems achieved 93% and mixed perennial systems achieved 112% of potential yields. Therefore, diverse perennial systems were more resilient to climate-related stresses compared to annual forage systems. Development of the US Forage Data Hub underscores the benefits of community-driven data sharing and curation for a given commodity to provide system-level sustainability assessments for identifying practices that promote ecological intensification and resiliency to climatic stochasticity. Data sharing and database creation will facilitate systematic analyses and prevent research redundancies.Forage Data Hub was created to host United States forage data to improve forage production management and analyze resiliency.Diverse perennial systems had greater resiliency under extreme climate spanning 51 years and 108 locations.Future work will expand the Forage Data Hub database and develop a dashboard for user engagement and query.

Climate change and its complex interactions with crops and cropping systems present challenges to agricultural production. Resilient systems that provide food security for a burgeoning population, built by improving crops and developing new alternative cropping systems, are needed to cope with the myriad impacts climate change has on agriculture. Relay cropping is a systems strategy to sustainably intensify crop production and provide environmental benefits. Relay cropping involves interseeding one plant species into an established crop, creating a temporary spatial-temporal overlap of the two crops. This system keeps living plant cover on the agricultural landscape most of the year, which has implications for adapting to and even mitigating climate change impacts. As global warming progresses, land area suitable for relay cropping or producing more than one crop per year will likely expand to more northerly latitudes. The following review specifically focuses on relay cropping, giving examples of how it can potentially improve agricultural system resilience and adaptability to climate change and reduce greenhouse gas emissions, while also addressing potential limitations. More research is needed to improve crop genetics, crop combinations, and management practices best suited for relay cropping to further develop systems that can adapt to changing weed and insect dynamics as well as improve nitrogen and water use under current and future predictions of climate change.

Camelina (Camelina sativa L., Crantz) is an oilseed crop consisting of both spring- and winter-biotypes. Winter biotypes of camelina need a low-temperature treatment to acquire freezing tolerance and floral competence. However, spring biotypes do not require a low-temperature treatment to initiate flowering and do not cold acclimate to the same extent as winter biotypes. Exposure of the camelina winter biotype 'Joelle' to low temperature (5 degrees C) for 0-, 1-, 2-, 4-, and 6-weeks resulted in freezing survival rates of similar to 0%, 0%, 20%, 36%, and 72%, respectively, after being exposed to freezing conditions (-15 degrees C for 4 h). Winter biotype plants that survived the freezing treatment (42 d post-treatment under greenhouse conditions) also flowered; however, time to flowering was dependent on the cold treatment duration. Plants exposed to 5 degrees C for six weeks flowered first followed in order by plants exposed to 4- and 2-weeks cold. To decipher molecular regulation associated with low-temperature acquired freezing tolerance and floral competence in camelina, we analyzed the transcriptomes of a spring biotype (CO46) and winter biotype (Joelle) exposed to 0-, 1-, 2-, 4-, 6- and 8-weeks low temperature (5 degrees C). Genes and transcription factors with significant differential abundance (4-fold up or down) in the wintercompared to the spring-biotype of camelina were used to identify those over-represented among gene ontologies. The results highlighted gene ontologies associated with abiotic and biotic defense responses, oxidative stress responses, cell wall modification and cell expansion, biosynthesis of very long chain fatty acids and anthocyanins, as well as processes involving photosynthesis, sugar metabolism, transport, and phytohormone (abscisic acid, auxin, jasmonic acid, and salicylic acid) signaling. Transcripts associated with these processes in the winter biotype of camelina may be regulated by transcription factors similar to Arabidopsis MYB47, MYB75, MYB90, NF-YA4 and NF-YB2, HATI, GRF7, CKG, and CBF1 and CBF2.

Camelina [(Camelina sativa (L.) Crantz], an oilseed species of Brassicaceae, does not have approved herbicides for weed control, which limits its expansion as a commercial crop. To evaluate agronomic traits and ecosystem services of non-transgenic cultivars of sulfonylurea-resistant camelina and canola (Brassica napus L.), a field study was conducted near Fargo, North Dakota. Two replicated locations (NDSU and NW22) were set up in a randomized complete block design including four blocks of camelina, canola, and fallow per location. Camelina and canola were seeded (18 May) at 4.9 and 2.9 kg ha−1, respectively, using 19-cm row spacing. Data was collected mid- and late-season (29 June and 22 July 2020 respectively) for crop and weed stem count (no. m−2), biomass dry matter (kg m−2), and nutrient (N, P, K, S) content (kg ha−1), as-well-as final season (7 August) seed yield (kg ha−1) for camelina and canola treated with and without sulfonylurea. Using Prefer 90 (NIS) at 0.25% v/v, camelina was treated with thifensulfuron at 6.3 g a.i. ha−1, and canola was treated with thifensulfuron at 10.5 g a.i. ha−1 and tribenuron at 5.3 g a.i. ha−1. Sulfonylurea-resistant camelina and canola reduced late-season dry weight biomass of weeds by >75% and ≥60%, respectively, compared with fallow plots. Application of sulfonylurea herbicides to camelina or canola prior to mid-season analyses was not a significant factor (p ≤ 0.05) for reducing weed pressure and generally had little impact on altering crop biomass, seed yield, and nutrient retention. However, in some cases, herbicide treatment had an additive effect of reducing weed pressure over that of camelina or canola alone. Depending on the rotational cropping system, sulfonylurea-resistant camelina and canola should provide additional options for integrated weed management approaches and reducing nutrient leaching in the upper Midwest and northern Great Plains of the USA.

Prevailing agricultural systems dominated by annual crop monocultures, and the landscapes that contain them, lack resilience and multifunctionality. They are vulnerable to extreme weather events, contribute to degradation of soil, water, and air quality, reduce biodiversity, and negatively impact human health, social engagement, and equity. To achieve greater resilience, stability, and multiple ecosystem services therein, and to improve socioeconomic outcomes, we propose a practical framework to gain multifunctionality at multiple scales. This framework includes forages within agroecosystems that have the essential structural features of diversity, perenniality, and circularity. These three structural features are associated with increased resilience, stability, and provision of several ecosystem services, which in turn improve human health and socioeconomic outcomes. This framework improves understanding of, and access to, tools and materials for promoting the adoption of diverse circular agroecosystems with perennial forages. Application of this framework can result in land transformations that solve sustainability challenges in agriculture if policy, economic, and social barriers can be overcome by a transdisciplinary process of equitable knowledge production.

Flowers of field pennycress (Thlaspi arvsense L.) and winter camelina (Camelina sativa (L.) Crantz.) produce abundant pollen and nectar in early spring and thereby may be valuable for pollinators. Insects observed in field plots of these flowers were classified into seven easily identifiable groups (bumblebee, honeybee, solitary bee, butterfly/moth, beetle, fly and other) and monitored for 2 years at three sites in the Upper Midwest region of the USA. Average seasonal observations across years and sites varied from 1.6 to 5.3 total insects/min for field pennycress and 1.4 to 4.5 insects/min for winter camelina. Lowest visitation rates occurred in central Iowa and highest rates in south‐eastern Minnesota for both crops. Multiple regressions showed that visitation rates for specific insect groups were correlated poorly but significantly (p < .10) with select variables. For example, in field pennycress, visitation by combined bumblebees and honeybees (Apidae) increased with greater air temperature at sampling time and annual site precipitation, whereas fly (Diptera) visitation was related to sampling date and flower cover. Similarly, in winter camelina, solitary bees were linked to increasing air temperature at sampling time and annual site precipitation, whereas flies were correlated with wind speed and flower cover at sampling. Field pennycress and winter camelina are reliably attractive to beneficial pollinating insects across a wide geographic region, but visitation rates and proportional representation of various insect groups depended on a range of site and weather characteristics.

Winter camelina [Camelina sativa (L.) Crantz] and field pennycress [Thlaspi arvense L.] are oilseed feedstocks that can be employed as winter-hardy cover crops in the current cropping systems in the U.S. upper Midwest. In addition to provide multiple ecosystem services, they can be a further source of income for the farmer. However, using these cover crops is a new agricultural practice that has only been studied recently. The objective of this study was to assess and compare the environmental performance of a maize [Zea mays L.]-soybean [Glycine max (L.) Merr.] cropping system with different winter cover crops - camelina, pennycress, and rye (Secale cereale L.) - in the U.S. upper Midwest. Field experiments were carried out from 2016 to 2017 (2-year maize-soybean sequence) at three locations: Morris (Minnesota), Ames (Iowa), and Prosper (North Dakota). The environmental impact assessment was carried out using a "cradle-to-gate" life cycle assessment methodology. Four impact categories were assessed: global warming potential (GWP), eutrophication, soil erosion, and soil organic carbon (SOC) variation. Two functional units (FU) were selected: (1) 1 ha year(-1), and (2) $1 net margin. When expressed with the FU ha yr(-1), across the three locations cover crops had (a) lower eutrophication potential and water soil erosion, and (b) lower GWP if the cover crop was not fertilized with nitrogen. Camelina and pennycress were more effective than rye in reducing soil losses, while the three cover crops provided similar results for eutrophication potential. The results for the SOC variation were mixed, but the sequence with rye had the best performance at all locations. When expressed with the FU $ net margin, sequences including camelina and pennycress were overall the worst sequences in mitigating greenhouse gas emissions and nutrient and soil losses. This negative performance was mainly due to the seed yield reduction in the second year of the sequence for both the main cash crop (soybean) and the relayed-cover crop compared with the conventional sequence maize-soybean. Such result led to a lower net margin per hectare in the sequences including camelina and pennycress when compared with the control. The results of this study suggest that the introduction of camelina and pennycress as winter-hardy cover crops has a strong potential for reducing the environmental impacts of the maize-soybean rotation. However, a field management optimization of these cover crops in a relay-cropping system is needed to make them a sustainable agricultural practice.

Field pennycress (Thlaspi arvense L.) (PC) and winter camelina [Camelina sativa (L.) Crantz] (WC) have the potential to provide ecosystem services and economic incentives when adopted as an oilseed cover crops in corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotations. However, PC and WC establishment and yield in the northern Corn Belt and their subsequent impact on row crops are not well known. This study was conducted to determine the effects of interseeding dates (R4, R5, and R6; and R6, R7, and R8 development stages for corn and soybean, respectively) and cover crop species (PC, WC, and winter rye [Secale cereale L.]) on seed yield and oil content of interseeded oilseeds (PC and WC) and relay soybean, and 3rd-year corn grain yield and quality. Study sites were initiated near Ames, IA; Morris and Rosemount, MN; and Prosper, ND. Late interseeding of PC and WC resulted in greater oilseed yield. Overall yields of PC (218-880 kg ha(-1)) and WC (15-770 kg ha(-1)), averaged across interseeding dates, were low when interseeded in corn and soybean. The PC and WC reduced relay-soybean grain yield by 13-32% and 13-42%, respectively. Corn grain yield and quality following relay soybean were not affected by the residual effects of oilseed cover crops. Based on the results of our study, we do not recommend relay cropping soybean with PC and WC in the upper Midwest.